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An Appraisal to Anthropogeomorphology of the Bhagirathi-Hooghly River System
Published in Balai Chandra Das, Sandipan Ghosh, Aznarul Islam, Suvendu Roy, Anthropogeomorphology of Bhagirathi-Hooghly River System in India, 2020
Balai Chandra Das, Sandipan Ghosh, Aznarul Islam, Suvendu Roy
Schemes that set out to stabilise and regulate river systems typically endeavour to fix a channel with a given size and configuration in a given position. Change is natural. Innately, the river will adjust. Once river is fixed in place, the cost of keeping it there rises inexorably (Brierley and Fryirs, 2005). Protection of societal, economical and institutional infrastructure has ensured that this course of action must be maintained. Emphasis is placed on dams and reservoirs, barrages, connectivity in river system, channelisation programs and sand and gravel extractions, and the resultant impacts are flood hazard, bank failure and land loss (Guchhait et al., 2016), urban flood risk, water crisis in river, channel migration and changes in channel morphology.
Proposing BEHI-NBS method for the estimation of river bank erosion on a river in Nepal
Published in Silke Wieprecht, Stefan Haun, Karolin Weber, Markus Noack, Kristina Terheiden, River Sedimentation, 2016
River bank erosion or channel migration is a natural and geomorphic process of change in river resulted by adjustment of channel size and shape. Such changes are quite variable in space, depending in part upon position within the basin, and influenced by local variation in geology, soil, bank characteristics, vegetation, hydraulics, and other factors that influence vulnerability such as various types of land use (Aher et al. 2012). River changes in response to variation of variables like discharge and sediment supply (Mossa & Coley 2004). Rivers always tend to remain in the dynamic equilibrium state and to maintain this state, river balances its flow and sediment transport. In a free-flowing river system this equilibrium is always maintained by process of erosion and deposition (CRJC 1996). Bank erosion are special features of meandering river, where river channel migration takes place by erosion of the cut bank and deposition of eroded materials on point bar forming point bar deposit (Briaud et al. 2007, Das et al. 2014a). When river reaches lower reach, most of its erosive force concentrates to cut laterally hence, forming the meandering pattern (Das et al. 2014a). The migrating stream has tendency to widen the channel and erode the bank by undercutting its toe material and caving the bank (Baishya 2013). The fertile upland soil is then washed away by flow of the channel and deposited in the floodplain. These floodplain provides better yield and because of this benefit, these land are over cultivated, trees are cut down and cultivated field are poorly managed (Kaunda & Chapotoka 2003). Hence, destruction of flood plain and a reduction in the resource value of the river is associated with serious bank erosion (Thorne 1999).
Evaluation of the river Padma morphological transition in the central Bangladesh using GIS and remote sensing techniques
Published in International Journal of River Basin Management, 2023
Anupom Halder, Rumman Mowla Chowdhury
The River Padma is a typical wandering river. This study applied GIS and Remote sensing techniques with multi-temporal satellite imageries to highlight the variations in channel morphology of the River Padma, which may be helpful in future management planning. The results showed a large morphological change because of the fluvial flow system alteration. This study determined that rapid changes in the erosion and accretion of river channels in the last four decades resulted in significant land development and loss and were the backdrop of the River Padma. There was more erosion during this period than accretion, and erosion in the right bank was dominant, meaning that the rivers became wider and prompted river channel migration. This analysis recognizes that the River Padma planform became sinuous-braided in recent times. For comparison with other rivers of the same scale, details on the dynamics and current state of fluvial erosion and deposition of this river may be used.