1978-2012年武陵山区公路通达性演化及其对经济发展的影响

利用通达性系数和加权平均出行时间,结合GIS网络分析和空间分析方法,探讨了1978-2012年武陵山区64个县（市、区）与武陵山区及其外围38个地级市以上城市之间通达性演化的格局和特征,并分析了2000-2012年武陵山区经济发展格局,采用柯布—道格拉斯生产函数模型,定量模拟了通达性对经济发展的影响。研究发现：1978-2000年,武陵山区通达性系数的稳定性较好,到2012年,通达性系数较小值具有向武陵山区东南部集聚的趋势。1978-2000年武陵山区的经济加权平均出行时间和人口加权出行时间的优劣程度均具有由东向西逐渐下降的“圈层式”布局的特点,到2012年,经济加权平均出行时间和人口加权平均出行时间较小值均具有向武陵山区东南部迁移的趋势,原因在于武陵山区及其外围的东部和南部城市较多且路网发展更为迅速和完善。2000-2012年,武陵山区经济发展格局相对稳定,形成了“东部和西北部强、西南部和中北部弱”的经济发展格局,但经济发展的绝对差距逐步扩大,两极分化的趋势越来越明显。2000-2012年武陵山区通达性的重要程度发生变化,通达性的优劣程度对于GDP的影响明显上升,通达性的改善在整体上较好地促进了武陵山区GDP的增长,对武陵山区经济发展的作用变得越来越重要。同时,通达性改善削弱了第一产业的发展,但对第二产业发展具有逐渐上升的正向影响,对第三产业发展的正向影响显著上升。研究充实了贫困地区交通与经济发展关系的实证和理论,对武陵山区通达性改善与经济发展具有重要的指导意义,可以为相关政策的制定提供参考依据。

Evolution of road accessibility and its effects on economy development in Wuling Mountain Areas from 1978 to 2012

The patterns and characteristics of accessibility evolution in 64 counties (county-level city, district) of Wuling Mountain Areas and 38 cities related to the surroundings from 1978 to 2012 are discussed. Based on the indexes of accessibility coefficient and weighted average travel time, the GIS network and space analysis are employed. Then after the pattern analysis of economic development in this region, Cobb-Douglas Production Function Model is used to simulate the impact of accessibility on economic development. The research shows that the accessibility coefficient was consistent from 1978 to 2000, but the smaller values of accessibility coefficient turned to be agglomerated towards the southeast areas from 2000 to 2012. During the period 1978-2000, both the qualities of economy weighted average travel time and population weighted average travel time showed a gradual decline from east to west, and constructed a "circling structure". However both the smaller value of economy weighted average travel time and population weighted average travel time mainly appeared in the southeast from 2000 to 2012, because of the rapid and advanced development of road networks in the eastern and southern areas. From 2000 to 2012, the patterns of economic development were relatively stable, forming an economic development pattern of "strong east and north, but weak south and central north", while the absolute gap in economic development was widening with a strong and obvious trend of polarization. At the same time, the importance of the accessibility for Wuling Mountain Areas changed. The accessibility quality had more effect on the growth of GDP, and the improvement of accessibility promoted the growth of GDP in the study area on the whole, which is more important for the local eonomic development. Meanwhile, the improvement of accessibility weakened the development of primary industry, but had a gradually increasing positive influence on the secondary industry and noticeably increasing positive influence on the tertiary industry. This paper enriches the empirical and theoretical relation between transportation and economic development in poor regions, provides reference to the formulation of relevant policies, and is instructive and meaningful to the enhancement of accessibility and economic development.