Identification of channel shifting patterns and bank erosion-prone sites and challenges of riverine livelihood in the lower Tista River basin.

Abstract

In fluvial environments, the shifting of river channels and bank erosion are frequently caused by both natural and anthropogenic factors. Riverine hazards like bank erosion and course alterations offer severe issues to the riparian villages along the lower basin of the Tista River in India, which substantially influence the livelihoods of inhabitants living there. This research addressed river channel shifting tendency and identified major bank erosion-prone villages along the lower course of the Tista River and challenges to the livelihoods of the riparian people. Along with these, land use and land cover changes of the riparian villages since 1993-2023 have been assessed with accuracy testing based on the Kappa coefficient. The results of this study observed that on the right bank of the Tista River, migration is occurring at a rapid pace. Due to the consequences of numerous riverine hazards, the demographic profile of the riparian villages (viz., Case Study-I: Domohani village in Jalpaiguri District) exhibited a negative tendency in the rate of population growth. The study of the riparian villages' changes in land use and cover reveals a 20% decrease in vegetation cover, and both sandbars and water bodies witnessed a declining quantity. The household survey was conducted based on Cochran's method (1963); acquired results demonstrated that floods, bank erosion, and the Tista River's channel shifting behavior negatively impacted the majority (more than 80 percent) of the inhabitant's income. The continuous erosion threatens the stability of the riparian villages; by acknowledging these hazards and implementing appropriate measures, riparian villages can enhance their resilience, protect their livelihoods, and ensure the well-being of their communities in the face of these natural threats.