Water, energy, food, and ecosystems (WEFE) are key resources that support human well-being and, as such, are security concerns for countries across the world. Awareness about the interconnection and interdependence between resource securities, the so-called “WEFE nexus”, is not new but the combination of intensifying resource demands, growing global uncertainties related to the ongoing climate crisis, and the geopolitical atmosphere, have intensified the interlinkages and amplified the cost of inaction and mismanagement of existing policies.

Promoting the development of sound and effective policies to deal with the growing security challenge and its spillovers on other sectoral domains, require actions across different fronts. A fundamental one is to strengthen the nexus research agenda in such a way that sufficient evidence is available and well communicated to inform the development of a more coherent and aligned policy framework.  This requires developing analytical frameworks that can help to unravel the complex interlinkages across sectors. But as important is to research how greater policy coherence can be achieved in practice and how to create the appropriate enabling environment i.e. nexus governance.

Scientific evidence on WEFE in Europe is substantial, and there is a wealth of scientific evidence probing the high interconnectedness that exists between natural resources, and how the sustained pressures we are exerting over them are generating cascading impacts and trade-offs. Despite the level of nexus science, there is barely any information available on the level of impact nexus research projects have had in shaping the policy agenda at the national or European level.

Our research builds on the efforts developed within the COST ACTION NEXUSNET (CA 20138) to map the nexus research projects funded by key European funding schemes (FP7, H2020, HORiZON, JPI Urban Europe, PRIMA) in the course of the last decade, and explore the type of nexus challenges addressed, main policy recommendations provided and the level of implementation of the proposed measures. Preliminary results show that between 2013 and 2022 more than 70 research projects and innovation actions have been funded, with over 222 case studies and demonstrators across European countries. A survey targeting case studies showcased that the level of implementation and adoption of proposed nexus policy measures was below 20%. These preliminary findings showcase that while the research effort in Europe on nexus has been substantive, the policy impact of such research remains unclear, and efforts are required to understand barriers and enablers to increase the relevance and policy impact of nexus research.

How to cite: Willaarts, B., Milliken, S., Caucci, S., Okzul, Z., Girotto, F., and Martinat, S.: Water, Energy, Food and Ecosystems NEXUS: Gaps and opportunities to increase the policy impact of nexus research in Europe, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8799, https://doi.org/10.5194/egusphere-egu23-8799, 2023.

Interdependencies between resource systems are projected to increasingly complicate efforts to develop individual water, energy, food and environment sectors and set their growth policies. Given the urgent need to mitigate climate change, investments in energy and water supply security are being co-driven by financial and international political incentives to decarbonize, and so the scrutiny of plans to modify interconnected resource systems will continue to increase. Additionally, given multiple government needs and priorities, economic, environment and social dimensions should be explicitly considered in the prioritisation of new interventions, whether they be new policies or new infrastructure. This talk considers two river basins in Africa, the Nile river basin and the Volta river basin. It describes efforts of the ‘Future Design and Assessment of water-energy-food-environment Mega-Systems’ (FutureDAMS) project to understand and recommend new interventions in these systems at country or multi-country scale. To this end four technical pillars were needed: credible and computationally efficient large-scale simulation of individual sectors, a multi-agent software integration framework that connects disciplinary models at run time, an efficient search technology to sift through large intervention spaces given multiple objectives and multiple uncertainties including climate change, and stakeholder facing tools and outputs. The talk reviews in detail two areas of model building and their application: linking river basin and economic analysis and linking river basins and regional power grids for joint intervention assessment. The talk will discuss which issues most complicated modelling, what solutions were found, and how future research might improve upon them to generate more useful understanding and decision-support for multi-sector human-natural systems.

How to cite: Harou, J., Basheer, M., Etichia, M., Gonzalez Cabrera, J., Panteli, M., and Calzadilla, A.: Multi-sector assessment and design for large scale water-energy-food-environment systems in Africa, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16263, https://doi.org/10.5194/egusphere-egu23-16263, 2023.

Global change has economic, environmental, and social impacts that threaten access to water resources for communities and ecosystems globally. Mismanagement in other sectors, such as food and energy, can further reduce water security. Scientists use the water-energy-food (WEF) nexus as a conceptual tool to identify the interactions between these three systems. Its implementation at natural-local scales (catchments) is essential for proposing sound policies for water resource management and adaptation to global change.
This study aims to identify synergies and trade-offs between WEF through the valuation of related ecosystem services in an Andean-Pacific transboundary catchment of Ecuador and Colombia (Mira-Mataje - 11,791 km²). We used remotely- sensed and globally available datasets in the spatially distributed assessment model Co$tingNature, to first screen interactions of the related ecosystems. Subsequently, we analyzed the polycentric knowledge from stakeholder’s: Non-Governmental Organizations (NGOs), community leaders, academics, and State sector workers. Finally, we combined the above analyses into a WEF-related ecosystem services weighted-hypernetwork.
Preliminary results show that some services related to energy and food production have negative impacts on water security throughout the catchment. We identify a significant overlap between areas rich in ecosystem services and ancestral territories of ethnic communities and recognize some key intensive anthropogenic activities that affect water security. In addition, we confirm the paramount dependency of Andean cities on water supply from mountain ecosystems. We identified a widespread perception among stakeholders that WEF-related ecosystem services are at risk due to global change and that, in different ways, all are taking steps to adapt to global change. Finally, there is the potential availability of water service in medium and low catchment areas, although the challenge is to improve distribution and purification systems to supply rural areas and make water service accessible to all.

Keywords: Ecosystem services, water-energy-food, remote sensing, weighted-hypernetwork, local knowledge, transboundary tropical catchment.

How to cite: Correa, A., Forero, J., Codato, D., Mulligan, M., and Marco Renau, J.: The water-energy-food nexus through the valuation of ecosystem services in an Andes-Pacific transboundary catchment., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15150, https://doi.org/10.5194/egusphere-egu23-15150, 2023.

Sub-Saharan Africa has a large portion of the population with no access to electricity, piped drinking water, or sanitation services. The lack of these basic services also affects farmers that mostly rely on rainfed agriculture instead of irrigation. Given the expected population growth and potential changes in hydrology and crop yield response due to climate change, future development for the region needs to be carefully studied to achieve increased access to basic services and, potentially, synergetic economic benefits in agriculture.

Within the LEAP-RE 4 AFRI project, we developed a framework that combines three high-resolution, single-sector simulation models (crop water requirements, electricity demand and rural electricity dispatchment) to a long-term water-energy-land integrated assessment model to explore different scenarios of future development for Zambia. This helps understand which regions would benefit of better water access and irrigation potential due to improved rural electrification.

We compare two scenarios of moderate and universal electricity-water access with a current trend scenario, we compare the expected costs and benefits for the rural population, including the economic benefits achievable by improving irrigation standards and crop yields.

Although Zambia is a relatively water-abundant region, we focus on it as a case study with a framework that can be transferred to any other country in Sub-Saharan Africa, where climate change impact might have a significant impact on water scarcity, electricity generation potential and crop yields.

