This presentation highlights recent case studies, models, and global analyses that reveal emerging trends and patterns in human-water interactions and feedbacks in our rapidly changing, human-dominated world. Human activities worldwide are increasingly altering hydrological regimes, including the frequency and intensity of extreme events such as floods and droughts. These alterations result from various interventions, including the construction of water infrastructure, river flow diversions for irrigation or other purposes, land-use changes such as deforestation and urbanization, as well as climate alterations driven by greenhouse gas emissions. While societies shape hydrological extremes, they are also profoundly affected by these events. Following floods or droughts, human responses range from informal adaptations to deliberate strategies, including modifications to agricultural practices, revisions of social contracts, and both temporary and permanent migration. These interactions between heterogeneous human and water systems often produce unintended consequences, amplify risk dynamics, and exacerbate existing inequalities. Such feedbacks complicate the development of equitable and sustainable policies, frequently resulting in unprecedented events with catastrophic and uneven impacts.
How to cite: Di Baldassarre, G.: Exploring Human-Water Feedbacks in a Rapidly Changing World , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4131, https://doi.org/10.5194/egusphere-egu25-4131, 2025.
GEB is a new socio-hydrological model coupling an agent-based adaptation model, a fully distributed hydrological model (CWatM), a hydrodynamic model (SFINCS), and a forest evolution model (plantFATE). The model simulates hundreds to millions of individual households, such as crop farmers, which can dynamically respond to their environment, for example, through switching crops and irrigation techniques. Moreover, households can dynamically adapt to changes in flood risk and respond to flood events by wet- or dry-proofing their house. All adaptation decisions consider heterogeneity in the agent population and are grounded in well-known behavioural theories, such as the subjective expected utility theory and the protection motivation theory.
Households also interact with each other (e.g. network effects) and with governmental or private sector stakeholders. Higher-level agents, such as water boards and governments, can test the effectiveness of investing in a wide range of measures and policies (e.g., increasing forested areas, creating water buffers and levees) or (dis)incentivize behaviour through subsidies or pricing.
GEB simulates hydrology and drought impacts at a daily to sub-daily timestep at field-scale resolution, while floods are simulated at a resolution of up to 5 meters. The model can simulate well-known human-natural feedbacks from the governmental to the household levels, and is suitable for assessing timely scientific themes such as the safe-development paradox, the irrigation efficiency paradox, supply-demand cycles, and the reservoir paradox.
The model is fully open source (https://github.com/GEB-model/GEB) and can be set up anywhere globally with reasonable default parameterization with little effort, while allowing for improved parameterization using local data. Current implementations include the Krishna basin (India), the Meuse (Western Europe), the Murray-Darling basin (Australia), and the Hetao irrigation area (China). We encourage other researchers and practitioners to test, use, and contribute to the model.
How to cite: de Bruijn, J., Kalthof, M., Bril, V., Sadana, T., Stefaniak, E., Busker, T., Oliveira, R., Smilovic, M., Guo, X., Tierolf, L., Wens, M., de Moel, H., Botzen, W., and Aerts, J.: GEB: A coupled socio-hydrological agent-based adaptation model for drought and flood risk management, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19228, https://doi.org/10.5194/egusphere-egu25-19228, 2025.
Water supply is one of the critical services that can be disrupted by climate-related disasters. Floods and droughts, in particular, can cause damages to infrastructure and alterations of water source quality and availability. In the Nordic water sector, concern about climate risks has been growing due to the successive dry summers from 2016 to 2018, major flooding events in 2023, various heavy rainfall events, as well as projections that floods and seasonal droughts could become more frequent and intense in many regions. Knowledge from past events is essential to prepare for potential climate impacts. However, learning opportunities are currently limited as small local impacts to water supply are rarely reported in national and global databases. This study examined climate impacts to water supply in Sweden, in the period 2010-2024. Drawing from reports by regional authorities, local surveys, and media articles, we mapped the occurrence of flood and drought events throughout the country and compiled both the impacts to water supply and post-event evaluations of the disaster response. The results indicate that past climate hazards have led to impacts ranging from sewage pipe breaks and inundated pump stations to poor raw water quality and low surface- and ground-water levels. Disruptions of drinking water services have been minor and manageable, while interruptions affecting consumers, such as water use restrictions or water boil advisories have generally been brief and of a preventive nature. However, regarding disaster management, official reports reveal a lack of hydrological knowledge, the absence of a big-picture understanding during events, and insufficient coordination with neighbor regions and across governance levels. These results concur with previous findings that societal impacts to drinking water supply have, so far, been limited in the Nordic region. Nonetheless, impacts are expected to become more serious in the future due to climate change and challenges in crisis management. This underscores the importance of building robust impact and response databases to support water managers in improving disaster preparedness and ensuring the continued security of safe drinking water supplies.
