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  • 1. Addor, Nans
    et al.
    Rössler, Ole
    Köplin, Nina
    Huss, Matthias
    Weingartner, Rolf
    Seibert, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Robust changes and sources of uncertainty in the projected hydrological regimes of Swiss catchments2014In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 50, no 10, p. 7541-7562Article in journal (Refereed)
    Abstract [en]

    Projections of discharge are key for future water resources management. These projections are subject to uncertainties, which are difficult to handle in the decision process on adaptation strategies. Uncertainties arise from different sources such as the emission scenarios, the climate models and their postprocessing, the hydrological models, and the natural variability. Here we present a detailed and quantitative uncertainty assessment, based on recent climate scenarios for Switzerland (CH2011 data set) and covering catchments representative for midlatitude alpine areas. This study relies on a particularly wide range of discharge projections resulting from the factorial combination of 3 emission scenarios, 10–20 regional climate models, 2 postprocessing methods, and 3 hydrological models of different complexity. This enabled us to decompose the uncertainty in the ensemble of projections using analyses of variance (ANOVA). We applied the same modeling setup to six catchments to assess the influence of catchment characteristics on the projected streamflow, and focused on changes in the annual discharge cycle. The uncertainties captured by our setup originate mainly from the climate models and natural climate variability, but the choice of emission scenario plays a large role by the end of the 21st century. The contribution of the hydrological models to the projection uncertainty varied strongly with catchment elevation. The discharge changes were compared to the estimated natural decadal variability, which revealed that a climate change signal emerges even under the lowest emission scenario (RCP2.6) by the end of the century. Limiting emissions to RCP2.6 levels would nevertheless reduce the largest regime changes by the end of the century by approximately a factor of two, in comparison to impacts projected for the high emission scenario SRES A2. We finally show that robust regime changes emerge despite the projection uncertainty. These changes are significant and are consistent across a wide range of scenarios and catchments. We propose their identification as a way to aid decision making under uncertainty.

  • 2.
    Adolfsson Lindahl, Frida
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Edholm, Sigrid
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Hagberg, Felicia
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Holmgren, Niclas
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Källbom, Jacob
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Magnusson, Astrid
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Våtmarkers potential att rena avloppsvatten från läkemedelsrester2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna studie genomfördes på uppdrag av det statliga forskningsinstitutet Formas. Syftet med rapporten var att undersöka hur effektiva våtmarker är som tilläggsrening av avloppsvatten, detta med avseende på reducering av läkemedel samt skadeeffekter på akvatiska organismer. Rapporten baserades på en tidigare studie utförd av Breitholtz et al. (2012) där mätningar av läkemedelshalter samt mortalitet och larvutveckling hos hoppkräftor, Nitocra spinipes, gjordes i fyra olika våtmarker.  De fyra våtmarkerna ligger i Eskilstuna, Oxelösund, Nynäshamn och Trosa. Deras mätningar undersökte mortalitet och larvutvecklingskvot för hoppkräftor i prover utspädda med bräckt vatten vid koncentration avloppsvatten på, 11,25 %; 22,5 %; 45% och 90 %. Proverna för läkemedelshalter späddes inte ut och enbart ett mätvärde per våtmark togs vid inflödet och utflödet.

    I denna rapport undersöktes dessa frågeställningar: (1) Är anlagda våtmarker som tilläggsrening en effektiv metod med avseende på skadeeffekter hos hoppkräftor, (2) till vilken grad reduceras halten läkemedel när våtmarker används som tilläggsrening samt (3) finns det ett samband mellan läkemedelsrester och hoppkräftornas överlevnad?

    För att besvara de tre frågeställningarna genomfördes en metaanalys av data från studien av Breitholtz et al. (2012). Hoppkräftors mortalitet, larvutvecklingskvot (LDR) och koncentration av läkemedel analyserades. Endast mortalitet och larvutvecklingskvot hade tillräckligt med data för utförande av en metaanalys. Läkemedelsanalysen kunde bara göras på en grundläggande nivå.

    Metaanalysen programmerades i MATLAB R2019b, där skillnaden i medelvärdet för mortalitet respektive larvutvecklingskvot beräknades mellan in- och utflöde för de fyra våtmarkerna. Skillnaderna för varje våtmark vägdes samman med invers-varians metoden för att få ett sammanvägt medelvärde. Analysen av läkemedel gjordes på nio läkemedel från Breitholtz et al. (2012). De nio valdes ut då de har pekats ut av Svenska Miljöinstitutet som intressanta ur ett avloppsreningsperspektiv. Excel användes för att göra enklare statistiska analyser mellan in- och utflöde i våtmarkerna. Slutligen gjordes en jämförelse mellan hoppkräftors skadeeffekter och läkemedelshalter genom att ta ut skillnaden i medelvärde mellan in- och utflöde.

    Resultatet från analyserna visade att när våtmarker användes som tilläggsrening minskade mortaliteten hos hoppkräftor för koncentrationerna 11,25 % och 90 % avloppsvatten. För koncentrationerna 22,5 % och 45 % fanns däremot ingen signifikant skillnad i mortalitet. Larvutvecklingskvoten minskade efter våtmarksbehandlingen för alla koncentrationer utom 90 %. Läkemedelshalten minskade i snitt med 30 % mellan inflöde och utflöde i våtmarkerna. För läkemedlen sulfametoxazol och oxazepam kunde dock en ökning ses efter behandling med våtmark. Ingen direkt trend kunde utläsas mellan läkemedelshalt och mortalitet hos hoppkräftor. Detta berodde troligtvis på att andra faktorer och föroreningar påverkade hoppkräftornas mortalitet och larvutvecklingskvot i högre grad än läkemedelshalterna.

    I studien kunde ingen slutsats dras om huruvida tilläggsvåtmarker är en effektiv reningsmetod med avseende på skadeeffekter hos hoppkräftor. Hoppkräftor är bra indikatorer på föroreningar i vattnet, dock är det svårt att bestämma vilka föroreningar som påverkar mest i detta fall. Detta medför att inga direkta samband mellan läkemedel och hoppkräftors mortalitet kunde påvisas i studien. De undersökta läkemedlen reducerades generellt. Eftersom mätningarna gjordes under vinterförhållanden då nedbrytningen i våtmarken är som minst effektiv bör resultatet ses som ett lägsta värde.

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  • 3.
    AghaKouchak, Amir
    et al.
    Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92697 USA; Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA USA.
    Mirchi, Ali
    Oklahoma State Univ, Dept Biosyst & Agr Engn, Stillwater, OK 74078 USA.
    Madani, Kaveh
    Yale Univ, MacMillan Ctr Int & Area Studies, New Haven, CT USA; Stockholm Univ, Dept Phys Geog, Stockholm, Sweden.
    Di Baldassarre, Giuliano
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Nazemi, Ali
    Concordia Univ, Dept Bldg Civil & Environm Engn, Montreal, PQ, Canada.
    Alborzi, Aneseh
    Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92697 USA.
    Anjileli, Hassan
    Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92697 USA.
    Azarderakhsh, Marzi
    Fairleigh Dickinson Univ, Sch Comp Sci & Engn, Teaneck, NJ USA.
    Chiang, Felicia
    Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92697 USA.
    Hassanzadeh, Elmira
    Polytech Montreal, Dept Civil Geol & Min Engn, Montreal, PQ, Canada.
    Huning, Laurie S.
    Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92697 USA; Calif State Univ Long Beach, Dept Civil Engn & Construct Engn Management, Long Beach, CA 90840 USA.
    Mallakpour, Iman
    Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92697 USA.
    Martinez, Alexandre
    Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92697 USA.
    Mazdiyasni, Omid
    Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92697 USA.
    Moftakhari, Hamed
    Univ Alabama, Dept Civil Construct & Environm Engn, Tuscaloosa, AL USA.
    Norouzi, Hamid
    CUNY, New York City Coll Technol, Brooklyn, NY 11210 USA.
    Sadegh, Mojtaba
    Boise State Univ, Dept Civil Engn, Boise, ID 83725 USA.
    Sadeqi, Dalal
    Kuwait Inst Sci Res, Water Res Ctr, Kuwait, Kuwait.
    Van Loon, Anne F.
    Vrije Univ Amsterdam, Inst Environm Studies, Amsterdam, Netherlands.
    Wanders, Niko
    Univ Utrecht, Fac Geosci, Dept Phys Geog, Utrecht, Netherlands.
    Anthropogenic Drought: Definition, Challenges, and Opportunities2021In: Reviews of geophysics, ISSN 8755-1209, E-ISSN 1944-9208, Vol. 59, no 2, article id e2019RG000683Article, review/survey (Refereed)
    Abstract [en]

    Traditional, mainstream definitions of drought describe it as deficit in water-related variables or water-dependent activities (e.g., precipitation, soil moisture, surface and groundwater storage, and irrigation) due to natural variabilities that are out of the control of local decision-makers. Here, we argue that within coupled human-water systems, drought must be defined and understood as a process as opposed to a product to help better frame and describe the complex and interrelated dynamics of both natural and human-induced changes that define anthropogenic drought as a compound multidimensional and multiscale phenomenon, governed by the combination of natural water variability, climate change, human decisions and activities, and altered micro-climate conditions due to changes in land and water management. This definition considers the full spectrum of dynamic feedbacks and processes (e.g., land-atmosphere interactions and water and energy balance) within human-nature systems that drive the development of anthropogenic drought. This process magnifies the water supply demand gap and can lead to water bankruptcy, which will become more rampant around the globe in the coming decades due to continuously growing water demands under compounding effects of climate change and global environmental degradation. This challenge has de facto implications for both short-term and long-term water resources planning and management, water governance, and policymaking. Herein, after a brief overview of the anthropogenic drought concept and its examples, we discuss existing research gaps and opportunities for better understanding, modeling, and management of this phenomenon.

    Plain Language Summary

    This article reviews research and progress on the notion of anthropogenic drought broadly defined as drought events caused or intensified by human activities. Most commonly used drought definitions are based on deficit in hydrologic/meteorologic drivers such as precipitation and runoff. Within coupled human-water systems, however, drought must be defined and understood as the complex and interrelated dynamics of both natural and human-induced changes. This anthropogenic drought definition considers the full spectrum of dynamic feedbacks and processes (e.g., land-atmosphere interactions and water and energy balance) within human-nature systems. Ideally, anthropogenic drought and the corresponding human interactions should be incorporated in models that include land-atmosphere interactions, water balance, and energy balance. In this article, we review existing research gaps and opportunities for better understanding, modeling, and management of this phenomenon.

  • 4. Ahlers, R.
    et al.
    Cleaver, F
    Rusca, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Schwartz, K.
    Unleashing Entrepreneurs or Controlling Unruly Providers?: The Formalisation of Small-scale Water Providers in Greater Maputo, Mozambique2013In: Journal of Development Studies, ISSN 0022-0388, E-ISSN 1743-9140, Vol. 49, no 4, p. 470-482Article in journal (Refereed)
    Abstract [en]

    The existing legal and policy framework regulating water service provision in Greater Maputo, Mozambique appears fixated on the official service areas. In doing so it inadequately addresses the geographically varied service provision modalities which characterise the city. We argue that the predominant legal and policy framework does little to support development of improved services in areas unserved by the formal utility. Although ad hoc measures recognising small-scale providers as a temporary alternative to service provision by a formal utility have been implemented, these measures appear designed to increase control over these providers rather than support the service delivery capacity of small-scale providers.

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  • 5.
    Ahlstedt, Oskar
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    How variations of the duration and time to peak of the Chicago Design Storm affect the hydraulic response, as well as the areas contributing to peak runoff, of a synthetic urban catchment area2022Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    With an expanding urbanization in the world, and thus the expansion of impermeable surfaces, the risk of pluvial floods is an increasing factor that needs to be considered. This, in combination with increasing rain intensities and frequency of rain events indicates a problem both today and for the future. With this in mind, it is an advantage to increase the knowledge of how different variations of extreme rainfall affects the hydraulic response of urban catchments, as well as which areas in urban environments contribute to the flood peak.

    The aims of this study are, with a particle tracking approach, to investigate how the peak runoff contributing areas differ geographically depending on the duration and time to peak of the rainfall event. This also includes the evaluation of what sizes of urban catchment areas are relevant to include when modelling the hydraulic response of Swedish urban catchment in relation to the characteristics of the hyetograph. The catchment area used in this study is made synthetically to represent a generic Swedish urban catchment with regards to the proportions of hardened surfaces, buildings and low points, as well as the slope of the catchment. Various variants of the Chicago Design Storm were implemented in the model. This included three different durations of 2-, 4- and 6 hours of which each, separately, constituted of three different time to peak that is decided by an r-value when creating the design storms. The r-values used in this study is 0.1, 0.4 and 0.8 where the values correlates to an early-, centred- and late peak of the hyetograph. To be able to investigate the peak contributing area, a particle tracking approach was initially used as an equivalent to tracers where the particles are first evenly distributed over the catchment area to then be concentrated to the locations that shows a variation in in the peak contributing area. This was done by using the modelling program MIKE 21 Flow Model FM powered by DHI, which also was used to run the hydrodynamic simulations of the inundation.

    The results of the hydrodynamic simulations showed that the rain events generated more runoff as the duration was extended. In addition, the timing of the peak of the rainfall intensity also had an impact on the result as the runoff increased with increasing r-value. Thus, as the peak of the hyetograph is delayed, it imposes an increasing risk of severe flooding. Furthermore, with the use of particle tracking, it could be concluded that the different design storm had an influence on the peak contributing distance where the distance grew larger when the duration of the rainfall event was extended and when the peak of the storm was delayed.

