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| 长江皖江段岸崩特征、形成机理及治理对策 | |
| 引用本文： | 李长安,杨则东,鹿献章,邵磊,王节涛.长江皖江段岸崩特征、形成机理及治理对策[J].第四纪研究,2008,28(4):578-583. |
| 作者姓名： | 李长安 杨则东 鹿献章 邵磊 王节涛 |
| 作者单位： | 1. 中国地质大学地球科学学院地理系,武汉,430074 2. 安徽省地质调查院,合肥,230001 |
| 基金项目： | 国家重点基础研究发展规划项目 , 国家自然科学基金重点项目 |
| 摘 要： | 文章根据遥感影像和野外调查,对长江皖江段的崩岸特征、崩岸形成条件和治理对策进行了研究。结果表明,崩岸基本特征是左岸(北岸)强于右岸(南岸)。右岸崩岸带总长为66.1km,占该江岸总长的16.30%,左岸崩岸总长130.0km,占该江岸总长的29.36%。左岸强崩岸段有15处,共长80.5km,占该岸崩岸长度的61.92%,右岸强崩岸段仅4处,共长32.9km,占该岸段崩岸长度的49.77%;强崩岸段主要发生在长江主河道强弯曲段的凹岸处,特别是顶冲部位,弱崩岸主要发生在河道微弯曲河道的凹岸;区内崩岸大多发生在分汊河段,尤其是弯曲型汊道。崩岸形成条件主要为岸坡岩性和水流因素。易发生崩岸的岩性是形成时代较新的砂层,随着干湿变化体积张缩性变化较大的粘土层和二元相结构的岩性组合(即上层是河漫滩相的细颗粒粘土和砂质粘土,下层为粗颗粒的细沙层)。导致崩岸发生的水流因素主要有主流的冲蚀作用、横向环流的掏蚀作用和水位的快速涨落波动变化。文章还提出了崩岸环境系统的概念,指在一定河段内影响崩岸发生的各种因素(如河型、洲滩分布、水文特性、河宽、水深、岸线形态、河岸地貌和岩性条件等)的空间配置,以及诸因素之间的相互联系、相互作用所构成的有机整体。根据崩岸环境系统认为,崩岸治理的对策是以崩岸环境系统为单元进行系统治理,以治崩与治淤相结合的整体治理,以固岸与河道治理相结合的综合治理。 |
| 关 键 词： | 长江皖江段 崩岸 遥感信息 |
| 收稿时间： | 2008-01-05 |
| 修稿时间： | 2008-03-03 |
BANK COLLAPSE CHARACTERISTICS,FORMATION MECHANISM,AND COUNTERMEASURES OF THE CHANGJIANG RIVER IN ANHUI PROVINCE |
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| Li Chang'an,Yang Zedong,Lu Xianzhang,Shao Lei,Wang jietao.BANK COLLAPSE CHARACTERISTICS,FORMATION MECHANISM,AND COUNTERMEASURES OF THE CHANGJIANG RIVER IN ANHUI PROVINCE[J].Quaternary Sciences,2008,28(4):578-583. | |
| Authors: | Li Chang'an Yang Zedong Lu Xianzhang Shao Lei Wang jietao |
| Institution: | 1. Faculty of Earth Science, China University of Geosciences, Wuhan 430074; 2. Geological Survey Institute of Anhui Province, Hefei 230001 |
| Abstract: | This research is based on satellite image information and field investigation.Characteristics,formation condition,and countermeasures of bank collapse of the Changjiang River in Anhui Province have been studied.The results show that the northern bank has more bank collapses than the southern bank.The northern bank has 130.0km collapsed,occupying 29.36% of the whole bank length while the length of collapsed southern bank is 66.1km,occupying only 16.30% of the whole length.There are only four strong collapses on the southern bank with their total length of 32.9km,49.77% of the whole length of bank collapses.But on the northern bank,there are 15 strong collapses with their total length of 80.5km,61.92% of the whole length of bank collapses.Strong collapses are mainly located at the concave bank of strongly curved reaches of the Changjiang River,especially at the top-rush position.Weak collapses mainly occur at the concave bank of slightly curved reaches.In this region,bank collapses always occur in braided courses,especially the meandering braided courses.Formation of bank collapses is mainly controlled by two factors: bank slope lithology and water flow.Bank collapses generally occur in places with the following lithology: newly formed sand layers,clay layer with its volume differing along with the drought-wet change,and combined layers with binary structure(e.g.,the upper is clay of alluvial flat facies with fine particles and sandy clay,while the lower is fine sand layer with coarse particles).Flow factors such as mainstream's water erosion,transverse circulation's erosion,and sudden change of water level can result in bank collapses.We also propose a conception of "bank collapse formation system," in which all factors causing the formation of bank collapse,such as river pattern,distribution of sandbar and shoal,hydrological characteristics,river width,water depth,coastline configuration,river bank landform,and lithology should be considered together spatially.The system is usual a river section controlled by nods at the two ends.Within the system,the shoreline change has the property of transitivity and linkage.When a certain portion of the shoreline changes the whole shoreline even the river pattern within the system will possibly change.But the change will not affect beyond the nods.According to this bank collapse formation system,bank collapse should be treated as a unit rather than an isolated event.The governance of bank collapse should thus be combined with the governance of silt,as the bank fixation should be combined with river regulation. |
| Keywords: | Changjiang River in Anhui Province bankfailure formation mechanism |
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