Abstract: The error of inversing the tidal flat terrain by waterfront composite technology is large and the economic cost is high.Aiming at this problem,this paper proposed a remote sensing survey method,which is based on vegetation edge,scouring and silting traces,waterfront line and other multi-feature lines with combination of the tidal flat terrain inversion,using the strength of the measured data.Taking the eastern tidal flat of Chongming Island as the research object,the remote sensing technique is used to extract the multi-feature lines such as the waterfront line,the vegetation boundary line and the scouring and silting marks.The trend line method,which is based on measured data is used to assign values to the edge elevation,and take the characteristic lines with elevation information as the spatial interpolation method based on basic data to construct the DEM of the tidal flat by virtue of the GIS spatial analysis technique.Finally,the quality evaluation of DEM inversion results is carried out by using 1:10.000 topographic map and measured data.The results show that this method has the advantages of less demand for DEM images,short time span,low cost,inversion result conforms to the basic law of beach topography,vertical precision which is about 12 centimeters.The results of the study are of great reference value for the analysis of scouring and silting changes,also for the analysis of evolvement rule.

Key words: feature line, edge extraction, tidal flat DEM, remote sensing