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  • 6.
    Ahlström, Hanna
    et al.
    Royal Swedish Acad Sci, Global Econ Dynam & Biosphere, POB 50005, SE-10405 Stockholm, Sweden..
    Hileman, Jacob
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Government.
    Wang-Erlandsson, Lan
    Stockholm Univ, Stockholm Resilience Ctr, Stockholm, Sweden.;Stockholm Univ, Bolin Ctr Climate Res, Stockholm, Sweden..
    Garcia, Maria Mancilla
    Stockholm Univ, Stockholm Resilience Ctr, Stockholm, Sweden.;Univ Libre Bruxelles ULB, Fac Sci, Socioenvironm Dynam Res Grp SONYA, Brussels, Belgium..
    Moore, Michele-Lee
    Stockholm Univ, Stockholm Resilience Ctr, Stockholm, Sweden.;Univ Victoria, Dept Geog, Victoria, BC, Canada.;Univ Victoria, Ctr Global Studies, Victoria, BC, Canada..
    Jonas, Krisztina
    Stockholm Univ, Stockholm Resilience Ctr, Stockholm, Sweden..
    Pranindita, Agnes
    Stockholm Univ, Stockholm Resilience Ctr, Stockholm, Sweden.;Stockholm Univ, Bolin Ctr Climate Res, Stockholm, Sweden..
    Kuiper, Jan J.
    Stockholm Univ, Stockholm Resilience Ctr, Stockholm, Sweden..
    Fetzer, Ingo
    Stockholm Univ, Stockholm Resilience Ctr, Stockholm, Sweden..
    Jaramillo, Fernando
    Stockholm Univ, Bolin Ctr Climate Res, Stockholm, Sweden.;Stockholm Univ, Dept Phys Geog, Stockholm, Sweden..
    Svedin, Uno
    Stockholm Univ, Stockholm Resilience Ctr, Stockholm, Sweden..
    An Earth system law perspective on governing social-hydrological systems in the Anthropocene2021In: Earth System Governance, ISSN 2589-8116, Vol. 10, article id 100120Article in journal (Refereed)
    Abstract [en]

    The global hydrological cycle is characterized by complex interdependencies and self-regulating feedbacks that keep water in an ever-evolving state of flux at local, regional, and global levels. Increasingly, the scale of human impacts in the Anthropocene is altering the dynamics of this cycle, which presents additional challenges for water governance. "Earth system law" provides an important approach for addressing gaps in governance that arise from the mismatch between the global hydrological cycle and dispersed regulatory architecture across institutions and geographic regions. In this article, we articulate the potential for Earth system law to account for core hydrological problems that complicate water governance, including delay, redistribution, intertwinements, permanence, and scale. Through merging concepts from Earth system law with existing policy and legal principles, we frame an approach for addressing hydrological problems in the Anthropocene and strengthening institutional fit between established governance systems and the global hydrological cycle. We discuss how such an approach can be applied, and the challenges and implications for governing water as a cycle and complex social-hydrological system, both in research and practice.

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  • 7.
    Ahmerkamp, Soeren
    et al.
    Max Planck Inst Marine Microbiol, D-28359 Bremen, Germany..
    Jalaluddin, Farooq Moin
    Max Planck Inst Marine Microbiol, D-28359 Bremen, Germany..
    Cui, Yuan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Physiology and Environmental Toxicology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Brumley, Douglas R.
    Univ Melbourne, Sch Math & Stat, Parkville, Vic 3010, Australia..
    Pacherres, Cesar O.
    Alfred Wegener Inst, Helmholtz Ctr Polar & Marine Res, Bremerhaven, Germany.;Univ Copenhagen, Dept Biol, Copenhagen, Denmark..
    Berg, Jasmine S.
    Univ Lausanne, Inst Earth Surface Dynam, CH-1015 Lausanne, Switzerland..
    Stocker, Roman
    Swiss Fed Inst Technol, Dept Civil Environm & Geomat Engn, Inst Environm Engn, CH-8093 Zurich, Switzerland..
    Kuypers, Marcel M. M.
    Max Planck Inst Marine Microbiol, D-28359 Bremen, Germany..
    Koren, Klaus
    Aarhus Univ, Ctr Water Technol, Dept Biol, DK-8000 Aarhus, Denmark..
    Behrendt, Lars
    Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Physiology and Environmental Toxicology.
    Simultaneous visualization of flow fields and oxygen concentrations to unravel transport and metabolic processes in biological systems2022In: CELL REPORTS METHODS, ISSN 2667-2375, Vol. 2, no 5, article id 100216Article in journal (Refereed)
    Abstract [en]

    From individual cells to whole organisms, O-2 transport unfolds across micrometer- tomillimeter-length scales and can change within milliseconds in response to fluid flows and organismal behavior. The spatiotemporal complexity of these processes makes the accurate assessment of O-2 dynamics via currently availablemethods difficult or unreliable. Here, we present "sensPIV,'' a method to simultaneously measure O-2 concentrations and flow fields. By tracking O-2-sensitive microparticles in flow using imaging technologies that allow for instantaneous referencing, wemeasuredO(2) transportwithin (1) microfluidic devices, (2) sinkingmodel aggregates, and (3) complex colony-forming corals. Through the use of sensPIV, we find that corals use ciliarymovement to link zones of photosynthetic O-2 production to zones of O-2 consumption. SensPIV can potentially be extendable to study flow-organism interactions across many life-science and engineering applications.

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  • 8.
    Akhter, Firoza
    et al.
    KTH Royal Inst Technol, Dept Sustainable Dev Environm Sci & Engn, S-10046 Stockholm, Sweden..
    Mazzoleni, Maurizio
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Ctr Nat Hazards & Disaster Sci CNDS, S-75236 Uppsala, Sweden..
    Brandimarte, Luigia
    KTH Royal Inst Technol, Dept Sustainable Dev Environm Sci & Engn, S-10046 Stockholm, Sweden..
    Analysis of 220 Years of Floodplain Population Dynamics in the US at Different Spatial Scales2021In: Water, E-ISSN 2073-4441, Vol. 13, no 2, article id 141Article in journal (Refereed)
    Abstract [en]

    In this study, we explore the long-term trends of floodplain population dynamics at different spatial scales in the contiguous United States (U.S.). We exploit different types of datasets from 1790-2010-i.e., decadal spatial distribution for the population density in the US, global floodplains dataset, large-scale data of flood occurrence and damage, and structural and nonstructural flood protection measures for the US. At the national level, we found that the population initially settled down within the floodplains and then spread across its territory over time. At the state level, we observed that flood damages and national protection measures might have contributed to a learning effect, which in turn, shaped the floodplain population dynamics over time. Finally, at the county level, other socio-economic factors such as local flood insurances, economic activities, and socio-political context may predominantly influence the dynamics. Our study shows that different influencing factors affect floodplain population dynamics at different spatial scales. These facts are crucial for a reliable development and implementation of flood risk management planning.

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  • 9.
    Albertini, Cinzia
    et al.
    Univ Napoli Federico II, Dipartimento Ingn Civile Edile & Ambientale, I-80125 Naples, Italy.;Politecn Bari, Dipartimento Ingn Civile Ambientale Terr Edile &, I-70125 Bari, Italy..
    Mazzoleni, Maurizio
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Ctr Nat Hazards & Disaster Sci, S-75236 Uppsala, Sweden..
    Totaro, Vincenzo
    Politecn Bari, Dipartimento Ingn Civile Ambientale Terr Edile &, I-70125 Bari, Italy..
    Iacobellis, Vito
    Politecn Bari, Dipartimento Ingn Civile Ambientale Terr Edile &, I-70125 Bari, Italy..
    Di Baldassarre, Giuliano
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Ctr Nat Hazards & Disaster Sci, S-75236 Uppsala, Sweden..
    Socio-Hydrological Modelling: The Influence of Reservoir Management and Societal Responses on Flood Impacts2020In: Water, E-ISSN 2073-4441, Vol. 12, no 5, article id 1384Article in journal (Refereed)
    Abstract [en]

    Over the last few years, several socio-hydrological studies have investigated the risk dynamics generated by the complex interactions between floods and societies, with a focus on either changing reservoir operation rules or raising levees. In this study, we propose a new socio-hydrological model of human-flood interactions that represents both changes in the reservoir management strategies and updating of the levee system. Our model is applied to simulate three prototypes of floodplain management strategies to cope with flood risk: green systems, in which societies resettle outside the flood-prone area; technological systems, in which societies implement structural measures, such as levees; and green-to-techno systems, in which societies shift from green to technological approaches. Floodplain dynamics are explored simulating possible future scenarios in the city of Brisbane, Australia. Results show that flood risk is strongly influenced by changes in flood and drought memory of reservoir operators, while risk-awareness levels shape the urbanisation of floodplains. Furthermore, scenarios of more frequent and higher magnitude events prove to enhance social flood memory in green systems, while technological systems experience much higher losses. Interestingly, green-to-techno systems may also evolve toward green floodplain management systems in response to large losses and technical/economical unfeasibility of larger structural measures.

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  • 10.
    Alcolombri, Uria
    et al.
    Swiss Fed Inst Technol, Dept Civil Environm & Geomat Engn, Inst Environm Engn, Zurich, Switzerland..
    Peaudecerf, Francois J.
    Swiss Fed Inst Technol, Dept Civil Environm & Geomat Engn, Inst Environm Engn, Zurich, Switzerland..
    Fernandez, Vicente I.
    Swiss Fed Inst Technol, Dept Civil Environm & Geomat Engn, Inst Environm Engn, Zurich, Switzerland..
    Behrendt, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology. Uppsala University, Science for Life Laboratory, SciLifeLab. Swiss Fed Inst Technol, Dept Civil Environm & Geomat Engn, Inst Environm Engn, Zurich, Switzerland.
    Lee, Kang Soo
    Swiss Fed Inst Technol, Dept Civil Environm & Geomat Engn, Inst Environm Engn, Zurich, Switzerland..
    Stocker, Roman
    Swiss Fed Inst Technol, Dept Civil Environm & Geomat Engn, Inst Environm Engn, Zurich, Switzerland..
    Sinking enhances the degradation of organic particles by marine bacteria2021In: Nature Geoscience, ISSN 1752-0894, E-ISSN 1752-0908, Vol. 14, no 10, p. 775-780Article in journal (Refereed)
    Abstract [en]

    The sinking of organic particles in the ocean and their degradation by marine microorganisms is one of the main drivers of the biological pump. Yet, the mechanisms determining the magnitude of the pump remain poorly understood, limiting our ability to predict this carbon flux in future ocean scenarios. Current ocean models assume that the biological pump is governed by the competition between sinking speed and degradation rate, with the two processes independent from one another. Contrary to this paradigm, we show that sinking itself is a primary determinant of the rate at which bacteria degrade particles. Heterotrophic bacterial degradation rates were obtained from a laboratory study on model surface-colonized particles at atmospheric pressure under a range of flow speeds to mimic different sinking velocities. We find that even modest sinking speeds of 8 m day−1 enhance degradation rates more than 10-fold compared with degradation rates of non-sinking particles. We discovered that the molecular mechanism underlying this sinking-enhanced degradation is the flow-induced removal from the particles of the oligomeric breakdown products, which otherwise compete for enzymatic activity. This mechanism applies across several substrates and bacterial strains, suggesting its potentially broad occurrence under natural marine conditions. Integrating our findings into a mathematical model of particulate carbon flux, we propose that the coupling of sinking and degradation may contribute, in conjunction with other processes, to determining the magnitude of the vertical carbon flux in the ocean.

  • 11. Alda-Vidal, C.
    et al.
    Kooy, M.
    Rusca, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Mapping operation and maintenance: an everyday urbanism analysis of inequalities within piped water supply in Lilongwe, Malawi2018In: Urban Geography, Vol. 39, no 1, p. 104-121Article in journal (Refereed)
    Abstract [en]

    In this article, we analyze the production of inequalities within the centralized water supply network of Lilongwe. We use a process-based analysis to understand how urban infrastructure is made to work and explain the disparity in levels of service by tracing the everyday practices of those who operate the infrastructure. This extends existing analyses of everyday practices in relation to urban water inequalities in African cities by focusing on formal operators, rather than water users, and looking within the networked system, rather than outside it. Our findings show that these practices work to exacerbate existing water stress in poor areas of the city. We conclude with a reflection on how understanding these practices as the product of the perceptions, rationalizations, and interpretations of utility staff who seek to manage the city’s (limited) water as best they can offers insight into what is required for a more progressive urban water politics.

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  • 12. Alda-Vidal, C.
    et al.
    Rusca, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Zwarteveen, M.
    Schwartz, K.
    Pouw, N.
    Occupational genders and gendered occupations: the case of water provisioning in Maputo, Mozambique2017In: Gender, Place and Culture: A Journal of Feminist Geography, ISSN 0966-369X, E-ISSN 1360-0524, Vol. 24, no 7, p. 974-990Article in journal (Refereed)
    Abstract [en]

    Taking issue with how associations between technical prowess or entrepreneurship and masculinity tend to be taken for granted or are seen as stemming from natural or intrinsic gender differences, over the last two decades feminist scholars have developed theoretical approaches to understand the gendering of professions and abilities as the performative outcome of particular cultures and histories. We build on these insights to explore how associations between masculinities, technology and entrepreneurship shape ideas and practices of small-scale water provision in Maputo. Our findings show how activities (i.e. technical craftsmanship, hard physical work) or abilities (i.e. risk-taking, innovativeness) regarded as masculine tend to be considered the defining features of the profession. This shapes how men and women make sense of and talk about their work, each of them tactically emphasizing and performing those aspects best fitting their gender. Our detailed documentation of men’s and women’s everyday involvements in water provisioning challenges the existence of sharp boundaries and distinctions between genders and professional responsibilities. It shows that water provisioning requires many other types of work and skills and male and female household members collaborate and share their work. The strong normative-cultural associations between gender and water provisioning lead to a distinct under-recognition of women’s importance as water providers. We conclude that strategies to effectively support small-scale water businesses while creating more space and power for women involved in the business require the explicit recognition and re-conceptualization of water provisioning as a household business.

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  • 13.
    Alfieri, Lorenzo
    et al.
    European Commiss Joint Res Ctr, TP 122,Via E Fermi 2749, I-21027 Ispra, VA, Italy.
    Feyen, Luc
    European Commiss Joint Res Ctr, TP 122,Via E Fermi 2749, I-21027 Ispra, VA, Italy.
    Di Baldassarre, Giuliano
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Increasing flood risk under climate change: a pan-European assessment of the benefits of four adaptation strategies2016In: Climatic Change, Vol. 136, no 3, p. 507-521Article in journal (Refereed)
    Abstract [en]

    Future flood risk in Europe is likely to increase due to a combination of climatic and socio-economic drivers. Effective adaptation strategies need to be implemented to limit the impact of river flooding on population and assets. This research builds upon a recently developed flood risk assessment framework at European scale to explore the benefits of adaptation against extreme floods. The effect of implementing four different adaptation measures is simulated in the modeling framework. Measures include the rise of flood protections, reduction of the peak flows through water retention, reduction of vulnerability and relocation to safer areas. Their sensitivity is assessed in several configurations under a high-end global warming scenario over the time range 1976-2100. Results suggest that the future increase in expected damage and population affected by river floods can be compensated through different configurations of adaptation measures. The adaptation efforts should favor measures targeted at reducing the impacts of floods, rather than trying to avoid them. Conversely, adaptation plans only based on rising flood protections have the effect of reducing the frequency of small floods and exposing the society to less-frequent but catastrophic floods and potentially long recovery processes.

