基于等高线的数字高程模型带状区域建模法

Zonal region method of digital elevation model generation based on contour line

为简化传统方法用等高线地形图建立数字高程模型(DEM)时需先提取离散点数据、构建大量不规则三角形网(TIN)的繁琐过程,提出简便的带状区域法.首先对等高线进行完整性处理并按多边形编号存储,利用既有的等高线及其单边邻接关系将整个地形图划分为相互独立的带状区域,形成DEM模型;通过搜索查询点所在的带状区域及对应的等高线高程值,采用距离加权平均法计算查询点的高程.该方法建立的DEM模型明显减少了网格数量和存储空间,高程插值计算精度不低于TIN法,建模效率提高,适合于建立基于等高线的大型DEM.

In order to avoid the tedious work of the traditional method of generating digital elevation model（DEM） based on the contour line, which picks out vast discrete points and then establishes the triangulated irregular networks （TIN）, the zonal region method is presented. The disconnected contour lines are dealt with and saved as number of polygon, by the contour lines and their unilateral adjacency relation the whole area is divided into independent zonal region, then DEM is generated. By searching the zonal region the inquiring point located in and the corresponding contour line altitude, the altitude of the inquiring point can be calculated by distance weighting method. The method reduces the number of mesh and the data storage space of the DEM significantly, the altitude computational accuracy is no lower than that of TIN method, it increases the efficiency of DEM generation, and it is suitable for large scale DEM generation.