How to cite: Fernandez, J., Di Baldassarre, G., Teutschbein, C., and Mård, J.: Climate hazard impacts to water supply - Learning from past floods and droughts in Sweden, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6037, https://doi.org/10.5194/egusphere-egu25-6037, 2025.
The African Sahel has long been a focal point for research and policy discourse on drought. Inhabitants heavily rely for sustenance and economy on agriculture. Thus, crop yield is a key measure of success or failure. Since crop yield depends heavily on water availability, it is indicative of the function and efficiency of the farming-water system used. This system is said to have undergone significant variations in the biophysical and socioeconomic features during the past five decades. Understanding the interactions of climate variability and especially drought process and farming system development is important to sustainable and adaptive resource management. This study explores the coevolution of farming-drought relationship in the Sahel with a special reference to Sudan. We aim at synthesizing a number of insights into the sociohydrological resilience of the Sahel farming system. To this end, we analyzed two gridded datasets on drought indices and two staple crop statistics since 1970 in addition to structured survey questionnaires with ~1100 farmers. The analysis is further bolstered by recent findings from DFG funded SHADRESS project. The analysis shows that farmers have developed different agricultural strategies to cope with drought. Sorghum and millet yields have not kept pace to match the steadily expanding planted areas as would be expected. Both crops thereon reveal an inconsistent performance in terms of yield vulnerability and resilience to both dry and wet conditions. Farmers reported that sorghum (51%) is more affected by climate vagaries as compared to millet (15%). Inadequate rainfall is perceived by more than two-third of the respondents as the main reason for declining yield. However, during the last three decades, the importance of drought characteristics in determining crop yield levels decreased. Notwithstanding the benefits brought about by wet conditions, the farming system is likewise vulnerable to wet extremes, though somewhat to a lesser extent. The above observations suggest that the adjustment measures adopted by farmers are not sufficiently reducing the risk of crop failure. The respondents indicated other non-climatic issues beyond drought as being responsible for low yields, putting constraints on farming adaptations. In conclusion, identifying suitable pathways to adaptive agricultural management is needed to increase stability and resilience. These pathways should address vagaries of both the natural and the societal conditions. The combined implications of both droughts and floods as well as the integrated multi-faceted factors currently influencing the interplay between the farmer and water system must be recognized.
How to cite: Elagib, N. A., Rahma, A. E., and Schneider, K.: Perception versus reality: Farmers’ adaptation and the dynamics of Sahel drought, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4584, https://doi.org/10.5194/egusphere-egu25-4584, 2025.
Characteristics of flood risk research and methodological requirements to understand the dynamics of human-flood relationships
Flood risk is one of the most pressing global challenges, exacerbated by climate change, urbanisation and land-use change leading to more frequent and severe flood events. Addressing these risks requires overcoming three key challenges: building a robust knowledge base for disaster risk reduction at all stages, developing strategies and measures that address current risks while managing uncertainties, and effectively implementing these strategies within the disaster risk reduction cycle. Understanding the feedback loops in human water and flood risk systems is a prerequisite for overcoming these challenges.
Transdisciplinary approaches integrate scientific methods with regional knowledge and practical expertise. For example, transdisciplinary or participatory methods can be used to validate data, identify regional hot spots, develop relevant scenarios and possible adaptation measures and identify implementation and decision-making structures for the actual realisation of measures.
Flood risk research has certain characteristics. It is highly complex. Various interlinked factors influence flood risk within and between environmental and social systems. Different flood risk factors at different spatial and temporal scales influence the occurrence of floods, and exposure and vulnerability affect the actual risk that materialises. Different temporal scales lead to different levels of flood risk and require targeted measures. Technical tools such as hydrological and hydrodynamic flood models are crucial for understanding and visualising processes and interrelationships as well as possible development options. Missing data or a lack of detail influence the informative value and increase uncertainties, especially at the local level. Finally yet importantly, flood risk and vulnerability are highly context-specific and localised in specific historical, cultural and social circumstances.
In this article, we describe the requirements arising from these characteristics and the resulting demands on and potential for transdisciplinary research. We draw on findings from the PARADeS project, a collaborative research initiative on flood risk management in Ghana.
We describe the framework and possible methods for a. knowledge co-production to understand interactions within the flood risk system, among others; b. social learning to understand the complexity of human-flood interactions and causes; and b. capacity building, e.g. to create and use a flood information system to learn about impacts and feedbacks in the Ghanaian flood risk system.
The combined and complementary quantitative and qualitative methods significantly improve the information base for proactive flood risk prevention, clarify structural and social conditions, interlinkages and contexts for implementation and thus identify efficient flood risk reduction measures.
How to cite: Evers, M., Höllermann, B., and Kruse, S.: Characteristics of flood risk research and methodological requirements to understand the dynamics of human-flood relationships, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7143, https://doi.org/10.5194/egusphere-egu25-7143, 2025.