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  • 14.
    Alfonso, L.
    et al.
    UNESCO IHE Inst Water Educ, Integrated Water Syst & Governance, Delft, Netherlands..
    Mukolwe, M. M.
    UNESCO IHE Inst Water Educ, Integrated Water Syst & Governance, Delft, Netherlands.;Masinde Muliro Univ Sci & Technol, Estates Dept, Kakamega, Kenya..
    Di Baldassarre, Giuliano
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Probabilistic Flood Maps to support decision-making: Mapping the Value of Information2016In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 52, no 2, p. 1026-1043Article in journal (Refereed)
    Abstract [en]

    Floods are one of the most frequent and disruptive natural hazards that affect man. Annually, significant flood damage is documented worldwide. Flood mapping is a common preimpact flood hazard mitigation measure, for which advanced methods and tools (such as flood inundation models) are used to estimate potential flood extent maps that are used in spatial planning. However, these tools are affected, largely to an unknown degree, by both epistemic and aleatory uncertainty. Over the past few years, advances in uncertainty analysis with respect to flood inundation modeling show that it is appropriate to adopt Probabilistic Flood Maps (PFM) to account for uncertainty. However, the following question arises; how can probabilistic flood hazard information be incorporated into spatial planning? Thus, a consistent framework to incorporate PFMs into the decision-making is required. In this paper, a novel methodology based on Decision-Making under Uncertainty theories, in particular Value of Information (VOI) is proposed. Specifically, the methodology entails the use of a PFM to generate a VOI map, which highlights floodplain locations where additional information is valuable with respect to available floodplain management actions and their potential consequences. The methodology is illustrated with a simplified example and also applied to a real case study in the South of France, where a VOI map is analyzed on the basis of historical land use change decisions over a period of 26 years. Results show that uncertain flood hazard information encapsulated in PFMs can aid decision-making in floodplain planning.

  • 15.
    Alfonso, Leonardo
    et al.
    IHE-Delft.
    Ridolfi, Elena
    Sapienza University of Rome, Rome, Italy.
    Gaytan-Aguilar, Sandra
    Deltares, Rotterdamseweg 185, Delft 2629 HD, Netherlands.
    Napolitano, Francesco
    Sapienza University of Rome.
    Russo, Fabio
    Sapienza University of Rome.
    Ensemble entropy for monitoring network design2014In: Entropy, E-ISSN 1099-4300, Vol. 16, no 3, p. 1365-1375Article in journal (Refereed)
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  • 16. Ali, A Md
    et al.
    Di Baldassarre, G
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Solomatine, Dimitri P
    Testing different cross-section spacing in 1D hydraulic modelling: A case study on Johor River, Malaysia2014In: Hydrological Sciences Journal, no just-acceptedArticle in journal (Refereed)
  • 17. Ali, Genevieve
    et al.
    Tetzlaff, Doerthe
    McDonnell, Jeffrey J.
    Soulsby, Chris
    Carey, Sean
    Laudon, Hjalmar
    McGuire, Kevin
    Buttle, Jim
    Seibert, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Shanley, Jamie
    Comparison of threshold hydrologic response across northern catchments2015In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 29, no 16, p. 3575-3591Article in journal (Refereed)
    Abstract [en]

    Nine mid-latitude to high-latitude headwater catchments - part of the Northern Watershed Ecosystem Response to Climate Change (North-Watch) programme - were used to analyze threshold response to rainfall and snowmelt-driven events and link the different responses to the catchment characteristics of the nine sites. The North-Watch data include daily time-series of various lengths of multiple variables such as air temperature, precipitation and discharge. Rainfall and meltwater inputs were differentiated using a degree-day snowmelt approach. Distinct hydrological events were identified, and precipitation-runoff response curves were visually assessed. Results showed that eight of nine catchments showed runoff initiation thresholds and effective precipitation input thresholds. For rainfall-triggered events, catchment hydroclimatic and physical characteristics (e.g. mean annual air temperature, median flow path distance to the stream, median sub-catchment area) were strong predictors of threshold strength. For snowmelt-driven events, however, thresholds and the factors controlling precipitation-runoff response were difficult to identify. The variability in catchments responses to snowmelt was not fully explained by runoff initiation thresholds and input magnitude thresholds. The quantification of input intensity thresholds (e.g. snow melting and permafrost thawing rates) is likely required for an adequate characterization of nonlinear spring runoff generation in such northern environments.

  • 18.
    Allesson, Lina
    et al.
    Univ Oslo, Dept Biosci, Oslo, Norway..
    Koehler, Birgit
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Thrane, Jan-Erik
    Norwegian Inst Water Res, Oslo, Norway..
    Andersen, Tom
    Univ Oslo, Dept Biosci, Oslo, Norway..
    Hessen, Dag O.
    Univ Oslo, Dept Biosci, Oslo, Norway..
    The role of photomineralization for CO2 emissions in boreal lakes along a gradient of dissolved organic matter2021In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 66, no 1, p. 158-170Article in journal (Refereed)
    Abstract [en]

    Many boreal lakes are experiencing an increase in concentrations of terrestrially derived dissolved organic matter (DOM)-a process commonly labeled "browning." Browning affects microbial and photochemical mineralization of DOM, and causes increased light attenuation and hence reduced photosynthesis. Consequently, browning regulates lake heterotrophy and net CO2-efflux to the atmosphere. Climate and environmental change makes ecological forecasting and global carbon cycle modeling increasingly important. A proper understanding of the magnitude and relative contribution from CO2-generating processes for lakes ranging in dissolve organic carbon (DOC) concentrations is therefore crucial for constraining models and forecasts. Here, we aim to study the relative contribution of photomineralization to total CO(2)production in 70 Scandinavian lakes along an ecosystem gradient of DOC concentration. We combined spectral data from the lakes with regression estimates between optical parameters and wavelength specific photochemical reactivity to estimate rates of photochemical DOC mineralization. Further, we estimated total in-lake CO2-production and efflux from lake chemical and physical data. Photochemical mineralization corresponded on average to 9% +/- 1% of the total CO2-evasion, with the highest contribution in clear lakes. The calculated relative contribution of photochemical mineralization to total in-lake CO2-production was about 3% +/- 0.2% in all lakes. Although lakes differed substantially in color, depth-integrated photomineralization estimates were similar in all lakes, regardless of DOC concentrations. DOC concentrations were positively related to CO2-efflux and total in-lake CO2-production but negatively related to primary production. We conclude that enhanced rates of photochemical mineralization will be a minor contributor to increased heterotrophy under increased browning.

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  • 19.
    Ameli, A. A.
    et al.
    Univ Western Ontario, Dept Biol, Biol & Geol Sci Bldg, London, ON N6A 3K7, Canada.;Univ Saskatchewan, Global Inst Water Secur, Saskatoon, SK, Canada.;Uppsala Univ, Dept Earth Sci Air Water & Landscape Sci, Uppsala, Sweden..
    McDonnell, J. J.
    Univ Saskatchewan, Global Inst Water Secur, Saskatoon, SK, Canada.;Univ Aberdeen, Sch Geosci, Aberdeen, Scotland..
    Bishop, Kevin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Uppsala Centre for Sustainable Development, CSD Uppsala. Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Swedish Univ Agr Sci SLU, Dept Aquat Sci & Assessment, Uppsala, Sweden..
    The exponential decline in saturated hydraulic conductivity with depth: a novel method for exploring its effect on water flow paths and transit time distribution2016In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 30, no 14, p. 2438-2450Article in journal (Refereed)
    Abstract [en]

    The strong vertical gradient in soil and subsoil saturated hydraulic conductivity is characteristic feature of the hydrology of catchments. Despite the potential importance of these strong gradients, they have proven difficult to model using robust physically based schemes. This has hampered the testing of hypotheses about the implications of such vertical gradients for subsurface flow paths, residence times and transit time distribution. Here we present a general semi-analytical solution for the simulation of 2D steady-state saturated-unsaturated flow in hillslopes with saturated hydraulic conductivity that declines exponentially with depth. The grid-free solution satisfies mass balance exactly over the entire saturated and unsaturated zones. The new method provides continuous solutions for head, flow and velocity in both saturated and unsaturated zones without any interpolation process as is common in discrete numerical schemes. This solution efficiently generates flow pathlines and transit time distributions in hillslopes with the assumption of depth-varying saturated hydraulic conductivity. The model outputs reveal the pronounced effect that changing the strength of the exponential decline in saturated hydraulic conductivity has on the flow pathlines, residence time and transit time distribution. This new steady-state model may be useful to others for posing hypotheses about how different depth functions for hydraulic conductivity influence catchment hydrological response.

  • 20.
    Ameli, A.A.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Department of Biology, Western University, London, Ontario, Canada.
    Amvrosiadi, Nino
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Grabs, T.homas J.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Laudon, Hjalmar
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Creed, I.F.
    Department of Biology, Western University, London, Ontario, Canada.
    McDonnell, J.J.
    Global Institute for Water Security, School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; School of Geosciences, University of Aberdeen, Aberdeen, UK.
    Bishop, Kevin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Hillslope permeability architecture controls on subsurface transit time distribution and flow paths2016In: Journal of Hydrology, Vol. 543, no A, p. 17-30Article in journal (Refereed)
    Abstract [en]

    Defining the catchment transit time distribution remains a challenge. Here, we used a new semi-analytical physically-based integrated subsurface flow and advective–dispersive particle movement model to assess the subsurface controls on subsurface water flow paths and transit time distributions. First, we tested the efficacy of the new model for simulation of the observed groundwater dynamics at the well-studied S-transect hillslope (Västrabäcken sub-catchment, Sweden). This system, like many others, is characterized by exponential decline in saturated hydraulic conductivity and porosity with soil depth. The model performed well relative to a tracer-based estimate of transit time distribution as well as observed groundwater depth–discharge relationship within 30 m of the stream. Second, we used the model to assess the effect of changes in the subsurface permeability architecture on flow pathlines and transit time distribution in a set of virtual experiments. Vertical patterns of saturated hydraulic conductivity and porosity with soil depth significantly influenced hillslope transit time distribution. Increasing infiltration rates significantly decreased mean groundwater age, but not the distribution of transit times relative to mean groundwater age. The location of hillslope hydrologic boundaries, including the groundwater divide and no-flow boundary underlying the hillslope, changed the transit time distribution less markedly. These results can guide future decisions on the degree of complexity that is warranted in a physically-based rainfall–runoff model to efficiently and explicitly estimate time invariant subsurface pathlines and transit time distribution.

  • 21.
    Ameli, Ali A.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Univ Saskatchewan, Global Inst Water Secur, Saskatoon, SK, Canada.;Western Univ, Dept Biol, London, ON, Canada..
    Controls on subsurface transport of sorbing contaminant2017In: Hydrology Research, ISSN 1998-9563, E-ISSN 2224-7955, Vol. 48, no 5, p. 1226-1239Article in journal (Refereed)
    Abstract [en]

    Subsurface transport of a sorbing contaminant is poorly understood and characterized. Here, a new semi-analytical saturated-unsaturated flow and transport model is coupled to a kinetic sorption algorithm to assess the impact of changes in the subsurface permeability architecture and flow rate on sorption characteristics. The model outputs reveal the pronounced effect of the rate of vertical decline in K-s on the frequency of occurrence and spatial distribution of subsurface sorption as well as the timing and rate of sorbing contaminants discharged into stream. Sorption potential is weakened with infiltration rate. The impact of infiltration rate on the decline in sorption potential becomes more accentuated as the degree of subsurface vertical heterogeneity in saturated hydraulic conductivity increases. Porosity pattern also impacts sorption characteristics; but its effects highly depend upon the degree of vertical heterogeneity in Ks. The results and methodology presented in this paper have potential implications for assessing water quality in integrated groundwater-surface water systems as well as designing remediation systems.

  • 22.
    Ameli, Ali A.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Univ Saskatchewan, Global Inst Water Secur, Saskatoon, SK, Canada.;Western Univ, Dept Biol, London, ON, Canada.
    Beven, Keith
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Univ Lancaster, Lancaster Environm Ctr, Lancaster, England..
    Erlandsson, Martin
    Stockholm Univ, Dept Phys Geog, Stockholm, Sweden..
    Creed, Irena F.
    Western Univ, Dept Biol, London, ON, Canada..
    McDonnell, Jeffrey J.
    Univ Saskatchewan, Global Inst Water Secur, Saskatoon, SK, Canada.;Univ Aberdeen, Sch Geosci, Aberdeen, Scotland.;Oregon State Univ, Dept Forest Engn Resources & Management, Corvallis, OR 97331 USA..
    Bishop, Kevin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Swedish Univ Agr Sci, Dept Aquat Sci & Assessment, Uppsala, Sweden..
    Primary weathering rates, water transit times, and concentration-discharge relations: A theoretical analysis for the critical zone2017In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 53, no 1, p. 942-960Article in journal (Refereed)
    Abstract [en]

    The permeability architecture of the critical zone exerts a major influence on the hydrogeochemistry of the critical zone. Water flow path dynamics drive the spatiotemporal pattern of geochemical evolution and resulting streamflow concentration-discharge (C-Q) relation, but these flow paths are complex and difficult to map quantitatively. Here we couple a new integrated flow and particle tracking transport model with a general reversible Transition State Theory style dissolution rate law to explore theoretically how C-Q relations and concentration in the critical zone respond to decline in saturated hydraulic conductivity (K-s) with soil depth. We do this for a range of flow rates and mineral reaction kinetics. Our results show that for minerals with a high ratio of equilibrium concentration ( Ceq) to intrinsic weathering rate ( Rmax), vertical heterogeneity in K-s enhances the gradient of weathering-derived solute concentration in the critical zone and strengthens the inverse stream C-Q relation. As <mml:mfrac>CeqRmax</mml:mfrac> decreases, the spatial distribution of concentration in the critical zone becomes more uniform for a wide range of flow rates, and stream C-Q relation approaches chemostatic behavior, regardless of the degree of vertical heterogeneity in K-s. These findings suggest that the transport-controlled mechanisms in the hillslope can lead to chemostatic C-Q relations in the stream while the hillslope surface reaction-controlled mechanisms are associated with an inverse stream C-Q relation. In addition, as <mml:mfrac>CeqRmax</mml:mfrac> decreases, the concentration in the critical zone and stream become less dependent on groundwater age (or transit time).

  • 23.
    Ameli, Ali A.
    et al.
    Univ British Columbia, Dept Earth Ocean & Atmospher Sci, Vancouver, BC, Canada.
    Laudon, Hjalmar
    Swedish Univ Agr Sci, Dept Forest Ecol & Management, Umeå, Sweden.
    Teutschbein, Claudia
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Bishop, Kevin
    Swedish Univ Agr Sci, Dept Aquat Sci & Assessment, Uppsala, Sweden.
    Where and When to Collect Tracer Data to Diagnose Hillslope Permeability Architecture2021In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 57, no 8, article id e2020WR028719Article in journal (Refereed)
    Abstract [en]

    The permeability architecture has a major influence on hillslope flow path and hydrogeochemistry. To constrain this architecture and overcome equifinality in the diagnosis of hillslope flow paths within hydrologic transport models, different types of complementary data (e.g., tracer) have been recommended. However, there is still little information on the extent to which such complementary data can unravel the permeability architecture, and where and when to measure such data to most efficiently constrain models. Here, we couple a Richards-based flow and transport model with extensive long-term field measurements to compare the relative value of different types of hydrometric and tracer data in discriminating between contrasting permeability (or saturated hydraulic conductivity ()) architectures, in the absence of macropore flow. Our results show that compared to streamflow and water table observations, stream tracer data have a stronger evaluative potential to constrain hillslope vertical pattern in , in particular during seasons when flow is on average low (e.g., winter or summer). Tracer data from within the hillslope are even more helpful to discriminate between different vertical patterns in Ks than stream tracer data. This suggests a higher evaluative potential for hillslope tracer observations. This evaluative potential of hillslope data depends on where and when the data are collected, and increases with depth from the soil surface, with distance from the stream and during seasons when flow is low. The findings also emphasize the importance of incorporating hillslope permeability architecture in hydrologic transport models in order to reduce the uncertainty in the predictions of stream water quality.

