Abstract: Study of altitudinal variations of snow line in Koshi basin of Nepal using multi- temporal MODIS and AWiFS data

Figure 1:Geographical region showing Koshi basin

Koshi basin covers eastern part of Nepal and geographically located in the central Himalayan region(figure1).The northern part of the Koshi basin has high altitude  region. This high altitude region remains covered with snow during months of October to May/June of consecutive year. This region also has few glaciers which also remain under blanket of snow during these months. The snow line rises high from July onwards up to approximately the end of September before the fresh snowfall. The behaviour of snowline is dependent on the prevailing weather conditions of the basin. In view of the climate change scenario, it has been attempted to study the altitudinal variations of the snow line during peak accumulation and ablation period. For this purpose snow cover products from MODIS sensor(figure 2) have been utilized. A series  of snow cover products were superimposed on the SRTM DEM data(figure 3). The altitude of snowline were noted. The lowest altitude in the accumulation season  and highest altitude in the ablation season have been considered as the key parameters. The observations have also correlated with MODIS-LST products.  For a few cases, AWiFS data also has been used. NDSI based algorithmis utilised to extract snow cover from AWiFSdata. This study provides a new approach for climate change studies using altitudinal variations in snow line as indicator. 

Figure 2: MODIS Snow cover product of Koshi basin

Figure 3: SRTM image covering Koshi basin

ACKNOWLEDGEMENT: 

I, Sami Kunwar, want to acknowledge

Project Guide-Dr. I.M. Bahuguna and Shri Sushil K Singh,  SAC(ISRO), Ahmedabad, India

Course Director-Dr. B.M. Rao

Advisors- Shri B.P. Rathod and Ms. Rupal Brahmbhatt