Droughts and water scarcity are increasingly challenging agricultural production and increasing water storage is a common solution. In the Orcia catchment – Tuscany region, Central Italy – the main type of storage is represented by Small Agricultural Reservoirs (SmARs), which were largely realized in the 20th century to boost agricultural production of herbaceous crops. Recently, the underutilized SmARs (>1000 with an average area of 0.15 hectares) received renewed interest due to the challenges posed by climate change. Rising temperatures and erratic precipitation patterns threaten the high-quality productions of the Orcia catchment, which now often requires supplemental irrigation during summer. At the same time, as a response to recent droughts, institutions are promoting the realization of a large reservoir (17 million m3) in the Orcia catchment. In this study, we aim to simulate the two types of water storage and assess climate change consequences on the future water stored. To represent them, we use the flexible and integrated Soil and Water Assessment Tool Plus (SWAT+). The model is calibrated and validated for monthly streamflow and basin actual evapotranspiration through an unusual approach of finding the best parameters in a “simplified” model set-up, and then transferring them to the so-called “complex” model (which requires very long simulation run time and includes the SmARs). We set up alternative models to represent the conditions without any type of water storage, both combined and only the SmARs or the large dam. Then, we use five General Circulation Models under the Business as Usual emission scenario to simulate the implication of climate change on future water stored in the Orcia catchment until 2100. In response to the decreasing precipitation and increased temperature, the outputs of the validated SWAT+ model show a decline in water flowing into the reservoirs (-30%) and a surge in evaporation from the reservoirs (8.7%). This will have consequences on the future water stored that is expected to decrease (-6.2%) by the end of the century. Additionally, infiltration from the bottom of the reservoirs will also decline (-10%), hence reducing aquifer recharge. While the trends assessed with the Mann-Kendall test are often significant, these are strongest when considering only the summer season or only the SmARs. Therefore, preliminary results show that SmARs might be more susceptible to climate change compared to large dams. As SmARs remain a crucial adaptation strategy to climate change, these aspects should be considered in sustainable water management and planning in the Orcia catchment.
Acknowledgments
This research was carried out within the AG-WaMED project, funded by PRIMA, an initiative supported and funded under Horizon 2020, Grant Agreement Number No. [Italy: 391 del 20/10/2022, Egypt: 45878, Tunisia: 0005874-004-18-2022-3, Greece: ΓΓP21-0474657, Spain: PCI2022-132929, Algeria: N° 04/PRIMA_section 2/2021], and the RETURN Extended Partnership funded by the EU Next-GenerationEU (NRRP, Mission 4, Component 2, Investment 1.3 – D.D. 1243 2/8/2022, PE0000005). The content of this abstract reflects the views only of the authors, and the Commission cannot be held responsible for any use that may be made of the information contained therein.
How to cite: Villani, L., Castelli, G., Forzini, E., Bouizrou, I., Piemontese, L., Lucca, E., Chiarelli, D. D., Bertoli, G., Lompi, M., Giuliano, A., Pacetti, T., Caporali, E., and Bresci, E.: Assessment of alternative water storage strategies in a Mediterranean catchment in a changing climate, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13422, https://doi.org/10.5194/egusphere-egu25-13422, 2025.
The increasing population, rising water demand, and the multifaceted impacts of climate change have exacerbated global water scarcity challenges. Water reservoirs serve as critical infrastructure to ensure a reliable supply for agricultural, domestic, industrial, and environmental purposes. Among single-purpose dams, 48% are dedicated to irrigation; however, a study conducted by the World Commission on Dams revealed that irrigation dams frequently fail to deliver the projected water supply for the initially planned areas, underscoring inefficiencies in reservoir management. Furthermore, climate change is projected to amplify these challenges by increasing crop water demand and reducing reservoir storage. This highlights the urgent need for sustainable irrigation reservoir management at the global scale, beginning with the crucial step of identifying the command area—the designated region receiving water from a reservoir for irrigation purposes. Accurately delineating this area is essential for precise estimation of irrigation water demand, facilitating optimal water release planning, mitigating risks of over- or under-supply, and enhancing overall reservoir management, particularly in the context of climate change impacts. Knowledge of the location and extent of command areas can inform large-scale systematic planning efforts to ensure water supply under climate change conditions by identifying those command areas that are likely to face water shortages and those reservoirs where future releases may fall below historical trends.
