Glacier and glacial lake classification for change detection studies using satellite data: a case study from Baspa basin, western Himalaya

Using high-resolution Google Earth(TM) images in conjunction with Landsat images, the glaciers and lakes in the Baspa basin are classified to explore the recent changes. A total number of 109 glaciers (187 +/- 3.7 km(2)) are mapped and subsequently classified as compound valley glaciers, simple valley glaciers, cirques, niches, glacieretes and ice aprons. The compound and simple valley glaciers contribute 67.1 +/- 1.3% and 19.8 +/- 0.3% to the total glacier cover of the basin. Similarly, a total number of 129 glacial lakes (0.360 +/- 0.007 km(2)) are identified. From 1976 to 2011, the compound valley glaciers have lost a small area of 10.3 +/- 0.03% at a rate of 0.41 +/- 0.002 km(2) a(-1), whereas the niche glaciers have lost higher area of 40.1 +/- 0.001% at a rate of 0.04 +/- 0.0001 km(2) a(-1). Change detection of two benchmark glacial lakes revealed a progressive expansion during recent decades. The Baspa Bamak proglacial lake has expanded from 0.020 +/- 0.0004 km(2) (2000) to 0.069 +/- 0.001 km(2) (2011). Due to the complete loss of source ice, another glacial lake has expanded from 0.09 +/- 0.001 km(2) (1994) to 0.10 +/- 0.002 km(2) (2011). During the study period, the mean annual temperature that is T-avg, T-min and T-max have increased significantly at the 95% confidence level by 1.5 C-o (0.070 degrees C a(-1)), 1.8 C-o (0.076 degrees C a(-1)) and 1.6 C-o (0.0071 degrees C a(-1)) from 1985 to 2008. However, the precipitation has decreased significantly from 1976 and 1985 to 2008.