Dept. of Geography and Environmental Studies, University of Rajshahi, Rajshahi, 6205, Bangladesh.
Environ Monit Assess. 2022 Nov 10;195(1):96. doi: 10.1007/s10661-022-10638-z.
The present study is designed to illuminate the dynamics of the Jamuna River in Bangladesh for 46 years, from 1973 to 2019. About 240 km of the Jamuna River course was assessed using remote sensing and GIS. Landsat remote sensing imageries were processed, and bank lines were extracted and analysed using GIS. The main objective of the study was to understand the pattern of bed movement of the Jamuna River. The river dynamics were assessed based on bank erosion, accretion, bank line shifts, channel width, and river course and confluence shift. Area vulnerable to erosion was assessed using historical erosion rate and trend analysis. The result revealed that the river area increased by about 48% over 46 years. The total eroded area was about 1038 km, with 35.40% more erosion on the left bank than on the right. Due to higher erosion than deposition, the river widened. The average width of the river increased by about 56.40% during the period. The average rate of shifting was higher on the left bank than on the right, indicating the eastward movement of the river. Impact analysis showed that overall, a total of 822 km and 390 km of croplands and settlements were eroded during the period 1973-2019. The width of the confluence at the Padma River junction decreased by about 28%. The straight shift of the confluence was 9.27 km towards the southeast. The vulnerable area assessment anticipated that there would be more erosion on the left bank than on the right, and that Kurigram, Tangail and Jamalpur are the districts most susceptible to future left bank erosion. And, the lower reach of the right bank of the Padma River is at high vulnerable to erosion at the confluence. The methods and analysis adopted in this study can be applied to any other braided river to monitor the dynamics of the river and to formulate an action plan to protect the river from erosion.
本研究旨在阐明 1973 年至 2019 年期间，孟加拉国杰纳布河 46 年来的动态变化。利用遥感和 GIS 技术对杰纳布河约 240 公里的河道进行了评估。对 Landsat 遥感图像进行了处理，并利用 GIS 提取和分析了河岸线。该研究的主要目的是了解杰纳布河河床移动的模式。根据河岸侵蚀、淤积、河岸线移动、河道宽度以及河道和汇流点的移动来评估河流的动态变化。利用历史侵蚀速率和趋势分析评估了易受侵蚀的区域。研究结果表明，46 年来，该河流面积增加了约 48%。总侵蚀面积约为 1038 公里，左岸侵蚀面积比右岸多 35.40%。由于侵蚀大于淤积，河流变宽。在此期间，河流的平均宽度增加了约 56.40%。左岸的平均移动速率高于右岸，表明河流向东移动。影响分析表明，1973 年至 2019 年期间，共有 822 公里和 390 公里的耕地和居民区受到侵蚀。在帕德玛河汇流处，河道的宽度减少了约 28%。汇流点的直线移动方向向东南方向移动了 9.27 公里。易受侵蚀区的评估预计，左岸的侵蚀将超过右岸，而库尔纳、坦盖尔和杰马勒布尔是最容易受到未来左岸侵蚀影响的地区。并且，帕德玛河右岸下游在汇流处易受侵蚀。本研究采用的方法和分析可以应用于任何其他辫状河流，以监测河流的动态变化，并制定保护河流免受侵蚀的行动计划。
