利用GIS和数字地图自动生成交通需求模型中三维道路网

Automatic constructing of 3-D road network with GIS and digital map

以GIS的空间计算功能和已有的空间数据为基础,同时考虑道路在水平面和纵断面上的空间特征,为交通需求模型开发出一种半自动的道路网的制作方法.在手工矢量化平面路段后,实现了自动调整路段端点和自动插入节点,在路段的平面曲线的顶点间插入高程点,并将高程点和DEM(digitalelevatedmodel)数据重叠计算路段的高程起伏,进一步得到了路段的实际地理长度.

A method of semi\|automatically constructing road network for traffic analysis with GIS is developed. The method is based on spatial analysis of GIS and takes both vertical and horizontal alignments of road into account. After the manual digitizing of road links, this method adjusts the ends of links and inserts nodes at the ends automatically. Further it inserts height points between the vertexes on horizontal curves of links, and then overlaps height points with DEM to calculate the ups and downs along the links, finally obtains the actual spatial length of links.