  • 24.
    Amland, Sølvi
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Hvor er de markene i Sverige som er mest sensitive ovenfor forsuring og nitrogentap?2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Several factors affect whether the ground is prone to acidification and nitrogen loss. Removal of biological materials is an important factor that can trigger this. In Sweden, three dominant forest tree species are spruce, pine and birch trees. For forestry purposes, these trees are being logged at their potimal harvesting ages which are averaged at 70 years of age. This is of interest beacuse the forest ages can be used to predict future forestry practices, specifically in Dalarna, Sweden. The forest ages were observed at a catchment based level so that the effects of forestry can easily be measured. It was found that cathcments in the north of Dalarna consist of higher percentages of forest over the age of 70 in comparsion to the south and areas surrounding lakes. From this, it is expected that forestry will occur in the near future in the north.

    Hopefully the work that has been done in Dalarna, can be used as a model for the rest of Sweden.

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  • 25.
    Amvrosiadi, Nino
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Temporal Dynamics of Total Organic Carbon Export Rates in Swedish Streams: Importance of discharge conditions and seasonal effects2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The amount of total organic carbon (TOC) in water is a rough indicator of the waterquality. Driven by the question how the TOC concentration would vary acrossstreams in Sweden under different climate conditions (e.g. more extreme dischargeevents), the temporal dynamics of TOC were examined for different stream subgroupswith six orders of magnitude catchment area span. In addition, the relationshipbetween dissolved inorganic carbon (DIC) export (both downstream and evasion) anddischarge conditions was also studied. Another question addressed was if the amountof TOC exported can be affected by export conditions dominating the previousseason. TOC export followed closely the discharge, which is in agreement withprevious studies, and all 42 catchments studied across Sweden were described by thispositive relationship regardless their size. A linear TOC export response to dischargewas identified during extreme discharge conditions. Furthermore, the TOC export wassignificantly related to the antecedent TOC export conditions for approximately halfof the 18 studied catchments with areas ranging between 2.5·10-3 and 67 km2.

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    Temporal Dynamics of Total Organic Carbon Export Rates in Swedish Streams: Importance of discharge conditions and seasonal effects
  • 26.
    Amvrosiadi, Nino
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    The value of experimental data and modelling for exploration of hydrological functioning: The case of a till hillslope2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Successfully modeling one system response (e.g. hydrograph or solute transport) sometimes gives the false sense of well-characterizing the modeled system. This is partly because of the well-known equifinality issue; during the calibration process multiple parameter combinations can produce similarly good results. One step forward towards a better-defined system is using measured (at relevant scale) values for the model parameters, as well as using multiple conditions to constrain the model.

    But when not enough, or relevant, field measurements are available, virtual experiments (VE’s) can be used as a supplementary method to model calibration. The advantage of VE’s over model calibration is that they can also be used to explore assumptions both on the system hydrological processes, and on the model structure.

    One goal of this study was to utilize both field measurements and models for better characterization of the S-transect hillslope, located in Västrabäcken catchment, Northern Sweden. This included (a) characteristics in space: system vertical boundaries, hydraulic parameters, pore water velocity distribution, spatial correlation of flowpaths, soil water retention properties; (b) characteristic of system’s dynamic behavior: storage – discharge relationship, transit time distribution, turnover time; and (c) outputs’ sensitivity to external forcing, and to small scale structure assumptions. The second goal was to comment on the value of field measurements and virtual experiments for extracting information about the studied system.

    An intensely monitored study hillslope was chosen for this work. Although the hillslope has already been the subject of multiple field and modelling studies, there are still open questions regarding the characteristics listed above. The models used were the Vertical Equilibrium Model (VEM), and the Multiple Interacting Pathways (MIPs) model.

    It was found that the hillslope was well connected; from the near-stream areas up to the water divide the storage – discharge relationship could be described as an exponential function. Also, the dynamic storage (which controls the hydrograph dynamics) was much smaller comparing to the total hillslope storage. The unsaturated soil storage was found to be more sensitive to water table positions than vertical flux magnitude. The dynamic condition of external forcing (precipitation and evapotranspiration) affected the transit time distribution (TTD) shape. And, opposite to expectations, TTD was not sensitive to micro-scale structural assumptions tested here.

    List of papers
    1. Water storage dynamics in a till hillslope: the foundation for modeling flows and turnover times
    Open this publication in new window or tab >>Water storage dynamics in a till hillslope: the foundation for modeling flows and turnover times
    2017 (English)In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 31, no 1, p. 4-14Article in journal (Refereed) Published
    Abstract [en]

    Studies on hydrology, biogeochemistry, or mineral weathering often rely on assumptions about flow paths, water storage dynamics, and transit times. Testing these assumptions requires detailed hydrometric data that are usually unavailable at the catchment scale. Hillslope studies provide an alternative for obtaining a better understanding, but even on such well‐defined and delimited scales, it is rare to have a comprehensive set of hydrometric observations from the water divide down to the stream that can constrain efforts to quantify water storage, movement, and turnover time. Here, we quantified water storage with daily resolution in a hillslope during the course of almost an entire year using hydrological measurements at the study site and an extended version of the vertical equilibrium model. We used an exponential function to simulate the relationship between hillslope discharge and water table; this was used to derive transmissivity profiles along the hillslope and map mean pore water velocities in the saturated zone. Based on the transmissivity profiles, the soil layer transmitting 99% of lateral flow to the stream had a depth that ranged from 8.9 m at the water divide to under 1 m closer to the stream. During the study period, the total storage of this layer varied from 1189 to 1485 mm, resulting in a turnover time of 2172 days. From the pore water velocities, we mapped the time it would take a water particle situated at any point of the saturated zone anywhere along the hillslope to exit as runoff. Our calculations point to the strengths as well as limitations of simple hydrometric data for inferring hydrological properties and water travel times in the subsurface.

    Keywords
    flow pathways, storage, storage dynamics, turnover time
    National Category
    Earth and Related Environmental Sciences
    Identifiers
    urn:nbn:se:uu:diva-331679 (URN)10.1002/hyp.11046 (DOI)000441296100001 ()
    Available from: 2017-10-16 Created: 2017-10-16 Last updated: 2018-10-12Bibliographically approved
    2. Soil moisture storage estimation based on steady vertical fluxes under equilibrium
    Open this publication in new window or tab >>Soil moisture storage estimation based on steady vertical fluxes under equilibrium
    2017 (English)In: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 553, p. 798-804Article in journal (Refereed) Published
    Abstract [en]

    Soil moisture is an important variable for hillslope and catchment hydrology. There are various computational methods to estimate soil moisture and their complexity varies greatly: from one box with vertically constant volumetric soil water content to fully saturated-unsaturated coupled physically-based models. Different complexity levels are applicable depending on the simulation scale, computational time limitations, input data and knowledge about the parameters. The Vertical Equilibrium Model (VEM) is a simple approach to estimate the catchment-wide soil water storage at a daily time-scale on the basis of water table level observations, soil properties and an assumption of hydrological equilibrium without vertical fluxes above the water table. In this study VEM was extended by considering vertical fluxes, which allows conditions with evaporation and infiltration to be represented. The aim was to test the hypothesis that the simulated volumetric soil water content significantly depends on vertical fluxes. The water content difference between the no-flux, equilibrium approach and the new constant-flux approach greatly depended on the soil textural class, ranging between similar to 1% for silty clay and similar to 44% for sand at an evapotranspiration rate of 5 mm.d(-1). The two approaches gave a mean volumetric soil water content difference of 1 mm for two case studies (sandy loam and organic rich soils). The results showed that for many soil types the differences in estimated storage between the no-flux and the constant flux approaches were relatively small.

    Keywords
    Volumetric soil water content, Vertical flux, VEM, Catchment water storage
    National Category
    Oceanography, Hydrology and Water Resources
    Identifiers
    urn:nbn:se:uu:diva-331688 (URN)10.1016/j.jhydrol.2017.08.042 (DOI)000412612700061 ()
    Funder
    Swedish Research Council, 2011-4889
    Available from: 2017-10-16 Created: 2017-10-16 Last updated: 2018-01-13Bibliographically approved
    3. Value of virtual experiments for a hillslope scale system understanding
    Open this publication in new window or tab >>Value of virtual experiments for a hillslope scale system understanding
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    (English)Manuscript (preprint) (Other academic)
    National Category
    Oceanography, Hydrology and Water Resources
    Identifiers
    urn:nbn:se:uu:diva-331730 (URN)
    Available from: 2017-10-17 Created: 2017-10-17 Last updated: 2020-05-12
    4. Water age dependence on vertical flux assumptions
    Open this publication in new window or tab >>Water age dependence on vertical flux assumptions
    (English)Manuscript (preprint) (Other academic)
    National Category
    Oceanography, Hydrology and Water Resources
    Identifiers
    urn:nbn:se:uu:diva-331731 (URN)
    Available from: 2017-10-17 Created: 2017-10-17 Last updated: 2020-05-12
    5. Following tracer through the unsaturated zone using a multiple interacting pathways model: Implications from laboratory experiments
    Open this publication in new window or tab >>Following tracer through the unsaturated zone using a multiple interacting pathways model: Implications from laboratory experiments
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    2019 (English)In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 33, no 17, p. 2300-2313Article in journal (Refereed) Published
    Abstract [en]

    Models must effectively represent velocities and celerities if they are to address the old water paradox. Celerity information is recorded indirectly in hydrograph observations, whereas velocity information is more difficult to measure and simulate effectively, requiring additional assumptions and parameters. Velocity information can be obtained from tracer experiments, but we often lack information on the influence of soil properties on tracer mobility. This study features a combined experimental and modelling approach geared towards the evaluation of different structures in the multiple interacting pathways (MIPs) model and validates the representation of velocities with laboratory tracer experiments using an undisturbed soil column. Results indicate that the soil microstructure was modified during the experiment. Soil water velocities were represented using MIPs, testing how the (a) shape of the velocity distribution, (b) transition probability matrices (TPMs), (c) presence of immobile storage, and (d) nonstationary field capacity influence the model's performance. In MIPs, the TPM controls exhanges of water between pathways. In our experiment, MIPs were able to provide a good representation of the pattern of outflow. The results show that the connectedness of the faster pathways is important for controlling the percolation of water and tracer through the soil. The best model performance was obtained with the inclusion of immobile storage, but simulations were poor under the assumption of stationary parameters. The entire experiment was adequately simulated once a time-variable field capacity parameter was introduced, supporting the need for including the effects of soil microstructure changes observed during the experiment.

    Keywords
    celerity, soil properties, tracer mobility, velocity
    National Category
    Oceanography, Hydrology and Water Resources
    Identifiers
    urn:nbn:se:uu:diva-331732 (URN)10.1002/hyp.13466 (DOI)000477502900001 ()
    Available from: 2017-10-17 Created: 2017-10-17 Last updated: 2019-12-06Bibliographically approved
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  • 27.
    Amvrosiadi, Nino
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Beven, Keith
    Bishop, Kevin
    Laudon, Hjalmar
    Seibert, Jan
    Value of virtual experiments for a hillslope scale system understandingManuscript (preprint) (Other academic)
  • 28.
    Amvrosiadi, Nino
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Beven, Keith
    Bishop, Kevin
    Seibert, Jan
    Water age dependence on vertical flux assumptionsManuscript (preprint) (Other academic)
  • 29.
    Amvrosiadi, Nino
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Bishop, Kevin
    Swedish Univ Agr Sci, Dept Aquat Sci & Assessment, Uppsala, Sweden.
    Seibert, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Univ Zurich, Dept Geog, Zurich, Switzerland.
    Soil moisture storage estimation based on steady vertical fluxes under equilibrium2017In: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 553, p. 798-804Article in journal (Refereed)
    Abstract [en]

    Soil moisture is an important variable for hillslope and catchment hydrology. There are various computational methods to estimate soil moisture and their complexity varies greatly: from one box with vertically constant volumetric soil water content to fully saturated-unsaturated coupled physically-based models. Different complexity levels are applicable depending on the simulation scale, computational time limitations, input data and knowledge about the parameters. The Vertical Equilibrium Model (VEM) is a simple approach to estimate the catchment-wide soil water storage at a daily time-scale on the basis of water table level observations, soil properties and an assumption of hydrological equilibrium without vertical fluxes above the water table. In this study VEM was extended by considering vertical fluxes, which allows conditions with evaporation and infiltration to be represented. The aim was to test the hypothesis that the simulated volumetric soil water content significantly depends on vertical fluxes. The water content difference between the no-flux, equilibrium approach and the new constant-flux approach greatly depended on the soil textural class, ranging between similar to 1% for silty clay and similar to 44% for sand at an evapotranspiration rate of 5 mm.d(-1). The two approaches gave a mean volumetric soil water content difference of 1 mm for two case studies (sandy loam and organic rich soils). The results showed that for many soil types the differences in estimated storage between the no-flux and the constant flux approaches were relatively small.

  • 30.
    Anderberg, Hilda
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Olsson, Sofia
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Bjerklund, Frida
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Larsson, Therese
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Junegard, Frida
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Risker vid översvämning och åtgärdsförslag för MSB:s skola i Revinge2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    På skolan i Revinge utbildar Myndigheten för samhällsskydd och beredskap (MSB) personer inom områdena skydd mot olyckor och krisberedskap. Vid ett flertal tillfällen har Kävlingeån översvämmat skolområdet vilket resulterat i att verksamheten blivit stillastående i flera veckor. Grundvattennivån ligger nära markytan på skolområdet och platsen är därför extra känslig för översvämningar både från ån och extrem nederbörd.

    För att kunna minimera konsekvenserna vid en översvämning identifierades olika objekt, byggnader och områden, som i rapporten är benämnda som skyddsobjekt, som drabbas mest vid översvämning. För att ta hänsyn till att framtida väderförhållanden kan bli mer extrema undersöktes två klimatanpassade scenarier, höga flöden från ån och extrem nederbörd. Olika åtgärder mot översvämningar som potentiellt kan passa skolområdet togs fram och viktades utefter kostnader, lagar och skyddskapacitet.

