EROSION-ACCRETION ANALYSIS OF A TIDAL REACH OF THE MEGHNA ESTUARY

Abstract

The Meghna Estuary, situated in Bangladesh, is renowned for its dynamic morphological characteristics, influenced by sedimentation from the GangesBrahmaputra-Meghna Delta and intense tidal currents. This research delves into the erosion-accretion dynamics within the Meghna Estuary, particularly focusing on the reach between Urir Char and Char Elahi. Through a comprehensive study utilizing remote sensing, GIS analysis, and field surveys, this research aims to assess morphological changes and sediment transport patterns over thirty years. The study reveals significant erosion-accretion fluctuations, with accretion rates exceeding erosion rates, leading to the formation of new landmasses and alterations in the estuarine landscape. The image analysis results revealed that over the past thirty years (1993-2023), the study area experienced a total erosion of 1422.86 ha and 3658.47 of accretion. Analysis of sediment concentration profiles indicates a sediment surplus system, characterized by accretion-prone areas. The findings underscore the critical role of sediment dynamics in shaping estuarine morphology and highlight the potential of remote sensing and GIS techniques in monitoring and managing coastal environments so that appropriate measures or structures can be built to protect the island.