Climate Change and its Impact on Glaciers in Hindu Kush Region: A Case Study of Yarkhun Valley, Chitral Pakistan

摘要

The impact of Climate change on water resources, especially glaciers, is an important issue today. Glaciers located in mountainous ranges namely the Alps, Himalaya, Karakoram and Hindu Kush have thousands of glaciers and glacial lakes. The Hindu Kush (HKH) glaciers, particularly the Chitral valley glaciers, are a visible indicator of climate change through the decrease of glacier cover area, recently formed glacial lakes and the increase of glacial lake outburst flood events. This paper presents a spatiotemporal analysis of precipitation and temperature trends and a GIS&RS base investigation of the related glacier dynamic in Yarkhun valley Chitral district. Temporal glacier coverage was delineated using objected base classification coupled with manual digitization of accurate glacier outline in the debris cover area with high resolution imagery. Finally, the results were validated with field data acquired from field assessment and ICIMOD inventory data. Trend and correlation analysis for the period of 1990 to 2010 at 2 climate stations and 10 weather monitoring posts (WMPs) shows that there is 1.2 degree increase in annual temperature and an increase of 20 mm for precipitation. Temporal dynamic analysis Yarkhun valley glaciers shows that there is a decrease of snow and glacier cover area -from 679.61 to 632.54 sq.km and an increase of debris cover area - from 60.52 to 84.51 sq.km between 2000 and 2015. Overall the glaciers of Yarkhun valley glacier faces are retreating and the need for vigilance in assessing glacier behaviors regarding climate change is apparent.