关键词: RS, GIS, 崇明东滩, 数值模拟, 冲淤速率, 数字高程模型

Abstract:

The exploration and development of tidal flat is restricted by the wide range and frqguent variaton of tidal flat and lack of temrain data.In this article，taking Chongming Dongtan as an experiment area,waterlines were extracted from different bands according to tidal conditions on the analysis of spectrum characteristics of multitemporal remote sensing images (1999~2004).The assignment of an elevation to the waterlines was performed according to two elevation survey profiles.The waterlines labeling elevation were used to construct TINs (Triangulated Irregular Networks).Then an interpolation for each grid elevation was performed in accordance with the associated triangle.The initial DEM， produced by using model heights generated by running the model with available topography，was then used to refine the topography in the intertidal zone，and the model was rerun to produce improved water levels and a new DEM.This procedure was iterated by comparing models and actual waterlines until no further improvement occurred.Finally，the DEM of Chongming Dontan was examined according to the four transects measured in the year of 2005.The results indicated that the standard deviation of the approach was 055 m，021 m，018 m and 016 m，respectively，which eliminated the effects of unavailable tidal height and discrepancy of waterlines on DEM precision.

Key words: RS, GIS, Chongming Dongtan, numerical simulation, accretion/erosion rate, DEM