| 摘要: |
| 对现代黄河三角洲地区地面沉降的特点和对三角洲发育演变的影响进行了分析研究。分析认为,现代黄河三角洲地区普遍发生的地面沉降具有多因素和时空不连续性的特点, 给沉降区带来了一系列的危害, 使多种海岸带灾害的破坏和影响加剧; 地面沉降不仅可以造成地面标高损失, 影响三角洲的垂向发育, 还通过改变地面坡降来影响河道的演变和尾闾的摆动, 同时能引起相对海平面上升, 在淹没沿岸低地的同时, 加大潮差和滩面水深, 使沿岸潮流和波浪作用增强, 增加风暴潮的成灾几率, 加速海岸蚀退和滩面冲刷。正确认识三角洲地面沉降对洲体演变的影响机理, 做好科学防范措施, 有利于三角洲的可持续发展。 |
| 关键词: 黄河三角洲 地面沉降 河道演变 海岸侵蚀 |
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| 基金项目:国家自然科学基金资助项目(40676037, 40706035); 中国科学院知识创新工程重要方向项目(KZCX2-EW-207) |
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| Land subsidence in the modern Yellow River Delta and its impacts upon its evolvement |
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| Abstract: |
| The causes for the evolvement of the modern Yellow River Delta have been a main topic for a long time. Recent studies have shown that the entire modern Yellow River Delta has experienced complicated patterns of land subsidence. Our study analyzed the characteristics and impacts of the land subsidence, and particularly discussed the effect to the development of the delta. Factors including structural geology, the sediment consolidation, and human activity have simultaneously affected the pattern of land subsidence over the highly developed Modern Yellow River Deltaic area but with various degrees of effect as a function of region and time. Subsidence has induced marked environmental geologic changes, including coastal erosion, storm surge disaster enhanced, and salt water incursion. Its impact is particularly critical because of the flat low-lying topography and the presence of a thick soft silt layer at the ground surface. The accumulating land subsidence can change the surface slope, consequently influencing the riverbed and estuary evolution. Additionally accumulating land subsidence has increased the rise of the relative sea level, changed the models of coastal erosion, forced the coastline retreat landward, and narrowed the tidal flats at an accelerating rate with the strengthened hydrodynamic action. The land subsidence in the Yellow River Delta will continue owing to the time-dependent consolidation behavior of the soft silt layer and anthropic activity; therefore, the further research on the land subsidence is urgently needed to be actualized. |
| Key words: the modern Yellow River Delta land subsidence riverbed deposition coastal erosion |
