Implications of Shrinking Cryosphere under Changing Climate on the Streamflows in the Lidder Catchment in the Upper Indus Basin, India

Abstract

Lidder tributary in the Upper Indus Basin (UIB) of the Himalayas, an important source of surface and ground water, is experiencing clear indications of climate change. In the basin, minimum, maximum, and average temperatures are showing a significant increasing trend in all the four seasons. Precipitation is showing insignificant decrease over time in the basin. However, the proportion of snow is decreasing and correspondingly, the proportion of rains is increasing. The temperature projections also show increasing trends for the end of this century. The time-series analysis of the Normalized Difference Snow Index (NDSI) shows a depletion of the snow-cover in the region. Furthermore, during the past 51 years, the glacier area in the basin has decreased from 46.09 km2 in 1962 to 33.43 km2 in 2013, a depletion of 27.47%. As a result of glacier recession in the basin, the streamflow fed predominantly by snowmelt and glacier melt, is showing a statistically significant decline since the mid-1990s. The declining streamflows have potential to adversely affect agriculture, energy production, tourism, and even domestic water supplies. The Snowmelt Runoff Model (SRM) was tested for estimating the runoff from this glaciated basin on an operational basis. The average simulated runoff 11.94 m3 s-1 at the outlet is in concordance with the average measured runoff 13.51 m3 s-1 showing R2 of 0.82. The model could thus be used for snowmelt runoff estimation, on an operational basis, for judicious utilization of the depleting water resources in the region.