Responses of water resource of the Yarlung Zangbo River Basin to climate changes and glacier-snow fluctuations in recent years

Abstract

Responses of river water resource of the Yarlung Zangbo River (YR) Basin to climate change and glacier-snow fluctuations in recent years were systematically studied by taking the best use of meteorological data and remote sensing images. Climate variation trends over the YR basin, mainly focusing on temperature, precipitation and actual evapotranspiration during 1979-2006, were examined by means of the GIS spatial interpolation techniques, meteorological statistics analyses, Mann-Kendall nonparametric test, etc. Based on the daily snow depth dataset derived from SMMR and SSM/I, annual snow-cover days and average snow depth (maximum and mean) were collected and analysed in the YR basin during 1979-2006. According to the water budget for a closed watershed, in association with the relevant achievements obtained from pioneer studies, the response of river water resources to the variation of climate, glaciers and snow cover in the YR basin was systematically studied. The results suggest that, under the background of the increasing temperature, precipitation, actual evapotranspiration and glacier melting together with the decreasing snow cover over the basin, river runoff presented the increasing trend to respond the climate and glacier changes at the speed of 18.7 m3s-1a-1 with the significant level of a<0.1 from 1979 to 2006.