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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.
    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.

  • 3.
    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.

  • 4. 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)
  • 5. 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.

  • 6.
    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.

  • 7. Ameli, A.A.
    et al.
    Amvrosiadi, Nino
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Grabs, Thomas
    Laudon, Hjalmar
    Creed, I.F.
    McDonnell, J.J.
    Bishop, Kevin
    Hillslope permeability architecture controls on subsurface transit time distribution and flow paths2016In: Journal of Hydrology, Vol. 543, p. 17-30Article in journal (Refereed)
  • 8.
    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.

  • 9.
    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).

  • 10.
    Amland, Sølvi Amland
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Where are the soils in sweden that are most sensitive to acidification and nitrogen loss?2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 11.
    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.

  • 12.
    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
    2016 (English)In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 31, no 1, p. 4-14Article in journal (Refereed) Published
    Keyword
    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)
    Available from: 2017-10-16 Created: 2017-10-16 Last updated: 2017-11-14
    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.

    Keyword
    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
    Show others...
    (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: 2018-01-13
    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: 2018-01-13
    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
    (English)Manuscript (preprint) (Other academic)
    National Category
    Oceanography, Hydrology and Water Resources
    Identifiers
    urn:nbn:se:uu:diva-331732 (URN)
    Available from: 2017-10-17 Created: 2017-10-17 Last updated: 2018-01-13
  • 13.
    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)
  • 14.
    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)
  • 15.
    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.

  • 16.
    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.

  • 17.
    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.

  • 18.
    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
  • 19. 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.

  • 20.
    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.

  • 21. 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)
  • 22.
    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.

  • 23.
    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.

  • 24.
    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.

    Keyword
    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: 2017-11-30
    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.

    Keyword
    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: 2017-11-29
    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)
    Abstract
    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: 2018-01-13
  • 25.
    Basirat, Farzad
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Jung, Byeongju
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Institute of Geoscience and Mineral Resources (KIGAM), Daejeon, South Korea.
    Yang, Zhibing
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Niemi, Auli
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Numerical simulation of geological storage of CO2 with impurities in large scale saline aquiferManuscript (preprint) (Other academic)
    Abstract
  • 26.
    Basirat, Farzad
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Yang, Zhibing
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
    Niemi, Auli
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Pore-scale modeling of wettability effects on CO2–brine displacement during geological storage2017In: Advances in Water Resources, ISSN 0309-1708, E-ISSN 1872-9657, Vol. 109, p. 181-195Article in journal (Refereed)
    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.

  • 27.
    Bastviken, Paulina
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Flood Risk Mapping in Africa: Exploring the Potentials and Limitations of SRTM Data in the Lower Limpopo, Mozambique2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Many regions in Africa are presently faced with an increasing flood risk due to impending climate change and population growth. One useful mitigation strategy to decrease this risk would be to map it, so that urban planning, warnings systems and emergency response subsequently could be designed to reduce societal vulnerability. This is, however, not widely feasible on the African continent, as developing countries often lack access to the topography and discharge data required to produce high- quality flood risk maps. To seek a way around this problem, on-going research is investigating the possibility of obtaining alternative model inputs, by using global datasets of elevation, derived from remote sensing, and methods to estimate flood flows. This thesis presents a case study within this context where the aim was to determine the accuracy of an African catchment-scale flood map, produced with the satellite product SRTM (Shuttle Radar Topography Mission) as topography input, and to explore the potentials and limitations of such a model scheme. Two high-magnitude floods, occurring in year 2000 and 2013 in the Lower Limpopo Basin (Mozambique), were modelled for inundation extent, using a no-channel 2D model built for the LISFLOOD-FP flood modelling software. Flood water levels were also simulated to assess the models vertical performance. Model outcomes were evaluated against satellite imagery and recordings of high watermarks, adjusting the value representing the roughness of the floodplain to optimize flood extent correspondence. Due to different hydrograph dynamics, simulations of the two floods required different values of roughness (0.02 and 0.09 s m-1/3) to reach maximum accuracy (F = 0.59 and 0.64, respectively). However, the results also indicated that a model calibrated with a flood of relatively low return period potentially could be used to map rare flood events. Simulation inaccuracies were mainly attributed to (1) reservoirs and streams, temporarily connecting to the river system during high flow conditions, (2) limitations of the topography data, in terms of recognizing riverbed geometry and floodplain micro-topography, and (3) cloud cover, reducing the accuracy of flood extent reference data. The vertical simulation accuracy, with an average error of ± 2 m, was well within the uncertainty bounds of input data. Errors were in this case ascribed the SRTM’s representation of high slope terrain and possible radar speckles in urban areas. The findings of this study indicate that there is high potential in using SRTM data for mapping of high-magnitude flood risk in Africa, but also that consideration to river system complexity is crucial. 

