Assessment of human response to river bank erosion through demographic changes—a study on the Malda district, West Bengal

Abstract

This work is focused on the nature of bankline shifting of the Ganga River only along its left bank in Malda and corresponding responses of the inhabitants. The study attempts to analyse the channel-shifting dynamism during the last 43 years (1980–2022) where the Digital Shore Line Analysis System (DSAS) model was used to compute the rate. Considering the selected villages, the net erosion was found most intense between 1980 and 1990, while after 2000 overall magnitude of deposition outpaced overall magnitude of deposition and foci of erosion also shifted southward. The temporal changes in selected demographic variables were computed on a multi-temporal basis in correspondence to time span selected for measuring bank erosion dynamics. The demographic variables were made to run through multiple correspondence analysis and partial least-square regression to test the response pattern with bank erosion and dominant variables that responded mostly to bank erosion intensity respectively. The generated findings were verified through focus-group survey (N = 131) and to judge whether the changes are persistent or not. With intense erosion, the villages had experienced a decrease in population density, cultivating population and agricultural labours. While with intensification of erosion, the villages had experienced net increase in marginal labour stock with a higher literacy rate in later period (2001–2011). Between 1991 and 2001, the changes in marginal labour stock due to erosion were the most dominant among all to respond, but its strength decreased in 2001–2011 due to out-migration of labours. The uncertainty of livelihood options from cultivation compels cultivators and agricultural labours to change occupation which affects the land bound emotions of the inhabitants. These certain changes have a wide impact on the association of village settlement pattern and urges for prompt government actions.