Impacts of Dredging on Fluvial Geomorphology in the Jamuna River, Bangladesh

作     者：Md Mosiur Rahman Md Sazadul Hasan Moniruzzaman Khan Eusufzai Md Munsur Rahman Md Mosiur Rahman;Md Sazadul Hasan;Moniruzzaman Khan Eusufzai;Md Munsur Rahman

作者机构：Institute of Water Modelling (IWM) Dhaka Bangladesh Department of Civil Engineering Stamford University Bangladesh Dhaka Bangladesh River Research Institute (RRI) Faridpur Bangladesh Institute of Water and Flood Management (IWFM) Bangladesh University of Engineering and Technology Dhaka Bangla-desh 

出 版 物：《Journal of Geoscience and Environment Protection》 (地球科学和环境保护期刊（英文）)

年 卷 期：2021年第9卷第6期

页      面：1-20页

学科分类：0202[经济学-应用经济学] 02[经济学] 020205[经济学-产业经济学] 

主　　题：Sediment Transport Erosion Dredging Satellite Image River Morphology 

摘      要：Jamuna, a major braided river in Bangladesh, has an enormous hydrological impact on the surrounding areas and streams. Erosion and sedimentation in the Jamuna river cause a large flow fluctuation and floods round the year. Bangladesh Water Development Board has initiated a pilot capital dredging project in the Jamuna river in 2011-2012, aiming to guide the flow to reduce the risk of failure of the city area and right guide bundh of the Jamuna Bridge. This study explores the long-term role of dredging on river morphology us-ing erosion-sedimentation numerical modeling approaches. Primary data were employed in numerical models to estimate the erosion-sedimentation and compared outputs with the real-time cross-sectional variation at selected sections along the reach during 2012-2013. The analysis suggested that the rate of sedimentation is higher (60% to 80%), where the dredging alignment crosses through the existing sandbar/char. Moreover, a cross-section com-parison revealed that the channel near Sirajganj Hardpoint shifted towards the left (east) bank, and the channel within the study area developed very fast along the right (west) bank. However, satellite image analysis revealed that the major bankline shifting occurred from 2000 to 2010 and the channel shifting was observed from 2014 to 2018 along the reach, mostly, after the construction of some river training works. The variation of the channel per-sistence (40% - 100%) selected part of the study area in the channel inci-dence map, indicating the rapid dynamic behavior of the river morphology. This study showed a good agreement of measured data and simplified em-pirical relationships to predict the long-term morphodynamic behavior of the braided Jamuna river.