This study presents a structured approach for delineating and allocating reservoir command areas at the global scale using geospatial analysis. Command areas are estimated within a range of up to 100 km from the reservoir, reflecting economically viable water transfer distances. To estimate potential command area locations, landscape pixels are ranked based on five criteria: elevation, proximity to the reservoir, terrain slope, hydrologic connectivity, and land use (i.e., irrigated areas and croplands). Pixels at lower elevations relative to the reservoir are prioritized, assuming that natural downward gradients in water transfer are preferred over artificial pumping to reach higher grounds. Close proximity to the reservoir is preferred as closer areas minimize water losses and reduce economic costs. Slope suitability is assessed by prioritizing flat terrain below a threshold of 10%. Hydrologic connectivity is determined by tracing the downstream part of the watershed in which the reservoir is located, avoiding command area allocations across higher terrain in neighboring catchments. Finally, areas that are identified on ancillary maps as irrigation areas or croplands are assumed to have a high likelihood of representing the command area of the nearest reservoir; however, it is recognized that groundwater and local streamflow abstractions can provide alternative water sources. These five criteria are combined using weighted overlays to iteratively allocate pixels to determine the potential command area. In cases where the command area extent is not known for a given reservoir, the irrigation capacity is estimated based on the storage volume of the reservoir, i.e., the command area extent is limited to the maximum area that can be supplied with enough water to sustain one crop cycle. The resulting command areas are validated using reported data and literature reviews to ensure accuracy.
How to cite: Soleimanian, E. and Lehner, B.: Determining Command Areas of Irrigation Reservoirs at a Global Scale to Support Sustainable Water Management under Climate Change, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7390, https://doi.org/10.5194/egusphere-egu25-7390, 2025.
The increased frequency of drought due to climate change has further underscored the need for sustainable water resources management, not only in water-limited but also in water-rich areas. In particular, the 2017-2020 drought years in Germany resulted in significant agricultural losses, prompting investigation of additional ways of supplementing irrigation demand. Here, we evaluate the potential of selected flood reservoirs in Southern Germany to supplement agriculture. Reservoir operation is modeled and modified to store water during high flow periods without impacting its original flood impounding function. The stored water is used to supply the agricultural irrigation demand within a radius from the main dam structure during the years 2017-2020. Agricultural irrigation demand is calculated on a daily scale using the FAO-56 method with crop maps derived from remote sensing. Preliminary results related to the efficacy of this strategy will be discussed and will provide insights onto the potential of repurposed flood reservoirs on sustainable water resources management.
How to cite: Ho, S. and Ehret, U.: Assessing the potential ability of repurposed small flood reservoirs to supply local agricultural irrigation demand in Southern Germany, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4401, https://doi.org/10.5194/egusphere-egu25-4401, 2025.
Climate change-induced heatwaves and extreme rainfall events present significant challenges to agricultural landscapes, particularly in rainfed farmland. These extreme events not only reduce food production but also result in economic losses and accelerate land degradation. For smallholder farmers, ensuring a self-sufficient supply of irrigation water during droughts—especially at the onset of a drought—is critical.
In this context, sustainable water resource management plays a vital role in enhancing the resilience of agriculture under changing climate conditions. Small, low-cost micro water storage systems are recognized as effective solutions for intercepting surface runoff and harvesting water when properly designed. However, limited research has explored the detailed water retention efficiency of such micro-storage systems under different conditions and the factors influencing their performance. This study aims to optimize water retention rates in micro-storage systems through best maintenance practices and identify the key factors affecting their efficiency. To achieve this, we established an experimental site in northern Italy with four micro-storage systems, each with a capacity of 150 m³. Additionally, water level transducers were installed in the reservoirs to monitor water levels at 30-minute intervals. A meteorological station was set up to record environmental variables, including solar radiation, precipitation, wind speed, and humidity.The findings of this study will provide crucial guidance for maintaining micro-storage systems, enabling local farmers to improve their resilience and contribute to the sustainability of rainfed agriculture in the face of climate change.
