The need to assess major infrastructure performance under a changing climate is widely recognized yet rarely practiced, particularly in rapidly growing African economies. Here, we consider high-stakes investments across the water, energy, and food sectors for two major river basins in a climate transition zone in Africa. We integrate detailed interpretation of observed and modeled climate-system behavior with hydrological modeling and decision-relevant performance metrics. For the Rufiji River in Tanzania, projected risks for the mid-21ˢᵗ century are similar to those of the present day, but for the Lake Malawi-Shire River, future risk exceeds that experienced during the 20ᵗʰ century. In both basins a repeat of an early-20ᵗʰ century multi-year drought would challenge the viability of proposed infrastructure. A long view, which emphasizes past and future changes in variability, set within a broader context of climate-information interpretation and decision making, is crucial for screening the risk to infrastructure.

This article highlights the link between low-quality water and food crops irrigation. A cross-sectional research was conducted to assess factors motivating farmers to use low-quality water from the waste stabilisation ponds for food crops irrigation in urban and peri-urban areas in Morogoro Urban and Mvomero, in Morogoro Region, Tanzania, from October 2013 to March 2015. Data were collected through farmers’ survey (n = 80), in-depth interviews with key informants (n = 7) and focus group discussions (n = 4). Both descriptive and inferential statistics were used in results presentation. The findings indicated alternative way of earning income during dry seasons, lack of alternative sources of irrigation water, alternative source of employment, the need to produce food, land availability near the low-quality water, plant nutrients in the water and limited awareness of the health problems associated with low-quality water irrigation as incentives for farmers to irrigate food crops using low-quality water. The results further showed that farming using low-quality water has been their livelihood strategy; farmers meet their family needs such as school fees, health and food by using the income generated from the sale of vegetables and paddy. Regardless of all these benefits, the existing use of low-quality water in farming activities is informal. Besides, there are no regulations guiding its use with no declaration to whether the resource is suitable for food crops irrigation. However, banning the practice on the ground of health risks might be devastating to farmers. This practice should therefore be regulated in such a way that low-quality water disposed from the ponds is considered as a potential source of water for food crops irrigation.

The discourse on the need for water, energy, and food security has dominated the development agenda of southern African countries, centred on improving livelihoods, building resilience, and regional integration. About 60% of the population in the Southern African Development Community (SADC) live in rural areas relying mainly on rainfed agriculture, lacking access to clean water and energy, yet the region is endowed with vast natural resources. The water-energy-food (WEF) nexus is a conceptual framework that presents opportunities for greater resource coordination, management, and policy convergence across sectors. This is particularly relevant in the SADC region as resources are transboundary and supports efforts linked to regional integration and inclusive socio-economic development and security. We conducted an appraisal of WEF-related policies and institutions in SADC and identified linkages among them. The present ‘silo’ approach in resource management and allocation, often conducted at the national level, contributes to the region’s failure to meet its development targets, exacerbating its vulnerabilities. The lack of coordination of WEF nexus synergies and trade-offs in planning often threatens the sustainability of development initiatives. We highlighted the importance of the WEF nexus to sustainably address the sectoral coordination of resources through harmonised institutions and policies, as well as setting targets and indicators to direct and monitor nexus developments. We illustrate the significance of the nexus in promoting inclusive development and transforming vulnerable communities into resilient societies. The study recommends a set of integrated assessment models to monitor and evaluate the implementation of WEF nexus targets. Going forward, we propose the adoption of a regional WEF nexus framework.

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.

Climate change is a complex and cross-cutting problem that needs an integrated and transformative systems approach to respond to the challenge. Current sectoral approaches to climate change adaptation initiatives often create imbalances and retard sustainable development. Regional and international literature on climate change adaptation opportunities and challenges applicable to southern Africa from a water-energy-food (WEF) nexus perspective was reviewed. Specifically, this review highlights climate change impacts on water, energy, and food resources in southern Africa, while exploring mitigation and adaptation opportunities. The review further recommends strategies to develop cross-sectoral sustainable measures aimed at building resilient communities. Regional WEF nexus related institutions and legal frameworks were also reviewed to relate the WEF nexus to policy. Southern Africa is witnessing an increased frequency and intensity in climate change-associated extreme weather events, causing water, food, and energy insecurity. A projected reduction of 20% in annual rainfall by 2080 in southern Africa will only increase the regional socio-economic challenges. This is exacerbating regional resource scarcities and vulnerabilities. It will also have direct and indirect impacts on nutrition, human well-being, and health. Reduced agricultural production, lack of access to clean water, sanitation, and clean, sustainable energy are the major areas of concern. The region is already experiencing an upsurge of vector borne diseases (malaria and dengue fever), and water and food-borne diseases (cholera and diarrhoea). What is clear is that climate change impacts are cross-sectoral and multidimensional, and therefore require cross-sectoral mitigation and adaptation approaches. In this regard, a wellcoordinated and integrated WEF nexus approach offers opportunities to build resilient systems, harmonise interventions, and mitigate trade-offs and hence improve sustainability. This would be achieved through greater resource mobilisation and coordination, policy convergence across sectors, and targeting nexus points in the landscape. The WEF nexus approach has potential to increase the resilience of marginalised communities in southern Africa by contributing towards attaining the Sustainable Development Goals (SDGs 1, 2, 3, 6, 7, and 13).