How to cite: Vinca, A., Falchetta, G., Ireland, G., Tuninetti, M., Awais, M., Byers, E., Semeria, F., and Giordano, V.: The benefits of rural electrification to improve water access and irrigation in Sub-Saharan Africa, a water-energy-land assessment framework applied to Zambia., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16277, https://doi.org/10.5194/egusphere-egu23-16277, 2023.

Increasing climate water stress and excessive and unbalanced water withdrawals by sectors are triggering substantial water depletion and environmental degradation in arid and semi-arid basins. Addressing the problem requires the integration of sectoral policies based on interdisciplinary knowledge and sustainable management strategies. The Water-Energy-Food-Ecosystems (WEFE) nexus is an innovative and comprehensive tool to guide river basin managers and stakeholders towards sustainable development goals. Several nexus approaches have been advanced for different sectors, basins, and time periods. However, none to date has presented a monthly dynamic optimization framework that includes ecosystems in order to assess the WEFE nexus for entire large basins. The contribution of this paper is to address water related challenges and highlight the gap in users engagement, by presenting the results of the cross-sectoral integration under future climate water stress (CC-2070; CC-2100), and by designing policy interventions to achieve sustainable outcomes. The WEFE nexus is analyzed for the Ebro River basin; first the analysis identifies the trade-offs and synergies among sectors and spatial locations, and then policy interventions under future climate water stress are evaluated for enhancing water, food and energy security, and for ecosystems protection. Findings provide efficient water allocation plans between competing sectors, emphasizing the importance of ecosystem services in maintaining biodiversity under future climate water stress scenarios. The policy analysis offers insights into the synergies between environmental and economic outcomes, although the costs of certain policies could be high for some groups of stakeholders. Results show that irrigation modernization, increasing reservoir storage capacity, and water trading policies provide efficient water use patterns, enlarging basin stream flows, protecting ecosystems and augmenting the private and social benefits. Sustainable agriculture and water storage management are crucial policies that promote food, water, and energy security and ecosystems protection. These critical results from interventions could help decision makers to bring about efficient water allocation planning among sectors, and advance resilience and adaptation to climate water stress.

How to cite: Baccour, S., Albiac, J., Ward, F., Kahil, T., Esteban, E., Uche, J., and Calvo, E.: Managing the water-energy-food-ecosystems nexus under future climate water stress scenarios in the Ebro Basin (Spain), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4342, https://doi.org/10.5194/egusphere-egu23-4342, 2023.

In this presentation we discuss methodologies, modeling tools and case studies on linking distributed disciplinary food, water, energy, environmental (FWEE) systems’ models into multi-systems multi-disciplinary integrated models for truly integrated analysis and managing of FWEE security NEXUS. Models’ linkage approaches enable to operationalize the concept of modeling and data platforms for distributed independent models’ “integration” and integrated FWEE security NEXUS management.

Local, national and global FWEE security in the presence of climate change and risks of various kinds depend on the consistent coordination between and within the interdependent FWEE systems regarding sustainable resource supply and utilization. Detailed independent sectoral and regional systems’ models are often used to address these challenges. However, the independent approaches overlook the close linkages and feedbacks between and within the systems and, therefore, possible cross-sectoral implications. Critical cross-sectoral FWEE systemic supply-demand imbalances can trigger a disruption in a FWEE systems network. Disruptions and failures can be induced by human decisions in combination with natural shocks. For example, overuse of water in one system, e.g., agricultural, can lead to drying up of wells, decrease of reservoir water level, shortage of water in other systems, e.g., for colling power plants or hydropower production; an extra load in a power grid triggered by a power plant or a transmission line failure can cause cascading failures with catastrophic systemic outages; a hurricane in combination with inappropriate land use management can result in a catastrophic flood and human and economic losses, similar to the induced by Hurricane Katrina. These are examples of systemic risks motivating the development of proper models’ linkage approaches and integrated systems analysis.

The linkage algorithms are becoming widely demanded in connection with the need for decentralized planning of distributed systems and technologies emerging in agriculture, water, energy, environmental systems, e.g., distributed precision agriculture technologies; hydro-economic models’ linkages; bio-physical crop modeling; distributed energy production.

In this presentation we define and illustrate the two main linkage methodologies:

• linkage of distributed FWEE optimization models (land use, water, energy systems models);
• linkage of simulation and optimization models (crop-yield meta-model from EPIC and a land-use GLOBIOM model).

Both methodologies are based on iterative sequential stochastic quasigradient (SQG) procedures of, in general, non-smooth nondifferentiable stochastic optimization, which converge to socially optimal solution maximizing an implicit nested nondifferentiable social welfare function. The linkage problem can be viewed as a general endogenous reinforced learning problem. The models act as “agents” that communicate with a “central hub” (a regulator) and take decisions in order to maximize the “cumulative reward". The procedure does not require models to exchange full information about their specifications. The distributed models can operate on distant computers of individual agents and “negotiate” with a central computer of a regional planner through the linkage procedure.

How to cite: Ermolieva, T., Zagorodny, A. G., Bogdanov, V. L., Wang, G., Havlik, P., Rovenskaya, E., Komendantova, N., Kahil, T., Ortiz-Partida, J.-P., Balkovic, J., Skalsky, R., and Folberth, C.: Consistent linkage of distributed food, water, energy, environmental (FWEE) models: perspectives of data and modeling platform for integrated FWEE security NEXUS analysis and planning., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4116, https://doi.org/10.5194/egusphere-egu23-4116, 2023.

Wastewater has been increasingly considered an untapped resource rather than a waste. It can be used for water supply, aquifer recharge, energy generation, and fertilizer production, contributing concurrently to achieving multiple Sustainable Development Goals. Currently, treated wastewater is used for irrigation in different water-scarce countries like Israel and Spain. Recent estimates suggest that treated wastewater irrigates 6 million hectares (Mha) of cropland worldwide, with global potential for irrigating 31-42 Mha. Nevertheless, these estimates often do not account for environmental, social, and economic conditions that may limit this potential, including irrigated crops’ spatial distribution, water quality requirements, and water conveyance options.

Our study advanced a spatial-explicit analysis of four different technological scenarios and estimated the untapped potential of wastewater irrigation at a global, regional, and national scale. We found that utilizing treated wastewater for irrigation can satisfy up to 4% of the global irrigation demand. Considering only water-scarce regions, reduce this global potential to roughly 2%. However, intensification and expansion strategies or scenarios can increase this irrigation share. For example, in ten countries, delivering treated wastewater to croplands by canals adds over 5% to the share of treated wastewater relative to total irrigation demand. An increase of over 1% is evident in 30 countries, mainly in the Middle East, North Africa, and Western Europe.

Increased wastewater treatment capacity (i.e., expansion strategy) potentially increases the share of global irrigation demand satisfied with treated wastewater to 6% -12%. Some regions’ potential exceeds 20% of their irrigation demand, e.g., China and North America. An increase in potential wastewater irrigation becomes significant when considering expansion scenarios (e.g., increased capacities to treat the wastewater).

Considering the changes in different regions’ water scarcity, we find that the potential share of irrigation demand satisfied by treated wastewater is significantly increased in North America, the United Kingdom, Europe, and Western Asia. We conclude that irrigation with treated wastewater in these regions can be an important climate change adaptation measure. Besides, we show that intensifying and expanding wastewater reclamation systems can help manage droughts in regions with high drought risk, like the Italian Po and French Loire River basins.