  • 28.
    Bastviken, Paulina
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Soil water solution DOC dynamics during winter in boreal hillslopes2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    When plants and animals die they are decomposed into microscopic particles of organic carbon. In the ground, these carbon particles are dissolved in the soil water and eventually transported to the streamchannel with the flow of the groundwater. Today the quantities of dissolved organic carbon (DOC) have been observed to increase in many lakes and streams around the world, which constitute a threat against the water quality and ecologic environment of these surface waters. The amount of organic carbon that is dissolved and transported in the soil water is mainly controlled by processes related to temperature and hydrology, two factors which vary seasonally. Because of difficulties to sample soil water at temperatures below 0°C studies of DOC transport between soil and water during the winter season are limited. This study therefore conducted a winter sampling of soil water, with the focus on DOC. Samples were collected in March 2014 at sites along three hillslopes, orthogonal to two streams, in a typical Swedish boreal forest northwest of Umeå. The soil water was extracted with the help of suction lysimeters installed at different depths in the soil, and heating equipmentpowered by batteries. The collected samples were analyzed for DOC concentration and absorbance after which the results were grouped together with results from previous sampling campaigns, conducted in the summer and autumn of 2013. Parallel to this, data representing a longer time series (2009 to 2012) at another hillslope was processed. During the summer and autumn an increase in DOC concentration was observed. The increase was assumed to be caused by high production and effective degradation of organic matter in the soil during this warm period. Generally, a decrease in the DOC concentration then followed during the winter season. One possible reason for this decrease could be that the bacterial degradation in the soil continued, during the winter, and transformed the dissolved carbon into CO2 and CH4. Another possibility is that the DOC was flushed into the streams by autumn rain events. The study also found differences concerning the DOC concentration and character in the soil water, as well as the seasonal variation of these parameters, with soil depth and distance from the stream along the hillslope profile. These differences could be correlated to the organic content of the soil, from which the soil water had been extracted.

  • 29.
    Beckholmen, Ingrid
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Källor i Lagga, en uppländsk slättbygd: Geografisk och geologisk påverkan påkällvattens egenskaper2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    For centuries, springs have played a significant role in our society as water supplies, reasons for where to settle down, and in folklore. There are different reasons why and where a spring forms, e.g. in what kind of soil it has its outflow. Geographic and geochemical surroundings have an influence on spring-water quality.For this project some of the springs in the Lagga perish, Knivsta municipality, Sweden, were selected for a closer study. Water samples were collected from springs for analysis. A short-term study was performed of temperature and conductivity changes during spring 2014. The investigated springs of this project were divided into four major groups according to their location in the landscape and their chemical properties: 1) springs that have their outflow in clay in valley bottoms, 2) springs that lie in the transition between glacial till soil and clay, 3) springs in till soil, and 4) springs in till soil with large boulders. Analyses show that the ion content in spring-water is higher in the valley than in the surrounding forest tills. Together with previous data it is shown that temperature and conductivity are more stable in the springs in the valley clay than in the uphill springs in till.