How to cite: Wang, W., Bettella, F., D’Agostino, V., and Tarolli, P.: The Potential of Micro-Storage Systems for Enhancing Resilience in Agricultural Water Resource Management under Climate Change, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8517, https://doi.org/10.5194/egusphere-egu25-8517, 2025.
Droughts represent a significant challenge in agricultural water management, and climate change is expected to increase the magnitude and duration of these events in many regions of the world due to rising evaporation rates and decreasing precipitation. Small agricultural reservoirs (SmAR) can serve as an effective adaptation strategy by harvesting water during wet periods. However, determining optimal sites for new SmARs requires consideration of various bio-geo-physical and socio-economic factors to identify agricultural areas where they would provide the greatest benefit. This study introduces a spatial Multiple-Criteria Decision Analysis (MCDA) framework to identify optimal locations for SmARs to enhance water resilience in Italy, also assessing irrigation demands under changing climatic conditions. Our methodology incorporates exclusion criteria, such as steep slopes, snow-covered areas, and regions with irrigation districts. Then, the suitability analysis is further refined by considering on-site natural risks and capacities, such as water availability, soil erosion potential, geological fitness, bluewater demand, surface sealing, and accessibility to facilities. The workflow involves cross-validating existing SMARs detected via remote-sensing against the suitability map derived from MCDA, ensuring robust evaluation of current and potential reservoir sites. To this end, we leveraged the national-scale repositories featuring terrain models, climate datasets, hydrology outputs, and land use/land cover data. Our findings highlight key spatial patterns and potential areas for new reservoir sites, providing actionable insights for sustainable water resource management. The MCDA approach demonstrates its capability to integrate diverse datasets and address complex trade-offs, offering a replicable model for other regions facing similar challenges.
ACKNOWLEDGMENTS
This study was carried out within the CASTLE project and received funding from the European Union Next-GenerationEU (National Recovery and Resilience Plan – NRRP, Mission 4, Component 2, Investment 1.1 – D.D. n. 104 02/02/2022 PRIN 2022 project code MUR 2022XSERL4 - CUP B53D23007590006). The research is also carried out within the RETURN – multi-Risk sciEnce for resilienT comUnities undeR a changiNg climate Extended Partnership and received funding from the European Union Next-GenerationEU (National Recovery and Resilience Plan – NRRP, Mission 4, Component 2, Investment 1.3 – D.D. 1243 2/8/2022, PE0000005).
How to cite: Sheikh Goodarzi, M., Piemontese, L., Mannucci, N., Bertoli, G., Lompi, M., Pacetti, T., Galli, N., Chiarelli, D. D., Castelli, G., Rulli, M. C., Bresci, E., and Caporali, E.: Spatial multicriteria analysis for potential water harvesting sites: a compensatory approach to enhance agriculture resilience, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20049, https://doi.org/10.5194/egusphere-egu25-20049, 2025.
The Flumendosa basin case study is characterized by a very attractive long-term (one-century) hydrological database, low urbanization, and its key role in the water resources of the Sardinian Island (the Flumendosa reservoir system has a total capacity of about 620 × 106 m3). It provides an interesting opportunity to analyze the response of water resource systems to historical and future climate change. The analysis of a long-term (1922 – 2022) hydrological database showed that the Flumendosa basin has been affected by climate change since the middle of the last century, associated with a decrease in winter precipitation and annual runoff (Mann-Kendall τ=-0.271), reduced by half in the last century, and an increase in the mean annual air temperature (Mann-Kendall τ=+0.373). The drier climate conditions of the last 40 years raise questions for the pre-existing regional water resource planning. The proposed distributed ecohydrological model effectively predicted one century of runoff data and becomes a powerful tool for water resource and environmental planning. We used the spatially distributed ecohydrological model and a water resources management model (WARGI) to define the economic efficiency and the optimal water allocation in the water system configurations throughout the evaluation of multiple planning and management rules for future climate scenarios. Using the IPCC future climate scenarios (up to the end of the century), the soil is predicted to become drier; the runoff will further decrease by about 18%, and up to 31% for 2076-2100 period. In these future hydrological conditions (2024-2100), irrigation demands will not be totally satisfied, with up to 74% of future years being in deficit for irrigation, with a mean deficit of up to 52% for irrigation a scenario C, the scenario with the maximum increase in irrigation in the future. Only a conservative scenario for irrigation, which will exclude the growth of irrigated areas, will be sustainable for the Sardinian water resources system under future climate change scenarios.
