基于MapGIS二次开发实现矢量河网拓扑关系的自动编码与统计

为使河网中河段的直接定位和拓扑关系更加直观,提出直接对矢量河网进行继承式编码的思想,首先通过基于节点大小平衡二叉树的最小代价路径搜索算法完成对DEM数据的填洼处理,并将修正后的矢量河网与DEM进行叠置分析;然后基于Horton-Strahler分级和Shreve-Smart分级方法设计河网拓扑继承式编码算法,解决多河道汇集,河道分叉及汇流分叉等复杂河段难以编码的问题,并通过MapGIS二次开发实现对河网拓扑关系的自动编码与参数统计。通过对实验区的矢量河网进行编码测试,从而验证了算法的可行性以及编码的合理性。

The automatic coding and statistics of vector river network topology based on the second development of MapGIS

The suitable river network coding rules make the direct location and topological relation of the reach more intuitive.The idea which directly encodes the vector river is put forward.Firstly,filling the hollow of the DEM data is completed based on the balanced binary tree node size minimum cost path search algorithm and then the superimposed analysis should be employed between revised vector and DEM.The complicated issue which codes the multichannel gathering and river branch and confluence river diverging can be solve with the assistance of the river network topological coding algorithm based on Horton-Strahler classification and Shreve classification.The upstream would always contain the downstream river coding information with this algorithm employed and the topology calculation can be realized between upstream and downstream.The automatic coding of river network topology and parameter statistics can be carried out via the MapGIS secondary development.The feasibility of the algorithm and the rationality of coding are verified through the coding test of the vector river network in the experimental area.