  • 30. Beldring, Stein
    et al.
    Gottschalk, Lars
    Rodhe, Allan
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Tallaksen, Lena M.
    Kinematic wave approximations to hillslope hydrological processes in tills2000In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 14, no 4, p. 727-745Article in journal (Refereed)
    Abstract [en]

    This work has been carried out within the framework of NOPEX - a NOrthern hemisphere climate Processes land surface EXperiment. Its purpose is to describe the spatial variability of groundwater levels and soil moisture content and their influence on runoff generation in small catchments in a landscape dominated by boreal forest and till soils, which is characteristic for the Nordic countries. Kinematic wave approximations have been used to describe saturated subsurface flow and saturation overland flow in hillslopes with a thin soil layer overlying a relatively impermeable bedrock. Simultaneous analyses of catchment runoff, groundwater-table depths and soil moisture in the unsaturated zone have been performed by including the kinematic wave descriptions in a precipitation-runoff model. The results have been compared with observed hydrographs and spatial patterns of groundwater levels and soil moisture content in two small experimental catchments. Results from this study indicate that is reasonable to apply the same parameter set when describing hydrological processes in computational elements with similar characteristics at a scale of about 1 km(2) in the NOPEX area. 

  • 31.
    Beldring, Stein
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Air and Water Science.
    Rodhe, Allan
    Tallaksen, Lena
    Kinematic wave approximations to hillslope hydrological processes in till soils2000In: Hydrological Processes, Vol. 14, p. 727-745Article in journal (Refereed)
  • 32. Benner, S G
    et al.
    Blowes, D W
    Gould, W D
    Herbert, Roger B
    Ptacek, C J
    Geochemistry of a permeable reactive barrier for metals and acid mine drainage1999In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 33, no 16, p. 2793-2799Article in journal (Refereed)
    Abstract [en]

    A permeable reactive barrier, designed to remove metals and generate alkalinity by promoting sulfate reduction and metal sulfide precipitation, was installed in August 1995 into an aquifer containing effluent from mine tailings. Passage of groundwater through the barrier results in striking improvement in water quality. Dramatic changes in concentrations of SO4 (decrease of 2000−3000 mg/L), Fe (decrease of 270−1300 mg/L), trace metals (e.g., Ni decreases 30 mg/L), and alkalinity (increase of 800−2700 mg/L) are observed. Populations of sulfate reducing bacteria are 10 000 times greater, and bacterial activity, as measured by dehydrogenase activity, is 10 times higher within the barrier compared to the up-gradient aquifer. Dissolved sulfide concentrations increase by 0.2−120 mg/L, and the isotope 34S is enriched relative to 32S in the dissolved phase SO42- within the barrier. Water chemistry, coupled with geochemical speciation modeling, indicates the pore water in the barrier becomes supersaturated with respect to amorphous Fe sulfide. Solid phase analysis of the reactive mixture indicates the accumulation of Fe monosulfide precipitates. Shifts in the saturation states of carbonate, sulfate, and sulfide minerals and most of the observed changes in water chemistry in the barrier and down-gradient aquifer can be attributed, either directly or indirectly, to bacterially mediated sulfate reduction.

  • 33.
    Bennich, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Bredberg, William
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Olsson, Jimmy
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Rulewski Stenberg, Louis
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Smith, Malin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Söderqvist, Johnny
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    En jämförelse mellan fjärranalystekniker och vågbojar för mätning av oceanografiska parametrar i svenska vatten2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    För övervakning av svenska vatten krävs noggranna mätningar av oceanografiska parametrar såsom våghöjd, vågriktning, ytvattentemperatur och ytströmmar. Mätdata för parametrarna samlas in av Sveriges Meteorologiska och Hydrologiska Institut (SMHI) och används till prognoser, sjöfart samt forskning. I denna studie undersöktes möjligheten att ersätta eller komplettera vågbojarna av modellen Directional Waverider MkIII som SMHI använder idag, med ny kommersiellt tillgänglig fjärranalysteknik. Projektet begränsades till att studera två högfrekvens-radartekniker och en X-bandradar. Studien är platsspecifik och utreder kvalitetsmässiga, ekonomiska och miljömässiga för- och nackdelar med de utvalda radarteknikerna i relation till vågbojarna. En litteraturstudie och modellering av data över parametrar som påverkar radarteknikernas räckvidd och datatillgänglighet genomfördes. Ur modelleringen drogs slutsatsen att det är möjligt att erhålla likvärdig datatillgänglighet med vågradar som med vågboj. Vidare modellering ledde till slutsatsen att radarteknikerna begränsas till ungefär hälften av sin optimala räckvidd i Östersjön på grund av den låga salthalten, och därför är Sveriges västkust bättre lämpad för placering av radarteknik. Undersökning av isbildning i havsvatten, som kan begränsa radarteknikernas räckvidd, ledde till slutsatsen att Sveriges västkust också är att föredra utifrån detta perspektiv. Med anledning av radarteknikers möjlighet att utföra mätningar över större områden, finner studien att det finns goda grunder för att motivera en ersättning eller komplettering av vågbojarna med modern radarteknik. Vidare talar radarteknikernas goda anpassningsförmåga, lägre inverkan på miljön och enklare underhållskrav jämfört med vågbojarna till dess fördel. Att övergå till radarteknik medför däremot högre installations- och driftkostnader i jämförelse med vågbojar.

