Analysis of rapid snow and ice cover loss in mountain glaciers of arid and semi-arid regions using remote sensing data

Abstract

This article investigates the effects of climate change on snow cover and glacier in mountainous glacial areas in northern region of Iran. Due to the lack of glacier measuring stations, accurately assessing changes in snow cover over the past two decades is a challenge for water experts. This research instead utilized remote sensing data from the MODIS sensor on the Terra satellite in Google Earth Engine (GEE) system covering the period from 2000 to 2020. The annual temperature changes near the Earth's surface, using ERA5 data, showed a significant increase of 1.5 °C in average temperature over the past thirty years. The Mann-Kendall test confirms the statistical significance of the temperature rise, with a significance value of 3.5 and a p-value of 0.002. For MODIS data validation, two methods of overall accuracy and the Kappa coefficient were used with 93% and 85% of accuracy. While the annual snowfall and volume have remained relatively stable over the past 20 years, the findings indicate a decreasing trend of snow cover during warmer months (summer) due to rising air temperatures. The findings show a strong negative correlation coefficient of −0.8 between snow cover and annual average temperature. The results indicate a 30% decrease in summer snow cover compared to the spatial extent of two decades ago. The rapid snowmelt poses a significant threat to permanent glaciers in the region as the protective snow cover diminishes, putting these glaciers at risk of completely melting in the future. The loss of these glaciers will have severe consequences for the environment, including impacts on local water supplies, river flows, and the ecosystem.