Recent morphological shifting of Padma River: geoenvironmental and socioeconomic implications
Nishat Rayhana Eshita, Mohammad Amir Hossain Bhuiyan, A. H. M. Saadat
Abstract
This study was carried out to evaluate the recent morphological changes of Padma River with consequent socioeconomic impacts on the downstream riverbank area. Morphological changes of the river reach were analyzed using remote sensing (RS) data (from 2010 to 2019) and GIS technique. Social survey was performed in Zajira and Naria upazilas of Shariatpur district among 150 respondents to determine the social and economic losses. The GIS analysis showed that the average rate of erosion of major channel was 42 m/yr and the average accretion rate was 38 m/yr at the secondary channel. The northeastern channel was abandoned and shifted toward south at the rate of 262 m/yr. Shariatpur site was affected by noticeable erosion at the rate of 52 m/yr. The changing pattern of chars showed that sedimentation rate was higher at the northern side comparing the south. Statistically significant differences were found from independent sample T test for the mean shifting in main channel (t (3) = − 3.87, p < .03), secondary channel (t (6) = 3.32, p < .02), and char area (t (8) = 4.32, p < .005) before and after 2014. Welch’s ANOVA showed significant differences in the mean river width shifting among the reference lines for both main and secondary channels. The data from social survey showed that 95% people living along riverbank had lost most of their lands in between 2014 and 2019. Majority of the respondents (67%) noticed the anthropogenic influences around the bridge site to be one of the contributors to accelerate the recent erosion. In addition to settlement, structural, and economic loss, both physical and mental health of the riverbank people is affected due to frequent migration. Immediate necessary steps through effective river management policy guidelines and implementation to adopt a permanent solution are required.