  • 34.
    Berga, Mercè
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Biological Oceanography, Leibniz Institute for Baltic Sea Research Warnemünde, Germany.
    Zha, Yinghua
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Székely, Anna J.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Langenheder, Silke
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Functional and Compositional Stability of Bacterial Metacommunities in Response to Salinity Changes2017In: Frontiers in Microbiology, ISSN 1664-302X, E-ISSN 1664-302X, Vol. 8, article id 948Article in journal (Refereed)
    Abstract [en]

    Disturbances and environmental change are important factors determining the diversity,composition, and functioning of communities. However, knowledge about how naturalbacterial communities are affected by such perturbations is still sparse. We performeda whole ecosystem manipulation experiment with freshwater rock pools where weapplied salinity disturbances of different intensities. The aim was to test how thecompositional and functional resistance and resilience of bacterial communities,alpha- and beta-diversity and the relative importance of stochastic and deterministiccommunity assembly processes changed along a disturbance intensity gradient.We found that bacterial communities were functionally resistant to all salinity levels (3, 6, and 12 psu) and compositionally resistant to a salinity increase to 3 psu andresilient to increases of 6 and 12 psu. Increasing salinities had no effect on local richnessand evenness, beta-diversity and the proportion of deterministically vs. stochasticallyassembled communities. Our results show a high functional and compositional stabilityof bacterial communities to salinity changes of different intensities both at localand regional scales, which possibly reflects long-term adaptation to environmentalconditions in the study system.

  • 35.
    Berghuijs, Wouter R.
    et al.
    Department of Civil Engineering, University of Bristol, Bristol, UK.
    Harrigan, Shaun
    Irish Climate Analysis and Research Units (ICARUS), Department of Geography, Maynooth University, Maynooth, Ireland.
    Kipnis, Evan L.
    Department of Ecosystem Science and Management, University of Wyoming, Laramie, Wyoming, USA.
    Dogulu, Nilay
    Department of Civil Engineering, Middle East Technical University, Ankara, Turkey.
    Floriancic, Marius
    Institute of Environmental Engineering, Swiss Federal Institute of Technology, Zurich, Switzerland.
    Müller, Hannes
    Institute of Water Resources Management, Hydrology and Agricultural Hydraulic Engineering, Leibniz Universität Hannover, Hanover, Germany.
    Pohle, Ina
    Chair of Hydrology and Water Resources Management, Brandenburg University of Technology Cottbus-Senftenberg, Cottbus, Germany .
    Saia, Sheila M.
    Department of Biological and Environmental Engineering, Cornell University, Ithaca, New York, USA.
    Sedlar, Frank
    Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, USA.
    Smoorenburg, Maarten
    Institute of Environmental Engineering, Swiss Federal Institute of Technology, Zurich, Switzerland.
    Teutschbein, Claudia
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    van Emmerik, Tim
    Water resources section, Faculty of Civil Engineering and Geosciences, Delft University of Technology, The Netherlands.
    Creating Community for Early-Career Geoscientists: Student involvement in geoscience unions: A case study from hydrology2015In: EOS: Transactions, ISSN 0096-3941, E-ISSN 2324-9250, Vol. 96Article in journal (Refereed)
    Abstract [en]

    The American Geophysical Union (AGU) and the European Geosciences Union (EGU) play central roles in nurturing the next generation of geoscientists. Students and young scientists make up about one quarter of the unions’ active memberships [American Geophysical Union, 2013; European Geosciences Union, 2014], creating a major opportunity to include a new generation of geoscientists as more active contributors to the organizations’ activities, rather than merely as consumers.

