Water, energy, and food resources are closely related in the water-energy-food (WEF) nexus, a tightly connected system in which impacts in one sector leads to changes in the other sectors. The WEF nexus approach studies these interactions to better understand their connections and implications across sectors, and is focused on making research practicable for policy. There is a clear lack of policy coherence studies to provide practical recommendations to achieve integrated resources management. This is true in the Tana River Basin (TRB), which provides abundant water, energy and food resources to the national economy and development of Kenya. This work carried out a WEF policy coherence assessment of the Tana River Basin. Results show that there are synergies and trade-offs across all resources sectors and their policy objectives. Water policies (e.g. to secure water availability) are generally evaluated as win-win, thus being supportive of attainment of goals in other policy sectors. Food policies (e.g. to develop the agricultural sector) show the highest number of trade-offs, suggesting these policies could be redesigned to minimise the trade-offs with other resource policies. This work highlights specifically which policies are relatively more or less supportive for holistic resources management in the TRB. In particular, the only TRB-level policy analysed (which is cross-resource in its ambition) shows synergies with national policy, offering opportunity for leveraging benefits and increasing implementation efficiency across resources. Strengthened cross-sectoral collaboration, joint workshops, and the establishment of a national cross-sectoral taskforce to develop aligned policies are recommended. This work provides a basis for similar studies across Africa, and promotes research that is of practical relevance.

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The need for an integrated approach to sustainable resources management to achieve the Sustainable Development Goals has become widely recognized. Population growth, climate change, environmental degradation, and scarcity of resources have been identified as the major factors affecting society’s future. Given the fundamental societal needs for food, energy, and water, the Water–Energy–Food (WEF) nexus has emerged as a useful sustainable resource management framework and has been widely applied. However, in the Middle East and North Africa (MENA) region, there have been relatively few studies that adopt a nexus approach. In this study, the Ain Temouchent region in Algeria is used as a WEF Nexus case study. The region has a strong agricultural-based economy and the increased intensity of agricultural production in the region has resulted in the overuse of groundwater resources. Establishing a reverse osmosis desalination plant with a daily production capacity of 200,000 m³ significantly alleviated the resulting water crisis, yet its energy consumption and environmental impact raise several questions. This study identifies the critical links between the WEF sectors and using this understanding, the dynamics between them are assessed using System Dynamics Modelling. The study reveals that any further increase in agricultural production in Ain Temouchent may lead to excessive use of groundwater resources. Although desalination can help alleviate the water crisis, its high energy consumption raises concerns. The analysis shows that the use of surface water and recycled wastewater for irrigation could be possible alternatives. The study emphasizes the value of adopting a WEF nexus approach to achieve a balance between agricultural development, energy sustainability, and water resource management in the Ain Temouchent region.

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This research explores the limitations and opportunities of Water Accounting Plus (WA+) for addressing water management issues in the MENA, focusing on Jordan. A comprehensive literature review and interview-based analysis were conducted to identify prevalent water management issues and evaluate information used in decision-making and strategy appraisals. The findings suggest that WA+ can enhance the spatio-temporal coverage of water resource assessments, refine estimates of irrigation water consumption, and facilitate demand management. Quantifying recharge and surface runoff requires integrating WA+ with hydrological models. Addressing climate change’s impact on future water resources requires integrating climate change projections with WA+.

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The high spatial variability of precipitation, heightened frequency of droughts and concomitant increases in exposure to water stress across southern Africa due to climate change, presents significant challenges for sugarcane production and the regional sugarcane production value chain. While production has intensified in the past few decades, yields have declined due to increased climatic variability and agronomic management approaches. Increased precipitation variability has enhanced sugarcane vulnerability to water stress and is likely to negatively affect yields. Combining crop simulations and relationships between sugarcane water use and observed rainfall, we introduce a crop productivity ratio (CPR) which assesses sugarcane water stress for six sugarcane mills across southern Africa. The CPR and simulation results were used to assess the adaptation potential or ‘space’ for mill areas that have varying rates of exposure and abilities to adapt to water stress. Simulation results were used to determine the long-term adaption potential of mill areas and to surmise the causes of yield declines. The results were used to offer recommendations to reduce vulnerabilities and enhance adaptation to water stress. We conclude that the amplification of inter-annual precipitation variability will enhance the exposure of sugarcane to water stress and require adaptation interventions. Adapting to external shocks is a multifaceted exercise that requires a holistic approach that includes every aspect of the sugarcane value chain.@en

