An estimate of glacier mass balance for the Chandra basin, western Himalaya, for the period 1984-2012

An improved understanding of fresh water stored in the Himalaya is crucial for water resource management in South Asia and can be inferred from glacier mass-balance estimates. However, field investigations in the rugged Himalaya are limited to a few individual glaciers and short duration. Therefore, we have recently developed an approach that combines satellite-derived snowlines, a temperature-index melt model and the accumulation-area ratio method to estimate annual mass balance of glaciers at basin scale and for a long period. In this investigation, the mass balance of 146 glaciers in the Chandra basin, western Himalaya, is estimated from 1984 to 2012. We estimate the trend in equilibrium line altitude of the basin as +113 m decade(-1) and the mean mass balance as -0.61 +/- 0.46 m w.e. a(-1). Our basin-wide mass-balance estimates are in agreement with the geodetic method during 1999-2012. Sensitivity analysis suggests that a 20% increase in precipitation can offset changes in mass balance for a 1 degrees C temperature rise. A water loss of 18% of the total basin volume is estimated, and 67% for small and low-altitude glaciers during 1984-2012, indicating a looming water scarcity crisis for villages in this valley.