    Both organizations are now explicitly expanding their bottom-up organizational structures to include early-career members (ECMs) by appointing student (AGU) and early-career scientist (EGU) representatives for their scientific divisions. (We refer to “early-career members” because AGU and EGU define student and postdoc members differently). Because this expansion is a recent development, it is still unclear what roles these representatives will play and how these roles will evolve over the coming years.

    We are ECMs in the hydrological sciences. Here we show how the Young Hydrological Society (YHS) used bottom-up initiatives, aligned closely with the newly appointed AGU and EGU representatives, to help improve the professional development of student and postdoc members by providing opportunities to increase their contributions to the geoscience unions. We call for a conversation on how ECMs can make the best use of these new opportunities to engage proactively with the unions.

  • 36.
    Bergström, Carolin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Vattenkemisk undersökning i Lissån2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The water chemistry in watercourses are constantly changing and processes such aswater flow, climate change and anthropogenic processes could affect the water’s chemical composition.

    The work has examined how the water chemistry changes in Lissån in the spring with respect to the electrical conductivity. It has also taken into account what sources in the catchment area that may affect a possible change in the electrical conductivity.

    During the thaw of the winter the flows in Uppsala streams will increase and will not subside until spring. This change in flow affects the water flow size, which in turn has a bearing on the electrical conductivity and the watercourses chemical composition. Within the catchment area you also find Hovgården waste plant which is a potential source of a possible change in the chemical composition in Lissån.Purified leachate from the plant is released into Hovgårdsbäcken which connects to the recipient Lissån and may be a cause of the changes in electrical conductivity.

    During the spring samples have been gathered in Lissån at Fribacken and these have been compared with samples taken where Hovgårdsbäcken intersects with Lissån. The water chemistry and the electrical conductivity in Lissån is concluded to be affected by the size of the water flow and to some extent also of the emissions from the waste plant.The results show that an increased water flow decreases the electrical conductivity. The water flow increases slightly with increased rainfall.

    The results show not only how anthropogenic processes such as emissions from waste plants can affect the water in rivers but also how climate change may affect water quality in the future.

  • 37.
    Beven, Keith
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Univ Lancaster, Lancaster Environm Ctr, Lancaster, England..
    Advice to a young hydrologist2016In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 30, no 20, p. 3578-3582Article in journal (Other academic)
  • 38.
    Beven, Keith
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Univ Lancaster, Lancaster Environm Ctr, Lancaster, England..
    Facets of uncertainty: epistemic uncertainty, non-stationarity, likelihood, hypothesis testing, and communication2016In: Hydrological Sciences Journal, ISSN 0262-6667, E-ISSN 2150-3435, Vol. 61, no 9, p. 1652-1665Article in journal (Refereed)
    Abstract [en]

    This paper presents a discussion of some of the issues associated with the multiple sources of uncertainty and non-stationarity in the analysis and modelling of hydrological systems. Different forms of aleatory, epistemic, semantic, and ontological uncertainty are defined. The potential for epistemic uncertainties to induce disinformation in calibration data and arbitrary non-stationarities in model error characteristics, and surprises in predicting the future, are discussed in the context of other forms of non-stationarity. It is suggested that a condition tree is used to be explicit about the assumptions that underlie any assessment of uncertainty. This also provides an audit trail for providing evidence to decision makers.

