基于分形理论的滨海新区土地利用空间格局变化研究

目的]探讨基于分形理论的滨海新区土地利用空间格局变化。方法]利用遥感和地理信息系统技术获取滨海新区1993～2008年城市土地利用现状数据,运用分形理论分别计算了各类用地的边界维数、半径维数、信息维数这3种分维,并对它们所揭示的土地利用空间格局变化特征予以分析。结果]滨海新区各土地利用类型的空间分布具有明显的分形特征,而各地类3种分维值的大小和变化有效揭示出了研究区土地利用空间格局的复杂性、向心聚集性和均衡性的变化。未利用地、盐田的边界维数不断上升,表明其边界日趋复杂。港口码头、滩涂的边界日趋简单。耕地的半径维数大于2,表明其面积从中心到四周逐步增长;盐田、水域则在距城市中心的不同半径空间中较为均匀的分布;其余地类则从中心向四周分布逐步衰减。林园地、未利用地、滩涂信息维数值较小,呈现较为明显的集中分布;耕地、盐田的空间分布逐渐向外围集中;港口码头则在原有基础上建设面积不断向四方扩展;水域和居民点与工矿用地的空间分布较均匀。结论]将分形理论运用于城市土地利用空间格局变化研究中能很好地弥补以往城市空间格局研究中定量论证的不足,具有较高的实践价值。

Study on the Spatial Pattern Changes of Land Use Based on Fractal Dimensions in Tianjin New Coastal Area

Objective] The aim was to discuss the spatial pattern changes of land use in Tianjin new coastal area based on fractal dimensions.Method] By dint of remote and geographic information system technology to obtain the data of urban land use in new coastal area from 1993 to 2008,the boundary dimension,radius dimension and information dimension of each land use type were calculated based on fractal dimension.In addition,the revealed land use spatial dimension changes characteristics were analyzed.Result] The spatial distribution of each land use type in new costal area had distinct fractal characteristics.And,the amount and changes of three types of dimension values effectively revealed the changes of complicatedness,centeredness and evenness of spatial pattern of land use in the study area.The boundary dimension of unused land and salty earth increased incessantly,which suggested its increasing complicatedness.The boundary of the port and wharf and shoal land was getting simpler.The radius dimension of the cultivated land was larger than 2,which suggested that its area spread from center to the surroundings;the one in salty land and waters distributed evenly within different radius space to the center of the city;the one in other land use types reduced gradually from center to the surroundings.The information dimension value in the woodland and orchard land,unused land and shoal land was small,and was in obvious concentrated distribution;the spatial distribution of cultivated and salty land concentrated in the outside area;the construction area in the port and wharf spread gradually on the basis of original state;the spatial distribution of waters and residents and mines were even.Conclusion] Applying fractal dimensions to the study of spatial pattern changes of urban land use can make up for some disadvantages in classical urban spatial pattern quantitative research,which has favorable practical value.