Riverbank Erosion: A Natural Process

The third chapter deals with bank erosion as a natural geoecological process essential in maintaining the balance of nature. The typology of bank erosion and their associated mechanisms are discussed in general and Bengal Delta in particular. The factors (erodibility and erosivity) and mechanism of bank erosion are analyzed in detail. Furthermore, measuring bank erosion is most important for monitoring and management purposes. Broadly, there are two types of measurements such as field-based measurements and measurements with geospatial technology. The field-based measurements taking different cross sections from the selected river help in identifying changes in the bank line shifting and volume of erosion over time. This technique renders accurate measurement but involves huge costs and time. However, detecting bank line shifts through geospatial techniques requires lesser cost and time but is constrained by the scale of the reach/river. A combination of both studies is also addressed with their applicability and limitations.