  • 39.
    Beven, Keith
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    So how much of your error is epistemic? Lessons from Japan and Italy2013In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 27, no 11, p. 1677-1680Article in journal (Other academic)
  • 40.
    Beven, Keith
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Cloke, Hannah L.
    Department of Geography, King's College London, London, UK.
    Comment on ‘‘Hyperresolution global land surface modeling: Meeting a grand challenge for monitoring Earth’s terrestrial water’’ by Eric F. Wood et al.2012In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 48, p. W01801-Article in journal (Refereed)
  • 41.
    Beven, Keith
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Univ Lancaster, Lancaster Environm Ctr, Lancaster LA1 4YQ, England.;Univ Lausanne, IDYST, Lausanne, Switzerland..
    Davies, Jess
    Univ Lancaster, Lancaster Environm Ctr, Lancaster LA1 4YQ, England..
    Velocities, celerities and the basin of attraction in catchment response2015In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 29, no 25, p. 5214-5226Article in journal (Refereed)
    Abstract [en]

    Catchment systems are interestingly nonlinear, but their dynamics are constrained from being unduly chaotic by mass and energy balance requirements. There have been no attempts in hydrology that we know of that have tried to map both the flow and transport dynamics of a catchment in any form of phase space. In part, this is because of the high dimensionality of the space-time patterns of response; in part because there is sufficient uncertainty about the input and output fluxes estimated by measurement that this might be expected to obscure any attractor-like behaviour. In this study we explore the basin of the catchment attractor for the Multiple Interacting Pathway (MIPs) model that in previous papers has been shown to give good results for the small Gardsjon catchment in Sweden. MIPs is based on particle tracking techniques and gives results for both the flow responses and for the travel and residence time responses of water in the catchment. Here it is used to provide consistent values of fluxes, total storage, travel time distributions and residence time distributions for a long simulation period. The nature of those responses in storage and input dimensions is then investigated. The results suggest that the range of behaviours is hysteretic in interesting ways and constrained by the forcing inputs, with space filling of trajectories in the basin of attraction as should be expected of a forced dissipative system. The range of behaviours exhibited defines a space that the responses of any simpler emulator model will need to span.

  • 42.
    Beven, Keith J
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Comment on “Equifinality of formal (DREAM) and informal (GLUE) Bayesian approaches in hydrologic modeling?” by Jasper A. Vrugt, Cajo J. F. ter Braak, Hoshin V. Gupta and Bruce A. Robinson2009In: Stochastic environmental research and risk assessment (Print), ISSN 1436-3240, E-ISSN 1436-3259, Vol. 23, p. 1059-1060Article in journal (Refereed)
  • 43. Beven, Keith J.
    Uncertainty in Predictions of Floods and Hydraulic Transport2007In: Transport phenomena in hydraulics / [ed] Rowiński, Paweł, Warszawa: Institute of Geophysics , 2007, p. 5-20Chapter in book (Other academic)
    Abstract [en]

    This paper provides a review of work within the Generalised Likelihood Uncertainty Estimation (GLUE) methodology on estimating uncertainties in predicting flood frequency, flood inundation, and hydraulic transport of solutes in rivers and soils. The issue of prediction uncertainty as an input decision making is also discussed. It is concluded that in real applications it is unlikely that a fully objective approach to uncertainty estimation is possible. It is therefore important that the assumptions made are stated explicitly so that they can be agreed or disputed with the users of the resulting predictions. It is also important that the modelling process be considered as a learning process of constraining uncertainty by adding new information.

  • 44.
    Bignert, Anders
    et al.
    Swedish Museum of Natural History, Stockholm, Sweden.
    Bäcklin, Britt-Marie
    Swedish Museum of Natural History, Stockholm, Sweden.
    Helander, Björn
    Swedish Museum of Natural History, Stockholm, Sweden.
    Roos, Anna
    Swedish Museum of Natural History, Stockholm, Sweden.
    9. Contaminants and Health of Aquatic Wildlife2012In: Ecology and Animal Health / [ed] Leif Norrgren and Jeffrey Levengood, Uppsala: Baltic University Press , 2012, 1, p. 73-85Chapter in book (Other (popular science, discussion, etc.))
  • 45. Bishop, Kevin
    et al.
    Beven, Keith
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Destouni, Georgia
    Abrahamsson, Katarina
    Andersson, Lotta
    Johnson, K
    Rodhe, Johan
    Hjerdt, Niclas
    Nature as the “Natural” Goal for Water Management: A Conversation2009In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 38, p. 209-214Article in journal (Refereed)
    Abstract [en]

