多元特征线遥感识别的滩涂DEM构建

Using Remote Sensing Identification Multi-feature Line Construction of Tidal Flat DEM

针对水边线复合技术反演滩涂地形误差较大、经济成本较高等问题,提出了基于植被边线、冲淤痕迹线、水边线等多元特征线结合实测数据反演滩涂地形的遥感测量方法。以崇明东滩为研究对象,应用遥感技术提取水边线、植被边界线及冲淤痕迹线等多元特征线,利用实测数据拟合趋势线方法对边线高程赋值,并借助GIS空间分析技术将具有高程信息的特征线作为基础数据空间插值法构建滩涂DEM。最后,利用1∶1万地形图及实测数据对DEM反演结果进行质量评价。结果表明:该方法构建DEM影像数量需求少、时间跨度短、成本低、反演结果符合滩涂地形基本规律,垂直精度约为12 cm,研究结果对于滩涂冲淤变化及演变规律分析等研究具有重要的参考价值。

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.