Regulation of Brahmaputra-Jamuna River around Jamuna Bridge Site, Bangladesh: Geoenvironmental Impacts
Regulation of Brahmaputra-Jamuna River around Jamuna Bridge Site, Bangladesh: Geoenvironmental Impacts
复制标题
孟加拉国贾木纳桥址周围雅鲁藏布江-贾木纳河的治理：地理环境影响
DOI：
10.4236/jwarp.2010.22014
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
Shigeyuki Suzuki
中科院分区：
文献类型：
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作者：
M. Bhuiyan;M. Rakib;K. Takashi;M. J. Rahman;Shigeyuki Suzuki
本研究旨在评估雅鲁藏布江-贾穆纳河（BJ）在贾穆纳大桥（JB）遗址附近的地质环境影响，该遗址在1996年贾穆纳大桥建成前进行了改造。采用遥感和GIS技术对时空地质灾害进行评价。研究表明，西拉—贾甘—布雅普尔河段河道宽度从11 km调整到4.8 km，河道移动强度有所增加。台地分析表明，主要通道向东运移（3.15 m/年）。预测河道变化现象是水流、泥沙和河道廊道相互作用的结果。由于调节断面周围水流和泥沙的突变，侵蚀和沉积具有复杂的时空变化。辫状体系中的桥址由于宽度减小，起到了闸门的作用，不能很好地容纳整个水流向下游释放。在导滩相互作用下形成的螺旋流形成局部冲刷，使河岸东移。
This study is conducted to evaluate the ongoing geoenvironmental impacts of Brahmaputra-Jamuna (BJ) River around the Jamuna Bridge (JB) site which was modified prior to the construction of Jamuna Bridge in 1996. Remote sensing and GIS techniques are adopted to evaluate the temporal and spatial geohazards. This study shows that the intensity of channel shifting has been increased due to regulation of river width at Sira-jganj–Bhuiyapur section from 11 km to 4.8 km. Planform analysis shows that the major channel has been stressed to migrate (315 m/year) eastwards. The phenomena of channel changes are predicted to be the con-sequences of interaction of water flow, sedimentation and channel corridor. The erosion and deposition have complicated variations over time and space due to the abrupt changes of flow and sedimentation around the regulated section. Due to width reduction, the bridge site in the braided system acts as sluice gate which can not accommodate the entire flow to release downstream properly. The helical flow developed with the inter-action of guide bund creates local scours and helps to shift the river bank eastward.