A Comparative Analysis of Selected Glaciers of Hunza Basin, Pakistan since 1972‒2018: Varied Responses to Climate Change

Snow and glaciers are very sensitive to changing climate. Glaciers in the central Karakoram, western Himalaya and eastern Hindukush mountain ranges are not responding to global warming in the same manner as their counterparts around the world. Glaciers in this region are behaving differently. Some are retreating, while others are stable or surging. It is important to monitor these changes to protect downstream communities from the negative consequences. This study is conducted to monitor the state of the selected glaciers of Hunza River Basin, such as Batura, Passu, Ghulkin, Gulmit, Baulter, Barpu, Samaiyar Bar, Muchuhar, and Shishper glaciers were analysed using Digital Elevation Model and satellite images for 1972, 1979, 1990, 1998, 2008 and 2018. A semi-automatic approach was adopted to delineate the glacier boundary supplemented by manual editing. These glaciers show different fluctuations over the last fifty years. The Batura glacier showed surge in the 1970s and then retreated followed by quiescence. There is no prominent change in Ghulkin, Barpu, and Samaiyar Bar glaciers while almost 40 m per year retreat was observed in Passu and Gulmit glaciers but Muchuhar retreated at a faster rate. The surge of Shishper results in the formation of glacier-dammed lake which has so far triggered four Glacial Lake Outburst Floods (GLOFs). Overall, area of nine glaciers decreased from 596.54 ± 31.02 km 2 in 1972 to 568.52 ± 8.51 km 2 in 2018, which accounts for 4.8% decrease in area. This decrease will affect landscape development, regional hydrology and people living downstream.