Ramganga River Basin A Geomorphological Study of Channel Dynamics and Palaeofloods

Abstract

newline The Ramganga river is a tributary of the Ganga. It is the first major tributary that joins the Ganga in the Indo-Gangetic Plain. It has a total length of ~649.11 km, out of which ~167.91 km is in the Himalaya and ~481.2 km in the Gangetic Plain. The total catchment area of Ramganga basin is ~30635.1 km². Koshi, Gangan, Deoha, Gagas, Aril, Bahagul, Dheela etc. are the major tributaries of Ramganga. Its watershed area covers nine districts of Uttarakhand and twelve districts of Western Uttar Pradesh. newlineIn the Indo-Gangetic Plain, the Ramganga river is very notorious owing to frequent shifting of its channel. Therefore the assessment of historical behaviour of alluvial river channel is a very important aspect of research as numerous hazards viz. floods, bank erosion, channel avulsion, bed aggradation etc. are largely associated with river channel dynamics. After having an understanding of the past, one can trace the recent and ongoing change of the channel. The nature, cause and rate of spatio-temporal dynamics of the channel have particular relevance where large scale lateral shifting threaten the hydraulic structures, infrastructure, agriculture, human habitation and properties in the study area. newlineThe course of Ramganga in alluvial plain is in an unconfined valley setting. Here, the river is characterised by high stream power. The lateral shifting of the course or remarkable changes in the channel morphology are largely attributed as a response to the varying water and sediment discharge. Since flood is a frequent occurrence in this region and it is associated with channel dynamics, the study of flood for both the present and ancient periods is a major concern of this study.