Glacier Classification and Movement Estimation using SAR Polarimetric and Interferometric Techniques

Glaciers are directly affected by the recent trends of global warming. Himalayan glaciers are located near Tropic of Cancer this belt receives more heat thus Himalayan glaciers are more sensitive to climate change. Major rivers of Asia originates from these glaciers and they are only source of fresh water for millions of people living in Indian sub-continent. Due to highly rugged terrain and inaccessibility of certain areas satellite obtained information is used to monitor glaciers. Mapping of accumulation and ablation areas and determining the rate of flow of the ice are important factors which determine its rate of melt of a glacier. Samudra Tapu glacier, used in this study, located in the Great Himalayan range of north-west Himalaya. This study focusses on the classification of the glacier and estimating its movement. Different glacier facies were mapped using multi-temporal SAR datasets and polarimetric decompositions. Support Vector Machines (SVMs) were used for final classification. Equilibrium Line Altitude (ELA) which divides the accumulation and ablation regions was determined at 5200 m. More than 50% of the total area is found as accumulation, since Samudra Tapu glacier from a cirque at high altitudes. Glacier flow was estimated using Interferometric Synthetic Aperture Radar (InSAR) using ascending pass ERS-1/2 datasets. High value of coherence of SAR return signal was obtained from these datasets with one day temporal difference. A maximum velocity of 57 cm/day in the month of May was found in the northern branch at high accumulation area. Spatial analysis of velocity patterns with respect to slope and aspect show that high rates of flow was fond in southern slopes and movement rates generally increase with increase in slope. Seasonal glacier flow and long term glacier monitoring was estimated for the ablation area of the glacier using offset feature tracking. Images pairs representing different seasons and time periods were used in this technique. A mean displacement of 13.1 cm/day in azimuth direction and 8.9 cm/day was estimated during the months of September and October 2013. Variation in glacier flow was noticed between different times periods this clearly suggests that glacier flow varies with season.