Communities around the globe are at substantial risk of being threatened by hydrological extremes, particularly by floods. Adapting to exacerbating flood risks is hence of utmost importance to safeguard people’s wellbeing. Households are critical for flood risk adaptation as their actions have proved effective and efficient in diminishing risks. At the same time, past flood experiences, as well as risk and adaptation capability perceptions are often considered important factors driving household adaptation. These linkages suggest complex human-water system dynamics, characterized by positive, i.e. reinforcing, and negative, i.e. hampering, feedback between household behavior and flood risks and impacts alike. Empirical evidence on this complex interaction is mixed, indicating diverting effects, and findings are predominately derived from case studies in the Global North. Therefore, additional data - particularly from the Global South - is needed to advance understanding of the complex human-water dynamics.
Building on this knowledge gap, our study presents insights into human-water dynamics from the highly flood-prone city of Hue in Central Vietnam. Drawing on a household survey (n=550) and follow-up semi-structured household interviews (n=30), we apply descriptive statistics, logistic regression, and qualitative content analysis to assess patterns and interlinkages of household flood adaptation behavior, past flood experiences, perceived future flood risks, and perceived adaptation capabilities.
Our results suggest that past flood experiences significantly shape households' flood risk perception. Interestingly, households that have been affected by floods in the past reported a higher perceived likelihood of being affected again in the future while their perceived future impact severity did not differ from non-affected households. In general, the perceived severity of flood impacts is assessed significantly lower than the perceived likelihood of impacts. This finding relates to an attitude of “living with the floods”, which strongly builds on the belief that floods cannot be avoided, but that people have always managed to cope with flood impacts. Therefore, risk perception generally only has a moderate effect on households' adaptation intention, although low levels of risk perception can act as a central barrier to future adaptation for some households. In contrast, perceived adaptation capabilities, particularly households' self-efficacy beliefs, have a strong effect on adaptation intention. While low self-efficacy, often driven by contextual factors including old age, poor health, or the lack of financial resources, acts as a significant barrier to adaptation, social networks were found to increase self-efficacy, thereby boosting adaptation intention.
In conclusion, our results decipher central human-water interlinkages and thereby provide vital hints for improved risk management and adaptation. For example, risk awareness-building campaigns should not be limited to increasing risk perception but also aim at strengthening perceived adaptation capabilities, such as through skills and knowledge building, to more effectively nudge households’ adaptation intention.
How to cite: Sett, D., Bao Chau, L. D., Giang Chau, N. D., Hagenlocher, M., Bubeck, P., and Thieken, A.: Advancing our understanding of human-water dynamics through empirical findings on households' flood adaptation behavior in Hue, Vietnam, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13506, https://doi.org/10.5194/egusphere-egu25-13506, 2025.
The floodplain of lake Rawa Pening, experience spatio-temporal dynamics due to regime shifts of wet and dry season as well as a more persisten land use changes in the upland area. The high yield of rice agriculture in the floodplain has also been bothered by additional entity rooted on the socio-economic value of the plain. Our research focused on floodplain in the vicinity of the Torong River, Banyubiru District that recently incurred river normalization project. Compare to the rest eight catchments delivering effluents into the lake, we assume normalization will change sediment budget, in way the dynamics can be captured well by detailing imagery acquired from Unmanned Aerial Vehicle (UAV) photography.
Land use change is observed using high temporal resolution of optical satellite imagery and the verification using UAV images. Sentinel-2 optical imagery is used for the macrozonation. Because of the high temporal resolution, we eliminate images with cloud interference exceeding the specified threshold while assuring data continuity. At time when Sentinel-2 is planned to pass over, we also acquire UAV photos of different heights aimed to detail reality mapping of the area. To get land productivity, we use statistical information and semi-structured interviews of randomly selected samples for each land use class.
Our initial results using longer period Google Earth images showed both extreme and gradual changes of land use, partly due to irregular temporal captures. Sentinel-2 is available in shorter historical period providing denser images every 5 days. At the same capture time, UAV capture images to opens potentials for further color manipulations matching the productivity. For the moment, our investigation on land productivity still relied on manual delineation of straight skeleton visible in both approaches. High productivity of ricefield in the floodplain area also still relied on semi-structured interviews and statistical reports by village adminstrations. With the constraints, risk of land use change observed using current satellite images and UAV accords on the manual delineation process. As a result, we found Sentinel-2 images is sufficient to predict risk changes particularly for fish culture and tourism, while spatial ricefield productivity using satellite and UAV images still require complex experimentation on color spectrum and operational acquisition height of the UAV.
How to cite: budiyono, Y., Ariyoko, I. D., Zahro, Q., and Sudiana, N.: Quantifying risk dynamics on Rawa Pening floodplain using optical images gathered by satellite and unmanned aerial vehicle, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11358, https://doi.org/10.5194/egusphere-egu25-11358, 2025.
