Glacial Lake Inventory and Evolution in Northwestern Indian Himalaya

Glacial lakes are forming and evolving in the high-mountain regions as a result of glacier recession induced by global climate change. To provide comprehensive information about the spatial distribution and temporal changes of glacial lakes an updated detailed inventory has been developed in a study area of 7300 km
²
for four subbasins of the northwestern Himalaya for 1971, 2003, and 2011 using Corona, ASTER, and IRS-R2 data. In total, 77, 133, and 154 glacial lakes larger than 1000 m
²
covered areas of 1.9, 3.4, and 4.3 km
²
in 1971, 2003, and 2011, respectively. The majority of the lakes (75%) are glacier-fed and exhibit a significant expansion trend as compared to stable nonglacier-fed lakes. Around 75% of the lakes have surface drainage and excess water from precipitation is drained off, hence we conclude that glacier meltwater and vacated space due to glacier recession dominates the expansion and formation of lakes in the region. In addition, the formation of new lakes at higher altitude and the growth of glacier-fed lakes correspond well with the glacier recession. The study presents a comprehensive database of glacial lakes for long-term monitoring, outburst flood hazard assessment, and water resource management in the northwestern Himalaya.