We demonstrated that the Flumendosa basin is hydrological sensitive to forest cover changes, as typical of water-limited basins. In this sense, extreme land cover change strategies, such as of deforestation, may help to increase water resources in future sce-narios but can clearly not be accepted because the deforestation will have a strong impact on the carbon assimilation amount in the basin, which will decrease by up to 37% at the end of the 2076-2100 period, as well as on other environmental factors (e.g., soil erosion control); this is not compatible with policies of climate change mitigation and resilience. Afforestation activities will bring a positive increase in carbon assimilation but a further reduction of runoff, slightly increasing the number of deficit years for irrigation.
These results, and the impact of climate change on water resources, need to be carefully considered in the Sardinian development plans. Although climate change is caused on a global scale, it impacts water resources and growth at a local scale, with consequences in an island, such as Sardinia, which has been a positive example of environmental and natural preservation.
How to cite: Montaldo, N., Sirigu, S., and Corona, R.: On the Hydrological Sustainability of Dam-based Water Resources system in a Mediterranean Basin Undergoing Climate Change, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11501, https://doi.org/10.5194/egusphere-egu25-11501, 2025.
Reservoir operations primarily serve three functions: water supply, power generation, and flood control. With the increasing frequency of extreme rainfall events driven by climate change, re-evaluating storage capacity, particularly flood control volume, has become essential to optimizing multi-objective operations. This study aims to simulate changes in flood control capacities, develop an optimal operation model, and analyze trade-offs among these objectives to assess their impact on reservoir performance. The study is divided into three phases. First, the multi-objective Standard Operating Policy (SOP), based on the water mass balance equation, simulates over 30 years of historical data to benchmark water supply, power generation, and flood control. The flood control capacity is then utilized to adjust reservoir water levels within this framework. Second, the model assesses the reliability of water supply and power generation while flood risk serves as a performance metric for flood control operations. Finally, quantitative results for the three objectives are expressed in monetary terms to evaluate the impacts of flood control capacity on reservoir operations and analyze trade-offs. Results suggest that under normal conditions, raising water levels to utilize flood control storage can enhance water supply and power generation benefits while maintaining manageable flood risk. However, during critical conditions, preserving flood control capacity remains essential to mitigate potential flooding and prevent disasters. By investigating changes in reservoir operations under climate change, this study highlights how adjusting water levels influences the trade-offs and benefits of each objective. Using simulations and economic value quantification, it provides a framework for maximizing reservoir benefits under varying scenarios.
How to cite: Chen, P. C. and You, J.-Y.: Assessing Dam Operations under High Water Levels by Reducing Flood Control Volume for Water Supply, Power Generation, and Flood Management, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5698, https://doi.org/10.5194/egusphere-egu25-5698, 2025.
Despite the fact that Japan generally receives a considerable amount of rainfall annually, the steep terrain and limited size of rivers results in rapid outflow to the sea. Consequently, in numerous regions of Japan, small-scale agricultural reservoirs have emerged as the predominant water storage infrastructure and the primary source of water for irrigating rice paddies. It is estimated that there are approximately 150,000 such reservoirs in Japan, with the majority having been constructed over a century ago. This study investigates how changes in rainfall patterns due to climate change and the aging of the population, as well as the accompanying changes in agricultural practices, particularly in rural areas, are affecting the fate of Japan's agricultural reservoirs.