    Skyddsobjekten som togs fram är skolans övningytor, kontorsbyggnader, hus med källare, spillvattenbrunnar, områden som kan sprida miljöfarliga ämnen, elskåp samt fordonshall/förråd. Skyddsobjekten viktades utefter översvämningskonsekvensernas direkta kostnader, hinder för utbildning samt fara för människor och natur, i relation till hur sannolikt det är att objekten blir översvämmade. Övningsytor, spillvattenbrunnar och områden som kan sprida miljöfarliga ämnen fick högsta prioritet.

    De åtgärder mot översvämning som undersöktes var gröna tak, regnmagasin, regnbäddar, träd, kontrollerad översvämningsyta och permanent vall. De fyra förstnämnda bedömdes billiga och lagligt sett icke komplicerade i relation till permanent vall och kontrollerad översvämningsyta. En summering av vilka skyddsobjekt varje åtgärd skyddar lades till. En effektivitetsfaktor togs fram i relation till vilka scenarier åtgärderna verkar mot och i vilken grad de kan motverka ett scenario på egen hand. Detta gav värderingen, från högst till lägst, permanent vall, träd, översvämningsyta, regnmagasin, regnbäddar och gröna tak.

    Som ytterligare åtgärder rekommenderas det att utesluta användning av källare helt och bestämmelser kring nybyggnation bör tas i relation till var det finns störst risk för översvämning på området. Ett förslag till MSB finns om att ta kontakt med Kävlingeå-projektet som arbetar med att utöka andelen våtmarker utmed Kävlingeån, där ett av målen för projektet är att motverka översvämningar. Arbetet drivs av Kävlingeåns Vattenråd, vilka också kan ha mer information kring hur regleringen av Vombsjön kan påverka risken för översvämning på skolområdet. 

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  • 31.
    Andersson, Elinor
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Starttillståndets inverkan på hydrologisk prognososäkerhet i HYPE-modellen2016Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Hydrological Forecast and Warning Service of The Swedish Meteorological and Hydrological Institute (SMHI) use meteorological ensemble forecasts as input in hydrological models. The hydrological ensemble forecasts take the uncertainty of future temperature and precipitation into account and serve as the basis of issued risks and warnings of high flows. Currently not considered is the uncertainty of the initial state, which consists of state variables in the model describing for instance soil water content and snow pack. This study assessed the impact of the initial state on forecasts in the hydrological model HYPE aiming to quantify the uncertainty and eventually enable more accurate forecasts.There were three aims of this study : 1) Evaluate a suggestion about how the initial state can be varied to give a good estimation of forecast uncertainty related to the hydrological initial state. 2) Examine the relationship between the spread of initial states and the hydrological forecast error. 3) Analyze the impact of seasons, catchment area, lake percentage, forest percentage and elevation on forecast uncertainty. A central hypothesis was that a smaller difference between the discharge of the initial state and the observed discharge results in more accurate forecasts. A restriction of the study was that the initial states only could be generated by disturbances of forcing data in before the forecast.Input data to the HYPE model were fifteen temperature and precipitation series, manipulated to generate an ensemble of different initial states. This ensemble was then used to make discharge forecasts with observed temperature and precipitation as forcing data. The study was performed on 76 catchments all over Sweden with data from the time period 1999-2008. Forecasts were made every day and the ensemble spread was evaluated 2, 4 and 10 days into the forecast. Autoregressive forecasts where the modelled discharge is corrected after the observed discharge were executed and evaluated as well. The results indicated a relationship between ensemble spread and forecast error, which implies that the spread can be used as a measure of the uncertainty of the initial state. The forecast error and ensemble spread correlated positively to forest percentage and negatively to catchment area, lake percentage and elevation. The same trend was detected between spread and catchment characteristics. The spread was biggest in winter and spring when normalization was made with mean discharge for the ten-year period and in spring and summer when normalization was done with mean discharge per month. The hypothesis that a smaller difference between the discharge of the initial state and the observed discharge results in more accurate forecasts was confirmed by the results. An implementation of an ensemble of different initial states in operational forecasts at SMHI’s Hydrological Forecast and Warning Service is suggested in order to further quantify the uncertainty of hydrological forecasts, and thereby improve the basis of judgment when issuing risks and warnings.

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  • 32.
    Andersson, Sofia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Lundkvist, Elin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Torkans effekt på dricksvattenförsörjningen i Mälarregionen: En studie om kommuners arbete med vattenfrågor utifrån erfarenheter från 20172018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of this paper is to examine how municipalities in the Mälar region of Sweden were affected by the low surface and groundwater levels in the summer of 2017, how municipalities handled the situation, how they work with water related questions in their daily work and whether they had an action plan for dealing with shortage of water prior to 2017. Lastly, we also aim to compile the roles and responsibilities for different authorities when it comes to water supply. The area of study was limited to 39 municipalities in four counties: Södermanlands, Upplands, Västmanlands and Örebro county. To answer the aim, a survey was sent out to all municipalities and interviews were done with two of the municipalities. A literature study was done in order to answer the division of responsibilities between different authorities. The survey was answered by 26 municipalities. The main result we got from the survey was that even though the water levels were below normal, the municipalities didn’t experience water shortages in the extent we had expected. Five municipalities indicated that they had been affected by the water shortages. The main measure that were done was the irrigation ban. From the survey it was found that most of the municipalities were lacking action plans to deal with a water shortage situation before2017. The majority of the municipalities believe that their water supply can be affected by climate change, but only 14 indicated that they have an action plan for it. The results obtained from our interviews primarily marks the division of responsibilities for water conservation areas. As conducted from the literature study, the processes to constitute water conservation areas does not seem to be smooth and quick enough to meet the goals of sustainable and long-term water supply.

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  • 33.
    Andersson, Ulla-Maria
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Physical Geography.
    Eriksson, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Physical Geography.
    Hydrochemical investigations in three representative basins in Sweden1978Report (Other academic)
    Abstract [en]

    Summary

    During the IHD-period 1965—1974 chemical investigations were carried out in the three representative basins Velen, Kassjöån and Lappträsket, mainly to obtain balances of common constituents in surface waters, taking into account deposition from the atmosphere.

    As to the seasonal variation of concentrations in discharge from the basins and sub-basins it is remarkably suppressed compared to variations in discharge rates. This can be explained by the storage in lakes and as groundwater which tend to smooth rapid fluctuations in concentrations. However, it also indicates that surface run-off during snow-melt is in no way a dominant process. The largest fluctuations are found for the nitrogen compounds ammonia and nitrate where complex biological processes may at times either "fix" or release nitrogen compounds from organic matter.

    Considering balances of incoming — outflowing constituents, sulphur and nitrogen compounds always show a deficit; much more is deposited from the atmosphere than carried away from the basins by run-off. There are two possible mechanisms which explain this. One is a loss as volatile sulphur and nitrogen compounds from soils due to microbiological processes in reducing environments. The other possibility is a steady increase in soil sulphur and nitrogen (bound in organic matter) revealing an ongoing adjustment of soil sulphur and nitrogen to the increasing levels of atmospheric deposition of these.

    As to the balances of calcium, magnesium, sodium and potassium they indicate losses in the ground due to weathering. There are differences in the rates of weathering in the three basins which can be explained on basis of differences in the mineralogical composition of the hard rocks which are so common in Sweden. 

  • 34.
    Andin, Caroline
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Sundin, Madelene
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Jämförelse av Sveriges geologiska undersöknings och Naturvårdsverkets extraktionsmetoder för metaller i morän2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Sveriges geologiska undersökning, SGU, och Naturvårdsverket, NV, tillämpar sig av olika geokemiska extraktionsmetoder för att analysera jordprover. Detta görs för att undersöka metallhalter i mark. SGU använder en metod som liknar den som rekommenderas av NV, men utan lakning i tryckkärl, och det är oklart om metoderna lakar samma jordfraktion och kan jämföras. Syftet med arbetet är att fastställa om SGUs och NVs extraktionsmetoder för jordprover är jämförbara. Detta har gjorts genom en kvalitets- och regressionsanalys, samt genom en statistisk analys. Proverna kommer från tre olika områden i Sverige och de är analyserade med både fin- och grovfraktion. För att hitta relationer mellan metoderna har SGUs och NVs analysresultat kopplats till NVs riktvärden för förorenad mark. Detta gjordes för att undersöka hur pass jämförbara SGUs resultat är med NVs riktvärden. Det visade sig att SGUs och NVs extraktionsmetoder för jordprover korrelerar väl med varandra och att de har en god förklaringsgrad. Prov som analyserades efter NVs metod extraherade mer metall än SGUs metod. Dessutom lakades högre metallhalter ur prov av finare fraktion än prov av grövre fraktion. Sammanfattningsvis är alltså SGUs och NVs extraktionsmetoder jämförbara.

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  • 35.
    Andrén, Jakob
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    An Overview of State-of-the-art Hydraulic Conductivity Measurements in Coarse Grained Materials2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Embankment dams are made from soil materials of varying sizes and widely used all over the world.When constructing these, knowing the hydraulic conductivity (K) of the soil materials is a keyparameter in order to construct safe embankment dams. A knowledge gap regarding K measurementsin coarse grained soils has been identified. This thesis aims to provide a theoretical overview ofpresent day state-of-the-art methods for measuring hydraulic conductivity and the controllingcharacteristics for K. Coarse grained soils refers to a soil with the coarsest grain fraction being > 20mm and/or have a K > 10-4m/s.   It was found that the fixed wall permeameter is the most suitable laboratory method. In the field, itis possible to estimate K using tracer methods, these however show more potential for leakagepathway detection. Common for all K measurement methods are the controlling characteristics of K,grain size distribution, pore geometry, degree of compaction, particle movement and flow regime.These need to be considered when testing to produce useful measurements. If the relationshipbetween flow velocity and hydraulic head is non-linear, Darcy's law is not valid for calculating K.

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  • 36. Archfield, Stacey A.
    et al.
    Clark, Martyn
    Arheimer, Berit
    Hay, Lauren E.
    McMillan, Hilary
    Kiang, Julie E.
    Seibert, J.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Hakala, Kirsti
    Bock, Andrew
    Wagener, Thorsten
    Farmer, William H.
    Andreassian, Vazken
    Attinger, Sabine
    Viglione, Alberto
    Knight, Rodney
    Markstrom, Steven
    Over, Thomas
    Accelerating advances in continental domain hydrologic modeling2015In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 51, no 12, p. 10078-10091Article in journal (Refereed)
    Abstract [en]

    In the past, hydrologic modeling of surface water resources has mainly focused on simulating the hydrologic cycle at local to regional catchment modeling domains. There now exists a level of maturity among the catchment, global water security, and land surface modeling communities such that these communities are converging toward continental domain hydrologic models. This commentary, written from a catchment hydrology community perspective, provides a review of progress in each community toward this achievement, identifies common challenges the communities face, and details immediate and specific areas in which these communities can mutually benefit one another from the convergence of their research perspectives. Those include: (1) creating new incentives and infrastructure to report and share model inputs, outputs, and parameters in data services and open access, machine-independent formats for model replication or reanalysis; (2) ensuring that hydrologic models have: sufficient complexity to represent the dominant physical processes and adequate representation of anthropogenic impacts on the terrestrial water cycle, a process-based approach to model parameter estimation, and appropriate parameterizations to represent large-scale fluxes and scaling behavior; (3) maintaining a balance between model complexity and data availability as well as uncertainties; and (4) quantifying and communicating significant advancements toward these modeling goals.

  • 37. Arheimer, Berit
    et al.
    Cudennec, Christophe
    Castellarin, Attilio
    Grimaldi, Salvatore
    Heal, Kate V.
    Lupton, Claire
    Sarkar, Archana
    Tian, Fuqiang
    Kileshye Onema, Jean-Marie
    Archfield, Stacey
    Blöschl, Günter
    Chaffe, Pedro L. Borges
    Croke, Barry F.W.
    Dembéle, Moctar
    Leong, Chris
    Mijic, Ana
    Mosquera, Giovanny M.
    Nlend, Bertil
    Olusola, Adeyemi O.
    Polo, María J.
    Sandells, Melody
    Sheffield, Justin
    van Hateren, Theresa C.
    Shafiei, Mojtaba
    Adla, Soham
    Agarwal, Ankit
    Aguilar, Cristina
    Andersson, Jafet C.M.
    Andraos, Cynthia
    Andreu, Ana
    Avanzi, Francesco
    Bart, Ryan R.
    Bartosova, Alena
    Batelaan, Okke
    Bennett, James C.
    Bertola, Miriam
    Bezak, Nejc
    Boekee, Judith
    Bogaard, Thom
    Booij, Martijn J.
    Brigode, Pierre
    Buytaert, Wouter
    Bziava, Konstantine
    Castelli, Giulio
    Castro, Cyndi V.
    Ceperley, Natalie C.
    Chidepudi, Sivarama K. R.
    Chiew, Francis H. S.
    Chun, Kwok P.
    Dagnew, Addisu G.
    Dekongmen, B. W.
    del Jesus, Manuel
    Dezetter, Alain
    do Nascimento Batista, José A.
    Doble, Rebecca C.
    Dogulu, Nilay
    Eekhout, Joris P.C.
    Elçi, Alper
    Elenius, Maria
    Finger, David C.
    Fiori, Aldo
    Fischer, Svenja
    Förster, Kristian
    Ganora, Daniele
    Gargouri Ellouze, Emna
    Ghoreishi, Mohammad
    Harvey, Natasha
    Hrachowitz, Markus
    Jampani, Mahesh
    Jaramillo, Fernando
    Jongen, Harro J.
    Kareem, Kola Y.
    Khan, Usman T.
    Khatami, Sina
    Kingston, Daniel G.
    Koren, Gerbrand
    Krause, Stefan
    Kreibich, Heidi
    Lerat, Julien
    Liu, Junguo
    Madruga de Brito, Mariana
    Mahé, Gil
    Makurira, Hodson
    Mazzoglio, Paola
    Merheb, Mohammad
    Mishra, Ashish
    Mohammad, Hiba
    Montanari, Alberto
    Mujere, Never
    Nabavi, Ehsan
    Nkwasa, Albert
    Orduna Alegria, Maria E.
    Orieschnig, Christina
    Ovcharuk, Valeriya
    Palmate, Santosh S.
    Pande, Saket
    Pandey, Shachi
    Papacharalampous, Georgia
    Pechlivanidis, Ilias
    Penny, Gopal
    Pimentel, Rafael
    Post, David A.
    Prieto, Cristina
    Razavi, Saman
    Salazar-Galán, Sergio
    Sankaran Namboothiri, Adarsh
    Santos, Pedro P.
    Savenije, Hubert
    Shanono, Nura J.
    Sharma, Ashutosh
    Sivapalan, Murugesu
    Smagulov, Zhanibek
    Szolgay, Jan
    Teng, Jin
    Teuling, Adriaan J.
    Teutschbein, Claudia
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Tyralis, Hristos
    van Griensven, Ann
    van Schalkwyk, Andries J.
    van Tiel, Marit
    Viglione, Alberto
    Volpi, Elena
    Wagener, Thorsten
    Wang-Erlandsson, Lan
    Wens, Marthe
    Xia, Jun
    The IAHS Science for Solutions decade, with Hydrology Engaging Local People IN a Global world (HELPING)2024In: Hydrological Sciences Journal, ISSN 0262-6667, E-ISSN 2150-3435Article in journal (Refereed)
    Abstract [en]

    The new scientific decade (2023-2032) of the International Association of Hydrological Sciences (IAHS) aims at searching for sustainable solutions to undesired water conditions - may it be too little, too much or too polluted. Many of the current issues originate from global change, while solutions to problems must embrace local understanding and context. The decade will explore the current water crises by searching for actionable knowledge within three themes: global and local interactions, sustainable solutions and innovative cross-cutting methods. We capitalise on previous IAHS Scientific Decades shaping a trilogy; from Hydrological Predictions (PUB) to Change and Interdisciplinarity (Panta Rhei) to Solutions (HELPING). The vision is to solve fundamental water-related environmental and societal problems by engaging with other disciplines and local stakeholders. The decade endorses mutual learning and co-creation to progress towards UN sustainable development goals. Hence, HELPING is a vehicle for putting science in action, driven by scientists working on local hydrology in coordination with local, regional, and global processes.

