摘要
等时线是道路网中参考于某特定点位的系列时间可达性的可视化表达,其生成需要分析道路网络特性及通行状况,其形态可以反映可达性规律。本文对等时线进行了定义、特性分析及生成方法研究;通过类比水滴沿木板的纹理扩散的过程,提出水流扩展算法生成等时线,在网络栅格化模型的基础上,考虑等时线扩展独特的约束条件,如道路状况、移动条件及时间分段等获得可达性扩展路径,通过扩展凸包和角平分线移位生成等时线。水流扩展算法基于场论思想,可以针对网络空间中任意感兴趣部分灵活负载约束条件,方便生成实时等时线;类比等高线表示地貌特征,对基于以上构建机制生成的等时线的排列、疏密、弯曲形式、弯曲方向及延伸方向等进行了分析,发现空间可达性规律。
An isochrone is a visual representation of time accessibility which refers to a particular point in the road network .Features of road network and traffic conditions should be considered when generating isochrones .Accessibility rules can be found through analyzing the morphological features of isochrones .This article systematically studied the definition ,characteristics and generation methods of isochrones T.he flow method was proposed to generate isochrones ,which was analogous to the process of water drop spreading along the wood texture .Accessibility expansion paths were obtained on the basis of the network rasteriza‐tion model , considering unique constraints of isochrones extension , such as road conditions , moving criteria and time sections .Then we used the extending convex hull and angle bisector displacement to generate isochrones .Since the algorithm was based on field theory , we could flexibly load space constraints for any part of interested zones .This advantage made it convenient to generate real‐time isochrones .Similar to extracting geomorphic traits from contour lines ,accessibility rules were found by analyzing the arrangement form , density , bending form , bending direction and stretching direction of isochrones which was generated by the above approach .After that ,accessibility rules were inferred .
出处
《测绘学报》
EI
CSCD
北大核心
2014年第11期1190-1196,共7页
Acta Geodaetica et Cartographica Sinica
基金
国家科技支撑计划(2012BAJ22B02-01)
国家863计划(2012AA12A404)
关键词
道路网络
等时线
可视化
形态分析
可达性
road network
isochrones
visualization
morphological analysis
accessibility
