World Water Demand And Supply 1990 To 2025

World Water Demand and Supply, 1990 to 2025

Presents two alternative scenarios of water demand and supply for 118 countries over the 1990 to 2025 period and develops indicators of water scarcity for each country and for the world as a whole. This study is the first step in IWMI’s long-term research goal: to determine the extent and depth of water scarcity, its consequences for individual countries and what can be done about it.

Global Water Demand Projections: Past, Present and Future

A review of global water demand projections (WDPs) show substantial over- or under-estimation. The pre-1990 WDPs, with population as the main driver of change, over-projected current water use by 20 to 130%. The post-1990 WDPs, with sophisticated modeling frameworks, show substantial underestimation under the ‘business-as-usual’ scenarios and are more downward biased under sustainable scenarios. Overall, the value of long-term country-level projections in global WDPs is inadequate for local water resource planning. To increase the accuracy and value of global WDPs, future WDPs should take into account the spatial variation and influence of rapidly changing key exogenous and endogenous drivers of water demand in different sectors across and within countries, and provide a sensitivity analysis of projections.

The World's Water 2002-2003