Water, food, energy, and the ecosystems they depend on interact with each other in highly complex and interlinked ways. These interdependencies can be traced particularly well in the context of a river basin, which is delineated by hydrological boundaries. The interactions are shaped by humans interacting with nature, and as such, a river basin can be characterized as a complex, coupled socioecological system. The Niger River Basin in West Africa is such a system, where water infrastructure development to meet growing water, food, and energy demands may threaten a productive and vulnerable basin ecosystem. These dynamic interactions remain poorly understood. Trade‐off analyses between different sectors and at different spatial scales are needed to support solution‐oriented policy analysis, particularly in transboundary basins. This study assesses the impact of climate and human/anthropogenic changes on the water, energy, food, and ecosystem sectors and characterizes the resulting trade‐offs through a set of generic metrics related to the sustainability of water availability. Results suggest that dam development can mitigate negative impacts from climate change on hydropower generation and also on ecosystem health to some extent.

In less than one year the Niger Basin Authority, an intergovernmental body tasked with the sustainable development of the Niger waters and associated resources, passed the first ever nexus policy in a transboundary river basin, contributing to a true acceleration of change for improved water and associated development in the Niger River Basin. The guidelines were developed in close collaboration with the nine basin countries and complemented by a large capacity building program. Using the guidelines can reduce the threat of adverse impacts on the Basin’s shared water and land resources and save millions of dollars of investment funds, while meeting various Shared Vision objectives. Doing so can also help strengthen positive impacts, reduce crosssectoral constraints of single-sector solutions, and identify multisector solutions. Application of the nexus guidelines will increase the efficiency of natural resources use and support implementation and monitoring of (multipurpose) investments. If this can be achieved, the River of Rivers—thought to be the original meaning of the name Niger—will continue to enhance water, food and energy security, and environmental sustainability for generations to come. To support the application of the guidelines, the study team developed an online, simplified nexus assessment tool that is summarized in Appendix 4.

West Africa's rice imports currently satisfy 70% of the soaring local demand, worsening the food vulnerability of an increasingly urbanized population. Despite considerable rice-growing potential, lack of water control systems, access to improved seeds, agrochemicals and appropriate mechanization have resulted in modest production growth rates, unable to alter the region's dependency on imported rice. Governments aim to boost production with import duties and input subsidies. However, questions remain as to whether these policies enable the rice sector to respond to changing consumers preferences for high grade rice and to contribute to national economic growth. We present the results from a Policy Analysis Matrix (PAM) on rice production in Ghana, Burkina Faso and Niger and under three water management systems: irrigation (public scheme), supplemented rain-fed (rainfall aided by autonomously-sourced water supplies) and purely rain-fed. Our results show that policy interventions in these West African countries (i.e., input subsidies and import taxes) did not significantly enhance the profitability of rice production to farmers due to the effect of market failures (limited capital access and non-competitive market for rice) and the low quality of local milled rice. The PAM results point strongly to the importance of improving rice quality and yields through more efficient water management and post-harvest handling/processing and targeted breeding to match consumers' preferences.

As befits a CGIAR Challenge Program , the CPWF has welcomed a wide range of stake holders and partners in accord with their ability to achieve program goals. Decision on research investments (project selection) have been based on a competitive grants in which proposal quality was evaluated by an interdependent external panel. The usual weakness of a competitive grants approach - lack of coherence in research agenda has been address by Basin Focal Projects and synthesis research.