In the present study, the primary objective was to establish a comprehensive database of reservoirs. Despite the availability of official data on reservoirs, it has been observed that this data does not accurately reflect the current situation, particularly in the case of small reservoirs. This is primarily due to the large number of reservoirs and the limited capacity of the government to effectively monitor these bodies of water. Additionally, the database has not been updated to reflect the changes in the reservoir environment that have occurred in tandem with the rapid advancements in agricultural practices and the shifting social landscape, characterized by declining birth rates and an aging population. To address these challenges, we have developed a technology capable of detecting these reservoirs through the analysis of aerial images and satellite observations.
The results of case studies of several regions based on the database suggest that the background to the abandonment and abandonment of small reservoirs is the decline in demand and the existence of modern irrigation facilities that make it possible to use the water of large-scale, highly efficient reservoirs rather than small reservoirs nearby. A significant proportion of these reservoirs, constituting the bulk of the total number of reservoirs, have been either abandoned or are on the verge of being abandoned, particularly those with a capacity of less than 10,000 m3. This is primarily attributable to their suboptimal utilization and management efficiency. Moreover, it has been observed that the recent increase in precipitation in the form of heavy rainfall has accentuated the risks associated with reservoirs. Consequently, stakeholders are being prompted to make decisions that lead to the abandonment or closure of these reservoirs. This presentation will draw from the trends in the fate of reservoirs for agricultural use in Japan, with a focus on abandonment and closure, to discuss sustainable and effective water management and the various environmental and socio-economic factors that affect reservoirs.
How to cite: Watanabe, S.: Assessing the Impact of Climate Change and Demographic Shifts on Japan's Small Agricultural Reservoirs, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15391, https://doi.org/10.5194/egusphere-egu25-15391, 2025.
Small on-farm reservoirs play a vital role in sustaining irrigation and livestock water demands, particularly in regions facing acute water scarcity (Aminzadeh et al., 2024). However, comprehensive understanding of their global distribution and contribution to local water budgeting and management remains limited. This research leverages high-resolution satellite data from Sentinel 1 and Sentinel 2 to develop a global database of small agricultural reservoirs (<0.1 km2) across geographic and climatic zones. Machine learning algorithms are employed to improve the accuracy of reservoir detection from satellite imagery. In addition to mapping the spatial and temporal distribution of these reservoirs, we estimate their storage capacity by correlating surface area and depth metrics. The study enables monitoring of surface water storages across scales thus offering critical insights into the role of small reservoirs in water budgeting and accounting, particularly in water-stressed regions of the world.
Reference
Aminzadeh, M., Friedrich, N., Narayanaswamy, S.G., Madani, K., Shokri, N. (2024). Evaporation loss from small agricultural reservoirs: An overlooked component of water accounting, Earth’s Future, 12, e2023EF004050, https://doi.org/10.1029/2023EF004050.
How to cite: Govindaiah Narayanaswamy, S., Aminzadeh, M., Madani, K., and Shokri, N.: Global distribution of small reservoirs and their role in surface water storage, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1571, https://doi.org/10.5194/egusphere-egu25-1571, 2025.
Agricultural production increasingly relies on irrigation to withstand droughts, precipitation variability or support agricultural intensification. Small agricultural reservoirs (SmAR) can contribute to sustainable agricultural water management by providing additional water without increasing pressure on surface or groundwater resources. The construction of new SmARs is usually subject to a phase of suitability analysis, which helps discern suitable places within a large area, before exploring the potential locations with major details. This task is traditionally performed using top-down approaches relying on multi-criteria analysis (MCDA), which are based on relevant macro criteria for the location of SmAR, often supported by hydrological modelling. In this work we present a bottom-up approach based on statistical modelling of a large database of existing SmAR locations. We compare this empirical approach with the conventional MCDA to show the potential advantages of data-driven suitability analysis within a case application in the Italian region of Tuscany. Our results can directly support high level suitability in Tuscany, while the proposed approach can be further extended and applied in different contexts, scales, and applications.
