Conflicting demands for food and water, exacerbated by increasing population, increase the risks of food insecurity, poverty and environmental damage in major river systems. Agriculture remains the predominant water user, but the linkage between water, agriculture and livelihoods is more complex than “water scarcity increases poverty”. The response of both agricultural and non-agricultural systems to increased pressure will affect livelihoods. Development will be constrained in closed basins if increased demand for irrigation deprives other users or if existing agricultural use constrains non-agricultural activities and in open basins if agriculture cannot feed an expanding or changing population or if the river system loses capacity due to degradation or over-exploitation.

Population growth, increasing demands for food, ever-growing competition for water, reduced supply reliability, climate change and climate uncertainty and droughts, decline in critical ecosystems services, competition for land use, changing regulatory environments, and less participatory water resources governance are contributing to increasing difficulties and challenges in water resource management for agriculture and food. The need for sustainable food security for our global population and the need for preserving the environment, namely natural and man-made ecosystems and landscapes, have created an increased need for integrated, participative and scalable solutions focusing the various levels of irrigation and nature water management, from the field crop to the catchment and basin scales. Meanwhile, challenges and issues relative to water management for agriculture and food have evolved enormously in the last 30 years and the role of active management of the components of the water cycle is assuming an increased importance since their dynamics are key to assure water use sustainability, mainly agriculture and natural ecosystems sustainability. However, different regions face context-specific challenges associated with water scarcity, climate, governance, and population requirements. The main and first challenge is producing enough food for a growing population, which is intimately related with challenges placed to agricultural water management, mainly irrigation management. This paper revises challenges and progress achieved in the last 30 years focusing on irrigated agriculture, mainly water management, and its contribution to food security and the welfare of rural communities.

Conflicting demands for food and water, exacerbated by increasing population, increase the risks of food insecurity, poverty and environmental damage in major river systems. Agriculture remains the predominant water user, but the linkage between water, agriculture and livelihoods is more complex than “water scarcity increases poverty”. The response of both agricultural and non-agricultural systems to increased pressure will affect livelihoods. Development will be constrained in closed basins if increased demand for irrigation deprives other users or if existing agricultural use constrains non-agricultural activities and in open basins if agriculture cannot feed an expanding or changing population or if the river system loses capacity due to degradation or over-exploitation.

Evaluations of food, energy and water (FEW) linkages are rapidly emerging in contemporary nexus studies. This paper demonstrates, from a food consumption perspective, the potential of life cycle thinking in understanding the complex and often “hidden” linkages between FEW systems. Our study evaluates the upstream virtual water and embodied energy in food consumption in the Tamar catchment, South West England, distinguishing between domestic production and imports origin. The study also evaluates key inputs, including virtual nutrients and animal feed, when tracking supply chain of food products. Based on current dietary patterns and food products selection, the catchment consumes annually 834 TJ, 17 hm³ and 244 hm³ of energy, blue water and green water, respectively. Tamar is not self-sufficient in terms of food and requires imports of food products, as well as imports of virtual nutrients and animal feed for local production. Consequently, 51% of the embodied energy and 88% blue and 45% green virtual water in food consumed within the catchment are imported. Most of the embodied energy (58%) and green virtual water (90%) are because of animal feed production, where nearly half of embodied energy (48%) and green virtual water (42%) come from imports. 92% of blue virtual water is used for irrigation and primarily happens elsewhere due to imports. Irrigation is the process that demands the largest amount of energy for the crop-based products, with 38% of their total energy demand, followed by fertilisers production (24%). Our study illustrates water and energy hotspots in the food life cycle and highlights potential FEW risks and trade-offs through trade. This is useful considering potential unexpected changes in trade under recent global socio-political trends. Currently available databases and software make LCA a key tool for integrated FEW nexus assessments.

In the developing world’s irrigated areas, water management and planning is often motivated by the need for lasting food security. Two important policy measures to address this need are improving the flexibility of water appropriation rules and developing irrigation storage infrastructure. Little research to date has investigated the performance of these two policy measures in a single analysis while maintaining a basin wide water balance. This paper examines impacts of storage capacity and water appropriation rules on total economic welfare in irrigated agriculture, while maintaining a water balance. The application is to a river basin in northern Afghanistan. A constrained optimization framework is developed to examine economic consequences on food security and farm income resulting from each policy measure. Results show that significant improvements in both policy aims can be achieved through expanding existing storage capacity to capture up to 150 percent of long-term average annual water supplies when added capacity is combined with either a proportional sharing of water shortages or unrestricted water trading. An important contribution of the paper is to show how the benefits of storage and a changed water appropriation system operate under a variable climate. Results show that the hardship of droughts can be substantially lessened, with the largest rewards taking place in the most difficult periods. Findings provide a comprehensive framework for addressing future water scarcity, rural livelihoods, and food security in the developing world’s irrigated regions.

Global population growth exerts stresses on river basins that provide food, water, energy and other ecosystem services. In some basins, evidence is emerging of failures to satisfy these demands. This paper assembles data from nine river basins in a framework that relates water and food systems to development. The framework provides a consistent basis for analysis of the water and food problem globally, while providing insight into specific conditions within basins. The authors find that successes occur when demand is met by increased productivity, while failure occurs when factors conspire to prevent development of land and water resources.

This article summarizes some major factors that influence the Water–Energy–Food (W–E–F) Security Nexus and how they are perceived in different basins. These findings are based on a survey that was undertaken for the Global Catchment Initiative (GCI) within the Global Water System Project (GWSP) complemented by case studies for a transboundary basin (the Lake Winnipeg Basin), a national basin (Yellow Basin in China), and a number of the basins in a nation (India). The analysis also includes ranking of river basin issues related to the WEF Nexus based on the views of experts in nine basins. Based on this analysis, factors that have affected the evolution of the W–E–F Nexus, including the applications of Earth observations, are discussed. The study concludes that the W–E–F Nexus could be an effective vehicle for advancing water and sustainability issues and recommends research and demonstration projects to test the extent to which the WEF framework could be helpful in increasing understanding and collaborative governance approaches.

Climate change is expected to considerably affect the water resources in the Indus River basin in Pakistan and thus agricultural production in the country. This article reports an analysis of the impacts of various climate scenarios on both water resources and food production out to 2050. While changes in water availability range from –12% to +24%, depending on the scenario, crop yield and production impacts are negative across all scenarios, and net food imports increase. We suggest a combination of accelerated investment in agricultural research and increased water-use efficiency in agriculture to reduce the adverse impacts of climate change on water and food.