Attention on the use of transboundary aquifers (TBAs) and their cross-border impacts is growing as countries become increasingly concerned about their long-term water security. Cross-border impacts, in groundwater quality and quantity, tend to concentrate in specific parts of TBAs, as they largely depend on the transboundary flow dynamics where anthropogenic actions operate. Thus, there is a growing consensus that strategies intended to prevent or mitigate such impacts should be implemented in strategic zones rather than in the whole TBA. These transboundary groundwater management zones (TGMZs) are relatively recent but have become a prominent topic in TBA management. However, until now, limited effort has been put into exploring the concept of TGMZs and the methods for their delineation. This research aims to fill these gaps and provide a basis for the delineation of TGMZs, thus helping neighbouring countries meet international responsibilities regarding the right to use and enjoy groundwater in TBAs. By reviewing academic and grey literature accessible from public sources, we present an overview of the concept and terminology of TGMZs, the approaches proposed for their delineation, and current operating examples. Additionally, we build a conceptual framework for assessing cross-border groundwater impacts by identifying their typologies and causal factors. We then apply our framework to evaluate and compare three reported methods which identify and delineate TGMZs from distinct perspectives, thereby gaining insights into their principles, performances, and limitations. Finally, we provide recommendations for further research towards optimising methods for delineating TGMZs.

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Water resources assessments are essential for effective planning in water-scarce regions such as Jordan. Such assessments require sufficient data in space and time. The WaPOR-based Water Accounting Plus (WA +) framework is relevant as it integrates remote sensing data and the Pixel-Based Soil Water Balance model to simulate a basin’s water balance. However, since it relies on remote sensing, this framework only tracks water consumption in irrigated agriculture and does not consider non-irrigation water use and its return flow. This paper modifies the WaPOR-based WA + framework to include non-irrigation manmade consumption and its return flows. The modified framework provides a more comprehensive water budget for the Amman-Zarqa (AZ) basin, presented in a modified WA + resource base sheet for 2018 through 2021. The results show that water availability in the AZ basin is highly responsive to precipitation changes. Average precipitation was approximately 926 Mm³/year between 2018 and 2020, corresponding to an average available water of 485 Mm³/year. However, a reduction in average precipitation by 28% in 2021 corresponded to a reduction in available water to 243 Mm³/year. Nevertheless, substantial groundwater outflows to neighbouring basins may indicate that available water is being overestimated. Manmade consumption increased by 18% from 2018 to 2021, and the total demand exceeded the available supply by 150%. This underscores the pressing need to investigate supply augmentation and conservation methods. Future studies could focus on improving the representation of groundwater dynamics in the modified framework by improving groundwater dynamics in PixSWAB and testing the modified framework with other remote sensing datasets.

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Sugarcane yields have steadily declined across southern Africa for the past 25 years and, despite research into the causes, there has been limited progress in addressing these trends. This study developed a methodology of assessing yield declines and performed a yield gap analysis to assess and develop recommendations to assist in combating yield declines and offering potential safeguards for the sugarcane industry against climatic extremes. Mill areas from South Africa, eSwatini, Malawi and Tanzania were selected, providing a diversity of regional hydroclimatic conditions and sugarcane agronomic management approaches. Using the AquaCrop crop model, maximum potential yields and yield gaps were simulated based on observed climate and yield data spanning 25 years. Results show that yields are declining for the mill areas in South Africa, Malawi and Tanzania, resulting in increased yield gaps, whilst yields are stagnant in eSwatini resulting in relatively fixed yield gaps. Yield gaps remained high across all six mill areas, suggesting that they remain vulnerable and exposed to climatic extremes. Modelling results suggest that these yield trends, including yield gaps, are primarily attributed to existing crop management approaches as opposed to the climatic regimes in these areas. Recommendations include several solutions that could result in an immediate response and reduce yield gaps while increasing harvestable yields. Such measures include increasing technology transfer and agronomic management education to small-scale outgrowers, adopting drought-resistant, high-yielding sugarcane varieties, contouring and mulching, improving soil structural properties and minimizing in-field traffic. The study concludes that if sugarcane growers are to withstand the effects of extreme climatic events, they have to consider shifting crop management approaches and be proactively included in related research.

