Geomechanical Hazards related to River Hydraulics and Remedial Measures: Selected Case Studies in India

Abstract

River science and engineering has been one of the important study areas for geologists, hydrologists and engineers. The open channel flow and associated hydraulics often initiate several geomechanical hazards including silting and scouring, meandering and migration, floods, etc. Such hazards may lead to disastrous consequences if adequate remedial measures are not undertaken by proper river training works. This paper presents selected case studies in northern and north-eastern parts of India where such hazards occurred due to migration of river channel and flooding of adjacent lands. The two study areas have been the Kosi and the Brahmaputra river basins. In the former study area, hazards took place due to eastward migration, whereas in the latter case, significant damages occurred due to scouring and erosion. The descriptions of the hazards occurred, and the mitigation techniques adopted have been briefly summarized in this paper. A critical analysis with prediction techniques for flood occurrence probability and erosion potential has been conducted as well. The relevant conclusions are drawn therefrom.