| Accessibility is one of the research focuses of human geography, urban andregional planning, transportation economics and other disciplines. We divided theaccessibility into weighted-accessibility and unweighted-accessibility. Theunweighted-accessibility was measured by space syntax and isochronous rings. Andthe weighted-accessibility（weighed average travel time and location potentiality）wassynthetically evaluated by spatial autocorrelation of spatial-temporal proximity,spatial association index and semivariable function model. Finally, the hinterland ofcentral city was carved out according to the diffusion mode of accessibility and thecomprehensive strength of central city. The result shows:（1）The line segment space stretch patterns of regional transportationaccessibility are those diffusing along the “point–axis†shape, centralizing obviously,the connection of the segments of the road network is non-balanced and the serviceability of road network matches nearly. The spatial patterns of axis type are thosestretching along the“trunk–branchâ€shape, making a distinction between the importantand the lesser one. The distribution of axis grade is closely related to the urbansystem, transportation and the development of social economic.（2）Spatial diffusion of isochronous ring along the national road, provincialroad, and county road is continuous while Spatial diffusion of isochronous ring alongclosed railway and highway is leaps. The terrain of the economic region ofHohhot-Baotou-Erdos-Yulin greatly influences the daily accessibility of central city.The correlation relationship between city’s regional accessibility and centricity isstrongest in all.（3）The spatial autocorrelation of spatial-temporal proximity model shows: inthe economic region of Hohhot-Baotou-Erdos-Yulin, the special economic mutualinfluence is strong positive correlation within3h, weak positive correlation within5hand irrelevant beyond5h. The regional autocorrelation exist a reasonable time range.（4）The difference of spatial distribution proportionality of4cities’ weightedaverage travel time is obvious. The proportionality of Yulin is best. Hohhot is the citymost responsibility for the regional weighted average travel time. The effect of specialdistance on regional hot point and cold point is remarkable. （5）According to the research about accessibility indexes, the regional core cityhas a top score of weighted average travel time, the regional secondary cities have thetop score of regional potential, and the outlying cities have the low scores of weightedaverage travel time and regional potential. Considering the outlying regional Yulinwhich is lack of the core and transport advantage greatly influents the development ofregional integration, the government should foster the complementary industries andimprove own economic strength.（6）The strong affected zone distributing in regional northeast, Hohhot, Baotou,Ordos and Jungar Banner is in accord with the high score regional of weightedaverage travel time. It shows the accessibility is very important to the filed strength.Most cites’hinterland is in accord with own administrative region. As the relief of theterrain is great, most cities around the desert have not been the hinterland of their ownhigh grade administrative cities. |
