兰州新区土地利用分形特征

Fractal characteristics of land use in Lanzhou new area

为了分析土地利用空间结构的复杂性、稳定性以及动态变化性,该文利用兰州新区1993、2000、2010、2012及2013年5期土地利用数据,以GIS技术为支持,应用分形理论并通过叠加分析统计,计算出了5个时间段各主要地类动态度。结果表明:1除水域之外,研究区域主要的土地利用类型均具有空间分形特征。2近20年来,耕地和草地分维值最大,形状复杂度最高;构筑物和林地分维值略小,形状复杂程度次之;房屋建筑和园地分维值最小,形状复杂度最低。3各土地利用类型的平均结构稳定性指数中人工设施的结构稳定度显著高于自然植被的结构稳定度。41993—2013年,兰州新区城镇化趋势显著,且满足退耕还林政策,下一步的城市建设需要特别注意对水系的规划。

In order to analyze complexity,stability and dynamic tendency of spatial structure of land use,Based on GIS technology,with the data of land use in Lanzhou New Area in the year of 1993,2000,2010,2012 and 2013,this paper used the fractal theory to analyze the,and the dynamic indexes were calculated by using of land use types were in the five periods from 1993 to 2013as well,respectively.The result shows that：1major land use types in this research all possessed spatial fractal features except in water areas.2in recent twenty years,the fractal dimensions reached the maximum value and the complexity in shape achieved the highest in terms of farmland and grassland in Lanzhou New Area;the fractal dimensions and the complexities in shape were lower in terms of the structure and woodland;the fractal dimensions reached the minimum value,and the complexity in shape was the lowest in terms of housing building and garden;3the average index of structural stability in the different land use types showed that the structure stability of artificial facilities was significantly higher than that of natural vegetation.4from 1993 to 2013,Lanzhou New Area has undergone a remarkable urbanization process with its rapid urban expansion and met the policy of returning farmland to forest.The special attention should be paid to the planning of water system in further urban construction.