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Droughts, traditionally less associated with high-latitude regions, are emerging as significant challenges due to changing climatic conditions. Recent severe droughts in Europe have exposed the vulnerability of northern catchments, where shifts in temperature and precipitation patterns may intensify drought impacts. This study investigates the dynamics of drought propagation in high-latitude regions, focusing on four key aspects: (1) the typical lag time for drought conditions to propagate from initial precipitation deficits to impacts on soil moisture, streamflow, and groundwater systems; (2) the probability of precipitation deficits leading to these droughts; (3) the key catchment characteristics influencing drought propagation; and (4) the way in which drought propagation has evolved under changing climate conditions. By analyzing long-term observational records from 50 Swedish catchments, the study reveals that drought propagation is highly variable and influenced by a complex interplay of catchment characteristics, hydroclimatic conditions, and soil properties. Soil moisture exhibits the shortest propagation times, often responding within a month to precipitation deficits, while groundwater shows the longest and most variable response times, sometimes exceeding several months. The probability of precipitation deficits propagating into soil moisture droughts is highest, followed by streamflow and groundwater, with these probabilities increasing over time. Across all drought types, annual precipitation and streamflow emerge as the most influential factors governing both propagation time and probability. Although most catchments have become wetter year-round due to climate change, southern catchments are increasingly vulnerable to spring droughts (particularly soil moisture drought), driven by increasing evaporative demand. Despite these hydroclimatic shifts, no significant long-term trends in propagation times or probabilities have been observed over the past 60 years. These findings highlight the need for tailored region-specific water management strategies to address seasonal and regional variations in drought risks, particularly as climate change continues to reshape hydrological regimes.

The European continent has experienced several large-scale drought events in recent years, and climate projections suggest an increasing drought risk in many parts of the world. As droughts can have large impacts on socio-hydrological systems, analyzing drought risk is an important part of proactive drought risk management and disaster risk reduction. Drought risk can be expressed as a product of hazard, exposure, and vulnerability, where vulnerability is highly contextual and complex. As droughts can affect all parts of the hydrological system, from precipitation and soil moisture to groundwater and surface water reservoirs, drought vulnerability differs depending on what part of the system is studied. Building on previous results from a survey analyzing drought vulnerability across seven water-dependent sectors, this paper explores how vulnerability factors vary based on sectors' dependency on blue water (surface and subsurface freshwater) or green water (soil moisture) in mid- and high-latitude regions. The findings reveal that drought vulnerability differs based on water type dependency, especially concerning water supply and species characteristics. Perceptions of vulnerability factors vary in number, category, and overall ranking, highlighting the importance of considering water dependency when choosing vulnerability factors for drought risk assessments and to clearly define the drought hazard types involved.

There is a global call for proactive drought risk management, stressing the need to further our understanding of the systemic nature of drought risk. Proactive drought risk management requires not only an understanding of the drought hazard itself, but also of the underlying vulnerabilities in socio-hydrological systems. As a result, drought vulnerability assessments are increasingly conducted across the globe. However, drought vulnerability is complex and shaped by the social, ecological and hydroclimatic context. Thus, understanding how vulnerability is manifested depending on regional, sectoral or societal differences is crucial. Yet, a detailed overview of drought vulnerability factors relevant for socio-hydrological systems in specific climate regions and ecozones, is currently lacking. Therefore, a first ever attempt was made to identify user-validated drought vulnerability factors, relevant for water-dependent sectors and societies in forested cold climates. User-validation was performed through an online survey conducted in Sweden, Northern Europe, targeting stakeholders from seven water dependent sectors, working in authorities, private and public enterprises, NGOs and trade associations. Respondents were asked to rate a comprehensive list of vulnerability factors, connected to sectoral and societal vulnerability as well as governance, based on their impact on drought risk in their sector as well as for society as a whole. The study successfully identified several relevant drought vulnerability factors for the climate region, as well as the relative impact of each vulnerability factor on drought risk in sectors as well as society. Results showed that the relevance and impact of individual vulnerability factors differed for different sectors, where the forestry sector especially stands out compared to other sectors. Furthermore, the results indicate regional differences in societal vulnerability factors. The substantial list of vulnerability factors found to be relevant by the respondents, demonstrate the complex nature of drought risk, as well as the importance of adopting cautiousness when selecting generic vulnerability factors for applied vulnerability assessments. Furthermore, the results provide a comprehensive guide to both sectoral and societal drought vulnerability in socio-hydrological systems located in forested cold climates.