Construction of the Simulating Model for Geomorphic Evolution of the Yangtze Delta, China
长江三角洲地貌演变模拟模型的构建

Based on the existing data of the Yangtze delta area, a preparatory simulation has been done by the model on the Holocene geomorphic evolution in the Yangtze delta area, and a good simulative effect has been observed from the paleotopographic maps, which are generated from the model. The simulation shows that (1) the coastline evolution can be divided into three stages by taking 3000 aBP and 7000 aBP of the Holocene as a divide, the early stage is a rapid transgression stage, the middle stage is a transgression-regression repeated fluctuating stage and the late stage is a transgression stage; (2) the core region of the Taihu lake plain maintained basically a land environment all through the Holocene, not being suffered from large-scale transgression. But it is quite possible that transgressions have happened in the western part of the Taihu lake plain and part of the Taihu lake basin. In order to validate the simulation modeling, we have conducted qualitative and quantitative analyses from different aspects using data of the 304 archaeological sites in different cultural periods and the 73 14C dating data corrected by tree-ring. The validation results showed that the simulation method is a preferably reliable one to reconstruct the Yangtze delta geomorgraphic evolution and the simulation results are believable. So this study has set up the model simulation experimental method based on the GIS/DEM technology, which can be used to reconstruct and inverse the delta geomorgraphic evolution.