Title

Irrigation from the cryosphere - a global analysis of the contribution of melt water to irrigation water supply

Abstract

Water storage in and release from snow packs and glaciers constitute an important component of the hydrological cycle that has a significant impact on the timing and magnitude of runoff in many regions of the world. The dynamics of melt control the availability of water during the crop growing season in many heavily populated regions of the world. Recent observed and anticipated future changes in the accumulation and melt processes have raised concerns about the reliability of this source of water. We use PCR-GLOBWB, a global hydrological model that simultaneously simulates irrigation water use, to estimate the contribution of melt water to irrigation water supply for both contemporary and future conditions. We use high resolution maps of irrigated crops and take into account the storage of water in reservoirs. An analysis for major river basins shows important changes in the timing of runoff, which, in combination with increased demand for irrigation water to supply a growing population, could potentially create additional water stress if the growing season cannot be adapted. Variations in the snow melt can partly be buffered by water resources management options such as reservoirs and water transfers whereas structural changes in glacier storage result in a permanent change in water availability.

Publication Date

12-2011

Journal Title

Fall Meeting, American Geophysical Union (AGU)

Publisher

American Geophysical Union Publications

Document Type

Conference Proceeding