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Satellite remote sensing (RS) data are increasingly being used to estimate total evaporation, often referred to as evapotranspiration (ET), over large regions. Since RS-based ET (RS-ET) estimation inherits uncertainties from several sources, many available studies have assessed these uncertainties using different methods. However, the suitability of methods and reference data subsequently affects the validity of these evaluations. This study summarizes the status of the various methods applied for uncertainty assessment of RS-ET estimates, discusses the advances and caveats of these methods, identifies assessment gaps, and provides recommendations for future studies. We systematically reviewed 676 research papers published from 2011 to 2021 that assessed the uncertainty or accuracy of RS-ET estimates. We categorized and classified them based on (i) the methods used to assess uncertainties, (ii) the context where uncertainties were evaluated, and (iii) the metrics used to report uncertainties. Our quantitative synthesis shows that the uncertainty assessments of RS-ET estimates are not consistent and comparable in terms of methodology, reference data, geographical distribution, and uncertainty presentation. Most studies used validation methods using eddy-covariance (EC)-based ET estimates as a reference. However, in many regions such as Africa and the Middle East, other references are often used due to the lack of EC stations. The accuracy and uncertainty of RS-ET estimates are most often described by root-mean-squared errors (RMSEs). When validating against EC-based estimates, the RMSE of daily RS-ET varies greatly among different locations and levels of temporal support, ranging from 0.01 to 6.65 mm d−1, with a mean of 1.18 mm d−1. We conclude that future studies need to report the context of validation, the uncertainty of the reference datasets, the mismatch in the temporal and spatial scales of reference datasets to those of the RS-ET estimates, and multiple performance metrics with their variation in different conditions and their statistical significance to provide a comprehensive interpretation to assist potential users. We provide specific recommendations in this regard. Furthermore, extending the application of RS-ET to regions that lack validation will require obtaining additional ground-based data and combining different methods for uncertainty assessment.@en

Remote sensing (RS) data are becoming an increasingly important source of information for water resource management as they provide spatially distributed data on water availability and use. However, in order to guide appropriate use of the data, it is important to understand the impact of the uncertainties of RS data on water resource studies. Previous studies have shown that the degree of closure of the water balance from remote sensing data is highly variable across basins and that different RS products vary in their levels of accuracy depending on climatological and geographical conditions.

In this paper, we analyzed the water-balance-derived runoff from global RS products for 931 catchments across the globe. We compared time series of runoff estimated through a simplified water balance equation using three precipitation (CHIRPS, GPM, and TRMM), five evapotranspiration (MODIS, SSEBop, GLEAM, CMRSET, and SEBS), and three water storage change (GRACE-CSR, GRACE-JPL, and GRACE-GFZ) RS datasets with monthly in situ discharge data for the period 2003–2016. Results were analyzed through the lens of 10 quantifiable catchment characteristics in order to investigate correlations between catchment characteristics and the quality of RS-based water balance estimates of runoff and whether specific products performed better than others under certain conditions.

The median Nash–Sutcliffe efficiency (NSE) for all gauges and all product combinations was −0.02, and only 44.9 % of the time series reached a positive NSE. A positive NSE could be obtained for 73.7 % of stations with at least one product combination, while the overall best-performing product combination was positive for 58.4 % of stations. This confirms previous findings that the best-performing products cannot be globally established. When investigating the results by catchment characteristic, all combinations tended to show similar correlations between catchment characteristics and the quality of estimated runoff, with the exception of combinations using MODIS evapotranspiration, for which the correlation was frequently reversed. The combinations with the GPM precipitation product generally performed worse than the CHIRPS and TRMM data. However, this can be attributed to the fact that the GPM data are available at higher latitudes compared to the other products, where performance is generally poorer. When removing high-latitude stations, this difference was eliminated, and GPM and TRMM showed similar performance.