By exploring expansion and intensification strategies to reclaim treated wastewater, this work establishes an essential step towards planning the global and regional pathways to utilize this untapped resource, abating current and future water scarcity risks.

How to cite: Fridman, D., Kahil, T., and Wada, Y.: Evaluating the global wastewater’s untapped irrigation potential, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7018, https://doi.org/10.5194/egusphere-egu23-7018, 2023.

Smallholders make up the vast majority of farms globally in terms of numbers (over 400 million), cultivate around 20% of global cropland, and produce 30% of global food. Although 70-80% of smallholders are located in areas already facing water scarcity which may be further exacerbated by climate change and population and economic growth, little is known about the relationship between smallholder farming and water scarcity. This study aims to shed light on this relationship, both regarding how water scarcity affects smallholders’ production and vice versa, how smallholders’ production and water productivity contribute to local water scarcity.

Hereto, we first estimated smallholders’ green and blue water consumption using ACEA 2.0 (AquaCrop-Earth@lternatives 2.0) in 56 countries around 2010, for main crops, and three farming systems. ACEA 2.0  is an updated version of the ACEA global gridded crop model based on AquaCrop-OSPy with a soil fertility module. It leverages a recently developed gridded global crop map that is both farm-size-specific and crop-specific. This inclusion allows us to incorporate the effects of soil fertility stress at an unprecedented level of granularity based on GAEZv4, which is highly relevant for evaluating the low-input rainfed, high-input rainfed, and (high-input) irrigated farming systems separately. The water productivity of smallholders was assessed in terms of a unit of water footprints and nutritional water productivity. Water scarcity was evaluated at the subnational basin level using global hydrological models PCR-GLOBWB, H08, and WaterGAP2-2C through ISIMIP 2a. The individual and combined effects of water and soil fertility stress on smallholders’ production were assessed and compared.

How to cite: Su, H., Foster, T., S. Krol, M., J. Hogeboom, R., Willaarts, B., V. Luna-Gonzalez, D., Mialyk, O., and F. Schyns, J.: Smallholder farming and water scarcity: contributions, benefits, and limitations, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1529, https://doi.org/10.5194/egusphere-egu23-1529, 2023.

Currently, achieving food, energy and water security, and the conservation of ecosystems, are some of the main sustainability challenges. Traditionally, in these sectors, the policy measures and decisions have been taken separately, causing a lack of coordination and high trade-offs across sectors. Consequently, it is necessary to design policies or solutions capable of addressing cross-sectoral challenges. The water-energy-food-ecosystems nexus (WEFE nexus) approach analyses the impacts generated by socioeconomic activities on the production, consumption and management of water, energy and food resources, and the interrelationships with ecosystems. In this sense, the use of this approach can facilitate the identification of coherent solutions that promote the transition toward sustainability.  In this study, an evaluation framework for co-designing and evaluating nexus solutions (GoNEXUS SEF) to improve the governance of the WEFE nexus is presented. GoNEXUS SEF is a new methodological framework developed by the authors and has five main phases: (1) identify nexus solutions; (2) nexus dialogues; (3) model toolbox; (4) nexus evidence; and (5) nexus-coherence assessment. For its development, the ability to evaluate at different spatial scales and forecast at different temporal scales through data projections has been considered. GoNEXUS SEF is a participatory process that integrates qualitative and quantitative methods. On the one hand, we engage stakeholders and experts from the different nexus sectors to understand the cross-sectoral interlinkages, identify challenges, and co-design solutions. On the other hand, we apply system dynamics models (SDM), cross-impact analysis (CIA), and network theory to quantify the synergies and trade-offs.

The framework was applied to a practical case study, an increase in the irrigation water price in Andalusia – Spain for the horizon 2030. Case study results revealed that a water price change could generate synergies since it favours water security and ecosystem conservation. However, trade-offs are observed, mainly undermining the food sector in the region. The main difficulties in applying the framework are the integration of qualitative and quantitative information and the conciliation of the spatial and temporal scales across sectors. Beyond the results obtained, the evaluation of this case allowed us to examine the applicability, usefulness, and potential of the framework. GoNEXUS SEF has proven capable of evaluating nexus solutions; it highlights hidden properties and identifies leverage points and key aspects of complex cross-sectoral systems. In addition, it allows the evaluation and coordination of multiple policies at the same time; in that sense, it can help to achieve nexus-coherence policymaking. The framework can be adapted to fit different case studies, considering their own challenges and their spatial and temporal scales, which gives it a competitive advantage over other methodologies focused on analysing the nexus. Participatory approaches, that combine qualitative and quantitative methods, are adequate to identify and evaluate solutions that aim to improve nexus governance.

Acknowledgements:  This research has received funding from the European Union’s Horizon 2020 research and innovation programme under the GoNEXUS project (grant agreement No 101003722). 

How to cite: González-Rosell, A., Blanco, M., and Arfa, I.: GoNEXUS-SEF: A novel participatory framework to co-design and evaluate water-energy-food-ecosystems nexus solutions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16179, https://doi.org/10.5194/egusphere-egu23-16179, 2023.

The water, food, energy and environment (WFEE) Nexus has recently gained attention from researchers and policymakers. This paper reviews the WFEE Nexus articles. Google Scholar search engine was used for the survey.  By examining the articles, we found that 48 articles focused on this approach. Our systematic review found that existing nexus tools rarely used social science methods and failed to apply replicable methods. Our review indicates that  The environment was considered in the nexus after 2017.  The term “Environment”  was only mentioned in 14% of these articles (Fig.1). In articles, we found close synonyms to “Environment,” such as “Earth”; “Ecosystem,” but also the term “Climate.” WFEE approach survey the interdependencies between water demand sectors and social, economic and environmental changes in water resource and demand management. WFEE is a water-centred approach. Based on the (Zhang et al., 2019) study, it is necessary to strengthen the interaction between resources management in different sectors in a structured way. Otherwise, actions in one system of resources will affect another system of resources.  Hence, the value of WFEE for coproducing adaptation scenarios (Momblanch et al., 2019).  Applying the nexus is complex as it needs many inputs and tools for capturing nexus interactions (Albrecht et al., 2018a; Kaddoura and el Khatib, 2017). In order to accomplish this, it is necessary to use methods from various disciplines (Albrecht et al., 2018a), depending on the analysis's aim, scope, and scale. An integrated systems perspective is enhanced by a multidisciplinary approach(Al-Saidi and Elagib, 2017; Khan et al., 2018), which facilitates sector-specific decision-making and planning. The WFEE has been analyzed using a wide range of modelling tools. There are some tools, such as WEAP (Sieber, 2006) and OSeMOSYS (Akute and Cannone, 2022), that follow a silo-based approach in which only one element of nexus is considered (Albrecht et al., 2018b; Leck et al., 2015; Smajgl et al., 2016). while other integrative application like MuSIASEM [44] combines the three modules, food, energy and Water (Fig.2). A significant gap is the lack of attention to the dynamic concept and the interaction between the components. To assess the effects of climate change, most studies combined various hydrological models, such as hydro-economic models,HEM (Bekchanov et al.,2019), WAEP, LHMs (Monteagudo et al., 2022), with IPCC scenarios. However, downscaling IPCC scenario output with different models is a relatively confident technique for climate data and water resources at the basin level (Yoosefdoost et al., 2022), incorporating this downscale output into the environment models are challenging. It is a big limitation to assess one section of the environment without considering the impact of the other parts. The environment is a complex system with all its parts interconnected. Moreover, since several factors affect the environment, using downscaled data on the environment reduces the reliability of the results. To address these issues, the article (Correa-Cano et al., 2022) proposes a conceptual structure for the WEFE modelling package, a system dynamic model combining hydraulic, environmental, and economic models(Fig.3).

