武汉城市群交通运输体系与城镇空间扩展关联分析

Relationship between transportation system and urban spatial expansion in Wuhan Urban Agglomeration

交通运输体系与城镇空间扩展的关联分析是揭示交通运输与经济增长作用关系的重要切入点。采用等时线叠置法和指标分区法,分析了武汉城市群交通可达性及交通优势度与城镇空间扩展的时空格局、关联特征及其作用机理。研究表明,交通运输体系与城镇空间扩展具有内在联系,呈现出互动耦合、协同演进格局。从作用机理来看,交通运输体系通过直接效应、外部效应和乘数效应对城镇空间扩展起着重要的支撑和推动作用;城镇空间扩展在"量"和"质"上对交通运输提出了新要求,刺激并保障了交通运输体系的发展,两者相互反馈、相互依赖。从政策启示来看,交通运输体系的空间不均衡是造成区域经济发展水平差异的重要因素,制定差别化的交通运输发展战略和完善一体化的交通运输体系是加快区域经济增长和缩小地区差距的重要途径。

Investigating the relationship between transportation system and urban spatial expansion is an important starting point for revealing interactions between transportation and economic growth.Existing studies in development economics and transportation economics frequently used indicators such as transportation investment and operating mileage of railways and highways to reflect the level of development of traffic infrastructure.These indicators can well demonstrate the investment and construction scale in relation to transportation system as well as well fit the inherent requirement of economic models,yet they are insufficient in reflecting the operation level and efficiency of transportation facilities and their spatio-temporal differentiation.Taking the Wuhan Urban Agglomeration(WUA) as an example,this paper extracted urban land area information and road network in 2000 and 2010 using Landsat imageries through the application of remote sensing and GIS technology.It investigates the spatio-temporal pattern,relationship and driving mechanism of accessibility as well as transport dominance and urban spatial expansion with the application of isochrone overlay and index classification methods.The results indicate that an interdependent and bi-directional relationship exists between transportation system and urban spatial expansion.The transportation system plays an important role in supporting and promoting economic growth and agglomeration of population and industry,which are intrinsically related to spatial expansion of urban land,through direct impacts,external effects as well as multiplier effects.Correspondingly,urban spatial expansion stimulates and ensures the improvements in the quantity and quality of transportation system.Unbalanced distribution of the transportation system is contended to be an important factor causing increased regional economic disparity.The policy implications are that,the government should attach more attention to formulating differentiated transportation development strategies and improving the integrated transportation system in the metropolitan area,which may facilitate accelerated economic growth and reducing regional economic disparities.