Morphomertic and neotectonic study of Upper Teesta River basin, Sikkim Himalaya using geospatial techniques

This study is done on the basis of the surface and subsurface faults and active tectonic processes which disrupt the pattern of the drainage system present in the basin. The pattern of the drainages and their morphological features shown in the morphometric drainage basin areas which are used as a sign of neotectonics activity. This study is focused on the Upper Teesta River basin of the Sikkim Himalayan. For the study of the morphometric and morphotectonic analysis of the Upper Teesta River basin, ALOS PALSAR DEM was used to generate the drainage order of the basin with the help of the Arc GIS Software. The estimated drainage order of the basin is 6th. In this study, morphotectonic parameters such as asymmetry factor, elongation ratio, transverse topography asymme-try, mountain-front sinuosity, ratio of valley floor width to valley height, and hypsometric Integral was estimated 45.66, 0.55, 0.25, 1.08, 0.94, 0.44 respectively. These all-parameters value show the Upper Teesta River Basin is tectonically active. The stream gradient index of the basin was calculated >500 indicate the study region tectonically active. This research is validated using 50 years (1971-2020) earthquake data. Therefore, geospatial tool is an important tool to know the area is neo tectonically active.