Riverbank Erosion and Vulnerability Assessment for the Alluvial Section of Barak River in North-East India by In-situ Approach

Abstract

Riverbank erosion is a significant and distinct problem in the floodplains of alluvial rivers in North East India. The Barak River has experienced an alarming increase in bank erosion rate over the last few decades, resulting in embankment breaches and biodiversity loss, but there is a dearth of field studies to evaluate riverbank fluvial erosion. This study aims to assess the river bank erosion and Vulnerability Assessment of the Barak River in India using an in-situ submerged Jet Erosion Test (JET). The riverbank erosion was estimated for a span of the riverbank on one side of the stream using the excess shear stress equation and impinging jet theory. Data was collected using a JET along the riverbank to determine the erodibility parameter of the bank soil. The results show that the spatial variation in erosion parameters of river banks varies significantly, which is dependent on the specific location. Annual bank erosion was computed using measured erodibility parameters and stage record data, which shows the bank erosion of the Barak River will occur in many places, particularly at the critical area. The measured bank erosion was compared with the observed satellite imagery map for the 2000–2020. This study shows that JET results should be used with caution; further, the findings can be helpful in planning river training and management strategies for vulnerable areas and may serve as a model for similar alluvial river studies.