Abstract: Rivers are easily accessible resources of water for miscellaneous uses. But the erosion and sedimentation for different rivers are unique and so its study is importance. The analysis of sediment in river under different conditions is a base for predicting a river’s behaviour and for decision making on engineering aspects. River Kulsi, a southern tributary of the Brahmaputra, is considered as one of the last refuges of the endangered Gangetic dolphin in Assam. Kulsi originates in the Meghalaya (2538N, 9138E) and enters Assam after travelling about 12 km from its place of origin. It finally discharges into the main Brahmaputra at Nagarbera.
In river like kulsi, where sufficient data is not available, numerical model is of high demand for sediment transport analysis. Since bathymetric data of the river is not available, QGIS and remote sensing act as important tools for extraction of the bed profile of the river. QGIS and HEC-RAS was used for this purpose in this study. This study is carried out to simulate the process of erosion, deposition and sedimentation using HEC-RAS model to assess sedimentation and erosion processes in 2.5 Km stretch of Kulsi River downstream from the Kulsi River at upstream site. Ackers-White sediment transport equation is used to analyse the characteristics of sediment transport and helps to obtain total erosion and deposition of the river for different cross section.

Keywords: GIS mapping, Erosion, Sedimentation, Kulsi River, HEC-RAS 5.05, Ackers white formula.

| DOI: 10.17148/IARJSET.2022.9538