Terrain Evolution of Subaqueous Deltain Chengdao Sea Area Based on IDW

Bathymetric data for seven different periods during 1958 to 2014 were collected to study the terrain evolution of subaqueous delta in Chengdao sea area. By comparing the applicability of different interpolation methods,this study selected the inverse distance weighted method to produce the digital elevation model(DEM), and seven depth maps were generated for the study area. Then, by using grid calculation, This work studied the depth and topography of different periods,compared the topographic characteristics, and analyzed the terrain evolution in the study area. The results showed that, 1) The overall topography is high in the southwest and low in the northeast while the terrain of the offshore slope between 3 m and 12 m isobaths was strongly being changed. 2) During river runs, the sedimentation center goes forward to north-east and the maximum deposition thickness was over 12 meters. 3) Since the river is abandoned, the erosion center gradually moves toward the shore and finally forms the topographic characteristics of ^"steep to gentle to steep^".