Keywords: WFEE, weaknesses

How to cite: Yoosefdoost, I. and Zekri, S.: Water, Energy, Food  and Nexus' Weaknesses, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15269, https://doi.org/10.5194/egusphere-egu23-15269, 2023.

Disasters and their associated physical and social risks pose challenges for local, national, and international relief agencies and disaster management organizations globally.  Novel approaches are desperately needed for vulnerable communities.  Combining season-ahead predictions, proactive management strategies, and communication efforts in disaster planning represents an emerging field in disaster management, particularly when paired with short-term early warnings and post-disaster response.  However, these long-lead action protocols are still in their infancy as only a few have been activated - triggering and financing preparedness actions.  While these protocols have generally been rigorously established, a holistic evaluation of the framework, including interactions, feedbacks, and dynamic components, is urgently warranted.  Open questions across both physical and social aspects remain, including agreeable triggers for action, clarity of roles and responsibilities, and sufficiency of funding.  The large number of disparate actors involved and the highly interdisciplinary nature lead to a complex decision-making setting.  Further, most protocols are static plans, yet disasters, impacts, infrastructure, communities, and vulnerability states are all dynamic, changing in time; how can protocols better reflect a changing world?  Surveys of disaster agencies and communities help to highlight how decision-makers perceive flood-related risk and vulnerability, and how these perceptions impact disaster preparedness and risk communication. These insights, paired with additional holistic analysis for hazard planning and management, are critical for developing proactive preparation and response strategies.  We will discuss the current state of anticipatory actions related to disaster management, followed by current barriers and potential opportunities toward reduction of disaster impacts and community vulnerability.

How to cite: Block, P., Southard, K., Lee, D., and Bazo, J.: Emerging Opportunities and Challenges of Anticipatory Actions for Disaster Preparedness, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4574, https://doi.org/10.5194/egusphere-egu23-4574, 2023.

Awash River is the most utilized river basin in Ethiopia. The basin has a total of 110,000 km². The water resources are exploited for various competing needs; domestic, agriculture, livestock's, energy, industry and environment. This study is aimed at enhancing the existing water resources management practices to make them climate resilient in light of climate variability and change. Frequent rainfall extremes, floods and droughts, an imbalance in water availability and demand, water over use in irrigated fields, water use competition and water quality deterioration are the key water management challenges of the basin. Small scale food producers reliant on rain-fed agriculture, small scale irrigators, pastoral and semi-pastoral communities are vulnerable to climate variability and experiencing its impact already. This study identified that their livelihoods are being impacted due to rainfall failure to produce adequate production in the growing period and shortage of fodder for their cattle due to limited soil moisture availability. Based on the identified problems and the existing water management practices, this study developed a conceptual framework, that encompass Climate Smart Water Management (CS-WM) definitions, CS-WM strategies, actions and recommendations to enhance the existing practices on multiple spatial scales. The proposed strategies briefly include improving data and information for more adaptive water resources planning and management, raising awareness and community engagement for improved water management; enhancing effectiveness of water management via technology and innovations, and enhancing alternative clean energy sources to support economic development while minimizing negative consequences of climate variability and change. The strategies and recommendations proposed are tailored to site specific locations and based on societal needs that could solve the identified water management problems and manage tradeoffs among different sectors in the basin.

How to cite: Taye, M. T., Tekleab, S., Geressu, R. T., Alemu, M., and Seid, A.: Strategies for Climate Smart Water Management in Awash River basin, Ethiopia, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11769, https://doi.org/10.5194/egusphere-egu23-11769, 2023.

Water resource management strategies are often identified and evaluated using performance metrics within a simulation-optimization framework. These metrics are likely to have varying levels of sensitivity to input variables such as inflows, model-related choices, and errors from the implementation of the strategies. Quantifying the sensitivity of the performance metrics to the aforementioned uncertain factors may therefore be useful for decision-makers in understanding the relative importance of these factors and their interactions. Furthermore, the total variation in the performance measures, arising as a consequence of the uncertain factors, may be useful to quantify the stability of the performance measures. Here, we quantify the first, second, and total order sensitivity of the performance metrics to uncertain factors using Sobol’s variance-based sensitivity analysis. The stability of the performance metric is quantified as the coefficient of variation of the metric evaluated for varying input factors.

We then assess these sensitivity and stability indices for four performance metrics of the multi-purpose Nagarjuna Sagar reservoir, the largest reservoir in the Krishna river basin in southern India. The reservoir supplies water to meet irrigation, industrial and domestic demands while also generating hydropower with an installed capacity of 810MW. The performance metrics evaluated in this study are: (i) maximize hydropower generation, (ii) maximize the reliability of maintaining minimum environmental flows, (iii) maximize the reliability of avoiding high flow exceedance, and (iv) minimize demand deficits. We identify the Pareto approximate set of reservoir operation strategies using evolutionary multi-objective direct policy search (EMODPS), which employs a state-aware operating rule based on radial basis functions. We consider the following uncertain factors in our analysis: (i) the length of the planning horizon (varied from 1 to 15 years), (ii) model timestep (daily, 15-day, monthly timesteps), (iii) imperfect operations while applying optimized strategies, (iv) stochastic and deep uncertainties related to inflows. Our results show that the objective related to hydropower generation is the most sensitive to the model choices. In contrast, high flow non-exceedance reliability, demand deficits, and minimum environmental flow reliability objectives are most sensitive to deep uncertainties in inflows. We find that hydropower generation, environmental flow reliability, and demand deficits are not sensitive to the interaction effects of these factors. On the other hand, high flow non-exceedance-related objectives are sensitive to the interactions between deep uncertainties and model uncertainty. We also find that the first-order sensitivity indices can be calculated with a greater confidence level than the total-order sensitivity indices. We identify that the flood reliability objective is the most stable, and the demand deficits objective is the least stable when subjected to uncertainty. Our framework can be used to identify the relative importance of the uncertain factors and the stability of the performance measures in any water management problem.

How to cite: Molakala, M. and Singh, R.: Quantifying the sensitivity and stability of the performance of a multi-purpose reservoir to model, inflow, and operational uncertainties , EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-630, https://doi.org/10.5194/egusphere-egu23-630, 2023.

