【作者】 郭建强；

【导师】 茅志昌；

【作者基本信息】 华东师范大学 ， 自然地理学， 2008， 硕士

【摘要】 随着经济全球化趋势和中国现代化建设步伐的加快,上海港在国内和国际航运市场中的地位不断提高,全港的货运量已居世界第一,集装箱吞吐量跃居全球第三位,上海港的发展对上海市的经济、社会可持续发展起到了重要作用。然而近年来,长江口航道水深不足、深水岸线资源短缺问题日益突出,成为制约上海港发展的重要因素。而长江口崇明、长兴、横沙三岛的港口、岸线资源尚未得以充分开发利用,这些岸段部分集中在外沙里泓河段,具有一定的水深条件和开发利用前景。基于此,对于长江口外沙里泓河段的深水岸线的保护与开发利用的研究具有十分重要的现实意义。本文将现场观测与室内分析相结合、定性与定量分析相结合,利用GIS技术、数理统计法,从动力、沉积、地貌等方面着手,通过对长江河口典型外沙里泓地形的形成演变过程分析,研究外沙里泓地形的形成机理及其在河口整治开发中的作用。研究结果表明:1.长江河口三个典型外沙里泓河段的形成过程,具有一定的规律性和相似性,其前提都有沙脊形成并分隔河槽,使河槽形成涨潮槽—沙脊—落潮槽的复式格局,在落潮流作用下沙脊下延北移,外沙里泓效应显现。2.南支扁担沙、新桥水道河段20世纪50年代末形成外沙里泓地形:北港六滧沙脊、六滧涨潮槽河段在20世纪80年代初形成外沙里泓地形;南港瑞丰沙嘴、长兴南小泓河段在20世纪60年代初形成外沙里泓地形。近年来,南支下扁担沙处于不稳定态势,南港瑞丰沙下沙体遭水流北偏冲刷及人为挖砂的影响,外沙里泓河势受到破坏。3.外沙里泓地形形成一般模式:在开阔的长江河口,强大的涨落潮流在科氏力作用下,流路发生分歧,其间出现缓流区,泥沙易于落淤,形成沙脊,在丰富的泥沙供应条件下,沙脊不断淤涨下延,发展成涨潮流在北、落潮流在南的复式河槽。沙脊向北淤涨,涨潮槽宽度束狭,水深增加,岸滩受冲,外沙里泓效应显现。4.维持外沙里泓地形的条件:保持上口通道有一定的径流量进入涨潮槽;控制浅滩串沟的位置、宽度;严禁无序不合理的采砂行为。5.外沙里泓河段具有一定的建港条件和开发利用前景。南支河段的整治重点是建设护滩工程稳定扁担沙体及扁担沙通道,维持南北港分流比均衡;北港河段的整治开发可采用开挖方案或促淤圈围方案,笔者推荐开挖方案;南港河段的整治重点是保护瑞丰沙体的稳定,维持两岸的深水岸线。更多还原

【Abstract】 Along with the faster economic economic globalization trend and modern construct step, the status of Shanghai port is continuously increased in domestic and international shipping market. The cargo volume is the biggest and the container throughput in Shanghai port is the third biggest in the word. Shanghai port is vital important to the sustainable development of economy and society in Shanghai. However, there is a lack of navigations and bank resources with deep water in Changjiang Estuary, which restrict the development of Shanghai port. In fact, there are some port and bank resources which have foreground in exploitation and use. Some of them are located in the reach of out-bar and inner-stream. Therefore, research on the protection and exploitation to the bank of out-bar and inner-stream is practical important.This paper will conbine with field measurement and inside analysis, qualitative analysis and quantitative analysis to research the formative mechanism and application in estuarine regulation and exploiture of out-bar and inner-stream topographty in Changjiang Estuary though the angle of dynamical, sedimention and geomorphology. GIS technology and mathematical statistics method are necessary. The research result as follows.1. The formative process of the three reach of out-bar and inner-stream in Changjiang Estuary has similar rules. At first, the channel is divided into flood channel and ebb channels by the sand sidge. Then under the effect of the ebb tidal currents, the sand ridge extends downstream and moves northward. Thus the out-bar and inner-stream effect appeared.2. The out-bar and inner-stream topographty in the Biandansha and Xinqiao channel of the South Branch formed in the end of 50’s in the 20^th century, while the one in the Liuxiaosha Spit and the Liuxiao Flood Channel of the North Channel formed at the beginning of 80’s in the 20^th century and the one in the Ruifengsha Spit and the South Changxing Channel of the South Channel formed at the beginning of 60’s in the 20^th century. In recent years, the Down Biandansha is in instability and the Down Ruifengsha has almost disappeared. The out-bar and inner-stream topographties are facing with destruction.3. The common patten of out-bar and inner-stream topographty: the strong flood and ebb tidal currents is branching under the actions of Coriolis force in Changjiang Estuary. There is a reach with slow current between the route of the flood and ebb tidal currents. The sediment is prone to deposit and forms a sand ridge. Then the sand ridge extends downstream in rich sediment supply condition, and the channel is divided into the flood and ebb channels. While the sand ridge silts northward, the width of the flood channel will decrease, the water deep will increase and the beach will erode. The out-bar and inner-stream effect appeared.4. The condition to maintain the out-bar and inner-stream topographty: Retain the up mouth channels and let the runoff come into the flood channel. Control the location and width of gullies. Forbid sand-exploitation out of order.5. There are harbor-built condition and exploitation and use foreground in the out-bar and inner-stream reach. The regulation emphases in the South Branch are to build shoal-protected projects to stabilize the Biandansha and Biandansha channel, and maintain the sand discharge ratio between the South and North Channel. Dredging projects and reclaime projects can be used in the regulation and exploitation in the North Channel. The auther is apt to the dredging projects. And the regulation emphases in the South Channel are to stabilize the Ruifengsha Spit and insure the safty of the harbors on the bank.更多还原