  • 38.
    Arnlund, Jonathan
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Utredning av reningsfunktionen hos Kungsängens dagvattendamm: en studie med flödesproportionell provtagning2014Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Stormwater is the name for rainwater and snowmelt runoff from impervious surfaces in the urban environment. This water often carries large amounts of pollutants such as heavy metals, nutrients, and oil-related substances, which can cause great damage if they reach the receiving waters. To clean the storm water and thus reduce the pollution load, more and more open storm water systems are being built, such as wetlands and ponds. Studies have shown that these systems have high pollutant removal efficiency and are cost effective. Knowledge of how these systems work and how they best are evaluated is limited.

    “Kungsängsdammen” near Uppsala is a newly constructed stormwater facility that is designed to clean and retard stormwater from the industrial and commercial area Boländerna. This thesis aims to investigate the purification function of the facility. Flow proportional sampling was carried out at the inlet and outlet for 8 weeks. Substances that were analyzed were nutrients P and N, suspended solids, heavy metals As, Cd, Co, Cr, Cu, Mo, Ni, Pb, V, Zn and petroleum hydrocarbons. On some occasions, the petroleum-related organic parameters PAHs, octyl and nonylphenols and tributyltin were analyzed. Flow proportional sampling is recommended to determine the efficiency of a stormwater pond, but the problem is that it takes much time and considerable resources. In addition to this method, additional measurements were carried out with sediment traps, and a calculation of pollution load at the inlet with the program StormTac.

    The flow proportional sampling showed that the “Kungsängsdammen” pond-, functions well as a treatment facility for pollutions. Suspended solids, nutrients and heavy metals are separated effectively and the outlet concentrations for these substances were below proposed guideline values. This is observed, despite the fact that zinc, copper, nitrogen and suspended solids had intake concentrations above the guideline values. Flow calculations showed that the bypass flow is important when estimating the pollutant removal efficiency. For organic compounds, tributyltin was measured at concentrations above the Environmental Quality Standards (EQS) for surface water both at the inlet and outlet. The inlet concentrations that were calculated in StormTac were consistent with the results of the flow proportional sampling for heavy metals and nutrients. Moreover, the investigation of sediments showed that sedimentation occurs mainly in the ditch before the pond and at the inlet to the pond. The ditch is in need of cleansing, because of the risk of sediment being washed away during high flows.

    The flow proportional sampling showed that the “Kungsängsdammen” pond-, functions wellas a treatment facility for pollutions. Suspended solids, nutrients and heavy metals are separated effectively and the outlet concentrations for these substances were below proposedguideline values. This is observed, despite the fact that zinc, copper, nitrogen and suspended solids had intake concentrations above the guideline values. Flow calculations showed that the bypass flow is important when estimating the pollutant removal efficiency. For organiccompounds, tributyltin was measured at concentrations above the Environmental Quality Standards (EQS) for surface water both at the inlet and outlet. The inlet concentrations that were calculated in StormTac were consistent with the results of the flow proportional sampling for heavy metals and nutrients. Moreover, the investigation of sediments showedthat sedimentation occurs mainly in the ditch before the pond and at the inlet to the pond. The ditch is in need of cleansing, because of the risk of sediment being washed away during high flows.

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  • 39. Aronica, Giuseppe T.
    et al.
    Apel, Heiko
    Di Baldassarre, Giuliano
    UNESCO-IHE Institute for Water Education, Delft, the Netherlands.
    Schumann, Guy J-P.
    HP - Special Issue on Flood Risk and Uncertainty2013In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 27, no 9, p. 1291-Article in journal (Refereed)
  • 40.
    Ashkriz, Elnaz
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Regional Sources of Precipitation in the Ethiopian Highlands2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this essay is to investigate the origin of the large amount of precipitation that is present in the northern Ethiopian Highlands. With Moisture transport into the Ethiopian Highlands by Ellen Viste and Asgeir Sorteberg as a base, this essays intents to compare the same data but by focusing on a much smaller time scale. This frame was chosen to see if the data would deviate (i.e. a small and specific time scale versus a large and general time scale). Whilst the investigation by Viste and Sorteberg focuses on the two most rain rich months, July and August during 1998-2008, this essay focuses on only July during 2008.

                          To investigate where the precipitation originates from, this essay has analyzed different meteorological parameters such as horizontal and vertical winds at different altitudes and the moisture content of these winds.

                          This essay has like Viste’s and Sorteberg’s paper used ERA-Interim data as a basis. However the course of action has differed. This essay has made conclusions by visually drawing conclusions by studying the data images while Viste and Asgeir have drawn their conclusions by backtracking the wind to its origin.

                          This investigations results showed that great amounts of moisture were transported into the highlands from the south-west, and to some extent also from the north. While the moisture transport from the south-west was large due to the level of moist in the air, these winds where fairly small and at low altitudes. The winds from the north were visible at higher altitudes and were stronger, however they carried much less water vapor. However, exactly how much each of these winds actually contributed to producing rain is more difficult to say.

                          The results from Viste and Asgeir (2011) showed that the amount of moist that was transported into the highlands were about 46 percent more from the north compared to from the south. The contribution to moisture release within the area was however almost equally great from north and south.

                          Both investigations thus showed that the largest amount of moist was transported from the south and north. What this study did however not address was how large amount of the entire moist that had contributed to rain.

                          One anomaly of large amounts of precipitation was registered on the 20th of July 2008. This study looked closer into this which showed that large winds were registered this date as well as an upwind cell. One can presume that these winds carried large amounts of moisture, which previous results has shown, and that this might be an explanation to the large amount of precipitation that was measured on the 20th of July.

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  • 41.
    Atmosudirdjo, Aryani
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Simulation of Leachate Generation from a Waste Rock Dump in Kiruna Using HYDRUS-1D2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The percolation of water through waste rock dumps at mine sites can lead to the production of a leachate with high concentrations of dissolved metals, sulfate and nitrogen compounds. It is important to understand how water flows in waste rock dumps in order to predict the environmental impact of this leachate on recipients. The dynamics of percolation and leachate discharge are controlled by climatological conditions at the site, where relatively large flows in northern Sweden correspond to snowmelt during late Spring. Rock dumps are often tens of meters in height, resulting in an unsaturated water flow system through heterogeneous material. Hence, the simulation of leachate generation requires an accurate representation of the subsurface materials as well as the flow processes, where water flow in waste rock dumps is dominated by matrix flow with macropore flow being of secondary importance. Matrix flow is rather slow and may thus potentially yield relatively high concentrations of contaminants in the leachate, in response to precipitation and snow melt.

    This study uses Hydrus-1D to predict leachate generation from a small-scale waste rock dump in Kiruna in terms of discharge magnitude and timing. The 3-dimensional geometry of the waste rock dump is approximated by summing simulations from 1225 one-dimensional columns of different length, with a surface area of 1 m2 each. There are four output parameters that are compared between the model results and measured data: snow accumulation, water content, temperature, and discharge. There are some discrepancies between the model results and field measurements, most likely due to uncertainties in the input parameters (especially waste rock properties), limitations in the Hydrus-1D model (i.e. freeze-thaw dynamics), and assumptions that are used in constructing the conceptual model. For better agreement between model results and measured data, a new modelling approach is recommended, potentially using a different program than Hydrus-1D.

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  • 42.
    Attermeyer, Katrin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Andersson, Sara
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Catalán, Núria
    Catalan Institute for Water Research (ICRA), Girona, Spain.
    Einarsdóttir, Karólina
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Groeneveld, Marloes M.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Szekely, Anna J.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Tranvik, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Potential terrestrial influence on transparent exopolymer particle (TEP) concentrations in boreal freshwaters2019In: Journal of limnology, ISSN 1129-5767, E-ISSN 1723-8633, Vol. 64, no 6, p. 2455-2466Article in journal (Refereed)
    Abstract [en]

    Transparent exopolymer particles (TEP) are ubiquitous in aquatic ecosystems and contribute, for example, to sedimentation of organic matter in oceans and freshwaters. Earlier studies indicate that the formation of TEP is related to the in situ activity of phytoplankton or bacteria. However, terrestrial sources of TEP and TEP precursors are usually not considered. We investigated TEP concentration and its driving factors in boreal freshwaters, hypoth- esizing that TEP and TEP precursors can enter freshwaters via terrestrial inputs. In a field survey, we measured TEP concentrations and other environmental factors across 30 aquatic ecosystems in Sweden. In a mesocosm experi- ment, we further investigated TEP dynamics over time after manipulating terrestrial organic matter input and light conditions. The TEP concentrations in boreal freshwaters ranged from 83 to 4940 μg Gum Xanthan equivalent L−1, which is comparable to other studies in freshwaters. The carbon fraction in TEP in the sampled boreal freshwaters is much higher than the phytoplanktonic carbon, in contrast to previous studies in northern temperate and Medi- terranean regions. Boreal TEP concentrations were mostly related to particulate organic carbon, dissolved organic carbon, and optical indices of terrestrial influence but less influenced by bacterial abundance, bacterial production, and chlorophyll a. Hence, our results do not support a major role of the phytoplankton community or aquatic bac- teria on TEP concentrations and dynamics. This suggests a strong external control of TEP concentrations in boreal freshwaters, which can in turn affect particle dynamics and sedimentation in the recipient aquatic ecosystem.

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  • 43.
    Attermeyer, Katrin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. WasserCluster Lunz Biol Stn, Lunz Am See, Austria; Univ Vienna, Dept Funct & Evolutionary Ecol, Vienna, Austria.
    Casas-Ruiz, Joan Pere
    Catalan Inst Water Res ICRA, Girona, Spain.;Univ Girona UdG, Girona, Spain..
    Fuss, Thomas
    Univ Innsbruck, Dept Ecol, Fluvial Ecosyst Ecol, Innsbruck, Austria..
    Pastor, Ada
    Catalan Inst Water Res ICRA, Girona, Spain.;Univ Girona UdG, Girona, Spain.;Aarhus Univ, Dept Biol, Aarhus C, Denmark..
    Cauvy-Fraunie, Sophie
    Ctr Lyon Villeurbanne, UR Riverly, INRAE, Villeurbanne, France..
    Sheath, Danny
    Bournemouth Univ, Dept Life & Environm Sci, Poole, Dorset, England.;Univ Geneva, Fac Med, Inst Global Hlth, Campus Biotech, Geneva, Switzerland..
    Nydahl, Anna
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Doretto, Alberto
    Univ Piemonte Orientale, Dept Sci & Technol Innovat, Alessandria, Italy.;ALPSTREAM Alpine Stream Res Ctr, Ostana, Italy..
    Portela, Ana Paula
    Univ Porto, Res Ctr Biodivers & Genet Resources CIBIO InBIO, Vila Do Conde, Portugal.;Univ Porto, Fac Sci, Porto, Portugal..
    Doyle, Brian C.
    Dundalk Inst Technol, Ctr Freshwater & Environm Studies, Dundalk, Co Louth, Ireland..
    Simov, Nikolay
    Bulgarian Acad Sci, Natl Museum Nat Hist, Sofia, Bulgaria..
    Roberts, Catherine Gutmann
    Bournemouth Univ, Dept Life & Environm Sci, Poole, Dorset, England..
    Niedrist, Georg H.
    Univ Innsbruck, Dept Ecol River & Conservat Res, Innsbruck, Austria..
    Timoner, Xisca
    Catalan Inst Water Res ICRA, Girona, Spain.;Univ Girona UdG, Girona, Spain..
    Evtimova, Vesela
    Bulgarian Acad Sci, Inst Biodivers & Ecosyst Res, Dept Aquat Ecosyst, Sofia, Bulgaria..
    Barral-Fraga, Laura
    Univ Girona UdG, Girona, Spain..
    Basic, Tea
    Bournemouth Univ, Dept Life & Environm Sci, Poole, Dorset, England.;Ctr Environm Fisheries & Aquaculture Sci Cefas, Lowestoft, Suffolk, England..
    Audet, Joachim
    Swedish Univ Agr Sci, Dept Aquat Sci & Assessment, Uppsala, Sweden.;Aarhus Univ, Dept Biosci, Silkeborg, Denmark..
    Deininger, Anne
    Umeå Univ, Dept Ecol & Environm Sci, Umeå, Sweden.;Norwegian Inst Water Res, Oslo, Norway..
    Busst, Georgina
    Bournemouth Univ, Dept Life & Environm Sci, Poole, Dorset, England..
    Fenoglio, Stefano
    ALPSTREAM Alpine Stream Res Ctr, Ostana, Italy.;Univ Turin, Dept Life Sci & Syst Biol, Turin, Italy..
    Catalan, Nuria
    Catalan Inst Water Res ICRA, Girona, Spain.;Univ Girona UdG, Girona, Spain.;UVSQ, CEA, CNRS, Lab Sci Climat & Environm LSCE, Gif Sur Yvette, France.;US Geol Survey, Boulder, CO USA..
    de Eyto, Elvira
    Marine Inst, Furnace, Newport, Co Mayo, Ireland..
    Pilotto, Francesca
    Umeå Univ, Dept Ecol & Environm Sci, Umeå, Sweden.;Umeå Univ, Dept Hist Philosoph & Religious Studies, Environm Archaeol Lab, Umeå, Sweden..
    Mor, Jordi-Rene
    Catalan Inst Water Res ICRA, Girona, Spain.;Univ Barcelona UB, Fac Biol, Dept Evolutionary Biol Ecol & Environm Sci, Barcelona, Spain..
    Monteiro, Juliana
    Fletcher, David
    Bournemouth Univ, Dept Life & Environm Sci, Poole, Dorset, England..
    Noss, Christian
    Univ Koblenz Landau, Inst Environm Sci, Landau, Germany..
    Colls, Miriam
    Catalan Inst Water Res ICRA, Girona, Spain.;Univ Girona UdG, Girona, Spain..
    Nagler, Magdalena
    Univ Innsbruck, Inst Microbiol, Innsbruck, Austria..
    Liu, Liu
    Univ Koblenz Landau, Inst Environm Sci, Landau, Germany.;Leibniz Inst Freshwater Ecol & Inland Fisheries I, Expt Limnol, Stechlin, Germany..
    Gonzalez-Quijano, Clara Romero
    Leibniz Inst Freshwater Ecol & Inland Fisheries I, Ecohydrol, Berlin, Germany..
    Romero, Ferran
    Catalan Inst Water Res ICRA, Girona, Spain.;Univ Girona UdG, Girona, Spain..
    Pansch, Nina
    Leibniz Inst Freshwater Ecol & Inland Fisheries I, Expt Limnol, Stechlin, Germany..
    Ledesma, Jose L. J.
    Swedish Univ Agr Sci, Dept Aquat Sci & Assessment, Uppsala, Sweden.;Spanish Natl Res Council, Ctr Adv Studies Blanes, Blanes, Spain.;Karlsruhe Inst Technol, Inst Geog & Geoecol, Karlsruhe, Germany..
    Pegg, Josephine
    Bournemouth Univ, Dept Life & Environm Sci, Poole, Dorset, England.;South African Inst Aquat Biodivers, Makhanda, South Africa..
    Klaus, Marcus
    Umeå Univ, Dept Ecol & Environm Sci, Umeå, Sweden.;Swedish Univ Agr Sci, Dept Forest Ecol & Management, Umeå, Sweden..
    Freixa, Anna
    Catalan Inst Water Res ICRA, Girona, Spain.;Univ Girona UdG, Girona, Spain..
    Ortega, Sonia Herrero
    Leibniz Inst Freshwater Ecol & Inland Fisheries I, Expt Limnol, Stechlin, Germany..
    Mendoza-Lera, Clara
    Ctr Lyon Villeurbanne, UR Riverly, INRAE, Villeurbanne, France.;Univ Koblenz Landau, Inst Environm Sci, Landau, Germany..
    Bednarik, Adam
    PalackV Univ Olomouc, Dept Ecol & Environm Sci, Olomouc, Czech Republic.;Czech Acad Sci, Global Change Res Inst, Brno, Czech Republic..
    Fonvielle, Jeremy A.
    Leibniz Inst Freshwater Ecol & Inland Fisheries I, Expt Limnol, Stechlin, Germany..
    Gilbert, Peter J.
    Univ Highlands & Isl UHI, Environm Res Inst, Thurso, Scotland..
    Kenderov, Lyubomir A.
    Sofia Univ St Kliment Ohridski, Dept Gen & Appl Hydrobiol, Sofia, Bulgaria..
    Rulik, Martin
    PalackV Univ Olomouc, Dept Ecol & Environm Sci, Olomouc, Czech Republic..
    Bodmer, Pascal
    Univ Lisbon, Fac Ciencias, Ctr Ecol Evolut & Environm Changes cE3c, Lisbon, Portugal.;Univ Koblenz Landau, Inst Environm Sci, Landau, Germany.;Leibniz Inst Freshwater Ecol & Inland Fisheries, Chem Analyt & Biogeochem, Berlin, Germany.;Univ Quebec Montreal, Grp Rech Interuniv Limnol, Dept Sci Biol, Montreal, PQ, Canada..
    Carbon dioxide fluxes increase from day to night across European streams2021In: Communications Earth & Environment, E-ISSN 2662-4435, Vol. 2, no 1, article id 118Article in journal (Refereed)
    Abstract [en]

