The role of upstream water use on water stress in transboundary river basins: a global analysis

Abstract

Upstream-downstream relationship remains one of the many challenges of transboundary water management. Water use of upstream countries has always impact on the downstream water availability and in some cases it might lead to increased water scarcity in downstream part of a basin. In this study, aim is to assess the change in water stress level due to water use of upstream countries in the world’s transboundary river basins. Water stress level was first calculated considering only own water use of a sub-basin and this was then compared to the situation when both, own and upstream water use, were taken into account.

When only own water use was considered, 955 million people lived under water stress in world’s transboundary river basins. When the upstream water use was taken into account, the population under water stress increased by 6 percentage points (194 million people). The stress increased most in Asia (central and north-east parts), Africa and some parts of Europe. Further, the results were compared with International water Event Database (1950-2008) by Oregon State University to assess whether there is a link between increased water stress due to upstream water use and the occurrence of conflictive and cooperation events in the transboundary river basins. Although no direct relationship between these two variables was found, in many basins with high number of events also the stress index increased considerably due to upstream water use.

In case of transboundary river basin management, one of the key challenges is allocating shared water resources, and their benefits. My findings are thus important for international water bodies where equitable water allocation is at the center of water conflicts.