以分形理论与影响评价为基础的区域公路网发展分析

Analysis of Regional Highway Network's Development Based on Fractal Theory and Impact Assessment

以分形理论与影响评价为基础,将公路网自身发展与其对区域发展的影响作为有机整体进行分析,并对江苏省宜兴市公路网发展进行实证研究,以期得出全面、合理、具时空特征的定量化分析结果.在分析过程中采用综合路网密度、路网分形维数、国民经济增长贡献率、车流污染物排放量、景观碎化度等指标,并利用GIS空间分析方法,对宜兴市1996年、2000年和2002年公路网进行指标求解与发展分析.由分析结果得出:宜兴市1996年以来公路网建设取得较大发展,其综合路网密度、路网分形维数都呈持续增长趋势,但其对国民经济的增长贡献率较小,且其结构与功能有待进一步提升.公路网建设引起的生态环境问题日益严重,其车流污染物排放强度和景观碎化度都增长较快,因此必须重视公路网发展过程中的环境保护与土地利用问题.

Based on fractal theory and impact assessment, this paper analyzes highway network's own growth and its impact on regional development, which are regarded as an organic integrity, and conducts an empirical research on regional highway network's growth in Yixing City, Jiangsu Province in expectation of a quantitative result that is all-round, justifiable and spatial-temporal characterized. During the process of indexes calculation and development analysis on highway network of Yixing in 1996, 2000 and 2002, several indexes, such as integrated highway network density, fractal dimension, contribution ration of national economic growth, emission flux of traffic flow pollutant and degree of landscape fragmentation, are selected and GIS spatial analysis methods are employed. Conclusions are drawn from the analysis that the highway network construction made a great progress since 1996 in Yixing City, furthermore, its integrated highway network density and fractal dimension present continuously increasing trend, but its structures and functions need be improved.On the other hand, ecological environment problems resulted from highway network construction are increasingly severer, moreover, its emission flux of traffic flow pollutant as well as degree of landscape fragmentation both rise rapidly, hence much attention must be paid on the issues of environmental protection and land use.