Optimal allocation of the food, energy and water (FEW) resources is of emergent concern owing to depleting supply of the natural resources. Increasing demand for the FEW resources is attributable to growing population, migration, economic development, technological advancements and climate change. The FEW nexus (FEW-N) is an intricate system that requires robust quantitative decision-making tools to investigate the links between the various system components and sustainability. This study proposes a meta-model-based FEW-N system for addressing the issue of natural resource allocation for food and energy security. It incorporated an integrated model consisting of the Techno-Economic and Input/Output models in an Optimisation framework with maximum economic benefit as its objective function. The COINOR Branch and Cut (CBC) and CPLEX solvers in the Advanced Interactive Multidimensional Modelling System (AIMMs) were used to formulate and solve the optimisation problems. To validate the developed framework, the scenario analysis was performed on three cases in South Africa. First, it was found that using FEW resources for food production in dryland open fields, undercover greenhouses, and irrigated open fields was more profitable than for production of electrical energy from bioenergy, solar/wind-based hybrid renewable energy, and hydropower production systems. Second, the revenue of the sub-sector determined the percentage use of the FEW resources and the percentage contribution of technology options to food and energy security. Third, open fields, greenhouses, and irrigated open fields contributed significantly to food security. The holistic framework developed provided enhanced understanding of the FEW-N system. Resource security has significantly improved due to the ability of various technologies in each subsector to meet the food and energy demands of the specific population. Besides providing scientific support for national decisions regarding food, energy, and water policy, the proposed framework will also contribute to sustainable development at the subnational level.

The interconnectedness of water, energy and food production cycles translates into the interdependence of water, energy and food pricing. This paper interrogates the level of interconnectedness between these systems in South Africa and discusses how energy and water costs influence food prices in the country and affect the country's level of food security. The paper emphasizes that sustainable solutions to food security necessitate integrative thinking in the process of strategic planning for these resources.

The purpose of the study is to assess whether Corporate Social Responsibility regarding water is considered relevant for sustainability in companies related to agriculture in South Africa, considering that their impact directly influences public access to water. To accomplish this purpose, a qualitative approach was developed through the study of the 22 existing companies from the agriculture sector, food and beverages, forest and paper production, and Tobacco, which published their last integrated report within the Global Reporting Initiative framework. A thematic content analysis was carried out, involving the analysis of the written sustainability reports. For data analyses, ATLAS.ti 7.1 software was used to match the main aspects related to water management. Pragmatic advice for practitioners derives from the research results, considering that Corporate Social Responsibility in general—and sustainable water management in particular—represents an opportunity for companies to get competitive advantages in the market. The study also determines the best practices in the field in South Africa with benchmarking purposes.

Promoting household food security and reducing malnutrition rates of a growing population with the same amount of water is a challenge facing South African nutritionists and agriculturalists alike. Apart from non-food related effects of agriculture in general, the crop and livestock production practices of the South African smallholder farmer may have nutritional implications, primarily when practised on residential land and resulting in home consumption. Yet, few studies have systematically investigated the impact thereof. It appears that crop diversification, gender issues and nutrition education are among the important factors that strengthen the link between agriculture and nutrition. Since food production is the most water-intensive activity in society, nutritional water productivity (i.e. nutrition per volume water) of foods and the nutritional water footprint of diets should be investigated in order to achieve a sustainable solution. This implies that both the demand for a diet consisting predominantly of water-productive plant products, as well as the supply thereof, be addressed.

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.

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).