    Globally, inland waters emit over 2 Pg of carbon per year as carbon dioxide, of which the majority originates from streams and rivers. Despite the global significance of fluvial carbon dioxide emissions, little is known about their diel dynamics. Here we present a large-scale assessment of day- and night-time carbon dioxide fluxes at the water-air interface across 34 European streams. We directly measured fluxes four times between October 2016 and July 2017 using drifting chambers. Median fluxes are 1.4 and 2.1 mmol m−2 h−1 at midday and midnight, respectively, with night fluxes exceeding those during the day by 39%. We attribute diel carbon dioxide flux variability mainly to changes in the water partial pressure of carbon dioxide. However, no consistent drivers could be identified across sites. Our findings highlight widespread day-night changes in fluvial carbon dioxide fluxes and suggest that the time of day greatly influences measured carbon dioxide fluxes across European streams.

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  • 44.
    Attermeyer, Katrin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Chemical Analytics and Biogeochemistry, Germany.
    Grossart, Hans-Peter
    Leibniz-Institute of Freshwater Ecology and InlandFisheries, Experimental Limnology, Germany; Institute for Biochemistry and Biology, Potsdam University, Germany.
    Flury, Sabine
    Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Chemical Analytics and Biogeochemistry, Germany; Faculty of Science, University of Geneva, Switzerland.
    Premke, Katrin
    Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Chemical Analytics and Biogeochemistry, Germany; Leibniz Centre for Agricultural Landscape Research (ZALF), Institute for Landscape Biogeochemistry, Germany.
    Bacterial processes and biogeochemical changes in the water body of kettle holes: mainly driven by autochthonous organic matter?2017In: Aquatic Sciences, ISSN 1015-1621, E-ISSN 1420-9055, Vol. 79, no 3, p. 675-687Article in journal (Refereed)
    Abstract [en]

    Kettle holes are small inland waters formed from glacially-created depressions often situated in agricultural landscapes. Due to their high perimeter-to-area ratio facilitating a high aquatic-terrestrial coupling, kettle holes can accumulate high concentrations of organic carbon and nutrients, fueling microbial activities and turnover rates. Thus, they represent hotspots of carbon turnover in the landscape, but their bacterial activities and controlling factors have not been well investigated. Therefore, we aimed to assess the relative importance of various environmental factors on bacterial and biogeochemical processes in the water column of kettle holes and to disentangle their variations. In the water body of ten kettle holes in north-eastern Germany, we measured several physico-chemical and biological parameters such as carbon quantity and quality, as well as bacterial protein production (BP) and community respiration (CR) in spring, early summer and autumn 2014. Particulate organic matter served as an indicator of autochthonous production and represented an important parameter to explain variations in BP and CR. This notion is supported by qualitative absorbance indices of dissolved molecules in water samples and C:N ratios of the sediments, which demonstrate high fractions of autochthonous organic matter (OM) in the studied kettle holes. In contrast, dissolved chemical parameters were less important for bacterial activities although they revealed strong differences throughout the growing season. Pelagic bacterial activities and dynamics might thus be regulated by autochthonous OM in kettle holes implying a control of important biogeochemical processes by internal primary production rather than facilitated exchange with the terrestrial surrounding due to a high perimeter-to-area ratio.

  • 45.
    Ayala, Ana I.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Nonlinearity and Climate Group, Department of Applied Physics, University of Geneva, 1211 Geneva 4, Switzerland.
    Moras, Simone
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Pierson, Donald C.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Simulations of future changes in thermal structure of Lake Erken: proof of concept for ISIMIP2b lake sector local simulation strategy2020In: Hydrology and Earth System Sciences, ISSN 1027-5606, E-ISSN 1607-7938, Vol. 24, no 6, p. 3311-3330Article in journal (Refereed)
    Abstract [en]

    This paper, as a part of the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP2b), assesses the impacts of different levels of global warming on the thermal structure of Lake Erken (Sweden). The General Ocean Turbulence Model (GOTM) one-dimensional hydrodynamic model was used to simulate water temperature when using ISIMIP2b bias-corrected climate model projections as input. These projections have a daily time step, while lake model simulations are often forced at hourly or shorter time steps. Therefore, it was necessary to first test the ability of GOTM to simulate Lake Erken water temperature using daily vs hourly meteorological forcing data. In order to do this, three data sets were used to force the model as follows: (1) hourly measured data, (2) daily average data derived from the first data set, and (3) synthetic hourly data created from the daily data set using generalised regression artificial neural network methods. This last data set is developed using a method that could also be applied to the daily time step ISIMIP scenarios to obtain hourly model input if needed. The lake model was shown to accurately simulate Lake Erken water temperature when forced with either daily or synthetic hourly data. Long-term simulations forced with daily or synthetic hourly meteorological data suggest that by the late 21st century the lake will undergo clear changes in thermal structure. For the representative concentration pathway (RCP) scenario, namely RCP2.6, surface water temperature was projected to increase by 1.79 and 1.36 C when the lake model was forced at daily and hourly resolutions respectively, and for RCP6.0 these increases were projected to be 3.08 and 2.31 C. Changes in lake stability were projected to increase, and the stratification duration was projected to be longer by 13 and 11 d under RCP2.6 scenario and 22 and 18 d under RCP6.0 scenario for daily and hourly resolutions. Model changes in thermal indices were very similar when using either the daily or synthetic hourly forcing, suggesting that the original ISIMIP climate model projections at a daily time step can be sufficient for the purpose of simulating lake water temperature.

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  • 46.
    Badjana, Heou Maleki
    et al.
    Univ Reading, Dept Geog & Environm Sci, Reading, England.;Univ Lome, Fac Sci, Lab Bot & Plant Ecol, Lome, Togo.;Univ Reading, Dept Geog & Environm Sci, Reading RG6 6DW, England..
    Cloke, Hannah
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Univ Reading, Dept Geog & Environm Sci, Reading, England.;Univ Reading, Dept Meteorol, Reading, England.;CNDS, Ctr Nat Hazards & Disaster Sci, Uppsala, Sweden..
    Verhoef, Anne
    Univ Reading, Dept Geog & Environm Sci, Reading, England..
    Julich, Stefan
    Tech Univ Dresden, Inst Soil Sci & Site Ecol, Tharandt, Germany..
    Camargos, Carla
    Justus Liebig Univ Giessen, Inst Landscape Ecol & Resources Management ILR, Res Ctr Biosyst Land Use & Nutr iFZ, Giessen, Germany..
    Collins, Sarah
    British Geol Survey, Lyell Ctr, Edinburgh, Scotland..
    Macdonald, David M. J.
    British Geol Survey, Wallingford, Oxon, England..
    McGuire, Patrick C.
    Univ Reading, Dept Meteorol, Reading, England.;Univ Reading, Natl Ctr Atmospher Sci NCAS, Reading, England..
    Clark, Joanna
    Univ Reading, Dept Geog & Environm Sci, Reading, England..
    Can hydrological models assess the impact of natural flood management in groundwater-dominated catchments?2023In: Journal of Flood Risk Management, E-ISSN 1753-318X, Vol. 16, no 3Article in journal (Refereed)
    Abstract [en]

    Natural flood management (NFM) is widely promoted for managing flood risks but the effectiveness of different types of NFM schemes at medium (100-1000 km(2)) and large scales (>1000 km(2)) remains widely unknown. This study demonstrates the importance of fully understanding the impact of model structure, calibration and uncertainty techniques on the results before the NFM assessment is undertaken. Land-based NFM assessment is undertaken in two medium-scale lowland catchments within the Thames River basin (UK) with a modelling approach that uses the Soil and Water Assessment Tool (SWAT) model within an uncertainty framework. The model performed poorly in groundwater-dominated areas (P-factor 0.6). The model performed better in areas dominated by surface and interflow processes (P-factor >0.5 and R-factor <0.6) and here hypothetical experiments converting land to broadleaf woodland and cropland showed that the model offers good potential for the assessment of NFM effectiveness. However, the reduction of large flood flows greater than 4% in medium-sized catchments would require afforestation of more than 75% of the area. Whilst hydrological models, and specifically SWAT, can be useful tools in assessing the effectiveness of NFM, these results demonstrate that they cannot be applied in all settings.

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  • 47.
    Balmonte, John Paul
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Univ N Carolina, Dept Marine Sci, Chapel Hill, NC 27515 USA.
    Hasler-Sheetal, Harald
    Univ Southern Denmark, Dept Biol, Odense, Denmark.
    Glud, Ronnie N.
    Univ Southern Denmark, Dept Biol, Odense, Denmark;Tokyo Univ Marine Sci & Technol, Dept Ocean & Environm Sci, Tokyo, Japan.
    Andersen, Thorbjörn J.
    Univ Copenhagen, Dept Geosci & Nat Resources Management, Sect Geog, Copenhagen, Denmark.
    Sejr, Mikael K.
    Aarhus Univ, Arctic Res Ctr, Aarhus, Denmark;Aarhus Univ, Dept Biosci, Silkeborg, Denmark.
    Middelboe, Mathias
    Univ Copenhagen, Marine Biol Sect, Helsingor, Denmark.
    Teske, Andreas
    Univ N Carolina, Dept Marine Sci, Chapel Hill, NC 27515 USA.
    Arnosti, Carol
    Univ N Carolina, Dept Marine Sci, Chapel Hill, NC 27515 USA.
    Sharp contrasts between freshwater and marine microbial enzymatic capabilities, community composition, and DOM pools in a NE Greenland fjord2020In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 65, no 1, p. 77-95Article in journal (Refereed)
    Abstract [en]

    Increasing glacial discharge can lower salinity and alter organic matter (OM) supply in fjords, but assessing the biogeochemical effects of enhanced freshwater fluxes requires understanding of microbial interactions with OM across salinity gradients. Here, we examined microbial enzymatic capabilities-in bulk waters (nonsize-fractionated) and on particles (>= 1.6 mu m)-to hydrolyze common OM constituents (peptides, glucose, polysaccharides) along a freshwater-marine continuum within Tyrolerfjord-Young Sound. Bulk peptidase activities were up to 15-fold higher in the fjord than in glacial rivers, whereas bulk glucosidase activities in rivers were twofold greater, despite fourfold lower cell counts. Particle-associated glucosidase activities showed similar trends by salinity, but particle-associated peptidase activities were up to fivefold higher-or, for several peptidases, only detectable-in the fjord. Bulk polysaccharide hydrolase activities also exhibited freshwater-marine contrasts: xylan hydrolysis rates were fivefold higher in rivers, while chondroitin hydrolysis rates were 30-fold greater in the fjord. Contrasting enzymatic patterns paralleled variations in bacterial community structure, with most robust compositional shifts in river-to-fjord transitions, signifying a taxonomic and genetic basis for functional differences in freshwater and marine waters. However, distinct dissolved organic matter (DOM) pools across the salinity gradient, as well as a positive relationship between several enzymatic activities and DOM compounds, indicate that DOM supply exerts a more proximate control on microbial activities. Thus, differing microbial enzymatic capabilities, community structure, and DOM composition-interwoven with salinity and water mass origins-suggest that increased meltwater may alter OM retention and processing in fjords, changing the pool of OM supplied to coastal Arctic microbial communities.