    The goals for water-quality and ecosystem integrity are often defined relative to “natural” reference conditions in many water-management systems, including the European Union Water Framework Directive. This paper examines the difficulties created for water management by using “natural” as the goal. These difficulties are articulated from different perspectives in an informal (fictional) conversation that takes place after a workshop on reference conditions in water-resources management. The difficulties include defining the natural state and modeling how a system might be progressed toward the natural, as well as the feasibility and desirability of restoring a natural state. The paper also considers the appropriateness for developing countries to adopt the use of natural as the goal for water management. We conclude that failure to critically examine the complexities of having “natural” as the goal will compromise the ability to manage the issues that arise in real basins by not making the ambiguities associated with this “natural” goal explicit. This is unfortunate both for the western world that has embraced this model of “natural as the goal” and for the developing world in so far as they are encouraged to adopt this model.

  • 46.
    Bishop, Kevin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Gebrehiwot, Solomon
    SLU Aquatic Sciences and Assessment.
    Taye, Ayale
    Awassa University, Ethiopia.
    Forest Cover and Stream Flow in a Headwater of the Blue Nile: Complementing Observational Data Analysis with Community Perception2010In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 39, no 4, p. 284-294Article in journal (Refereed)
    Abstract [en]

    This study analyses the relation of forest cover and stream flow on the 266 km2 Koga watershed in the headwaters of Blue Nile Basin using both observed hydrological data and community perception. The watershed went from 16% forest cover in 1957 to 1% by 1986. The hydrological record did not reveal changes in the flow regime between 1960 and 2002 despite the reduction in forest area. This agrees with the perception of the downstream community living near the gauging station. The upstream community, however, reported both decreases in low flows and increases in high flows shortly after the forest cover was reduced. The upstream deforestation effect appeared to have been buffered by a wetland lower in the watershed. This study concludes that community perception can be a complement to observational data for better understanding how forest cover influences the flow regime.

  • 47.
    Bishop, Kevin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Uppsala Centre for Sustainable Development, CSD Uppsala.
    Seibert, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    A primer for hydrology: the beguiling simplicity of Water's journey from rain to stream at 30 Preface2015In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 29, no 16, p. 3443-3446Article in journal (Other academic)
    Abstract [en]

    Water's journey from rain to stream by Harald Grip and Allan Rodhe (1985, in Swedish: Vattnets vag fran regn till back) was one of the first textbooks to present groundwater contributions as a major feature of runoff generation, with implications for water quality and management. Three decades later, we have the privilege of presenting a special issue of Hydrological Processes, Runoff Generation in a Nordic Light: 30Years with Water's Journey from Rain to Stream' that seeks to introduce the book to a larger audience and continue the journey of ideas that the authors set in motion with their book.

  • 48.
    Bockgård, N.
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Air and Water Science. LUVA.
    Niemi, A.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Air and Water Science. LUVA.
    Role of soil-rock interaction on recharge into fractured rock2003In: Proceedings of TOUGH Symposium 2003 , May 12–14, 2003, 2003Conference paper (Refereed)
  • 49.
    Bockgård, N., Rodhe, A.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. AIR AND WATER SCIENCE.
    An experimental study of groundwater recharge to fractured bedrock2003In: Proceedings of the IAH International Conference on GROUNDWATER IN FRACTURED ROCKS, Prague 15-19 September 2003,J. Krasny, Z. Hrkal, J. Bruthans (Eds.), Prague: International Association of Hydrogeologists , 2003Conference paper (Refereed)
  • 50.
    Bockgård, Niclas
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. HYDROLOGY.
    Environmental tracer methods for dating of young groundwaters2000In: XXI Nordic Hydrological Conference; T. Nilsson Ed., Uppsala: Swedish Hydrological Council , 2000, Vol. 2, p. 503-509Conference paper (Refereed)
1234567 1 - 50 of 786
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