ABSTRACT
The glaciers contribute as health indicators to the climate of the region and impacts on the runoff at the lowlands and recharging of the aquifers. However, the monitoring gets severely hindered due to factors such as logistics, accessibility, adverse environmental conditions, and so on. Here, the application of geospatial techniques for spatio-temporal monitoring of glaciers (special reference to Himalayas) has been attempted. Various geomorphological features such as moraines, debris cover, crevasses, and snout can be identified with the help of satellite imageries to assess the glacio-fluvial activity as well as widely employed for the manual delineation of the glacier. A study comprising the mapping of 224 glaciers 28through manual delineation (1972–2006) in the Beas basin, Himachal Pradesh reveals that the glacier cover reduced from 419 to 371 km2, witnessing approximately 11.6% deglaciation (Dutta et al., 2012); whereas the Ravi basin (60 glaciers) gives a high deglaciation rate of about 16.37% during 1972–2006 (Dutta et al., 2013). Few studies have been done with different methods for automated mapping, which become immensely vital when applied over large area and more relevant for clean ice mapping. However, the accuracy of the results gets hindered by the presence of debris cover, proglacial/supra glacial lakes and turbid and frozen lakes. Another important aspect of glacial monitoring is the distribution of ice thickness estimated using surface velocities, slope, and the ice flow law. Digital elevation models (DEMs) are valuable tools for widespread applications in extracting various components of a glaciated environment. A detailed account of various methodologies to estimate the glacier thickness–volume–mass balance have been compiled, since these parameters become utmost crucial to assess the intricacies related to health of the glacier.