The results show the highest positive correlation between highly seasonal rainfall and runoff NSE. On the other hand, increasing snow cover, altitude, and latitude decreased the ability of the RS products to close the water balance. The catchment's dominant climate zone was also found to be correlated with time series performance, with the tropical areas providing the highest (median NSE = 0.11) and arid areas the lowest (median NSE = −0.09) NSE values. No correlation was found between catchment area and runoff NSE. The results highlight the importance of further studies on the uncertainties of the different data products and how these interact when combining them, as well as of new approaches to using the data rather than simple water-balance-type approaches. Efforts to improve specific satellite products can also be better targeted using the results of this study.@en

The intricate connections between water, land, food, energy, and climate change require a multicentric approach to evaluating the trade-offs and synergies needed to achieve sustainable development. For example, the amount of water required in irrigated agriculture, consumptive water uses, and hydro-power production can potentially lead to water pollution, and negatively affect hydrological regimes. However, Operationalizing Water Energy Food (WEF)-nexus thinking has evolved such that a division between researchers (e.g., academia), political actors (e.g., policymakers), and development partners (e.g., promoters) has formed. This lack of connection can lead to a situation where there is incoherent governance of WEF resources management. In the Southern African Development Community (SADC) context, the WEF nexus approach is at the core of regional sustainable development plans and strategies. This paper analyses the ambitions and the expected outcomes of the Songwe River Basin Development Programme (SRBDP) and reflects on how governance coherence of WEF resources rooted at the grassroots level contributes toward achieving “nexus-doing”. The SRBDP exhibits a multi-stakeholder connection of interests geared towards a common target (i.e. stabilisation of the River Songwe flow). The SRBDP creates a multi-centric action system within the water, energy, food, and climate change adaptation role-players to achieve this overarching goal. The connections espoused in this system form the basis for nexus-doing in the Songwe River Basin. The major findings are: (i) there is a significant infrastructural demand in the Southern Africa Development Community (SADC), anchored in the development of water, land, food, and energy resources; (ii) governance coherence in the SADC context can be identified at both vertical and horizontal levels; (iii) the nature of trade-offs and synergies exhibited in SRBDP is valuable for making progress towards the operationalization of integrated WEF-nexus resource management; (iv) governance inconsistencies/ambiguities are better diagnosed and addressed in implementing nexus-doing initiatives such as SRBDP. Based on the findings, the following recommendations are proposed: (i) build upon small wins and support snow-balling successes to upscale promising initiatives-for instance the joint agreement by Tanzanian and Malawian governments to stabilize Songwe River flow by inaugurating the joint cooperation and equitable sharing of the Songwe watercourses (AFDB, 2019); (ii) invest in capacity building and human resources for the Songwe River Basin Commission and associated stakeholders to become more effective;-for posterity of sustainable developments in the Songwe River Basin; both the Tanzanian and Malawian governments in partnership with development partners need to upscale the investment in human capacity development and resource capacity development of the Songwe River Basin Commission (SRBC) as the joint development vehicle for the basin. and (iii) enrich policy assessment tools tailor-made for SADC. This tool will help in policy accounting to help minimize duplication, and ambiguities by fostering cooperation and policy mapping across the WEF-nexus sectors in the SADC region. This work can guide approaches to close the gap between nexus-thinking, and nexus-doing, something that is increasingly called for.

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There is a need to address resource security and distributional justice in developing countries. People need water, energy, and food to sustain their livelihoods, grow economies, and achieve sustainable development. The interactions between these resource sectors form the crux of water-energy-food (WEF) nexus assessments. In this study, we have utilised the WEF Nexus Index to analyse the WEF nexus of 54 African nations. The results from the analysis were used to illustrate the opportunities and constraints for future development. Generally, African countries are performing sub-optimally in the WEF Nexus Index due to the insecurity of water, energy and/or food. The performance of countries varies with context, highlighting the need for contextual analysis in identifying challenges and potential solutions. Implementation of interventions for achieving WEF security needs to be planned from an integrated perspective to optimise synergies and minimize trade-offs. Implementation of the WEF nexus approach towards simultaneous security of WEF resources has potential to improve the WEF nexus. For example and for many African countries, policies that undergird investments in energy supply projects are needed to unlock available freshwater resources and meet food requirements—energy is shown to be a critical enabler of development. Such projects can be utilised to enhance the ability of farmers to manage water through drought-proofing rainfed agriculture, an increase in irrigation development, or both. WEF nexus-based studies, policies, and projects must be focused on the direct and indirect achievement of SDGs 1, 2, 6, 7, and 13, both in terms of access and availability, to ensure distributional justice, especially in the African context. Such actions, combined with broad public participation, can have a ripple effect on other SDGs such as SDGs 5, 10, and 17, thereby reducing inequalities and building partnerships to attain these aspirational goals. The assessment of Africa’s relatively low scores in terms of the WEF Nexus Index does not represent a negative narrative. Instead, it provides an entry point to identifying hotspots and understanding the underlying challenges, through which more detailed analyses can lead to identified solutions and policies. Many African countries are trapped in an environment that could be termed a ‘poverty-unemployment-inequality nexus’ (due to the interlinkages that exist between these ‘wicked’ problems). The WEF Nexus Index provides high-level insights into these opportunities.