Obtaining optimal reservoir operation policies is a challenging task and a strategic concern for policymakers. These policies are typically derived through a complex decision-making process with conflicting objectives, represented by nonlinear, nonconvex and multi-modal functions. The information on available inflow and various demands play a key role in developing optimal operation rules. However, they are characterized by various uncertainties which reduce the practical applicability of deterministic policy solutions. In literature, most of the studies handle streamflow uncertainty with single-demand scenarios. Although Stochastic Dynamic Programming (SDP) is a widely-used method for reservoir operations optimization under uncertainty, it suffers from the dual curses of dimensionality and modeling. This study considers the uncertainties for streamflow and various demands such as municipal, industrial, hydropower and irrigation water requirements. Here, we present a reinforcement learning framework that utilizes uncertainty-aware streamflow forecasts and demand requirements to yield optimal operation policies for Sardar Sarovar Dam, India. The proposed methodology incorporates the uncertainties of the underlying inflow and demand behavior, and demonstrates better performance than SDP in terms of net benefit. Overall, this work offers reliable techniques that can be used to develop multi-objective reservoir operation policies which are more adaptable in real-time.

How to cite: Upadhyay, D., Dubey, S., and Bhatia, U.: Deriving optimal single-reservoir operating policies with reinforcement learning based approach incorporating uncertainties of demand and streamflow, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-776, https://doi.org/10.5194/egusphere-egu23-776, 2023.

Mountains are an important source of freshwater for ecosystems and the livelihoods of around two billion people worldwide. However, this abundance of water resources is jeopardized by climatic and socioeconomic changes, particularly in the tropical Andes which are considered one of the most vulnerable regions to these impacts worldwide. Those changes not only impact water availability for local populations but also contribute to the declining health of the aquatic ecosystems reducing their provision of services to society. Adaptive water management has emerged as a concept to address such social and environmental challenges. However, there is limited information on how such an adaptive approach can be systematically implemented. Other important challenges in mountain regions include data scarcity (e.g. hydroclimatic or socioeconomic data), knowledge gaps (e.g. groundwater contribution to total runoff), and uncertain future climatic and socioeconomic changes (obtained from e.g. climate models or socioeconomic projections). All these knowledge gaps and limitations lead to deep uncertainties in water policies, the condition where experts do not know or cannot agree on which initial conditions and corresponding results are most relevant.

To deal with such deep uncertainties we tested the Exploratory Modeling and Analysis (EMA) framework to support adaptive water management. Therefore, we set a case study in the high-Andean Pitumarca catchment in the glaciated headwaters of the Vilcanota basin, Southern Peru. Three policy options were assessed along a large set of uncertainties to achieve water security for human and environmental needs by 2050. A total of 12,000 simulations were run, driven by three climate scenarios (SSP1-1.9, SSP1-2.6, and SSP5-8.5) and 15 climate models, and a wide range of irrigation and domestic water use scenarios.

Results from the applied EMA framework show that in 43% of simulations (5,182) the water system failed to supply water for human and environmental needs mostly driven by the way of implementation of water policies than by climatic or socioeconomic changes. The implemented framework also contributed to identify that a two combination of improvements of irrigation efficiencies and reservoir schemes can avoid system failures under a wide range of changes and uncertainties. These results highlight the importance of focused policy actions to deal with climatic and socioeconomic changes. Such a framework facilitates moving from traditionally broad problems that center on the impact of climate change to more specific and locally tailored questions, e.g. which reservoir scheme should be implemented to avoid system failure. In order to reduce uncertainties and optimize local water use, EMA should be combined with other methods such as citizen science, sensitivity analysis, joint knowledge production. Furthermore, EMA should be implemented through semi-distributed glacio-hydrological models to fully combine the advantages of different approaches and assess the spatio-temporal occurrence of water demand. We also encourage the use of socio-hydrological models where socioeconomic and environmental factors can actively interact.

How to cite: Muñoz, R., Vaghefi, S., Drenkhan, F., Santos, M. J., Viviroli, D., Muccione, V., and Huggel, C.: Exploratory modeling and analysis to inform adaptive water management under deep uncertainty in the Peruvian Andes, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9180, https://doi.org/10.5194/egusphere-egu23-9180, 2023.

The Netherlands is a low-lying country situated in the Rhine-Meuse delta. A significant portion of the Netherlands is located below sea level, making the proper management of local and national waterways essential. Polders are used to manage groundwater levels, drain excess rainwater, and store water during times of drought. These polders often have pumping stations that pump water into drainage canals, like the Noordzeekanaal-Amsterdam-Rijnkanaal (NZK-ARK), which receives water from the Rhine river and four local water authorities and connects to the North Sea at IJmuiden through a pumping station and a series of undershot gates.

The operators of the NZK-ARK utilize Model Predictive Control (MPC) to schedule the discharge of water through the gates and pumps. The combination of the pump and gate discharge allows the NZK-ARK to discharge excess water to the North Sea when the sea water level is both higher and lower than the water level in the canal. However, traditional MPC can lead to suboptimal schedules when uncertainty is introduced, resulting from, for example, incoming discharge, fluctuating electricity prices, and the availability of renewable energy. Stochastic MPC allows for the consideration of uncertainty in decision-making, optimizing control actions based on a range of potential scenarios. In the future, the objectives for the control system of the gates and pumps may become more complex and may need to take into account factors like renewable energy availability and electricity prices. Ensuring the effective and efficient management of water in the Netherlands is critical, and the use of polders for water storage and control of groundwater tables, and techniques like MPC and stochastic MPC play important roles in achieving this goal.

In this study, we present a framework that combines probabilistic forecasting, scenario generation and reduction, and stochastic MPC to minimize energy costs associated with pumping at the NZK-ARK. This framework is based on probabilistic forecasts of electricity prices and incoming discharge and is specifically designed for use at the NZK-ARK. By considering the uncertainty present in electricity prices and incoming discharge, our framework allows for the optimization of control actions through the use of stochastic MPC. The ultimate goal of this approach is to reduce energy costs at the NZK-ARK by effectively managing the discharge of water through the pumps and gates while complying with local constraints.

How to cite: van der Heijden, T., van de Giesen, N., Palensky, P., and Abraham, E.: A stochastic MPC framework for the control of pumping stations in polder systems with regard for uncertainty in inflow and hourly electricity prices, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6203, https://doi.org/10.5194/egusphere-egu23-6203, 2023.

Decision analysis techniques to meet water systems management challenges under climate change uncertainty have improved with advances in computational technology in the last decades. Infusing improved design and decision analysis techniques in developing countries can be of paramount importance given their higher vulnerability to climate change, fewer professionals with sufficient capacity, and generally high incentive for rapid expansion of low-cost solutions.  However, a large gap exists between scientific progress and practical and policy applications, especially in global south countries. In this paper we discuss the observed challenges in design, analysis and decision making process to achieve climate smart water management in the highly utilized Awash Basin of Ethiopia. The approach we followed is key-informant interviews with water professionals working across multiple disciplines (i.e., water supply, irrigation, hydropower infrastructure design) and working for different organizations (i.e., government ministries, research institutions, consultancy offices) and freelancers and academicians. Efforts were made to represent informants from different academic levels, gender, and professional responsibilities. The results demonstrate multiple but related challenges including the lack of incentive to apply changes at individual or institutional levels, cultural and policy inertia against transparency and public debate in decision making. Technical challenges emanate from the non-inclusion of up-to-date climate change science at higher education level along with lack of access to computational and communication technology. We present tailor made decision support tools to improve management by leveraging advances in computational and visualization of large data to reveal tradeoffs and synergies of water and food systems at multiple watershed scales.  Efficient and timely solutions for vulnerable small-scale producers can be best achieved by changing the role of institutions to reflect local capacity in the water system management sector.  Proposed solutions to help tackle these challenges include overhaul of the skill requirement for water resources professionals along with continuous skills training and evaluation.

