丝绸之路经济带交通运输的时空演化特征及对经济发展的影响

采用交通网络维数法、相关系数法和格兰杰因果检验分析法等定量统计方法，系统分析了自1998-2015年丝绸之路经济带九省区交通运输投资额、交通网络发育程度、交通运输能力的时空变化特征及对国民经济发展的影响。结果表明：丝绸之路经济带九省区交通运输投资额总体呈增长趋势，交通网络密度明显低于全国平均水平；交通网络发育程度不高，但增长发育速度较快，道路密度和网络维数均有很大幅度的提升，公路网的通达性水平及增速明显优于铁路网；交通设施建设对经济发展的影响显著，对国民生产总值的促进作用时滞长度为两年左右，但各省区之间的交通基础设施建设造成了不明显的空间溢出效应，体现出丝绸之路经济带各省区之间的经济联系尚处薄弱阶段。

Spatial-temporal evolution and impact on economic development of the transportation network in Silk Road Economic Belt

The Silk Road Economic Belt is a great national strategy for opening to the west and promoting economic cooperation with the surrounding region. Speeding up the transportation infrastructure construction is a principal measure to boost the construction of the Silk Road Economic Belt and promote the inter-state connectivity. Applying traffic network dimension, correlation coefficient and Granger causality test, we studied the dynamic change of transportation investment, track network development, traffic capacity and the impact on economic development of the Silk Road Economic Belt, 1998-2015. The results show that the transportation investment of 9 provinces in the Silk Road Economic Belt presented an increasing trend as a whole, and the speed of 4 southwest provinces was faster than that of the northwest provinces. The track network density was slower than the national average obviously, and the railway network density and the road network density in 2015 were respectively 0.04 km/sq.km and 0.14 km·km^-2 slower than the national average. Development degree of track network was not high. Traffic network dimension increased in 1998-2015, and the railway network dimension increased from 1.16 to 1.26, the road network dimension increased from 1.28 to 1.30, but always lower than the national average. This indicates that the traffic development degree of Silk Road Economic Belt was still lower than other regions. The track network development of the 4 southwest provinces was better than that of the 5 northwest provinces. The passenger and cargo capacity of the Silk Road Economic Belt showed an increase trend in 1998-2015 with the improvement of the Silk Road Economic Belt transportation conditions. The passenger and cargo capacity and turnover ability were gradually improving, and railway freight turnover capacity rose dramatically, but the status of road freight turnover throughout the country declined. Selecting gross domestic product(GDP)in 1998-2015 and fixed assets of traffic facilities construction( TI )as sample data, applying correlation coefficient analysis, this study demonstrates that transport infrastructure investment of the Silk Road Economic Belt had significant impact on the national economic development. The promotion of transportation infrastructure to the gross national product delayed for two years, and Gross national product had a direct effect on transport infrastructure investment in the same year. The spatial spillover effects of transportation infrastructure were not sizable, which indicated that the economic relation between different provinces was still weak. The innovation point of this essay is to reveal spatial-temporal evolution of the transportation network and its impact on economic development in Silk Road Economic Belt by qualitative and quantitative combined analysis, and this study could provide a scientific basis for promoting the economic development and the traffic infrastructure construction of the Silk Road Economic Belt.