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Evapotranspiration (ET), a key variable in both water and energy cycles. It is very challenging to measure or estimate in large regions. Among many approaches to estimate ET indirectly (e.g. through hydrological modelling), models that are based on satellite remote sensing data (RS) are increasingly being used. However, the RS-based models inherit uncertainty from many sources, such as the model’s algorithm and parameters, input satellite data, and processing techniques. It is challenging to assess this uncertainty due to limitations of validation data, high volume and high dimensionality of RS data. Many studies have evaluated uncertainty in RS-based estimation of ET using different methods and reference data. The suitability of methods and reference data subsequently affect the validity of these evaluations. Therefore, it is necessary to have an overview of different evaluation methods and their uses. This study aimed to systematically review original research papers that assessed uncertainty or accuracy of RS-ET model or data products. We categorized these papers and quantified based on (i) spatial and temporal scale of ET estimation, (ii) types of uncertainty, and (iii) methods used to assess uncertainty. Studies have been geographically concentrated in North Asia, North America, and Europe. Most studies used the validation method, which quantifies the discrepancy between pixel-based ET estimation with an in-situ estimation. Although a standardized validation approach for satellite-based ET estimates is not yet ready, most validation studies employed Eddy Covariance (EC) flux towers for reference estimation at field-scale. In regions where in-situ measurements are limited, many studies use the residual of the water balance as reference. However, few studies considered uncertainty in the reference estimation and mismatch of spatial and temporal scales. For monitoring agricultural fields, most RS-ET methods have been reported with high accuracy. When applying these methods to larger extent, additional assessments are required to better inform data users of the quality of RS-ET estimation. These include cross-validation, sensitivity, and uncertainty analyses. Overall, this review showed the progress in evapotranspiration estimation using satellite data in terms of uncertainty assessment.

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Over the past decade, the water, energy, and food (WEF) nexus approach has evolved to become a focus of the Southern African Development Community (SADC) development strategies. However, a lack of empirical evidence, appropriate methods, and qualitative and quantitative tools to implement the WEF nexus approach has been highlighted. This chapter describes the application of the WEF nexus approach in the Songwe River Basin (SRB) located on the border between Malawi and Tanzania as a demonstration of how this lack of evidence and tools is starting to be addressed. The basin is currently facing rapid population growth, which is leading to a considerable increase in resource demand and environmental issues and has been identified as a priority basin for SADC. The SRB Development Programme (SRBDP) includes several projects that collectively aim to improve the environmental and socioeconomic status of the basin. The integrated approach proposed to assess the SRBDP's expected outcomes through a WEF nexus lens is based on the development and application of qualitative and quantitative tools that support decision-makers to assess feasible sustainable development pathways in the basin, and more broadly in the SADC region. This chapter focuses on the qualitative analysis of the WEF nexus system and explains the process of identifying the major sectors and subsectors involved in the SRBDP, the main interlinkages between them, and potential synergies and trade-offs assessing how decisions made in a sector may influence others. The qualitative analysis of the SRB shows that although the projects included in the SRBDP are expected to have positive impacts on the environment and the socioeconomic system of the basin, downsides that may have an impact on human and ecosystem health are also possible. Early identification of such issues can help to limit detrimental impacts in the future. In the analysis, potential Sustainable Development Goals (SDGs), objectives, and indicators that may be addressed in the SRB are identified, highlighting the importance of applying the holistic approach to enhance and boost the achievement of SDGs in the basin.

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Water, energy, and food (WEF) systems form a complex interconnected network, operational at scales from the household up to the global. These scales, like the nexus sectors themselves, and mutually interconnected, with lower-level characteristics help drive higher-level resource management, and vice versa. This chapter highlights recent WEF nexus research at spatial scales from household, to national, and up to global. The studies demonstrate the vast diversity in nexus issues and challenges, along with a concomitant diversity of research and assessment approaches to tackling and better understanding these issues. This chapter closes with a discussion on interactions between the scales, and how policy developed at one scale may impact on other scales, potentially in unanticipated and detriment ways. The investigation into cross-spatial scalar nexus interactions is in its infancy and represents a promising avenue for future research effort. Another aspect not covered so far by research is the issue of differences in the temporal scale in the nexus, both in terms of policy setting and implementation and in terms of impacts to people. This chapter represents another major topic for future research to better guide, develop, and understand the impact of policy and climate change on nexus resources and livelihoods, and vice versa.