How to cite: Seid, A., Geressu, R., Tekleab, S., Alemu, M., and Taye, M. T.: Enhancing decision making tools for climate-smart water management in the Awash Basin, Ethiopia., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11772, https://doi.org/10.5194/egusphere-egu23-11772, 2023.

Dynamic operation of urban water infrastructure has many times been demonstrated as an efficient way to manage storm- and wastewater flows with a minimum of cost and material resources, and to improve the health of surface water environments by reducing, for example, combined sewer overflows. Adopting dynamic, real-time control strategies become even more important as climate change is challenging existing water infrastructure with increasing precipitation intensities and volumes. Nevertheless, urban water managers are hesitant to adopt such strategies and rather fall back to upgrading the infrastructure with e.g. underground basins and tunnels. Based on a series of semi-structured interviews and workshops with operators and planners from six Danish utilities, we can demonstrate that many aspects make utility employees feel uncomfortable with dynamic control schemes, e.g.:

• lack of knowledge on the environmental improvements that can be achieved with dynamic operation
• lack of understanding of the algorithms in applied control schemes
• lack of experience with dynamic operation
• lack of knowledge of the effect of system changes (e.g. construction work) on the dynamic control performance
• lack of collaboration across different departments within the utility
• lack of motivation from the operators

Furthermore, there is a general lack of time of the interviewed employees to engage in these aspects.

While the identified issues span across different stages of the planning and operation process, several issues (such as the lack of knowledge on potential environmental improvement, or the lack of collaboration between disciplines) arise in initial planning stages where strategic decisions are made. For this purpose, we have developed an automated screening approach for the potential environmental effects of dynamically operating urban water systems, where the approach and visualizations were developed iteratively and in close collaboration with the stakeholders.

Environmental improvements are in scientific literature often reported for the entire catchment (e.g. the total potential overflow volume reduction); however, a key learning from our work is that the environmental effects need to be visualized for each individual control point in the system. This makes it much more tangible for stakeholders to compare the potential environmental effect with the needed effort and cost, and the detailed result visualization of the dynamic control thus aligns much better with the decision-making process of the stakeholders. Furthermore, the stakeholders prefer simple, understandable control algorithms, even if these don’t fully exploit the potential of dynamic operation. This preference stands in direct contradiction to academic literature, which focuses on advancing control algorithms rather than making sure that existing algorithms are implemented.

Our results are currently implemented in a dashboard for screening the potential of dynamic operation of urban water systems, and will form the basis for generic rule-based operation strategies for urban water systems.

How to cite: Kirstein, N., Rungø, M., and Löwe, R.: Reasons for urban water utilities’ hesitance towards dynamic system operation – and solutions to mitigate these, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4178, https://doi.org/10.5194/egusphere-egu23-4178, 2023.

NASA has launched a new initiative; the Open-Source Initiative (OSSI) to enable and support science towards openness. The OSSI new initiative supports open-source software development and dissemination. This presentation highlights an open-source platform (i.e., NASAaccess) for accessing, reformatting, and presenting quantitative remote sensing earth observation data products. The main objective of developing the NASAaccess platform is to facilitate exploration, modeling and understanding of the data for scientists, stakeholders, and concerned citizens aligning with the new OSSI initiative goals. NASAaccess platform is available with an open-source software packages (i.e., R and python libraries), and an interactive format web-based environmental modeling application for earth observation data. NASAaccess software program is also linked to various downscaled climate change data products processed by NASA. The NASAaccess web application development and hosting environment is based on Tethys Platform (Swain et al., 2016). NASAaccess current capabilities (v.3.3.0) covers various NASA datasets and products that include the Global Precipitation Measurement (GPM) data products, the Global Land Data Assimilation System (GLDAS) land surface states and fluxes, and the NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP) CMIP5 & CMIP6 climate change dataset products. NASAaccess installation instructions and documentations along with tutorial materials are available at Open Science Framework repository ‘NASAaccess Home’ (doi:10.17605/OSF.IO/CTJ2K).

How to cite: Mohammed, I., Romero, G., Bolten, J., and Nelson, J.: NASAaccess – earth observation data tool, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1266, https://doi.org/10.5194/egusphere-egu23-1266, 2023.

Over the last few years, the Water-Energy-Food (WEF) Nexus has been brought forward by scientists as a novel way of analysing the interconnectedness of global resources systems, and by policy makers as an approach to achieving water, food and energy security while preserving the environment.  Implementing such an integrated thinking is crucial for the Mediterranean, a region characterised by increasing demand for food and energy, and vulnerable to water scarcity, impact of climate change and degradation of natural ecosystems.  Through an integrative review of scientific literature, we examined the evolution of Nexus research in the Mediterranean in terms of critical interlinkages being investigated, explored topics, methods and scales of analysis, and context of operationalizations. The 136 reviewed articles revealed that (a) water-energy interlinkages dominates Nexus research in the Mediterranean, driven by the need of satisfying water demands for drinking and irrigation through energy-intensive water resources; (b) the expansion of Nexus thinking to additional components is mostly limited to assessing the impact of Nexus sectors on the physical environment and the climate, without capturing feedback dynamics; (c) there are only few Nexus studies working  at the entire Mediterranean scale which would provide a much needed contextual setting to the impact of isolated case studies; (d) there is promising evidence that Nexus research in the Mediterranean is going beyond the biophysical dimension to encompass socio-economic interactions and governance aspects; yet, (e) their analysis often remain segregated in silos because of a limited integration of methods across disciplines; (f) Sustainable Technology and Natural Resources Management are the key drivers of Nexus research operationalization and would  benefit from an harmonisation to coherently advance Nexus implementation in the Mediterranean region. This review concludes that Nexus research in the Mediterranean would benefit from an integration of the knowledge developed so far in multi-scale, multi-sector, and multi-dimensional frameworks, which would be capable of supporting technological, socio-economic and governance interventions.

How to cite: Lucca, E., El Jeitany, J., Castelli, G., Pacetti, T., Bresci, E., and Caporali, E.: A Review on the Water-Energy-Food-Ecosystems Nexus Research in the Mediterranean: Evolution, Gaps and Applications, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-856, https://doi.org/10.5194/egusphere-egu23-856, 2023.

Climate change increases the frequency and severity of droughts in Central Europe and thereby threatens food production in the German agricultural sector, which is mostly rain-fed and heavily dependent on precipitation. Farmers need to adapt to these changing conditions, for instance by shifting to irrigated production systems. This increases the future agricultural water demand and may result in competition for water use and higher groundwater depletion. Simultaneously, farmers adapt their land-use patterns towards an optimal crop mix, responding to changes in climatic and economic conditions. This land-use adaptation also affects the irrigation water demand.

