Discussion: ʻChanging river courses in the western part of the Ganga–Brahmaputra delta’ by Kalyan Rudra (2014), Geomorphology, 227, 87–100

Late Quaternary sedimentation history of the Himalaya and its foreland

“…The Lower Ganga delta comprises part of Sundarbans between the Hooghly and the Hariabhanga rivers on the India-Bangladesh border with an area of ~ 9441 km 2 and the inland limit is taken as 70-100 km from the present shoreline close to the maximum transgression point (Sinha and Sarkar, 2009;Bandyopadhyay et al, 2014). This portion is the abandoned part of the delta in the west, comprising non-fluvial regime.Thefluvial regimeabandoned prior to ~5 ka, as the Ganges River migrated eastward towards its present position (Goodbred and Kuehl, 2000a;Sarkar et al, 2009;Rogers et al, 2013;Flood et al, 2018).…”

“…The Rarh plain is drained by the rivers emerging from the Chhotanagpur plateau and by the distributaries of the Ganga delta (Sengupta, 1966). The river system delivered craton-derived alluvium that formed coalescing paradeltas on the continental shelf (the Bengal basin; Das Gupta and Mukherjee, 2006;Bandyopadhyay et al, 2014;Rudra, 2014) which is identifiable intofour stratigraphic units in order of relative ages (oldest to youngest; Majumder, 1981, 1991;Vaidyanadhan and Ghosh, 1993;Roy and Chattopadhyay, 1997): (a) The LateriticFormation, the oldest unit, rests on the Precambrian boulder conglomerate in the westand on the Gondwana and Tertiary (pre-Mio-Pliocene) rocks in the eastern side. The lower part of this formation contains Mio-Pliocene fossil wood,whereas,the upper part is characterized by reworked nodular ferricretes cemented by the ferruginous sandy silt or clay containing mammalian remains of middle to upper Pleistocene age and the Acheulian Palaeolithic tools.The presence of ~75 ka Toba-Ash-Bed marker has been recorded in the laterite-topped Quaternary profile as well (Acharyya and Basu, 1993;Acharyya et al, 2000) from the Barakar River (a tributary of Damodar) from NW parts of the Raniganj Coalfield which is correlated with the upper part of this formation and assigned the Pleistocene age.…”

River Systems in India: The Anthropocene Context

“…The downstream area of the Ganga Plains and its deltaic region are also characterised by the shifting of meandering channels (Rudra, 2014; Bandyopadhyay et al, 2015) (Fig. 1B).…”

“…Downstream reaches are characterised by extensive coastal erosion in response to changes in the fluvial and coastal processes. The abandonment of western distributary and interception of westward movement of shelf sediments have reduced the sediment supply and hence enhanced coastal erosion process (Bandyopadhyay et al, 2015). These observations indicate that stream management strategies should be based on an understanding of river processes in the area.…”

Estimation and prediction of the oscillation pattern of meandering geometry in a sub-catchment basin of Bhagirathi-Hooghly river, West Bengal, India

“…This river system is the lifeline of part of West Bengal and supplying irrigation, industrialisation, and human habitation in an enormous scope. From the twentieth century, several studies are created based on meandering of altering course and effect of the dominant variable of fluvial-dynamics prediction, estimation and migration on the Bhagirathi-Hooghly river system [46][47][48][49][50][51][52][53][54][55]. Due to the diminishing rate of discharge, the nature of this distributary metamorphosed from braiding to the meandering character with modifications through meandering geometry [52,53,56,57].…”