Despite the primary aim of flood risk assessment and management to mitigate the negative impacts of floods on people, Italy lacks adequate tools for assessing flood human impact. In fact, current assessments are limited to estimating the number of residents in flooded areas. This approach underestimates the human impact as it disregards the broader spectrum of societal impacts and does not include indirectly exposed groups, who may, for example, suffer income losses due to the disruption of economic activities affected by the flood. However, addressing these impacts is key to guarantee healthy lives and well-being for all, as requested by the third Sustainable Development Goal. To better understand the broad spectrum of human impact, a questionnaire was distributed via a social media and local newspapers campaign to directly, indirectly and not affected citizens of the municipalities hit by the exceptional flood event that struck the Marche region, Italy, on September 15th, 2022. The survey elicited the perceived severity of flood impacts accounting for both direct (e.g., physical injuries, property damage) and indirect impacts (e.g., disruptions to daily life, post-event illnesses, psychological stress), together with socio-economic data and flood event information. About 700 responses were received, nearly half of which came from directly affected people. The analysis of the perceived severity of impacts across the three respondent groups revealed that, while direct tangible impacts were significant only for those directly affected, indirect intangible impacts were significant for both indirectly and not affected respondents. This finding confirms that the current approach, which focuses only on directly affected individuals, underestimates the human impact. Furthermore, the psychological stress induced by the flood was significant in all three groups, highlighting the need for targeted preventive measures and post-event mental health support for the whole community.
How to cite: Rrokaj, S., Bubeck, P., Thieken, A., and Molinari, D.: Flood human impacts within and beyond the flooded area: results of a survey conducted in Marche region after the flood of 2022., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15681, https://doi.org/10.5194/egusphere-egu25-15681, 2025.
Floods pose significant risks to societies worldwide. Private flood adaptation is considered important to reduce flood risk. Investigating the influential factors on individual adaptation behaviour is thus essential. Many behavioural theories hypothesise a vital role of the adaptation intention toward adaptation behaviour. However, the literature shows a substantial gap between intention and behaviour, referred to as intention behaviour gap. This could be because most existing research is based on cross-sectional data, which does not reveal the changes in attitudes, intentions, and behaviour over time. For example, implemented measures might reduce the intention and behaviour, but these changes cannot be captured by only one survey time point. Our research thus deploys a two-wave panel survey with 401 respondents from Central Vietnam to (1) examine the dynamics of behaviour and intention over time, (2) examine the role of intention on actual behaviour and vice versa, (3) find influential predictors explaining intention and behaviour, and statistically compare the predictors.
Linear mixed models (LMMs) show that adaptive behaviour and intention of three groups of measures, namely, preparing devices, retrofitting houses, and adapting livelihoods, have significantly increased after half a year, except for the intention of preparing devices. The most influential factors in explaining behaviour and behavioural change are housing situations, personality traits, social norms, coping appraisals, and intention. For intention, socio-demographic characteristics, risk perceptions, social norms, and personalities are more important. It is noteworthy that the influential factors are highly measure-specific. Specific models show a clear difference in predictors between intention and behaviour. Bivariate LMM and statistical comparisons further confirm that only a handful of predictors could be used as interchangeable proxies between behaviour and intention. For example, out of 18 examined factors, only wishful thinking, knowledge, and moving permanently show similar influence on both the intention and behaviour of retrofitting houses. By contrast, house type, respondent’s age, building a new home, and house located in an urban area show significantly different influences; the remaining factors are uncertain to use as interchangeable proxies. These results suggest carefully reconsidering the use of research on intention to draw policy recommendations for behaviour in the flood risk domain.
How to cite: Luu, T., Thieken, A., Haer, T., Tran, T., and Bubeck, P.: The dynamics and influential factors of intentions and actual behaviours in flood adaptation, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3645, https://doi.org/10.5194/egusphere-egu25-3645, 2025.
The paradoxical increase in flood-related damages, despite rising investments in flood protection measures, underscores the need to understand the two-way feedback between floodplain communities and floods. The phenomenon of increased exposure in the regions protected by levees, known as the "levee effect," has been examined by previous researchers through monitoring the change in flood hazard, exposure to flood risk, and flood vulnerability.
As flood risk perception, vulnerabilities, and coping mechanisms differ among individuals, it is evident that not everyone is inclined to settle near embankments. Moreover, this study posits that flood damages do not inherently compel entire communities to relocate from floodplains, especially when their livelihoods are intertwined with the resources provided by the floodplains. Further, specific households may manage to enhance their resilience while choosing to stay within the floodplains. In this study, we explore whether these interactions increase or decrease the aggregated vulnerability of the floodplain community.
Using an agent-based modeling approach, we prescribe rules for household agents’ interactions with their environment, incorporating heterogeneity of human behavior. The ABM conceptualized in this study aims to simulate the levee effect in Indian floodplains and evaluate the long-term efficiency of structural flood protection measures in the Indian floodplains. Moreover, this study seeks to contribute insights into community-based flood management practices and inform policies aimed at disaster resilience.