To project the future irrigation water demand in Germany considering land-use adaptation, we present the spatial multi-agent system (MAS) model DroughtMAS which simulates agricultural land-use adaptation of the 8 major field crops using a positive mathematical programming (PMP) approach. Each agent captures the behavior of farmers in one of Germany’s 401 NUTS-3 regions, is individually calibrated to the observed production conditions for a 20-year historic average, and is empirically validated for the same period. Therefore, the agent-based structure portrays the agroeconomic and biophysical heterogeneity of Germany. To consider uncertainties concerning future climate change levels and socioeconomic developments, we project the future land-use adaptation and irrigation water demand using integrated RCP-SSP scenarios. To this end, the MAS model is coupled to a statistical crop yield model driven by meteorological indicators and soil moisture, derived from the mesoscale Hydrologic Model (mHM). Projections of the agricultural crop prices are based on the SSP scenarios. The integrated hydro-economic model consequently reflects the adaptive behavior of agents responding to changing crop yields and prices.

The results emphasize the importance of accounting for land-use adaptation to accurately project farmers’ irrigation water demand and to consider changes in biophysical and socioeconomic variables simultaneously. Such estimates are crucial in planning for future agricultural water demands to prevent user conflicts and water resource depletion.

How to cite: Heilemann, J., Nagpal, M., Klassert, C., Peichl, M., Klauer, B., and Gawel, E.: From rain-fed to irrigated agriculture? Projecting the future irrigation water demand in Germany using a hydro-economic multi-agent system model, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6034, https://doi.org/10.5194/egusphere-egu23-6034, 2023.

Groundwater user groups in Tunisia face severe collective action problems. Aquifer depletion leads to empty wells and farmers’ unwillingness to pay water fees leads to bankrupt user groups – both disastrous for the many communities that rely on irrigation agriculture for their livelihoods. What conditions or combination of conditions drive water user behaviour in a system that is governed by institutional uncertainty and bounded rationality? What conditions or interventions are effective in avoiding or delaying system collapse? What is the role of social norms, particularly trust and leadership, in overcoming collective action problems? Based on and expanding on the theory of common pool resource governance, this paper ties institutional results to environmental outcomes. The complex common-pool resource system studied here is simulated by an Agent-Based Model (ABM) of groundwater user decision-making. This systematic coupling of social and biophysical data and models offers new insights into simulating dynamic interactions between human behaviour, social norms, and the underlying resource. The project aims to provide a guideline for alternative modes of policy-making and implementation to address the main water governance challenge in Tunisia, i.e. groundwater overexploitation. 

How to cite: Erfurth, S., Wildemeersch, M., Baggio, J., Sahu, R. K., and Garrick, D.: Governing Common Pool Resources in Fragile Political Systems: Modelling Behaviour, Institutions, and Social-Ecological Dynamics, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10277, https://doi.org/10.5194/egusphere-egu23-10277, 2023.

Wastewater treatment removes water pollutants and wastewater reclamation provides an alternative water supply. It is believed that increasing the rate of wastewater reuse and reclamation can reduce water stress. This study aims at understanding whether reusing more wastewater can help mitigate water stress in China. Through scenario analysis, it is found that the potential for reuse of reclaimed water under a water conservation scenario is only 12-56% of the actual situation, but regional water stress under a water saving scenario is 10-82% lower than the current reality. The results show that a higher amount of reclamation does not necessarily lead to a lower water stress in one region. The potential for wastewater treatment and reuse is determined by return flows, which can reduce water use efficiency and exacerbate water stress. To effectively alleviate water stress, it is important to not only increase wastewater reuse, but also prioritize water conservation.

How to cite: Wang, D., Sahu, R. K., Kahil, T., Tang, T., Shan, Y., and Hubacek, K.: The more wastewater reclamation, the less water stress?, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11240, https://doi.org/10.5194/egusphere-egu23-11240, 2023.

The management of water resource in China has been under pressures due to rapid socioeconomic growth that escalates the demands in food, energy and domestic sectors, which rely on reliable water provision. Together with climate change, water security is expected to face greater uncertainty in the future. To support sustainable water resource management, this study established a system dynamic model to investigate the impacts of policy, socioeconomic and climate change on water security in China during 2025 to 2100. Five policy options related to carbon neutrality and water management, three socioeconomic and climate scenarios (SSP1-RCP2.6, SSP2-RCP4.5 and SSP5-RCP8.5) were considered. The results show that water demand and water resource will both be greater in the future. Under BAU, water demand will reach 514, 544 and 717 km³ while water resource will increase to 989, 992 and 1032 km³ in 2086-2100 under SSP1-RCP2.6, SSP2-RCP4.5 and SSP5-RCP8.5, respectively. Future water demand for food sector is expected to decrease slightly and then increase under SSP1-RCP2.6, while it shows continuous increase under SSP2-RCP4.5 and SSP5-RCP8.5 due to the changes of planted area, livestock and temperature. Water demand for domestic sector will decrease under three SSP-RCPs because the population will reach a peak around 2030 and then decrease with time. Water demand for energy is expected to decrease under SSP1-RCP2.6 while it will increase under other SSP-RCPs because of more energy demand under SSP2-RCP4.5 and SSP5-RCP8.5. China may face low water security pressure without policy intervention in the future especially under SSP5-RCP8.5. The analysis shows that bioenergy-oriented agriculture cannot mitigate water scarcity risks in China, while low-carbon agriculture strategies can potentially ensure water safety under carbon neutral goal. Water scarcity can be averted if we follow the development path of SSP1-RCP2.6 as well as apply interventions on water management combining with carbon neutral policies that focus on low-carbon agriculture and supplemented by low fossil energy.

How to cite: Gao, D., Chen, A. S., and Memon, F. A.: Modelling the impacts of policy, climate and socioeconomic change on water security in China, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1572, https://doi.org/10.5194/egusphere-egu23-1572, 2023.

Arid and semi-arid regions such as the Middle East and North Africa are increasingly suffering from water scarcity, exacerbated by climate change and population growth. This trend calls for new strategies for managing water demand and supply to face global changes in social-economic development, water system expansions, and cross-border differences.

In this work, we explore the potential to mitigate the existing conflicts over the Nile River Basin, interconnecting water demand and supply using novel technological solutions, such as desalination and aquaponics, combined with traditional uses (i.e., groundwater extraction and water reuse). We analyse the complex dynamics and tradeoffs between energy production and irrigation water supply in Ethiopia, Sudan, and Egypt. We propose innovative portfolios of interventions that combine the coordinated operation of large water dams (i.e., the Grand Ethiopian Renaissance, Merowe, and High Aswan) and the main irrigation diversions with smart water demand management options. Desalination involves the process of removing salt and other minerals from seawater, making it suitable for irrigation and other domestic uses. Aquaponics involves the cultivation of fish and plants in a symbiotic environment, with the waste produced by the fish providing nutrients for the plants and the plants purifying the water for the fish. This technology can be an efficient and sustainable way to produce food with very low water consumption.

Our approach is used to study current and future tradeoffs, generating solutions that are efficient and resilient to future hydroclimatic and demographic scenarios. We first quantified the impacts of dynamically downscaled and bias-adjusted climate projections for three Representative Concentrated Pathways (i.e., RCP2.6, RCP4.5 and RCP8.5) on the runoffs of the main tributaries of the Nile. We also considered stochastic projections of water demand based on Shared Socioeconomic Pathways (SSPs), and a strategic model that reallocates crops according to future climatic and demographic scenarios, according to a balanced diet and agricultural intensification strategy to generate a positive impact on food self-sufficiency.

