Assessment of bank erosion and channel shifting of Padma River in Bangladesh using RS and GIS techniques

Bangladesh is a riverine country. Every year it faces many natural hazards due to river. Bangladesh is mainly formed by alluvial deposits. It faces riverbank erosion frequently due to regular shifting of river channels. This research work provides an overview of the trend of riverbank erosion of Padma River of Munshiganj, Madaripur and Shariatpur district. It also shows the land cover change due to riverbank erosion. The riverbank erosion was calculated by using remote sensing and geographic information systems (GIS) techniques. Only secondary data have been used to reach the research goals. Various computer software such as Erdas Imagine, Arc GIS, Google Earth, Environment for Visualizing Images etc. have been used to process and analyze raw data. In this study, using seven selected images of Landsat TM and OLI acquired from 1988 to 2017, the riverbank migration patterns and land dynamics of Padma resulted from accretion/erosion processes for 29 years were investigated. The migration rates are based on the differences in 1988-1993, 1993-1998, 1998-2003, 2003-2008, 2008-2013 and 2013-2017. The average erosion and accretion rates are 1472.056 and 1610.152 ha/year of Padma, respectively. This study shows Padma got meandered and braided from almost straight channel in the time span.