Estimation of Glacier Mass Balance using Remote Sensing and GIS Technology in the Hindu-Kush region of northern Pakistan

The Hindu Kush range of northern Pakistan has a large variety of Alpine and valley glaciers. These glaciers are subjected to volumetric changes owing to a host of factors (i.e., altitude, slope, glacier types, and aspect). The geodetic survey and field-based data are not available for assessment of glacier’s ELA for the Hindu Kush due to rough topography and rigorous climate. However, the mass balance of the alpine and valley glaciers can be obtained through Equilibrium Line Altitude (ELA) and Accumulation Area Ratio (AAR). Therefore, this study deals with the estimation of ELA, the hypsometrically controlled methods based on AAR and Accumulation Area Balance Ratio (AABR). The various ratio of AAR and AABR is applied to obtain the glacier ELAs of valley glaciers. AAR-ELAs are estimated based on ratios between 0.4–0.8 with 0.05 interval a d 0.67–4.4 with 0.01 for AABR-ELAs Moreover, the glacier contours with the interval of 50 m ± 5 m are employed for these estimations. This technique adjusted glacier hypsometry and area with the constant AAR ratio (rather than constant glacier area) to calculate the ELA variations. The results show that for AAR (0.5), 50m ELA declined from 5409 to 5359 m and reducing 4% the geometric area. The maximum decrease of 150 m ELA for these glaciers is reported for the AAR-AABR ratio 0.1–4.4, showing a significant decrease. The estimated decrease in the glacier area of Hindu-Kush glaciers is extremely variable specifically in Phargam, Khorabohr and Gordoghan.