How to cite: Piemontese, L., Bocci, C., Michelotti, E., Papini, T., Castelli, G., Giambastiani, Y., Preti, F., and Bresci, E.: A mixed top-down bottom-up approach to site suitability of small agricultural reservoirs and application in Tuscany (Italy), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6016, https://doi.org/10.5194/egusphere-egu25-6016, 2025.
Typhoons present both water resources and flood risks to coastal reservoirs. Forecasts of typhoon tracks are generally more accurate than precipitation over long lead times. However, existing dynamic control strategies consider precipitation forecasts without incorporating typhoon tracks. To address the issue, a dynamic control method is proposed by integrating both precipitation and typhoon forecasts. Typhoons are classified into categories based on their track characteristics and associated precipitation in the reservoir watershed. Dynamic water level control boundaries are established for each category. The Jiaokou Reservoir in Zhejiang, China, is selected for a case study. Results indicate that (1) the minimal distance of a typhoon from the reservoir and the corresponding precipitation are identified as control parameters, based on classification, (2) incorporating typhoon forecasts enables finer water level control with longer lead times compared to using precipitation forecasts alone, and (3) dynamic control integrating typhoon tracks and precipitation increases average water storage by 3.5 million m3 (5.6%) while maintaining the same flood control standards compared to dynamic control based solely on precipitation. The proposed method optimizes dynamic control strategies for reservoir water levels through typhoon and precipitation forecasts across varying lead times, effectively balancing flood risks and benefits.
How to cite: Ye, H., Liu, P., Zhang, X., Fan, J., Xu, H., and Liu, W.: Incorporating typhoon tracks for improved dynamic control of water level, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10331, https://doi.org/10.5194/egusphere-egu25-10331, 2025.
Endorheic lakes, critical components of terrestrial hydrology in closed drainage basins, serve as sensitive indicators of environmental and anthropogenic changes (Hassani et al., 2020). This study analyzed 635 endorheic lakes globally using high-resolution satellite datasets to quantify changes in surface area from 2000 to 2021 and identify the underlying causes. Of these, 134 lakes showed noticeable surface area reductions, with the highest rates observed in water-stressed regions, particularly in Asia and Semi-Arid climates. We found that anthropogenic activities, including agricultural expansion, were key drivers of shrinkage in 89 lakes, whereas meteorological factors, such as increased aridity, primarily influenced 45 lakes. For example, irrigation significantly impacted water balance in places like Wadi Al Rayan in Egypt and Chenghai Lake in China, while industrial activities like lithium mining were particularly notable in the basin of the Dongtai Jiner Lake in China. Additionally, changes in climatic variables, including reduced precipitation and heightened evapotranspiration, further exacerbated lake surface reductions in many regions. These findings highlight the complex interplay between human and natural factors affecting lake dynamics often resulting in what is referred to as anthropogenic drought. They offer valuable insights for the sustainable management of endorheic lake ecosystems, emphasizing the need for strategies that address both direct anthropogenic pressures and changes in climatic and environmental factors.
Hassani, A., Azapagic, A., D'Odorico, P., Keshmiri, A., Shokri, N. (2020). Desiccation crisis of saline lakes: A new decision-support framework for building resilience to climate change. Science of the Total Environment, 703, 134718, https://doi.org/10.1016/j.scitotenv.2019.134718.
How to cite: Nevermann, H., Aminzadeh, M., Madani, K., D'Odorico, P., AghaKouchak, A., and Shokri, N.: A Global Perspective on Endorheic Lake Shrinkage: Impacts of Anthropogenic and Atmospheric Factors , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8774, https://doi.org/10.5194/egusphere-egu25-8774, 2025.
