30 a青海省公路可达性及县域经济联系格局演化

Pattern variation of accessibility and economic linkage at county scale in Qinghai Province from 1986 to 2016

采用加权平均旅行时间、引力模型与克里金插值、XY to line、自然间断点分级法、分级符号等GIS分析方法,以1986年、1995年、2004年、2016年为时间断面,分析了青海省公路网络中43个主要节点城镇的可达性及县域经济联系格局的演化规律,结论为:1986—2016年,青海省公路网络等可达性线呈现不规则的半环状分布,影响因素主要有位置、交通、经济及其时间距离等,可达性插值表现为交通主干道指向性;青海省公路网络可达性水平均有提升,可达性值的变化呈现相似性与差异性并存的特点; 1986—2016年,青海省经济联系强度与对外经济联系总量均呈现增长态势,尤其经济联系总量增长愈来愈快;前五等级的经济联系强度与前三经济联系总量的县域基本集中于西宁、海东地区,体现出青海省典型的"单核"城市空间结构,省会城市辐射带动作用明显;经济联系强度、经济联系总量与可达性均呈现正相关。

Due to the natural geographical location,economic and other reasons,the traffic of Qinghai Province, China is relatively backward,the highway has been located at a very important position in the transportation network of Qinghai Province in the long time.This paper takes 1986,1995,2004and 2016as the time section,obtains Qinghai Province highway traffic network data based on Arcgis spatial analysis module,and analyzes the accessibility and evolution of the 43main points in the cities of Qinghai Province highway network using the weighted average travel time method,the spatial pattern of Kriging interpolation method.As a whole,the level of accessibility in the spatial distribution shows a decreasing trend from Xining City and Haidong City to other parts of the province,and the contour accessibility line presents a semi annular irregular distribution.The accessibility of Xining City and Haidong City is the best during the study period,especially it is the highest in Xining City.The main factors impacting the accessibility include the geographical location,traffic conditions ,urban economic and so on.The accessibility interpolation shows the directivity of traffic trunk road.Accessibility dynamic evolution shows that the road network accessibility levels of the 43nodes have been increased in Qinghai Province and the variation of accessibility represents concomitant characteristics of similarities and differences.The spatial distribution of the contour accessibility line variation ratio shows trunk road directivity,such as the national highway and the motorway.The similarity shows a declining trend from the northeast to the west and the south region of the province.But there were differences in the level of the accessibility in three research stages.During 1986-2016,the economic linkage intensity and economy linkage volume among the counties in Qinghai Province has shown a growing trend,especially the total volume of economy linkage grows faster and faster.The economic linkage intensity of the top five and the economy linkage volume of the top three mainly concentrate in Xining and Haidong City.It reflects the typical "single core" urban spatial structure of Qinghai Province,and the radiation and leading effect of the provincial administrative center is very obvious.There is a positive correlation between the accessibility and economic linkage intensity or volume in the region.