Investigation of temporal change in glacial extent of Chitral watershed using Landsat data: a critique.

Abstract

Himalayan glaciers are showing consistent signs of recession similar to glaciers elsewhere in the world with the exception of slight mass gain or stability in Karakoram. Deficient knowledge regarding the processes controlling the glacier dynamics together with remoteness, rugged terrain, insufficient in situ measurements, unsuitable datasets, and scanty network of meteorological stations has always been a big challenge in projecting future glacier dynamics in the region. Here, we present a number of scientific concerns regarding the appropriateness of data sets and methods adopted by a study carried out by Naeem et al. (2016), published in the journal of Environmental Monitoring and Assessment to investigate and project glacier dynamics in Chitral watershed using Landsat data. The use of predominantly snow and cloud covered satellite images especially for 2006 and 2007 strongly questions the glacier fluctuation estimates put forth by the authors. The inferences from existing scientific literature suggesting robustness of semi-automatic methods for glacier mapping challenge the use of unsupervised classification approach for delineating glacier extents as adopted in Naeem et al. (2016). Considering the scientific concerns and loopholes in the study by Naeem et al. (2016), the glacier fluctuations in Chitral watershed need to be reassessed.