淮海城市群城镇用地扩张的时空动态特征

Spatio-temporal characteristics of urban land expansion in Huaihai urban agglomeration

淮海城市群是典型的省际边缘型城市群,其发展水平和一体化进程与其他成熟型城市群相比差距较大.结合GIS与景观生态学方法,从整体尺度、区域尺度探讨了淮海城市群城镇用地扩张的规模、速度、方向、景观格局和扩张模式,进而对其城镇用地格局开展静态评估和动态变化分析.结果表明:淮海城市群城镇用地呈多核式分散分布,表现出“核心—外围”蔓延扩张的空间格局.近30年来经历了加速扩张、高速扩张、减速扩张的“S型”变化过程;扩张强度方面,整体尺度与非核心区各方向上的不均衡问题较为突出;景观格局方面,不同尺度下景观指数差异显著,城镇用地斑块破碎度增加,景观格局不稳定性问题突出;扩张模式上,城镇用地以飞地式扩张模式为主.总之,淮海城市群城镇用地发展尚处于“扩散阶段”,这主要与淮海城市群经济发展水平较低,中心城市的中心性不强有关.

Huaihai urban agglomeration is a typical provincial marginal urban agglomeration,among which the development level and integration process are far behind other mature urban agglomeration.The scale,speed,direction,landscape pattern and expansion mode of urban land expansion in Huaihai urban agglomeration from the whole scale and regional scale are investigated by GIS combined with land scape ecology method.The urban land use pattern is evaluated statically and analyzed dynamically.The results show that the urban land use in Huaihai urban agglomeration is distributed in multi-core type,and the spatial pattern of"core-periphery"spreading and expanding is shown.In the past 30 years,it has experienced the"S-shaped"change process of accelerating expansion,high-speed expansion and decelerating expansion.In terms of the expansion intensity,the imbalances of overall scale and at different directions in the non-core area are relatively prominent.In terms of the landscape pattern,there are significant differences in landscape index at different scales,which leads to increased fragmentation of urban land patches and prominent instability of landscape pattern.In terms of expansion mode,the expansion mode of urban land is mainly enclave expansion mode.In short,the development of urban land in Huaihai urban agglomeration is still in the"diffusion stage",which is mainly related to the low level of economic development in Huaihai urban agglomeration and the weak centrality of the central cities.