Spatio-Temporal Change Detection of Channel Migration Using Geo-Spatial Techniques: A Study on Ranganadi River Basin of Lakhimpur District, Assam

Abstract

The shifting of channels is one of the natural phenomena on the earth's surface; globally, it is considered one of the unpredictable natural calamities. Floods greatly impact many tropical regions and channel course shifting due to flood among them; state of Assam is one of them. During monsoon season, the state has suffered from high flood and riverbank erosion, leading to severe river and bank erosion, which impacts the environment in several social and physical ways. The present study primarily emphasized the spatiotemporal change detection of the Ranganadi River and how it affected on environment. Satellite data from 1995-2023, SOI topographical map, and Google Earth Pro were used for the study. For the spatio-temporal analysis of the river, GIS has been implemented and calculated the channel shifting by applying the different cross-sections. Ranganadi is one of the perennial rivers of Assam, a tributary of Subansiri. Due to high intensity of flooding and river bank erosion yearly, the local dwellers suffer from problems such as infrastructural damage, land loss, economic disbalance, etc. Land use/cover has also changed due to course shifting the channel. Maximum changes are observed from 2002-2023, mainly in lower part of the basin. The erosion rate will be high in 2023. Deforestation leads to high erosion of river banks, resulting in people facing tremendous problems and issues in various ways. It is essential to study proper watershed management planning for a better understanding of the geomorphological instability of the river basin.