One of the most common methods for operating reservoir systems is to follow pre-established rules that specify allowable release volumes at specific times of the year. In South Korea, traditional reservoir operation rules have primarily focused on human-centric objectives, such as flood control, water supply, and hydropower generation, with insufficient consideration for downstream environmental needs. A key challenge in this context is to develop methods for multipurpose reservoir operation that restore healthy flow regimes in upstream and downstream areas while minimizing disruptions to existing water use benefits. This study proposes water supply adjustment guidelines for multipurpose reservoirs to ensure the sustainable provision of environmental water. The proposed guidelines aim to prevent severe water shortages during drought conditions by gradually reducing allocations for instream flow, agricultural, industrial, and municipal water uses. Recently, the role of multipurpose reservoirs in South Korea has expanded to include the provision of environmental water, with some reservoirs allocating water specifically to improve downstream river water quality. However, specialized water supply adjustment guidelines tailored to environmental water management have not yet been established. This study examines multipurpose reservoirs with environmental water allocations and evaluates the feasibility of monthly environmental water supply plans during drought conditions. A phased water reduction plan focusing on environmental water is proposed, and stage-specific minimum reservoir storage volumes are calculated to meet reliability criteria. Simulated operations are conducted to develop effective and sustainable reservoir operation rules. This research offers a new direction for multipurpose reservoir management in light of the expanding role of environmental water and provides practical management strategies to address the challenges of climate change and extreme meteorological conditions.
Acknowledgement
This work was supported by Korea Environment Industry & Technology Institute(KEITI) through Water Management Program for Drought Project, funded by Korea Ministry of Environment(MOE).(RS-2023-00230286)
How to cite: Won, J. and Kim, S.: Development of reservoir operation rules for environmental water supply, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14286, https://doi.org/10.5194/egusphere-egu25-14286, 2025.
This study focuses on the Morava sub-basin in the upper Danube region, which contains several key reservoirs (e.g., Vranov, Vir, Mostiště) for water supply, energy generation and flood protection. If not managed sustainably under changing climatic conditions, these reservoirs could threaten water security in the Morava region and its downstream catchments. We employed the Community Water Model (CWatM), a state-of-the-art hydrological tool that simulates the water cycle at global and local scales at a 1-minute resolution. Using the calibrated model, we assessed the selected infrastructure's current storage capacities and release dynamics. We used a data-driven approach based on a 366-day cycle of releases based on observed water level or storage observations.
Due to the lack of data for several reservoirs in the Morava sub-basin, we integrated remote sensing data to enhance model accuracy and refine its assumptions. Currently, CWatM's lake storage function is simplified as a linear relationship between water level and storage. This assumption for small and medium reservoirs might not be accurate.
We utilized the Normalized Difference Water Index (NDWI) from the Landsat 7 and 8 missions to identify instances where this linear relation assumption does not hold. The identified relationships were used to recalibrate the model's storage relationships and run it under different SSP-RCPs scenarios for 2025 to 2100, analyzing reservoir performance and identifying potential risks.This study lays the groundwork for improving management strategies to address the challenges of climate change and growing socio-economic pressures.
How to cite: Catania, C., Politti, E., and Suresh, K.: Integrating remote sensing observations and hydrological modeling to assess reservoir sustainability in the Morava sub-basin. , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18315, https://doi.org/10.5194/egusphere-egu25-18315, 2025.
Undercover karst are characterized by limestone formations underneath a variability thick, low-permeability cover. Karst landforms such as sinkholes or swallow holes are thus not very frequent in these environments. This leads to a high inertia of the environment. In the current context of climate change, there is a growing interest in the impact on water resources in karst systems. While several scientific studies have modeled these impacts, most of them focus on outcropping karst system. Research on undercover karst remains limited, primarily due to a high level of inertia of these environments. It represents a challenge for the application of conventional tools and methods usually employed to characterize a system and complicating the interpretation of usual chemical methods to understand the role of the cover karst system
The Moulineaux spring is an example of a covered system. It is a key resource for the urban area of Perigueux (France) by ensuring the supply of drinking water to more than 60,000 inhabitants. It’s average flow rate is 820 L.s-1 and can range between 118 L.s-1 and 4 000 L.s-1. The karstic system is mostly covered by a thick semi-permeable layer of alternating marly limestone, alterite rocks and sediments dating from the Campanian period (Upper Cretaceous). Its sizeable catchment area spans more than 80 km² more than 50% of which is occupied by agricultural activities.