How to cite: Singh, A., Dawson, R., and Dhanya, C. T.: A Conceptual Agent-Based Model for Analyzing the Levee Effect in Indian Floodplains, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14101, https://doi.org/10.5194/egusphere-egu25-14101, 2025.
Coastal flooding and sea level rise (SLR) will affect farmers in coastal areas, as increasing salinity levels will reduce crop yields. These impacts will lead to net income loss for farming communities. In response, farmers can take various actions. To assess such responses under SLR at the global scale, we applied DYNAMO-M, a global agent-based model (ABM), to simulate the actions of 13 million farming households in global coastal areas, focusing on those living in 1-in-100-year floodplains and growing 23 major crops. The decision rules in the model (DYNAMO-M) for simulating migration and adaptation are based on the economic theory of subjective expected utility. This theory posits that households can maximize their welfare by deciding whether to (a) stay and face losses from salinization and flooding, (b) stay and adapt (e.g., switching to salt-tolerant crops and enhancing physical resilience such as elevating houses), or (c) migrate to safer inland areas. In our model, current and future coastal flood risk is assessed by combining flood hazard data (with- and without SLR and climate change), the exposure of farmers to flooding and crops to salinization. Vulnerability curves connect hazard and exposure data to estimate (future-) risk. We simulate flood and salinization risk for the period 2020-2080 at a yearly timestep. For each time step, the adaptive response of each individual farming household is simulated as well. Results show that major hotspots of coastal migration are coastal areas of Florida, New York, Oregon in USA, coasts of Japan, China, Philippines and Italy. We further run insurance and policy scenarios to show how government policies like damage coverage and aid in adaptation can help in offsetting the impact of flood risk.
How to cite: Pandey, K., de Bruijn, J., de Moel, H., Botzen, W., and C. J. H. Aerts, J.: How will 13 million global farming households respond to coastal flooding and salt intrusion under sea level rise? DYNAMO-M, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10487, https://doi.org/10.5194/egusphere-egu25-10487, 2025.
The impacts of climate change on water resource availability will be felt both directly and indirectly through changes in water supply and water demand, respectively. Physical water supply changes due to climate stem from modified precipitation, temperature and evaporation, and streamflow, while changes in water demand stem from the same, as well as additional land use and land cover and socioeconomic features. As urban and agricultural water demands are projected to increase under climate change, a regional understanding of both water supply and demand responses to climate change will be necessary to equip water resource managers with locally-relevant, research-driven insights to guide adaptation. In previous work, we investigated the water delivery response to temperature and precipitation changes within the semi-arid San Diego County, located in the Southern California region of the U.S. There, we established that water agency-scale water deliveries are sensitive to temperature and background hydrologic conditions (i.e., antecedent precipitation), and that the temperature sensitivity of water deliveries is mediated by geographic and demographic features such as land cover. Here, we build on this research to further investigate the role of climate in mediating water deliveries in the Southern California region. Specifically, we investigate the hypothesis that the timing of a warm period additionally mediates water deliveries depending on agency attributes such as land cover. For example, agricultural agencies may respond differently than urban agencies to warm periods that occur during pivotal crop growing stages. Additionally, we hypothesize that coastal low clouds may impact water deliveries through the modulation of temperatures during warm periods. We investigate these hypotheses for 20 San Diego region water agencies using daily records of water deliveries made to the agencies from a regional wholesale water supplier, temperature, coastal low cloud coverage, annual precipitation, and agency-level attributes such as income and land cover from May to September for the years 2007 - 2021. This study of a representative arid urban region improves our understanding of coupled human and water system responses to climate variability and change in order to support adaptive water resources management in water-stressed environments.
How to cite: Wicker, L., Clemesha, R., Guirguis, K., Baldwin, J., and Levy, M.: Effects of Warm Period Timing and Coastal Low Clouds on Water Deliveries in Coastal Southern California, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7394, https://doi.org/10.5194/egusphere-egu25-7394, 2025.
Human activities strongly rely on the availability of sufficient water and of adequate quality, yet water use sectors (e.g. irrigation, domestic, industry and energy), already experience clean water scarcity. Additionally, the availability of clean water is further compromised by increasing water demand of the growing population, deterioration of water quality due to pollution by emissions by the different sections, and by more frequent and intense hydroclimatic extremes (e.g. droughts, heatwaves, and compound events). These developments increase the cross-sectoral competition for the available water (Cárdenas Belleza et al, 2023). Current research on large-scale water scarcity related to insufficient water of good quality has provided limited understanding of the sector-specific impacts. This limits our understanding of how water quality affects water sources allocation to different water use sectors and how such responses will impact sector-specific and total water scarcity under global change.
