Freshwater under threat : South Asia : vulnerability assessment of freshwater resources to environmental change : Ganges-Brahmaputra-Meghna River Basin, Helmand River Basin, Indus River Basin

This report is one of the primary outputs of the Vulnerability Assessment of Freshwater Resources to Environmental Change project. Collectively, the assessed basins provide South Asia with a variety of water related challenges that encompass floods, water shortages, sedimentation and erosion in the river and associated flood plains; drainage congestion in low-lying areas; and environmental and water quality problems. The population explosion in the basins during the past century has exerted heavy pressures on its water resources, while Himalayan glaciers are reported to be receding. The vulnerability of the water resources of the selected river basins is assessed from two perspectives: main threats to the development of water resources and its utilization dynamics; and the management challenges in coping with these threats. The main threats are assessed based on three different components: (i) resource stresses; (ii) development pressures; and (iii) ecological insecurity. A composite vulnerability index (VI) is calculated for the three basins on the basis of four components of water vulnerability: (i) resource stresses; (ii) development pressures; (iii) ecological insecurity; and (iv) management challenges. A number of conclusions have been drawn from the analyses presented in this report.