| 摘要: |
| 为更好地了解近40年来孤东近岸的演变过程，以研究区剖面水深地形、Landsat影像和利津站水沙数据为数据源，采用遥感技术及数理统计法对研究区域岸线及面积变化进行监测计算，并分析1976-1986年、1986-1996年、1996-2002年、2002-2014年4个不同阶段的冲淤演变及影响因素。结果表明：（1）孤东近岸经历"强淤积-冲淤平衡-侵蚀-强侵蚀"4个阶段。孤东近岸海域由淤积向侵蚀转变始于1996年，且在2002-2014年间侵蚀最为严重，大部分近岸海域蚀深达到6~8 m，侵蚀最大深度超过8 m；（2）等深线变化时空差异明显，蚀退最先出现在北侧，且近岸5 m水深区域内冲淤变化较水深10 m内敏感；（3）研究区近岸侵蚀，离岸淤积，剖面冲淤平衡位置由CS19剖面的11 m水深变化到CS21剖面的5 m水深；（4）黄河入海水沙的减少、河口人工改汊、孤东大堤建设和海洋动力作用都对孤东近岸的冲淤演变产生影响，维持研究区冲淤平衡的年均来沙阈值为3.78亿t/a。通过此来进一步探究孤东近岸演变进程，为孤东近岸防护提供科学指导。 |
| 关键词: 黄河三角洲 孤东近岸 冲淤演变 入海水沙 河口改汊 |
| DOI：10.11759/hykx20180917001 |
| 分类号:TV148.1 |
| 基金项目:国家重点研发计划课题（2017YFC0405503）；国家自然科学基金（U1706214） |
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| Coastal evolution and its influencing factors in Gudong near-shore area of the Yellow River Delta |
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CHENG Hui1, CHEN Shen-liang1, XU Cong-liang2, JI Hong-yu1, FAN Yao-shen1
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1.State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China;2.Institute of the Yellow River Estuary and Coast Science, Dongying 257000, China
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| Abstract: |
| Since channel avulsion of the Yellow River shifted from Diaokou course to Qingshuigou course in 1976, morphological processes of Gudong have undergone tremendous changes owing to variations in fluvial water and sediment discharge, human activities, and marine dynamics. This study analyzed the four stages of the morphological evolution of Gudong area based on measured bathymetric data and hydrological data at Lijin station. Major results showed that the nearshore area of Gudong has undergone four stages of change:a rapid accretion stage, an accretion-erosion adjustment stage, an erosion stage, and a rapid erosion stage. This area has transformed from deposition to erosion since 1996. The erosion depth was about 6-8 m between 2002 and 2014, exceeding 8 m at the most serious erosion area. Isobathic change in this area had spatial and temporal differences, with erosion having begun in the north. The change in erosion and deposition within the 5-m depth area was more sensitive than within the 10-m depth area. Erosion occurred in the nearshore zone while accretion occurred in its offshore area. The balance depth of erosion and deposition changed from 11 to 5 m. Morphological evolution of the Gudong nearshore zone was influenced by the decrease in water and sediment discharge of the Yellow River, diversion of the river mouth channel, construction of the Gudong dyke, and marine dynamics. Moreover, the sediment discharge threshold value in the study area is estimated to be 3.78×108 t/a. |
| Key words: theYellow River Delta Gudong nearshore area erosion and deposition evolution water and sediment discharge estuarine diversion |