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The water-energy-food (WEF) nexus is shown to be a highly interconnected, complex system, operating over multiple time scales, and at spatial scales from household to global. The key WEF nexus foci issues and challenges are known to be extremely diverse and change depending on the local situation and setting, the scale at which the nexus is analyzed, and even according to the sector used as the nexus entry point. As such, there are a multitude of approaches and methodologies for studying, assessing, and analyzing the nexus, which can be adopted to suit the specific case under investigation. There is no “silver bullet” modeling or methodological approach to studying the nexus. Some common and regularly employed nexus investigation approaches are outlined in this chapter, ranging from purely qualitative conceptual systems mapping aiming at getting a high-level understanding of nexus connections for a given study area, through to quantitative approaches including system dynamics modeling, agent-based modeling, life cycle assessment, and (multiregion) input-output modeling. Each approach has strengths and limitations, explored here, and the selected tool should address the research questions being considered as well as the goals of the study. In addition to tools and models, results need to be translated into “real-world” practicalities to have a better chance of being taken up and adopted. To this end, this chapter also introduces some indices and metrics that are often applied to communicate nexus results and messages to policymakers in a nontechnical language. This effort hopes to better disseminate and communicate the idea of integrated nexus thinking, especially in a policy- and decision-making domain.

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Water, energy, and food are all essential components of human societies. Collectively, their respective resource systems are interconnected in what is called the “nexus”. There is growing consensus that a holistic understanding of the interdependencies and trade-offs between these sectors and other related systems is critical to solving many of the global challenges they present. While nexus research has grown exponentially since 2011, there is no unified, overarching approach, and the implementation of concepts remains hampered by the lack of clear case studies. Here, we present the results of a collaborative thought exercise involving 75 scientists and summarize them into 10 key recommendations covering: the most critical nexus issues of today, emerging themes, and where future efforts should be directed. We conclude that a nexus community of practice to promote open communication among researchers, to maintain and share standardized datasets, and to develop applied case studies will facilitate transparent comparisons of models and encourage the adoption of nexus approaches in practice.@en

Water-Energy-Food Nexus Narratives and Resource Securities: A Global South Perspective provides a knowledge synthesis on the water-energy-food (WEF) nexus, focusing primarily on the global south. By presenting concepts, analytical tools, and case studies, the book serves as a practical resource for researchers, policymakers, and practitioners in sustainability and functional roles across all three sectors. It addresses key issues related to data availability, tools, indices, metrics, and application across multiple scales, beginning with a summary of existing knowledge. Finally, it examines the WEF nexus, presents global insights, and discusses future considerations and implications. This book presents an overview of existing knowledge on the WEF nexus and examines how such research aligns with emerging global WEF nexus perspectives, making it ideal for professionals, government entities, private industry, and the general public.

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Human activities both aggravate and alleviate streamflow drought. Here we show that aggravation is dominant in contrasting cases around the world analysed with a consistent methodology. Our 28 cases included different combinations of human-water interactions. We found that water abstraction aggravated all drought characteristics, with increases of 20%-305% in total time in drought found across the case studies, and increases in total deficit of up to almost 3000%. Water transfers reduced drought time and deficit by up to 97%. In cases with both abstraction and water transfers into the catchment or augmenting streamflow from groundwater, the water inputs could not compensate for the aggravation of droughts due to abstraction and only shift the effects in space or time. Reservoir releases for downstream water use alleviated droughts in the dry season, but also led to deficits in the wet season by changing flow seasonality. This led to minor changes in average drought duration (-26 to +38%) and moderate changes in average drought deficit (-86 to +369%). Land use showed a smaller impact on streamflow drought, also with both increases and decreases observed (-48 to +98%). Sewage return flows and pipe leakage possibly counteracted the effects of increased imperviousness in urban areas; however, untangling the effects of land use change on streamflow drought is challenging. This synthesis of diverse global cases highlights the complexity of the human influence on streamflow drought and the added value of empirical comparative studies. Results indicate both intended and unintended consequences of water management and infrastructure on downstream society and ecosystems.

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