A Method for DEM Construction Considering the Features in Intertidal Zones

Abstract

Accurate Digital Elevation Model in intertidal zones (IZDEM) is crucial to coastal applications (e.g., coastal zone management and anti-flood directing systems). Considering the features of multisource data and the evident anisotropy in intertidal zones, we propose a method for IZDEM construction. The basic idea of the method is that the terrain of any area can be divided into two portions: the trend portion reflecting the overall trend of the changes of topography and the residual portion reflecting the local changes. Based on the idea, the proposed method includes three steps: (1) Considering the influence of both the distance and the data accuracy of different data sources on the interpolation, the optimal equivalent weight is adopted to create the trend surface, which fits better for the intertidal terrain. (2) Considering the anisotropy of the terrain changes, the residual surface is created by the Kriging interpolation method. (3) IZDEM is constructed by combining the trend surface and the residual surface. The experimental results demonstrate that the proposed method can improve the fitting accuracy of the trend surface by considering the accuracy differences of multi-source data, and also improve the accuracy of the residual surface by considering the anisotropy of the intertidal terrain changes, thus it makes the constructed IZDEM more accurate in the area where multi-source data exist and the anisotropy of the terrain changes is evident.