1.5 billion people live in fragility and conflict-affected settings (FCAS) and they face an increased risk of food insecurity and poverty trap. A systems approach in collaboration with innovators in FCAS is needed to produce practical and inclusive solutions that can improve the resilience of food, land, and water systems (FLWS). CGIAR is in the unique position to produce transformative policies, programming, and market strategies to bring science-driven innovation to improve resilience among FCA communities and create a bridge between the humanitarian, development, and peace (HDP) nexus. This market report conducts a market assessment across 14 countries in Africa, the Middle East, and South Asia to inform a science-driven acceleration programme to scale CGIAR innovations in FCAS. The analysis in the report is from a newly developed database on FLWS-HDP innovation ecosystem actors, which includes 600+ innovator data covering 90+ solution types and 200+ funding supporters, including investors, governments, NGOs, hubs, and other collaborative ecosystem enablers. Additionally, the report draws insights from consultations with experts in the ecosystem ranging from CGIAR practitioners to innovation hubs and innovators (Chapter 1). The ecosystem mapping shows that the FLWS-HDP innovation ecosystem is still nascent in many FCA countries, and is largely concentrated on food production. Water resources, migration, and anticipatory action innovations only take up 20% of all innovations. Financial support to enable private innovators has been rising and 25% of the innovators mapped in the selected countries have raised funding amounting to over $330M as of November 2023, with investors from the private sector paving the way and with public-private partnerships (PPPs) increasingly playing an important role. Funding support from private investors and PPPs support early-stage innovation development by creating hubs, de-risking funding by co-investing with the private sector, and directly providing financial support to the innovators. International donors, governments and investors from the Global North are also prevalent in the ecosystem as 90% of actors supporting innovators are from outside the FCA countries. Local actors often work with international actors to implement programmes, co-invest, and help source high-impact innovators. There is little evidence of international research organisations’ activities in the FCAS so far (Chapter 2). Developing a sustainable FLWS-HDP innovation ecosystem in FCAS is met with challenges related to limited infrastructural resources, value chain disruptions, and heightened security risks. However, opportunities also exist, especially when innovators flexibly adapt innovations to address local challenges, and in settings where the solutions become tools to better facilitate and coordinate humanitarian, government, and private sector initiatives. Hence, supporting private sector innovation should prioritise localising solutions for the specific context to increase longerterm sustainability. Research organisations should support by developing systems to bring science to sector value chains and becoming expert support for innovators. Lastly, partnerships with governments, local actors, and international NGOs should be leveraged to bring innovations to tackle local challenges (Chapter 3). Finally, he report provides an overview of the macroeconomic and FCA context and an analysis of the FLW-HDP innovation ecosystem for each of the 14 countries The country overviews highlight that each country has a unique set of challenges and opportunities for developing a resilient innovation ecosystem, yet there are strong signals that innovators, support initiatives, and actors are making an impact in improving the conditions for FLW and HDP systems in FCA contexts (Chapter 4).

This reports summarizes and synthesizes activities and achievements of the CGIAR Challenge Program on Water and Food (CPWF) through the end of 2007. The CPWF is an intiative of the CGIAR designed to take on the global challenge of water scarcity and food security. It is an international, multi-institutional researchfor- development initiative that brings together scientists, development specialists and river basin communities, and seeks to create and disseminate international public goods (IPGs) helpful in achieving food security, reducing poverty, improving livelihoods, reducing agriculture–related pollution, and enhancing environmental security. The CPWF conducts its research on water and food in nine ‘benchmark’ river basins, organized around five different themes. This work is being implemented through competitive-call projects, Basin Focal Projects (BFPs), small grant projects and synthesis research. This report is one example of the latter. Projects and outputs Part of the CPWF’s work has focused on increasing water productivity in rainfed environments. Achievements include the further development of conservation agriculture for no-till sowing into crop residues; “slash and mulch” to replace “slash and burn” practices in hillside agriculture; water harvesting systems for dryland locations; understanding livelihood vulnerability and farmers’ coping strategies; and developing and encouraging the distribution—through community ‘participatory’ varietal selection and seed schemes—of drought-tolerant sorghum, wheat, and other crops. Progress has also been made in increasing water productivity in irrigated and salt-affected environments, especially where water is scarce and there are opportunities to increase its productivity. Examples include the development and testing of salt-tolerant germplasm for rice and other crops to make more effective use of salt-affected areas; understanding how to use wastewater in irrigated peri-urban agriculture to produce safe and nutritious vegetables; and developing aerobic rice germplasm and management practices to produce more rice with less water.

