Changing Climatic Conditions Affect Snow Cover in Annapurna Region of Nepal

Abstract

Changing climatic conditions affecting the physical environment, hydrology, forest and wildlife, agriculture, and other sectors of the economy has become a major concern worldwide. The Annapurna Range in the Central Himalayas in Nepal is experiencing impacts of climate change on various fronts, including temperature increase and change in snow cover area (SCA). The objectives of this study were to assess spatio-temporal variation in temperature, precipitation, and SCA in the Annapurna massif and establish a relationship between these variables. This study analyzed the daily maximum and minimum temperature and precipitation records of six weather stations in the region, and performed a long-term analysis (1990–2020) of snow cover over Annapurna massif analysing Satellite images from the past three decades provided by satellite 5 through 8 of the Landsat program and Geographic Information System (GIS) technology. The SCA was determined through Landsat images using the Normalized Difference Snow Index (NDSI). Temperature analysis showed that the northeast (Chame) and northwest (Jomsom) parts of the massif were undergoing a consistent increase in average temperature at the rate of 0.07 and 0.03∘∘C per year, respectively. A north-south gradient was observed in total annual precipitation with total precipitation increasing in Ghandruk and Ranipauwa (Muktinath) at 50 mm and 4.8 mm per year, respectively, and decreasing in Manang Bhot at 4.7 mm per year. The precipitation events increased during spring in the west (Lete), northwest (Jomsom), and south (Ghandruk) of the massif, whereas it decreased in the north (Manang Bhot) and northeast (Chame) for all seasons. The SCA varied from 397 km22 to 1735 km22 with a significantly decreasing trend in December. There was a non-significant SCA increase during March, indicating that more snow coverage could appear in the spring in the future. These results could help local communities, government agencies, tourism industries, and other stakeholders develop resource management plans and climate change adaptation strategies.