遥感与水动力模型相结合的宽大潮滩历史地形反演

潮滩作为陆海交互区,面积宽广,测量困难,历史地形资料缺失,已经严重影响到潮滩的开发利用。以辐射沙脊群潮滩为实验区,利用1987年前后的TM、MSS影像提取不同潮情下的系列水边线,运用Mike21水动力模型模拟遥感图像对应时刻下的瞬时海面高度,为水边线赋值,进而通过地形反复迭代得到数字高程模型。结果表明,在辐射沙脊群潮滩区,水边线法获取的地形结果与海图上测点的相关性较高,决定系数R~2达0.864,绝对平均误差0.37 m,均方根误差0.41 m,地形结果可用于进一步的潮滩地貌演变分析。

Historical topographic reconstruction of large scale tidal flats based on remote sensing and hydrodynamic model

Tidal flats, which represent a wide land sea interaction zone, are difficult to measure. The lack of historical topographic data has seriously affected the development and utilization of tidal flats. Using a tidal flat of radial sand ridges as an example, waterlines under different tide conditions were extracted from TM and MSS remote sensing images from around 1987, and sea surface heights were simulated with a Mike21 hydrodynamic model. Elevations were assigned to the waterlines. The digital elevation model was obtained through the terrain iteration process. The results show that, in the tidal flat of radial sand ridges, there is a strong correlation between the topographic results obtained from the waterline method and the measured data from the nautical chart, with a coefficient of determination (R2) of 0.864, a mean absolute error of 0.37m, and a root mean square error of 0.41m, indicating that the topographic results can be further used to analyze the morphologic evolution of the tidal flats.