There is growing recognition that water insecurity – the inability to reliably access sufficient water for all household uses – is commonly experienced globally and has myriad adverse consequences for human well-being. The role of water insecurity in food insecurity and diet quality, however, has received minimal attention. Data are from panel surveys conducted during 2020–21 among adults involved in smallholder agriculture in Niger (n = 364, 3 rounds), Nigeria (n = 501, 5 rounds), Senegal (n = 501, 5 rounds), and Ghana (n = 543, 5 rounds). We hypothesized that household water insecurity (measured using the brief Household Water Insecurity Experiences Scale) would be associated with greater individual food insecurity (using 5 of the 8 Food Insecurity Experiences Scale items) and lower dietary diversity (using the Minimum Dietary Diversity Score for Women). At baseline, 37.1% of individuals were living in water-insecure households and of these, 90.6% had some experience of food insecurity. In multilevel mixed-effects regressions, individuals living in water-insecure households had 1.67 (95% CI: 1.47, 1.89) times higher odds of reporting any food insecurity experience and were estimated to consume 0.38-fewer food groups (95% CI: -0.50, -0.27) than those living in water-secure households. Experiences with suboptimal water access and use are associated with poor nutrition. The pathways by which water insecurity impacts nutrition should be identified. Global and national food and nutrition security policies could be strengthened by monitoring and developing strategies to address household water insecurity.

The countries sharing the Niger River suffer from poor access to clean water and energy as well as food insecurity. The Niger River Basin Authority is tasked with advancing progress in all these areas while also reducing environmental degradation. To help the basin authority and its investors prioritize portfolio activities that support multiple securities of interest, we developed a mixed-methods approach that engaged basin countries in qualitatively ranking projects to meet energy, environmental and food security goals, complemented by quantitative modelling for the more complex ranking of water and environmental sustainability goals, necessitated by complex upstream–downstream linkages.

The countries sharing the Niger River suffer from poor access to clean water and energy as well as food insecurity. The Niger River Basin Authority is tasked with advancing progress in all these areas while also reducing environmental degradation. To help the basin authority and its investors prioritize portfolio activities that support multiple securities of interest, we developed a mixed-methods approach that engaged basin countries in qualitatively ranking projects to meet energy, environmental and food security goals, complemented by quantitative modelling for the more complex ranking of water and environmental sustainability goals, necessitated by complex upstream–downstream linkages.

The ever-increasing demand for water, food, and energy is putting unsustainable pressure on natural resources worldwide, often leading to environmental degradation that, in turn, affect water, food, and energy security. The recognition of the complex interlinkages between multiple sectors has led to the creation of various holistic approaches to environmental decision making such as Integrated Natural Resources Management (INRM), Integrated Water Resources Management (IWRM), Virtual Water (VW), Water Footprint (WF) and lately the Food-EnergyEnvironment-Water nexus (WE2F). All these approaches aim to increase resource use efficiency and promote sustainability by increasing the cooperation between traditionally disjoint sectors, and mainly differ by the number and relative weights of the sectors included in their framework. They also suffer from the same face and the same barriers for implementation, some of which may never be fully overcome. The paper discusses the benefits of adopting a WE2F nexus approach in the Upper Niger Basin (UNB) and the Inner Niger Delta (IND), but also the multiple difficulties associated with its practical implementation. IWRM/WE2F initiatives in the UNB/IND such as the BAMGIRE project piloted by Wetlands International and funded by the Dutch Embassy in Mali to secure livelihoods and biodiversity in a changing environment, is taken as an example of partial success in the use of a nexus approach to watershed management. It was shown there are multiple barriers to the operational implementation of the WE2F. However, while a full understanding of all interlinkage between sectors may never be possible, data collection, scientific research and model development can improve our ability to understand the complex system in which we live, and hence take better decisions