The main objective of this research is to assess cross-sectoral water scarcity due to sectoral competition for limited clean water resources, explicitly considering water quantity and water quality requirements under global change. To address this, we developed a new globally applicable sectoral water use and allocation model, QUAlloc v1.0, that incorporates water quality requirements across main water use sectors (domestic, irrigation, livestock, manufacturing, and energy). QUAlloc v1.0 is linked to the PCR‑GLOBWB 2 hydrological model (Sutanudjaja et al, 2018) and the DynQual v1.0 global surface water quality model (Jones et al, 2023), forming a sectoral water quality, use and allocation modelling framework.
Our results show that present surface water quality strongly affects both water source allocation and sectoral water use competition in river basins globally, resulting in a significant reduction in global surface water withdrawals (by 17%) and an increased dependence on groundwater (e.g., Latin America, the Middle East, North Africa). Additionally, we show that sectors with less stringent water quality requirements, namely livestock and manufacturing, benefit by the reduced surface water withdrawal from other sectors (i.e., domestic, irrigation), enabling to increase its withdrawal. Projections of sector-specific water scarcity under climate change and socio-economic changes for the whole 21st century suggest that these inter-sectoral impacts will become increasingly stronger in the future. Our study is the first in exploring the impacts of present and future water quality in the cross-sectoral water use competition and their effects on sector-specific water scarcity globally.
References:
Cárdenas B., G.A., Bierkens, M.F.P., van Vliet, M.T.H.: Sectoral water use responses to droughts and heatwaves: analyses from local to global scales for 1990-2019. Environ. Res. Lett. 18 104008. https://doi.org/10.1088/1748-9326/acf82e, 2023.
Sutanudjaja, E.H., van Beek, L.P.H., de Jong, S.M., van Geer, F.C., and Bierkens, M.F.P.: Calibrating a large-extent high-resolution coupled groundwater-land surface model using soil moisture and discharge data, Water Resour. https://doi.org/10.5194/gmd-11-2429-2018, 2018.
Jones, E.R., Bierkens, M.F.P., Wanders, N., Sutanudjaja, E.H., van Beek, L.P.H., and van Vliet, M.T.H.: DynQual v1.0: a high-resolution global surface water quality model, Geosci. Model Dev., 16, 4481–4500, https://doi.org/10.5194/gmd-16-4481-2023, 2023.
How to cite: Cárdenas Belleza, G. A., van Beek, L. P. H. (., Bierkens, M. F. P., and van Vliet, M. T. H.: Present and future water quality affects water use and cross-sectoral competition globally, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7434, https://doi.org/10.5194/egusphere-egu25-7434, 2025.
River systems provide essential natural services to communities around the world. Throughout human history, rivers have provided natural water filtration, water and food provision, transport, and recreational opportunities. However, rivers can also expose human systems to natural hazards such as floods and droughts, which are expected to increase in magnitude and frequency due to future climate change. Large scale land use change has the potential to compound the effects of climate change by further altering downstream river flows. This complex relationship, between climate change, land use policy, land use, and river flows, is poorly understood to date.
Due to its extensive and long-standing river monitoring network, the UK provides a good place to explore the evolution of river flows over the past few decades. This project aims to illustrate how land use policy and planning frameworks can affect catchment hydrology, potentially compounding the effects of climate change on river flows. We focus on policy and river flows in the Trent and Clyde catchments, two catchments with diverse land uses covering the two largest devolved nations in the UK (England and Scotland respectively).
Through semi-structured interviews, spatial data analysis, and statistical decomposition techniques, we investigate complex relationships between policy, practice, land use, and river flow metrics. We identify three main patterns of land use change which may have affected river flows through this period: afforestation, agricultural intensification, and urbanisation. We also compile a timeline of policies which have affected these three identified land uses in each study catchment. The policy analysis is then related to observed changes in river flows using our climate change attribution methodology for river flow changes (Wray et al., 2024). Our attribution method employs regressions analysis of historical precipitation and temperature against streamflow to derive probability density functions (PDFs) representing the proportion of changes in various streamflow metrics attributable to climate change. The resulting PDF, representing the climate change attribution, varied depending on the flow metric chosen, as well as temporally over the decades.
Our transdisciplinary work suggests that certain policies have the potential to exacerbate the effects of climate change on flood and drought risk, and these effects are currently insufficiently represented in the planning process. We hope that by linking previously disconnected knowledge and data, this work will inspire future improvements in land and water management policy.
How to cite: Waxenberg, K., Wray, N., Beevers, L., Garcia Ferrari, S., and Angeloudis, A.: Disentangling Climate Change and Land Use Effects on UK River Flows: Policy and Flow interactions, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10821, https://doi.org/10.5194/egusphere-egu25-10821, 2025.