Soil and water conservation technologies are critical in reducing drought and soil erosion risks and increasing crop yields and incomes. Yet, there is limited empirical evidence on the extent and impacts of adopting soil and water conservation technologies in Tanzania. The study’s objective is to evaluate the adoption (as well as the duration of adoption) and the impacts of soil and water conservation technologies on income and food security in Tanzania. The study employs a control function approach and the instrumental variable quantile treatment effects model to survey data from 575 households to estimate the average and distributional impacts of adoption. The results show that the adoption and duration of adopting soil and water conservation technologies had significant and positive effects on the total value of crop production and household income. Moreover, we find that the adoption and its duration had a significant and positive impact on the food security indicator—household dietary diversity. The results from the instrumental variable quantile treatment effects model also show that the impacts of adopting soil and water conservation technologies on the outcome variables are positive and significant, although they vary significantly across the income and food security distributions. The results indicate that even though adoption benefits households in both the lower and upper quantiles of the income and food security distributions, the marginal impacts of adoption are generally more significant for the households in the upper quantiles. The paper concludes by discussing the policy options for increasing and sustaining the adoption and impacts of soil and water conservation technologies in Tanzania.

Soil and water conservation technologies are critical in reducing drought and soil erosion risks and increasing crop yields and incomes. Yet, there is limited empirical evidence on the extent and impacts of adopting soil and water conservation technologies in Tanzania. The study’s objective is to evaluate the adoption (as well as the duration of adoption) and the impacts of soil and water conservation technologies on income and food security in Tanzania. The study employs a control function approach and the instrumental variable quantile treatment effects model to survey data from 575 households to estimate the average and distributional impacts of adoption. The results show that the adoption and duration of adopting soil and water conservation technologies had significant and positive effects on the total value of crop production and household income. Moreover, we find that the adoption and its duration had a significant and positive impact on the food security indicator—household dietary diversity. The results from the instrumental variable quantile treatment effects model also show that the impacts of adopting soil and water conservation technologies on the outcome variables are positive and significant, although they vary significantly across the income and food security distributions. The results indicate that even though adoption benefits households in both the lower and upper quantiles of the income and food security distributions, the marginal impacts of adoption are generally more significant for the households in the upper quantiles. The paper concludes by discussing the policy options for increasing and sustaining the adoption and impacts of soil and water conservation technologies in Tanzania.

The threat of climate change is emerging at a time of rapid growth for many economies in sub-Saharan Africa (SSA). Dominant narratives comprising ambitious development plans are common and often based around sectors with strong inter-dependencies that are highly exposed to climate variability. Using document analysis and key informant interviews, this article examines how climate change is addressed in policy, how it is being mainstreamed into water, energy and agriculture sector policies and the extent to which cross-sectoral linkages enable coordinated action. These questions are addressed through a case study of Tanzania, highlighting broader lessons for other developing countries, particularly those in SSA facing similar challenges. The article finds that, while the agriculture and water sectors are increasingly integrating climate change into policies and plans in Tanzania, practical coordination on adaptation remains relatively superficial. Publication of the Tanzania National Adaptation Plan of Action (NAPA) in 2007 marked a step change in the integration of climate change in sectoral policies and plans; however, it may have reinforced a sectoral approach to climate change. Examining the policies for coherence highlights overlaps and complementarities which lend themselves to a coordinated approach. Institutional constraints (particularly structures and resources) restrict opportunities for inter-sectoral action and thus collaboration is confined to ad hoc projects with mixed success to date. The results highlight the need for institutional frameworks that recognize and address these constraints to enable development goals to be pursued in a more sustainable and climate-resilient manner. KEY POLICY INSIGHTS The NAPA has been successful at encouraging climate change mainstreaming into sectoral policies in Tanzania; however, the cross-sectoral collaboration crucial to implementing adaptation strategies remains limited due to institutional challenges such as power imbalances, budget constraints and an ingrained sectoral approach. Collaboration between nexus sectors in Tanzania is largely through ad hoc projects with limited progress on establishing deeper connections to enable collaboration as a process. Regular cross-sectoral planning meetings and consistent annual budgets could provide a platform to enhance cross-sectoral coordination. Plans to develop hydropower and agriculture are prevalent across sub-Saharan Africa. Insights from Tanzania highlight the importance of institutional and policy frameworks that enable cross-sectoral coordination.

Land Use Land Cover Change (LULCC) has a significant impact on water resources and ecosystems in sub-Saharan Africa (SSA). On the basis of three research projects we aim to describe and discuss the potential, uncertainties, synergies and science-policy interfaces of satellite-based integrated research for the Kilombero catchment, comprising one of the major agricultural utilized floodplains in Tanzania. LULCC was quantified at the floodplain and catchment scale analyzing Landsat 5 and Sentinel 2 satellite imagery applying different adapted classification methodologies. LULC maps at the catchment scale serve as spatial input for the distributed, process-based ecohydrological model SWAT (Soil Water Assessment Tool) simulating the changes in the spatial and temporal water balance in runoff components caused by LULCC. The results reveal that over the past 26 years LULCC has significantly altered the floodplain and already shows an impact on the ecosystem by degrading the existing wildlife corridors. On the catchment scale the anomalies of the water balance are still marginal, but with the expected structural changes of the catchment there is an urgent need to increase the public awareness and knowledge of decision makers regarding the effect of the relationship between LULCC, water resources and environmental degradation.