基于GIS的河南省地级市行政区边界形状研究

Research on the Prefectural City Boundary Shapes of Henan Province Based on GIS

利用河南省行政区界线图,借助GIS软件支持,分别计算了河南省地级市行政区边界的分维、紧凑度和放射状指数.结果表明:郑州市分维值最小而紧凑度最大,有利于行政区边界管理;安阳、濮阳、三门峡3市的分维值最大而紧凑度最小,说明行政区边界复杂,需要进一步加强边界管理.河南省地级市行政区边界的分维和紧凑度整体上与地貌复杂程度具有一定的耦合关系,表现出明显的地域分异.计算表明,驻马店的放射状指数最小,而三门峡则最大.说明优势点趋于质心且边界形状趋于圆时,放射状指数小,反之优势点趋于边界且边界形状远离圆时,放射状指数大.放射状指数较好地反映了区域内部的联系强度.

By using the map of city boundary of Henan province,the fractal dimension,the compact ratio and the radial index of the city boundary shapes are calculated by GIS soft. The result shows three major points. The first, Zhengzhou has the smallest fractal dimension value and the largest compact ratio value. That is convenient for management. The second,the cities of Anyang,Puyang and Sanmenxia have the largest fractal dimension value and the smallest compact ratio value. It shows that the city boundary shapes are complex,and the boundary management needs to strengthen. The third,because of the obvious regional difference,there has a coupling relat- ionship between the fractal dimension and the compact ratio of the city boundary shapes and the complex landform. The radial index value of Zhumadian is the smallest,and the value of Sanmenxia is largest. It shows that the radial index is small when the distance between the dominant point and the centroid is closer,and the city boundary shape looks like a circle. On the contrary,the radial index is large. Therefore,the radial index can reflect the strength of association in regional internal.