基于2 m格网点云数据的高精度DEM制作第三次国土调查坡度图

地形地貌随着时间的推移时刻发生变化，以高精度数字高程模型（EDE）数据制作坡度图，进而计算田坎系数，更精准地进行耕地面积计算及统计。以2 m格网点云数据生成的DEM数据为基础，按照第三次全国国土调查的相关技术要求，根据耕地坡度分级要求进行分级，生成坡度分级栅格数据图。对坡度分级栅格数据图进行矢量化，生成坡度分级矢量化数据。对矢量化数据进行图斑综合、界线平滑、拓扑重建、数据裁切等处理，制作完成调查区域坡度图及相关属性数据制作。并对生产的坡度图成果进行分析，找出不同尺度格网生产的坡度图的技术差异，并对高精度坡度的应用进行了展望。

Making slope map of the third national land survey based on high-precision DEM of 2 m grid cloud data

The topography changes with time. The slope map is made with high-precision EDE data, and then the ridge coefficient is calculated, which can more accurately calculate and count the cultivated land area. Based on the DEM data generated from the 2 m grid point cloud data, according to the relevant technical requirements of the third national land survey and the gradient classification requirements of cultivated land, the gradient classification grid data map is generated. Vectorize the gradient classification grid data map, generate the gradient classification vectorization data. Integrate the map spots, smooth the boundary, reconstruct the topology, and deal with the vectorization data according to the cutting and other processing, the slope map and relevant attribute data of the survey area are made. At the same time, the results of slope map production are analyzed, and the technical differences of slope map produced by different scale grid are obtained, and the application of high-precision slope map is prospected.