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为获得长江口滩涂地形的冲淤演变规律,运用GIS的数据处理与空间分析功能,提出了基于分区的冲淤量时间序列分析、冲淤量与上游来沙量相关分析、沙洲质心推移分析、典型断面分析的滩涂地形综合分析方法,即以滩涂分区和江心沙洲为对象、分时段定量研究冲淤变化的方法。在对全系列实测滩涂地形资料逐年分析的基础上,对长江口滩涂地形进行分区域的冲淤分析,并选取1991、2001和2008年3个代表年份,研究了长江南支上段主要沙洲地形演变规律。总体上,崇明东滩、长江南支、长江南港、长江北港、南汇东滩、九段沙近期冲刷大于淤积,而崇明北沿、横沙东滩以淤积为主,长江南支冲刷作用明显,江心沙洲往东南方向推移,分析表明长江入海泥沙年输移量以及年均含沙量变化是造成长江口江心沙洲冲淤演变的重要因素之一。
In order to obtain the evolution law of erosion and deposition of the beach landform in the Changjiang Estuary, the time-series analysis of the volume of the scouring and silting based on the zoning was put forward by using the data processing and spatial analysis functions of GIS. A typical cross-section analysis of tidal flat topography comprehensive analysis method, that is, the tidal flat and the Jiang Xin sandbank as an object, quantitative analysis of scouring and silting changes at different times. Based on the analysis of the full range of measured tidal flat topographic data year after year, the ebb and flow analysis of the tidal flat topography of the Yangtze River Estuary was carried out. According to the three representative years of 1991, 2001 and 2008, law. In general, the Chongming Dongtan, the South Branch of the Yangtze River, the Yangtze River Nangang, the Changjiang River North Harbor, the Nanhui Dongtan and the Jiuduansha Sediments are more than the siltation, while the north of Chongming and the Hengsha East Beach are mainly silted. The erosion of the south branch of the Yangtze River is obvious. The analysis shows that the annual sediment transport and annual sediment concentration in the Yangtze River basin are one of the important factors that cause the evolution of the sediment in the heart of the Yangtze Estuary.