合肥市城市形态特征及其演化

基于1987年、2000年和2006年合肥市Landsat5/TM遥感图像,在城市建设用地信息提取的基础上,根据分形理论,用半径法研究了合肥市的城市形态及其演化,发现合肥市城市形态具有分形性质,且存在双标度特征.从1987年到2006年,标度区间空间转折点变化不大,仅从5.5 km扩展到7.0 km,第一标度区的聚集维分别为1.765 9、1.922 6和1.915 9,第二标度区的聚集维分别为0.562 4、1.004 1和1.206 2.通过分析认为内城区城市功能过于集中,长期的填鸭式建设导致城市用地密度过大;外围区城市用地面积一直在增大,而其分形特征减小是人为因素的干扰改变了城市自行发展的结果.研究结果可为合肥市的长远规划提供参考.

Characteristics of the urban form of Hefei City and its changes

The build-up area in 1987,2000 and 2006 of Hefei city was obtained from the Landst5/TM remote sensing images.Based on the fractal theory,the characteristics of the urban form of Hefei and its changes are studied.The data indicate that the urban form of Hefei bears clear fractal characteristics.The computation shows that there exist double scaling ranges.The turning point of the scaling range increased just from 5.5 km to 7.0 km from 1987 to 2006.The fractal dimension of the first scaling range is 1.765 9,1.922 6 and 1.915 9 for each,and that of the second one is 0.562 4,1.004 1 and 1.206 2 respectively.The result reveals that the density of inner build-up area is excessive because the functions of city are too concentrated,which is caused by spoon-fed build.The periphery of build-up area is increasing ceaselessly,but its fractal character is abating because of the disturbance of humans who changed the development of city on its own.The results can offer a reference to the long term planning of Hefei.