Overview

Water availability and access are key constraints to poverty reduction and food security. Maintaining enough water for agriculture of reasonable quality will be increasingly difficult due to climate change, competition for water with industries, urban uses and the environment, and the need to produce biofuels. Much of the world is faced with a situation where water supplies for various uses are overallocated, with river flows much reduced, groundwater levels dropping, and important ecosystems threatened - a situation of physical water scarcity. Much of this is driven by agricultural water use. In other parts of the world, availability of water in rivers, wetlands, and aquifers is ample, but access is difficult because people have not found means to develop the water resource - a situation of economic water scarcity. The Theme considers both cases, as well as all sources of water and their interaction - rainfall, streamflow, groundwater, effluents and reuse of water - in an environment of increasing demands. Research in the Theme is organized in three cohesive sub-themes:

Sub-Theme

1.1: Drivers of change, water availability and access

The starting point for sustainable water resources management and all water use activities is to understand how much water will be available for various uses, including agriculture, the source of this water, its quality, and the variability in quality and quantity. Various drivers of change may fundamentally alter river regimes, water availability for agriculture and access to water which is a function of availability, water policies, infrastructure and institutions. The sub-theme aims to improve quantification of the impacts of drivers of change on water resources availability and access, and to determine how changing water availability and access affect food production, livelihoods and the environment.

1.2 Climate change, water and agriculture.

The major uncertainty is associated with the impacts of climate change on water availability. The research examines implications of global climate projections for particular river basins. This sub-theme aims to provide an in-depth analysis of potential impacts of climate variability and change, and examine implications of climate change mitigation measures on water availability and access, agricultural production systems, and associated livelihoods and ecosystems. It also aims to minimize impacts of climate variability and change on agricultural water management through identification of appropriate adaptation measures.

1.3 Adaptive management strategies and tradeoffs

Adaptive management strategies are required to balance decreasing availability with increasing demand, while coping with uncertainties. These include water allocation strategies, development of appropriate types of water storage ranging from small ponds to large reservoirs and from surface structures to managed aquifers, and adopting policies that provide incentives to use water differently. As new water infrastructure is a key strategy for improving secure access for agriculture, the theme considers various benefits and costs of infrastructural development. The overall aim here is to maintain equity in water access, agricultural productivity, human health and environmental quality in the face of increasing water scarcity at local, basin and transboundary scales via development of adaptive management strategies, policy responses and tradeoffs.