In the context of anthropogenic climate change and increasing pressure on water resources from human use, it is necessary to provide stakeholders with tools to quantify water availability under present and future conditions, and to guide public policy in water management. To this end, anthropogenic effects need to be integrated into hydrological modeling. One of the major challenges in modeling human-impacted hydrological systems is the quantification of water withdrawals at the appropriate temporal and spatial scales. Due to a general lack of direct observational data, these withdrawals must often be modeled. The strategy for data-based modeling of water withdrawals depends on the water use sector: irrigation is traditionally subject to a process-based approach, while public freshwater supply is often modelled using regression techniques. Recently, machine-learning techniques have been explored to model freshwater withdrawals and, in the irrigation sector, to identify drivers and, in rarer cases, to predict water withdrawals.
In this study, we present a data-driven framework to quantify irrigation water with limited data. We illustrate our methodological development with an application over 74 non-nested catchments in France, where water withdrawals are documented based on declarations for a short historic period (since 2008) and at a coarse temporal resolution (annual volumes). To obtain longer time series for the calibration of a hydrological model, we perform a temporal extrapolation of irrigation water withdrawals at the catchment scale. To predict the annual withdrawal, we use a mixed-effects model that explicitly distinguishes between structural variation (e.g. annual change in area equipped for irrigation) and random variation (e.g. change in meteorological and soil conditions). These two terms are modeled using a random forest algorithm. We evaluate the robustness of the model by excluding, at a turn, from the training set: (i) catchments located in the same region to evaluate the spatial extrapolation performance, and (ii) a year of data for all the catchments to evaluate the temporal extrapolation. Our results show that the structural variation modelling term is particularly robust on temporal extrapolation (overall RMSE of 25% of the predicted value), while the random variation modelling term performs well in both temporal and spatial extrapolation (overall Pearson correlation coefficient of 0.72 and 0.80). We discuss how the framework can be used to disaggregate annual values of water withdrawal and be integrated into hydrological modelling.
This work received funding from the European Life Revers'Eau project.
How to cite: Zarpas, P., Ramos, M.-H., Tallec, G., Sarrazin, F., Penasso, A., and Baron, S.: A data-driven framework for the temporal extrapolation of annual water withdrawals for hydrological modelling, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11405, https://doi.org/10.5194/egusphere-egu25-11405, 2025.
We state Ancestral Human-Water Feedbacks (AHWF) into derived regional models of anthropogenic effects and interactions with local communities. On the one hand, we revisit alternative AHWF models from Ailton Krenak’s ancestral future perspectives, quoted for the value of history in global hydrological paradigms (Beven et al, 2025) and even enhanced into hydrological heritage living with droughts (i.e. Pereira et al, 2025). On the other hand, we adapt AHWF models for regional scales from both non-formal cosmogony (e.g. Apgar et al, 2009) and externalist perspectives on metacognition (i.e. from Arfini & Magnani’s, 2022). Thus, the AHWF puts concepts of “knowledge”, “information” and “belief” into practice. In this AHWF, new “embodied”, “extended” and “distributed” anthropogenic effects, with novel sociohydrological archetypes, are theoretically modeled. To conceptualize and simulate feedbacks in human water systems, this AHWF is applied for the coevolution of the Center of Water Resources and Environ. Studies (CRHEA) in Cerrado Biome, Brazil, with river-lake-hydropower-urban settlements. Therefore, connections to regional biomes like the Amazon and the Atlantic Forest are possible to include in this AHWF model through the support of the DREAMS project (‘Flash DRought Event evolution chAracteristics and the response Mechanism to climate change considering the Spatial correlations). Moreover, the AHWF is now operationalised with the SOPHIE initiative (Sustainable Observatory of Planetary Health through Innovation and Entrepreneurship”), with the possibility of the creation of databases for future digital twins and serious games. Topical applications of this AHWF model range for all IPCC-climate impact-drivers and their composite risks (i.e. planetary health, agri-food systems, climate change, water security, biodiversity losses, etc.) with focus on adaptation to hydrological extremes like floods, droughts and water scarcity. Future works are envisaged for the co-alignment of legacies of the IAHS-HELPING Science Decade, the WMO Early Warnings for All initiative, the UNESCO-IHP-IX Strategic Plan, the IWA Digital Water Program and the UNEP World Water Quality Alliance.
References: Apgar et al (2009) Intl. J. Interdiscipl. Soc. Sci., https://doi.org./10.18848/1833-1882/CGP/v04i05/52925; Arfini, S., Magnani, L., 2022, https://doi.org/10.1007/978-3-031-01922-7; Beven et al, 2025, Hydrol. Sci. J., https://doi.org/10.1080/02626667.2025.2452357; Mendiondo, E M (2023) DREAMS Project, FAPESP 22/08468-0, https://bv.fapesp.br/en/auxilios/111385/flash-drought-event-evolution-characteristics-and-the-response-mechanism-to-climate-change-consideri/ ; Pereira et al, 2025, Hydrol. Sci. J., https://doi.org/10.1080/02626667.2024.2446272
How to cite: Mendiondo, E. M., Taffarello, D., Ambrizzi, T., Montenegro, S., Morellato, L. P., Marchioni, D. M. L., Nardocci, A., Saraiva, A., Doubleday, N., and Marengo, J.: Ancestral Human-Water Feedbacks Help on New Regional Models of Anthropogenic Effects and Interactions with Local Communities, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15950, https://doi.org/10.5194/egusphere-egu25-15950, 2025.
