根据最短时间距离模型和综合通达性模型计算了四川盆地城市群内18个城市的交通通达性,并建立最短时间距离矩阵表征各城市之间的空间联系强度。研究表明:用最短时间距离计算的成都通达性最优,而重庆通达性居于第13位;综合通达性模型表明重庆通达性最好,成都居第2位,川东北城市也居于前列。研究还表明在四川盆地城市群内形成了以成都为中心的紧密联系的空间一体化。但是,四川省各城市与重庆的空间联系紧密程度却很低,形成了明显的"空间背离"。未来几年内重庆将成为四川盆地城市群内最重要的交通枢纽。

The researches on the spatial connection among the cities in the urban agglomeration are the foundation to select region or sub-regional central city and make urban agglomeration planning reasonably. All the methods measuring spatial connection of cities,the gravitation model and urban flow model are being widely used. And accessibility denotes the ease with which activities may be reached from a given location using a particular transportation system, and reflects the opportunities and potentialities of a particular region to exchange with others. In this paper, the authors calculate the railway and highway comparative accessibility of 18 cities in Sichuan Basin Urban Agglomeration (SBUA) by the Shortest Time Distance Model (STDM). Considering various transportations, the authors establish Integrated Accessibility Model to measure integration accessibility of cities. Also, the Shortest Time Distance Matrix is established to analyze the spatial contact intensity among the 18 cities. The research shows that the accessibility of Chengdu is the best while that of Chongqing ranks on the thirteenth, and Panzhihua is the worst among all of the cities in terms of STDM. However, the result by the Integrated Accessibility Model indicates that accessibility of Chongqing is the best, Chengdu follows behind, and that of cities in northeast Sichuan is at the fore. Spatial Contact Intensity Matrix also shows that most of cities in SBUC have the tightest connecting with Chengdu, but low connecting with Chongqing, concluding that the Spatial-Deviation between Chongqing and other cities has been formed. The ranks of some cities in SBUA will be changed greatly in future. Specifically, as to the accessibility, Chongqing will rank first and become the most important transportation hinge in SBUA, and the accessibility of Nanchong, Suining, Guangan, Dazhou would become much better, but the tendency is that the changes of accessibility to the cities outside the agglomeration would be better than the cities inside the agglomeration. Therefore, it is imperative to strengthen spatial connecting between Chongqing and the other cities in SBUA, to advance regional cooperation and develop Cheng-Yu economic zone.