Inventory and Monitoring of Snow and Glaciers of the Himalaya Using Space Data

Abstract

The 2400 km long Himalayan mountain chain and the glaciers therein, contribute to most of the perennial rivers that constitute the life line for northern plains of India and adjoining areas because of their potential for irrigation, hydropower generation and being critical indicators of climate change. A large number of these glaciers, especially those in the Indus, the Ganga and the Brahmaputra basins, have been monitored for more than last two decades, using different satellite data. Space Application Centre of ISRO has prepared an updated inventory of Himalayan glaciers on 1:50,000 scale using Resourcesat-1 satellite data (2004–07), which serves an important document for monitoring the health of these glaciers. This inventory has shown presence of a total number of 32,392 glaciers, of different sizes, in the three above mentioned basins. The monitoring of snout of these glaciers in the two periods of 1989–90 to 2001–04 and 2001–02 to 2010–11 has presented a contrasting data. During the period of 1989–90 to 2001–2004, 76% of the glaciers have shown retreat, 7% have advanced and 17% have shown no change. As compared to this during the next decade i.e. 2001–02 to 2010–11, only 12.3% glaciers have shown retreat, 86.6% of glaciers have shown stable front and 0.9% have shown advancement. Though the space borne satellite data has been used for covering large tracks of inaccessible terrain of Himalaya for snout monitoring, there is need to include and develop models to estimate the thickness of glaciers using this space data. The data from space borne Lidar and interferometric SAR, used in association of GPR survey data and ground truthing, can help in estimation of thickness of glacier ice and mass balance an important parameter that is required to be added in the monitoring.