Following continuous monitoring of spring flows and rainfall since 2011, modelling of the Moulineaux karstic system was carried out using various existing modelling software packages, such as KarstID and KartsMod. A conceptual three-reservoir model was used to represent the karst system of the Moulineaux. The model consists of an epikarst, a cover, a matrix reservoir, and a bypass. Achieving a correlation of over 85% according to the Nash coefficient, this model appears to be the most representative of the real system. Based on this model, several scenarios of climate change set up by the “DRIAS portal” in the coming years were applied. The results obtained with the most likely future scenario (RCP 8.5) show a stabilization of the average flow over 100 years, but greater variability in the flows throughout the year. The results enable better management and protection of these karstic hydrosystems. In the future, the goal is to apply this approach to hydrochemical modeling.
How to cite: Lorette, G., Jolly, M., Peyraube, N., Lastennet, R., and Denis, A.: Using hydrodynamic modeling for an assessment of climate change impact on a covered karst system. Example of the Moulineaux spring (Dordogne, France), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18523, https://doi.org/10.5194/egusphere-egu25-18523, 2025.
Water storage infrastructures such as dams and reservoirs are crucial for meeting local water demands, especially in arid and semi-arid regions with varying rainfall patterns and frequent droughts. Notwithstanding the role of human-made reservoirs in stabilizing water supply for agricultural, municipal, and industrial demands (e.g., irrigation, hydropower), identifying their impact on the water balance in endorheic basins, particularly those with shrinking lakes, remains a challenge. Dams and reservoirs disrupt natural inflows thus accelerating lake shrinkage and altering hydrological processes with associated adverse impacts on ecosystem functioning in the basin. We combined satellite remote sensing, bathymetric information, and land and climatic data to quantify the influence of water storage infrastructures on groundwater dynamics and storage variation of shrinking endorheic lakes. Our preliminary findings reveal that among 134 endorheic lakes (>10 km2) worldwide that have experienced a reduction in surface area over the past two decades, nearly one-third have been significantly influenced by the expansion of storage capacity within their basins. We thus quantified the correlations between the expansion of storage capacity and local irrigation and livestock water demands with changes in groundwater levels and lake volume in these basins. These results highlight the need for a more comprehensive understanding of the interplay between water storage infrastructures and the long-term sustainability of endorheic basins.
How to cite: Aminzadeh, M., Nevermann, H., Seyedan, M., and Shokri, N.: The role of dams and reservoirs in transforming desiccating endorheic basins, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1246, https://doi.org/10.5194/egusphere-egu25-1246, 2025.
Posters virtual: Mon, 28 Apr, 14:00–15:45 | vPoster spot A
EGU25-9851 | ECS | Posters virtual | VPS8
Study on Reservoir Ecological Scheduling Based on Multi-Objective OptimizationMon, 28 Apr, 14:00–15:45 (CEST) | vPA.1
Hydropower development in river basins has significantly promoted economic growth while greatly changing the river ecosystems. Effective reservoir management is crucial to maintaining economic benefits while minimizing impacts on fish species. This study focuses on Reservoir X, which has annual regulation capacity, and proposes an ecological scheduling model for the fish spawning period using the NSGA-II algorithm combined with water temperature and TDG (Total Dissolved Gas) predictions. The model framework is as follows: first, hydrological analysis is conducted based on natural flow data at the dam site to determine the flow requirements for target fish species during their spawning period, providing constraints for optimization. Second, multiple regression methods are used to predict the discharge water temperature and TDG saturation of Station X. Finally, multi-objective optimization is performed considering hydropower generation, fish spawning period water temperature requirements, and TDG risks as objectives, with flow requirements during the spawning period, flood control, and water balance as constraints. The proposed model provides practical parameters for reservoir operation and guidance for different optimization objectives across various reservoirs.
How to cite: He, C. and Liang, R.: Study on Reservoir Ecological Scheduling Based on Multi-Objective Optimization, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9851, https://doi.org/10.5194/egusphere-egu25-9851, 2025.