Water scarcity has become an increasingly problematic issue due to the intensifying effects of climate change (e.g., rising temperatures, precipitation pattern change) and to the growing demands (e.g., population growth, economic development, intensive farming and industrial activities). Ensuring equitable water allocation is therefore becoming a major concern for stakeholders (e.g., managers, companies, citizens and local authorities).
To address these challenges, we are using the concept of Integrated Water Resource Management (IWRM). This aims to incorporate both the physical and social dimensions of water management. IWRM is a “process that promotes coordinated development and management of water, land and related resources, in order to maximize the resultant economic and social welfare in an equitable manner without compromising the sustainability of vital ecosystems” (GWP, 2000).
However, linking the physical and social dimensions of water management within a IWRM framework is always challenging. We have been exploring the potential of coupling two quantitative models in order to bridge this gap. One model is the AirGRiwrm hydrological model (Dorchies et al., 2021), built on the R-package airGR with new features to integrate human uses and regulations into simulated river flows. The other model is NetLogo, a programming language and integrated development environment (IDE) for Agent-Based Modeling (ABM); it can be used to model and simulate complex natural and social interactions.
Within the scope of modeling and simulation, we think that this model coupling can be used to bridge the gap between physical modeling and social simulation for IWRM. On the one hand, Role Playing Games used in our community as models of IWRM systems lack of quantitative robustness. On the other hand, airGR models are calibrated on data easy to validate. Agent-Based Models seems to be the right tool to combine both approaches.
This presentation focuses on a case study: the anthropized Basse Vallée de l’Hérault (France) located in the Hérault catchment. We present the development process of coupling of AirGRiwrm and NetLogo and how it allows us to simulate concrete scenarios, such as water allocation among competing stakeholders on this case study. We outline in our discussion to what extend the AirGRiwrm-Logo model coupling can be used in hybrid approaches combining participatory modeling based on role playing games and data driven hydrological modeling.
References:
Dorchies, D., Delaigue, O., and Thirel, G.: airGRiwrm: an extension of the airGR R-package for handling Integrated Water Resources Management modeling, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2190, https://doi.org/10.5194/egusphere-egu21-2190, 2021.
Global Water Partnership (GWP). (2000). Integrated water resources management (TAC Background Papers No. 4). https://www.gwp.org/globalassets/global/toolbox/publications/background-papers/04-integrated-water-resources-management-2000-english.pdf
How to cite: Dorchies, D., Bonté, B., Promduangsri, P., and Sil, D.: Fostering integrated water resource management coupling airGRiwrm hydrological model and agent-based modeling (NetLogo), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18255, https://doi.org/10.5194/egusphere-egu25-18255, 2025.
Dam construction poses a significant threat to the health of watershed ecosystems by altering natural hydrological regimes. This study assesses the impact of multiple dams on hydrological flow patterns and aquatic ecosystems in the Upper Cauvery River Basin, India. It focuses on the trade-offs between economic benefits and ecological services resulting from modified flow regimes. This study uses a previously developed integrated model that combines a landscape-based hydrological framework with a reservoir operations model at the basin scale to provide new insights into the daily-scale alterations of ecosystem services. This approach is flexible to simulate changes in flow regimes due to the synthetic placement of reservoirs at any location within the river network. As a proof of concept, the study evaluates economic and ecological consequences that may arise from alternative spatial configurations of existing reservoirs in the Upper Cauvery Basin. Further, the hydrological impacts of reservoir configurations are quantified using Indicators of Hydrologic Alteration (IHA). Two critical ecosystem services dependent on river flow regimes—irrigated agricultural production and fish biodiversity, represented by a normalized fish diversity index—are evaluated. A trade-off curve, or production possibility frontier, illustrates the relationship between these services. The findings indicate that smaller reservoirs located on lower-order streams are more favourable for balancing economic and environmental outcomes than larger reservoirs. Additionally, irrigating higher-value crops can maximize the economic return from stored water and result in similar economic benefits with lower storage needs and less hydrological disruption. This approach allows water and river basin managers to assess the provision of ecosystem services in hydrologically altered basins, optimize operations of reservoirs, and make decisions on removing dams where feasible and necessary, leading to a more balanced approach towards managing ecosystem services.
How to cite: Ekka, A., Jiang, Y., Pande, S., and van der Zaag, P.: Understanding Trade-Offs Among Ecosystem Services of Multiple Dams in the Upper Cauvery Basin: A Hydro-Economic Analysis Using a Landscape-Based Hydrological Model", EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19381, https://doi.org/10.5194/egusphere-egu25-19381, 2025.
