Glacier Facies Mapping and movement Estimation using Remote Sening Techniques: A Case Study at Samudra Tapu Glacier

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. Due to highly rugged terrain and inaccessibility of certain areas satellite obtained information can be used to monitor glaciers. Samudra Tapu glacier, used in this study, located in the Great Himalayan range of north-west Himalaya. Distinct glacier facies are visible using multi-temporal SAR datasets representing different seasons. Fully polarimetric SAR data were used to identify different glacier facies. The identified glacier facies are percolation facies, ice walls, ice facies, refreeze snow and supraglacial debris. Object oriented classification was used to map various glacier facies. Using the classified maps altitude on snow line and firn line was detected. More than 50% of the total glacier area is found as accumulation region. Interferometric Synthetic Aperture Radar (InSAR) technique was used for glacier surface velocity estimation using European Remote Sensing Satellite (ERS-1/2) tandem data. High value of coherence was obtained from the SAR return signal for one day temporal difference. A mean velocity of 24cm/day was estimated for the month of May, highest flow rate were seen in the high accumulation area of the northern branch. Spatial analysis of velocity patterns with respect to slope and aspect show that high rates of flow was found in southern slopes and movement rates generally increase with increase in slope. Feature tracking approach was used to estimate the glacier flow for long term and seasonal basis using SAR and optical datasets. The obtained results clearly suggest that glacier flow varies with season and there has been change in the rate of ice flow over the years. Mapping the extent of accumulation and ablation areas and also the rate at which the ice flows in these regions as these are important factors directly related to rate of melt of the glacier. KeywordsClimate change, Himalayan glaciers, Accumulation, Ablation, Polarimetric SAR, Glacier facies, Object oriented classification, Snow line, Firn line, Glacier flow, InSAR, Feature tracking.