摘要：Abstract
This study examines snow covered area (SCA) and associated geohazards in the Bhilangna watershed using the Normalized Difference Snow Index. Two Landsat images from 1990 and 2010 were analyzed. In order to estimate the average elevation of the snowline, a digital elevation model from the Shuttle Radar Topography Mission was used. In 1990, 124 km2 (9 % of the watershed) was snow covered. In 2010, 96 km2 (7 %) was snow covered. Therefore, during the study period (i.e., 1990–2010) SCA decreased by 28 km2 (2 %). Four snow types were identified and mapped: frost, fine, medium and coarse snow. In 1990, 38 km2 (30 % of SCA) was covered by frost snow, 86 km2 (69 %) was covered by fine snow, < 1 km2 (<1 %) was covered by medium granular snow, and an insignificant area was covered by coarse snow. In 2010, frost and fine snow covered 19 km2 (20 %) and 76 km2 (79 %) respectively, medium snow covered 1 km2 (1 %), and coarse snow was not traced. The snowline shifted from 4611 m in 1990 to 4698 m in 2010. These observations show the variability of snow cover in the Bhilangna watershed.
