绵阳城市土地利用结构和形态演变及其动力机制

Structure and form evolution of urban land use and its driving factors in Mianyang City,southwest China.

该文借助系统论中的信息论思想和分形理论,以地理信息系统技术为支撑,分析计算绵阳城市规划区范围内1980—2010年土地利用结构的信息熵和均衡度,揭示城市土地结构的熵值特征和演化规律;利用分形理论中的边界维数和半径维数对绵阳城区土地利用形态进行了定量判断,揭示了城市土地利用结构与形态演变特征,并分析了绵阳城市土地利用结构和形态演变的主要自然、交通、经济和政策因素。研究表明,30年来绵阳城市土地利用结构的信息熵从1980年的1.122增长到2010年的1.893,年增长幅度达2.57%;均衡度从1980年的0.487增长到2010年的0.823,城市土地结构的均质性逐渐增强。工业用地、水域和农业用地、村镇建设用地的边界维数均有所增大,是各类型斑块数量增多而导致的在空间上相互交错、相互渗透的结果;城市居住用地、工业用地、其他城市用地和村镇建设用地的半径维数呈逐渐增大的趋势,构成了从中心向外围的类似圈层状的"居住—工业—农业"空间格局特征。城市土地利用形态演变的主要驱动力为经济发展和政府调控,同时受到自然环境和交通条件的制约。

System ideas and the fractal theories are used to study land use structure and form evolution of the urban planning area from 1980 to 2010 in Mianyang,Sichuan Province,southwest China,supported by the technology of geographic information system (GIS).Information entropy and equilibrium degree were used to discover the entropy characteristics and change law of the land use structure.Boundary dimensions and radius dimensions were calculated to quantify the land use form.As well,the main driving factors were revealed, including local environment,traffic condition,economic development and government management.Results show that the information entropy increased from 1.122 to 1.893 during 1980 and 2010,2.57% each year. The equilibrium degree increased from 0.487 to 0.823 during 1980 and 2010,which means that land use structures approached to an equilibrium state.The boundary dimensions of urban industrial area,water area, farmland,village and small town construction area presented an ascending trend,which indicated that their boundary forms were complicated.The radius dimensions of residential area,industrial area,other urban landscape and village and small town construction area were increasing gradually.This formed an annular spatial pattern from residential area to industrial area and to agricultural area according to the distance from city.All these spatial-temporal feature changes were affected by the local environmental and traffic condition, economic development and government management.The latter two factors were the most important driving factors leading to urban form evalution.