Water scarcity

Water is essential to life and human wellbeing - directly as drinking water for people and livestock, crop production, and industry; and indirectly as environmental flows that support ecosystems. Some 1 400 million people live below the poverty line (World Bank 2005), 70 per cent of which live in rural areas (United Nations 2000). Most of these smallholders depend on rainfed farming. As water scarcity will increase with climate change, there is an urgent need for adaptive strategies to increase food and water security and alleviate poverty.

The above picture shows water scarcity around the world and the location of megacities.

Water resource management and water policy development has focused almost exclusively on management of accessible flows in rivers, lakes and groundwater – known as blue water. The management of rainwater that falls on the soil has largely been ignored. The water that is held in the soil, the so called green water, is used by plants, but also feeds blue water, when excesses to the groundwater. When green water is managed properly, by for example reducing soil evaporation and runoff, more water will be available to plants and for water users downstream.

References United Nations (2000). Sustainable agriculture and rural development. Report of the Secretary-General. Addendum: Linkages between agriculture, land and water, UN Economic and Social Council. World Bank (2005, updated 2008). "Regional aggregation using 2005 PPP and $1.25/day poverty line." from http://iresearch.worldbank.org/PovcalNet/povDuplic.html.