DOI: https://doi.org/10.59321/BAUETJ.V4I2.4
AUTHOR(S)
Md. Nazmul Hasan Fahad1*, Tanvir Mahmood1
ABSTRACT
The Meghna River, one of Bangladesh’s principal rivers, has undergone continuous changes due to significant riverbank erosion and accretion over the past decades. This study assesses the riverbank erosion, accretion, and bank line shifting of the lower Meghna River from 1990 to 2021 using GIS and remote sensing techniques. Landsat TM and OLI images, along with GIS and ERDAS Imagine software, were utilized to quantify these changes. The study found that the most severe erosion occurred between 1990 and 1995, totaling 574.04 sq. km, while the greatest accretion, 448.88 sq. km, occurred between 1995 and 2000. Over the entire study period, approximately 305 sq. km of land was lost. Erosion and deposition patterns fluctuated due to the increasing water discharge downstream from the Padma, the Ganges, and the Meghna. Erosion on the eastern (right) bank was more significant than on the western (left) bank, with the left bank experiencing the highest erosion (339.75 sq. km) between 1990 and 1995. The shifting riverbank has caused severe socio-economic issues, displacing communities and submerging farmland, leading to rural-urban migration. Continuous monitoring, satellite image analysis, planting, and construction of embankments are crucial to protecting the riverbank and reducing the impact of future erosion.