Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

Shabiha Yeasmin ¹, sohail Kabir ¹, T. M. Asaduzzaman ²

Affiliations
1 Department of Geology and Mining, University of Rajshahi, Rajshahi - 6205, BD
2 Geological Survey of Bangladesh, 153 Pioneer Road, Segunbagicha, Dhaka - 1000, BD

Abstract

The eastern bank of the Padma River is shifting eastward at Shibganj Upazila of Chapai Nawabganj distict of Bangladesh due to its rapid erosion. The shifting has continued for a length of about 50 kilometers from the point of entry of the Padma into Bangladesh up to the eastern part of Shibganj Upazila. The river shifting is gradual since 1776, which has created remarkable morphological changes. During the last 30 years major shifting took place at southwest margin of the Shibganj Upazila. The average rate of erosion in the study area during the period of 1973 to 2003 was 273 m/year with a minimum of 7 to maximum of 1100 m/year. The rate of bank erosion is high in the recent years. About 7 km of bank erosion has been observed from 1997 to 2003, south of Shibganj Upazila.

Floods caused by tropical monsoon and changes in seasonal flow regime are mainly responsible for the shifting of the bankline. Besides, neotectonic activity in the Barind Tract plays an important role in the shifting of the river Satellite imageries of 1997 and 2003 reveal that the channel has become more dynamic in recent times and shifting rates are much higher than that of the previous times due to huge onrush of sediments deposited on the riverbed and also perhaps due to the upliftment of the western side of the Padma River Studying the recent geomorphic map and satellite imageries of the area along with the evidence from the old maps since 1776, it could be predicted that the Padma is likely to capture the Pagla River in the study area in near future.

Keywords

River Shifting, Bank Erosion, Erosion Rates, Padma River, Bangladesh.

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