Monitoring of great Himalayan glaciers in Patsio region, India using remote sensing and climatic observations.

摘要

Three glaciers, namely Panchi-Nala, Zing-Zing-Bar and Baralacha-La in the Patsio region, Great Himalaya, India were monitored between 1971 and 2011 using satellite data. These glaciers were selected based on their terminus altitude, slope variations and debris cover. The Landsat, Corona, LISS-IV and Cartosat-1 satellite data were analysed to monitor variations in the area of glacier, terminus and annual snow line. Glacier outlines from the satellite imageries were generated using hybrid technique consisting of visual interpretation, band ratio, NDSII and thermal band (TM and ETM+) data. Glacier outline was also verified by GPS survey on Zing-Zing-Bar in 2011. The total loss in the area of a glacier was observed to be maximum (16.35+or-3.74%) for the smallest glacier, i.e. Baralacha-La glacier between 1971 and 2011. A maximum average retreat in glacier terminus of 22.5 ma-1 was observed for the Zing-Zing-Bar glacier, whereas for Panchi-Nala and Baralacha-La glaciers, the average retreat rate was observed to be 9.2 and 10 ma-1 respectively. An upward shift in Equilibrium Line Altitude was observed for all the glaciers between 1971 and 2011. The climate data collected at SASE meteorological station, Patsio (3800 m) between 1983 and 2011 suggests an increasing trend in the mean annual temperature and a decreasing winter precipitation. These observations support the effect of climate variability on spatial variation of glaciers in the Patsio region. Non-climatic factors such as size of the glacier, slope variation and debris cover were found to influence variable responses of different glaciers in the same climatic zone.