Our results show that the Nile River Basin features both strong tradeoffs and synergies across riparian countries, with the irrigation supply in Sudan playing a major role in allocating water between competing sectors. The results show a decrease of up to 20% of the Nile River's runoff and a doubling of the Egyptian municipal demand in the most severe scenario that leads to exacerbating tensions between the three countries. Notably, the potential reduction of the Egyptian water demand through different combinations of aquaponics, desalination, reuse, and groundwater pumping in the Nile Delta, along with a substantial decrease in Sudan irrigation demand through crop reallocation, can contribute to mitigating existing and future conflicts. Further technological improvements are needed for attaining large water demand reductions via soilless agriculture and desalination, which today cannot completely substitute reuse and groundwater contributions, whose high exploitation can induce relevant environmental risks.

How to cite: Piuri, V., Matta, E., Yang, G., Giuliani, M., Papagiannis, G., Yannacopoulos, A., Sardo, M., Chiarelli, D. D., Rulli, M. C., Kondouri, P., and Castelletti, A.: Closing the loop between water supply and demand in the Nile River Basin under global change, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13969, https://doi.org/10.5194/egusphere-egu23-13969, 2023.

Colorado River Basin faces a supply crisis that makes the water system vulnerable to failure, economic losses, conflicts between regions and water users, and ecosystem degradation. The crisis results from water management that allows excessive water withdrawals, legal restrictions established on historical facts, and decreased water availability due to climate change. The agricultural sector, urban centers, hydropower production, and aquatic ecosystems compete for the exhaust water resources in the basin. Despite the reduction in per capita urban water usage and reduction of irrigated land, projections of population and economic growth and increasing crop evapotranspiration indicate an expansion of water demand. The shrinking water availability and growing demand for water will exacerbate existing problems, hampering water management. This article evaluates several alternatives to water management to identify the sectoral and spatial trade-offs of water use by the agricultural sector, urban centers, hydropower production, and aquatic ecosystems. A hydro-economic model is developed to assess current and alternative water allocation’s economic impact on drought, climate change, and growing population. The model examines coalition arrangements among some or all basin states, Tribal Nations and Mexico and the implementation of institutional reforms such as water markets, proportional sharing, and mechanisms that promote water savings. The development of existing but unused Tribal Nation rights is analyzed to evaluate its impact and to determine the potential for new agreements. Simulation shows that shrinking water allocation promotes efficiency improvements and strengthens the sustainability of the water system. However, droughts and climate change erode the benefits of water use and environmental conditions. Reductions in hydropower generation results in economic losses and higher greenhouse gas emissions. Urban centers endure heavy welfare reductions due to water use restrictions, but purchasing water from irrigation districts alleviates the burden and enhances the social surplus. Water markets and cooperation mitigate benefit losses but increase the pressure on ecosystems. Water exchange and side payments (for improved water savings) between states and irrigation districts indicate potential improvements in water use efficiency. Crops with high economic value that are irrigated with advanced technologies are maintained in production. Instead, field crop producers suffer from water shortages. Improvements in irrigation technology reduce the risk of exposure to water scarcity but curtail water returns than sustain ecosystems and downstream activities. Maintaining tribal Nations' rights and establishing environmental flows rectify the inefficient use of water by other users.

How to cite: Crespo, D., Nemati, M., Dinar, A., Frankel, Z., and Halberg, N.: Policies to Achieve Sustainability in the Colorado River Basin under Climate Change Conditions and Growing Demand: A Hydro-economic Analysis, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8152, https://doi.org/10.5194/egusphere-egu23-8152, 2023.

Economic analysis has considerable power to guide a number of water development proposals to inform climate adaptation planning.  Much work has appeared in recent years on valuing water resources to support that planning, but little theoretically rigorous analysis exists on valuing resources in over a wide range of physical and economic conditions in a general equilibrium setting.   Moreover, no published work to date has solved the inverse problem of inferring the parameters of a system of water production functions when observed data are constrained by a single observation.  This paper addresses an important inverse problem in water economics, namely the process of inferring from a single observation on land and water use the parameters of the underlying production functions. It solves an inverse problem by going from data on observed factor use, factor prices, commodity production, and commodity prices to the underlying production function parameters.  From the recovered production function parameters, marginal values of water are calculated over a wide range of water supply and economic conditions.   An example is illustrated for land and water development planning in the American Southwest.  This paper’s original contribution can inform policy debates internationally over competing proposals for climate adaptation planning.

How to cite: Ward, F.: A Simple Method of Water Valuation for Climate Planning, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10363, https://doi.org/10.5194/egusphere-egu23-10363, 2023.

Prespa Lakes is a transboundary (Greece-Albania-North Macedonia) aquatic ecosystem with a unique ecological value that includes a great variety of habitats and life forms, endemic and rare species. The water quality of this ecosystem is essential to sustain ecosystem services, as well as local economic activity. Climate change may lead to a potential decrease in water quality and availability, increasing the competition among the different water users. Integrated water management and policy approaches that will engage all competing water users is the answer to achieve the sustainability of sensitive and high-value aquatic systems, as the one found in Prespa Lakes. This challenge is even greater when these aquatic systems are transboundary and belong to the Natura2000 network.

Recognizing the need for a rational management of high-value water ecosystems, the Greek administration adopted, in 2020, a new governance system, with the establishment of the Natural Environment and Climate Change Agency (NECCA), an agency responsible for all the protected areas in Greece, with an emphasis on the conservation and protection of biodiversity in the 446 Natura2000 sites in the country . Within this new administrative system, all 446 Natura2000 sites are grouped into 24 decentralized protected area units (DPAU) and at each DPAU, a Local Management Committee (LMC) is appointed, in order to  bring together all interested stakeholders at local level such as regional and municipal authorities, technical economic chambers, forest management authorities, environmental NGOs and professional associations. The LMC functions as a consultation body to the DPAU. Its primary focus is on the implementation of the relevant protected area management plan and monitoring scheme, for the conservation of protected habitats and species, but it also participates in every other action related to sustainable development, mitigation and adaptation to climate change. Special concern will be given to actions related to water quality, food production, ecosystem health and climate resilience, as critical elements of WEFE Nexus.

In this frame, climate resilience of all environmental, economic, and social sectors related to water use is analyzed in the Orhid/Prespa Lakes ecosystem as a whole, to secure a balanced use of available water resources in this transboundary ecosystem. A System Innovation Approach is implemented through the development of Working Groups functioning at national level followed by a transboundary Living Lab focusing on water scarcity issues. Stakeholders related to water management and representing all sectors at local level take part in these Working Groups and in the transboundary Living Lab to shape common pathways of innovations on climate adaptation and resilience. It is envisaged that the results will support the work of the LMC, as well as that of the transboundary Prespa Park Management Committee, and could also be transferred, by NECCA, to other protected areas with similar ecosystem characteristics, and challenges.

How to cite: Papadopoulou, M. P., Roussos, O., Papadopoulou, L., and Hatzilacou, D.: WEFE Nexus governance approach to tackle water management issues in a transboundary aquatic ecosystem, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1708, https://doi.org/10.5194/egusphere-egu23-1708, 2023.