  • 48.
    Balmonte, John Paul
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Univ North Carolina Chapel Hill, Dept Marine Sci, Chapel Hill, NC 27514 USA.;Univ Southern Denmark, Dept Biol, HADAL & Nordcee, Odense, Denmark..
    Simon, Meinhard
    Carl von Ossietzky Univ Oldenburg, Inst Chem & Biol Marine Environm, Oldenburg, Germany..
    Giebel, Helge-Ansgar
    Carl von Ossietzky Univ Oldenburg, Inst Chem & Biol Marine Environm, Oldenburg, Germany..
    Arnosti, Carol
    Univ North Carolina Chapel Hill, Dept Marine Sci, Chapel Hill, NC 27514 USA..
    A sea change in microbial enzymes: Heterogeneous latitudinal and depth-related gradients in bulk water and particle-associated enzymatic activities from 30 degrees S to 59 degrees N in the Pacific Ocean2021In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 66, no 9, p. 3489-3507Article in journal (Refereed)
    Abstract [en]

    Heterotrophic microbes initiate the degradation of high molecular weight organic matter using extracellular enzymes. Our understanding of differences in microbial enzymatic capabilities, especially among particle-associated taxa and in the deep ocean, is limited by a paucity of hydrolytic enzyme activity measurements. Here, we measured the activities of a broad range of hydrolytic enzymes (glucosidases, peptidases, polysaccharide hydrolases) in epipelagic to bathypelagic bulk water (nonsize-fractionated), and on particles (>= 3 mu m) along a 9800 km latitudinal transect from 30 degrees S in the South Pacific to 59 degrees N in the Bering Sea. Individual enzyme activities showed heterogeneous latitudinal and depth-related patterns, with varying biotic and abiotic correlates. With increasing latitude and decreasing temperature, lower laminarinase activities sharply contrasted with higher leucine aminopeptidase (leu-AMP) and chondroitin sulfate hydrolase activities in bulk water. Endopeptidases (chymotrypsins, trypsins) exhibited patchy spatial patterns, and their activities can exceed rates of the widely measured exopeptidase, leu-AMP. Compared to bulk water, particle-associated enzymatic profiles featured a greater relative importance of endopeptidases, as well as a broader spectrum of polysaccharide hydrolases in some locations, and latitudinal and depth-related trends that are likely consequences of varying particle fluxes. As water depth increased, enzymatic spectra on particles and in bulk water became narrower, and diverged more from one another. These distinct latitudinal and depth-related gradients of enzymatic activities underscore the biogeochemical consequences of emerging global patterns of microbial community structure and function, from surface to deep waters, and among particle-associated taxa.

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  • 49.
    Bar-Am, Maya
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Akademiska sjukhuset: Befintliga geotekniska och hydrogeologiska förhållanden och dess markförutsättningar för framtida byggnationer2021Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Uppsala University Hospital is a large institution of vital societal function and many new buildings have been constructed and others rebuild during the past ten years. The hospital area is located on Uppsalaåsen and within a primary protection zone, i.e. there is a complex geology and requirements for the protection of the groundwater used for Uppsala’s water supply. The ground contains large sections of clay and has drastic changes in soil types. This has resulted in a subsidence problem within the hospital area. Region Uppsala has several plans regarding upcoming constructions at Uppsala University Hospital and due to the complicated soil situation is an investigation of the geotechnics and hydrogeology within the area sought for. The focus of this master thesis is on subsidence capacity and the ground water’s pressure levels. Four zones within the hospital area have been pointed out by Region Uppsala for potential future construction projects. The zones are at the parking garage T3, production kitchen, NOP-complex and new cyclotron building.

    The master thesis was divided into three parts; locating the soil layer sequence, calculation of subsidence based on CRS tests and study of the ground water’s pressure level. The soil layer sequence was construed in GeoSuite based on 474 probes conducted by the consultant company Bjerking. The probs respective soil layer was interpolated and illustrated as level curves using Topocad. Eight cross-sections were made within the zones of extra interest and the sections were made from a 3D-model created in Civil 3D. The soil layers examined throughout the master thesis were filling material, clay, granular soil, rock and ground surface. The subsidence capacity and its time were calculated based on two CRS trials and max-, min- and average values of the ground water’s pressure levels under the hospital area was computed based on 20 years of daily data retrieved from a measuring well in Stadsträdgården facilitated by Uppsala Vatten.

    The results confirm the ridge complex geology consisting of varying depths of clay under the hospital area. Several buildings will probably require deep foundations, e.g. the parking garage T3. The results also show areas of shallow layers of clay indicating lower risk of subsidence and hence will require a shallow foundation. The conducted subsidence calculations indicate that the parking garage T3 will sink 20 to 70 cm after 158 to 213 years if no foundation is implemented, which is in line with the current subsidence occurring at the building. The ground water’s pressure level has had an average value of + 2.3 m (RH2000) during the last 20 years and will probably not fluctuate in the future due to the existing decision on water management. Hence, some buildings within certain parts of the hospital area will require permission prior to construction within the primary zone. 

    The results establish a valuable overview of the hydrogeology at Uppsala University Hospital and give indications regarding how the foundations in the zones of extra interest should be dimensioned sustainable and economically. However, more data is needed, e.g. additional probes and CRS trials, to gain an increased complexity of the hospital area in respect to soil layer sequences and subsidence tendency. 

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  • 50.
    Basirat, Farzad
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Process Models for CO2 Migration and Leakage: Gas Transport, Pore-Scale Displacement and Effects of Impurities2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Geological Carbon Storage (GCS) is considered as one of the key techniques to reduce the rate of atmospheric emissions of CO2 and thereby to contribute to controlling the global warming. A successful application of a GCS project requires the capability of the formation to trap CO2 for a long term. In this context, processes related to CO2 trapping and also possible leakage of CO2 to the near surface environment need to be understood. The overall aim of this thesis is to understand the flow and transport of CO2 through porous media in the context of geological storage of CO2. The entire range of scales, including the pore scale, the laboratory scale, the field experiment scale and the industrial scale of CO2 injection operation are addressed, and some of the key processes investigated by means of experiments and modeling.  First, a numerical model and laboratory experimental setup were developed to investigate the CO2 gas flow, mimicking the system in the near-surface conditions in case a leak from the storage formation should occur. The system specifically addressed the coupled flow and mass transport of gaseous CO2 both in the porous domain as well as the free flow domain above it. The comparison of experiments and modelling results showed a very good agreement indicating that the model developed can be applied to evaluate monitoring and surface detection of potential CO2 leakage. Second, the field scale CO2 injection test carried out in a shallow aquifer in Maguelone, France was analyzed and modeled. The results showed that Monte Carlo simulations accounting for the heterogeneity effects of the permeability field did capture the key observations of the monitoring data, while a homogeneous model could not represent them. Third, a numerical model based on phase-field method was developed and model simulations carried out addressing the effect of wettability on CO2-brine displacement at the pore-scale. The results show that strongly water-wet reservoirs provide a better potential for the dissolution trapping, due to the increase of interface between CO2 and brine with very low contact angles. The results further showed that strong water-wet conditions also imply a strong capillary effect, which is important for residual trapping of CO2. Finally, numerical model development and model simulations were carried out to address the large scale geological storage of CO2 in the presence of impurity gases in the CO2 rich phase. The results showed that impurity gases N2 and CH4 affected the spatial distribution of the gas (the supercritical CO2 rich phase), and a larger volume of reservoir is needed in comparison to the pure CO2 injection scenario. In addition, the solubility trapping significantly increased in the presence of N2 and CH4

    List of papers
    1. Experimental and modeling investigation of CO2 flow and transport in a coupled domain of porous media and free flow
    Open this publication in new window or tab >>Experimental and modeling investigation of CO2 flow and transport in a coupled domain of porous media and free flow
    2015 (English)In: International Journal of Greenhouse Gas Control, ISSN 1750-5836, E-ISSN 1878-0148, Vol. 42, p. 461-470Article in journal (Refereed) Published
    Abstract [en]

    A solid understanding of the transport mechanisms of gaseous CO2 near the land surface is necessary for developing reliable monitoring techniques and predictive models for possible CO2 leakage from deep underground storage. The objective of this work has been to develop an experimental method along with a simulation model for gaseous CO2 flow and transport in a system including both the porous media and the free air space above it. The experimental system consisted of a two-dimensional bench scale rectangular sandbox containing homogenous sand with an open space of still air above it. Gaseous CO2 was injected in different modes and the CO2 breakthrough was measured on specified ports in the system by using CO2 concentration sensors. A numerical model combining the gas flow in the porous medium and the free flow region was developed and used to model the experimental data. In this quest, the Discontinuous One-Domain approach was selected for modeling transport between the free flow and porous regions. The observed and simulated CO2 breakthrough curves both in the dried sand and in the free flow matched very well in the case of uniform injection and satisfactorily even in the case of point injection. Consequently, it seems that the model reasonably matches the observed data in the cases where the boundary condition is well defined. In summary, our results show that the developed experimental setup provides capability to study gaseous CO2 flow and transport in a coupled porous medium - free flow system and that our modeling approach is able to predict the flow and transport in this system with good accuracy.

    Keywords
    Carbon dioxide flow and transport, Coupling conditions, Discontinuous One-Domain Approach, Experimental method, Free flow, Porous media
    National Category
    Energy Engineering
    Identifiers
    urn:nbn:se:uu:diva-274707 (URN)10.1016/j.ijggc.2015.08.024 (DOI)000366947400041 ()
    Funder
    EU, FP7, Seventh Framework Programme, 282900Swedish Research Council, 2010-3657
    Available from: 2016-02-02 Created: 2016-01-25 Last updated: 2022-06-29
    2. Numerical modelling of CO2 injection at small-scale field experimental site in Maguelone, France
    Open this publication in new window or tab >>Numerical modelling of CO2 injection at small-scale field experimental site in Maguelone, France
    Show others...
    2016 (English)In: International Journal of Greenhouse Gas Control, ISSN 1750-5836, E-ISSN 1878-0148, Vol. 54, p. 200-210Article in journal (Refereed) Published
    Abstract [en]

    To evaluate the performance of downhole and surface geophysical monitoring methods, a series of shallow gas injection-monitoring experiments has been performed in a coastal saline aquifer at Maguelone, France. The recorded data include pressure measurements with a Westbay multilevel completion and CO2 saturation at an observation well derived from electrical resistivity with a modified Waxman-Smits (MWS) model. In this work, the aim is to develop a simulation model capturing the gas transport behavior and consistent with field data. For this purpose, the simulation of the CO2 injection experiment is carried out with two conceptual models, a homogeneous model and a heterogeneous model treated with multiple realization Monte Carlo simulations. Numerical simulator TOUGH2 with the equation of state module EOS7C is used for the simulations. Comparison of the model results with field data suggests that the pressure responses are captured with relatively good accuracy. Similarly, the model also provides an overall reasonable agreement and correct order of magnitude for predicted gas saturation values. However, as the heterogeneity pattern in the field data remains largely unknown, the model predictions can only be used to capture the mean behavior as well as to provide insights into how heterogeneity can influence the system behavior, by means of sensitivity analyses of the influence of heterogeneities on individual realizations.

    Keywords
    CO2 storage, CO2 injection, Shallow aquifer, Downhole and pressure monitoring, Numerical simulation, Heterogeneity, Electrical resistivity, Downhole geophysical monitoring
    National Category
    Geosciences, Multidisciplinary
    Identifiers
    urn:nbn:se:uu:diva-311204 (URN)10.1016/j.ijggc.2016.09.006 (DOI)000387781500015 ()
    Funder
    EU, FP7, Seventh Framework Programme, 227286 309367
    Available from: 2016-12-22 Created: 2016-12-22 Last updated: 2022-06-29
    3. Pore-scale modeling of wettability effects on CO2–brine displacement during geological storage
    Open this publication in new window or tab >>Pore-scale modeling of wettability effects on CO2–brine displacement during geological storage
    2017 (English)In: Advances in Water Resources, ISSN 0309-1708, E-ISSN 1872-9657, Vol. 109, p. 181-195Article in journal (Refereed) Published
    Abstract [en]

    Wetting properties of reservoir rocks and caprocks can vary significantly, and they strongly influence geological storage of carbon dioxide in deep saline aquifers, during which CO2 is supposed to displace the resident brine and to become permanently trapped. Fundamental understanding of the effect of wettability on CO2-brine displacement is thus important for improving storage efficiency and security. In this study, we investigate the influence of wetting properties on two-phase flow of CO2 and brine at the pore scale. A numerical model based on the phase field method is implemented to simulate the two-phase flow of CO2-brine in a realistic pore geometry. Our focus is to study the pore-scale fluid-fluid displacement mechanisms under different wetting conditions and to quantify the effect of wettability on macroscopic parameters such as residual brine saturation, capillary pressure, relative permeability, and specific interfacial area. Our simulation results confirm that both the trapped wetting phase saturation and the normalized interfacial area increase with decreasing contact angle. However, the wetting condition does not appear to influence the CO2 breakthrough time and saturation. We also show that the macroscopic capillary pressures based on the pressure difference between inlet and outlet can differ significantly from the phase averaging capillary pressures for all contact angles when the capillary number is high ( log Ca > -5). This indicates that the inlet-outlet pressure difference may not be a good measure of the continuum-scale capillary pressure. In addition, the results show that the relative permeability of CO2 can be significantly lower in strongly water-wet conditions than in the intermediate-wet conditions.

    Place, publisher, year, edition, pages
    Elsevier, 2017
    National Category
    Oceanography, Hydrology and Water Resources
    Research subject
    Hydrology
    Identifiers
    urn:nbn:se:uu:diva-315304 (URN)10.1016/j.advwatres.2017.09.004 (DOI)000416037100014 ()
    Funder
    EU, FP7, Seventh Framework Programme, 309067Swedish Research Council, 637-2014-445Swedish Energy Agency, 43526-1
    Available from: 2017-02-14 Created: 2017-02-14 Last updated: 2018-02-23Bibliographically approved
    4. Numerical simulation of geological storage of CO2 with impurities in large scale saline aquifer
    Open this publication in new window or tab >>Numerical simulation of geological storage of CO2 with impurities in large scale saline aquifer
    (English)Manuscript (preprint) (Other academic)
    National Category
    Water Engineering Oceanography, Hydrology and Water Resources
    Identifiers
    urn:nbn:se:uu:diva-315303 (URN)
    Available from: 2017-02-14 Created: 2017-02-14 Last updated: 2020-05-12
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