Zhongshan Clear On The Rural Road Network Evaluation Research

Accessibility means interaction chance of the nodes in the road network and travel convenience from departure to destination. Road network is the foundation of the rural social and economic development. Accessibility is an effective evaluation index on road network quality and level.Based on the data from the Second National Land Survey and fieldwork, this paper has designed quantitative indexes according to the characteristics of rural areas and the meaning of road network accessibility, such as proximity to road, inner accessibility within townships and connectivity to trunk road to study and evaluate on road network accessibility of Danfeng County in Shaanxi Province, which lies in Qin-ba mountainous region. And improvement approaches of road network accessibility in different regions of Danfeng County have been analyzed too. The study has been supported by GIS software, and uses townships and administrative villages as its basic research unit. The research methods of road network accessibility in rural areas in this paper has been an effective improvement, and the research results have certain referential value to road network construction and improvement, immigration moving project and rural residential land consolidation in the rural areas of Qin-ba mountainous region in South Shaanxi Province.The level of road network accessibility in rural areas is determined by the convenience of road use by the residents and the convenience and quickness of economic and social communication both inside and outside. Proximity to road which measures the scale and proportion of the residential settlements within different distance from road of different ranks can reflect the convenience of road use by the residents; Inner accessibility within townships which measures the mean value of distance of the shortest route between every two administrative villages with in a township can show the convenience and quickness of economic and social communication inside a township; Connectivity to trunk road which measures the mean value of the distance of the shortest route that connects every administrative village to the trunk road can reveal the convenience and quickness of economic and social communication with outside communities. The evaluation of the road network accessibility can be conducted by the use of the three indexes above.The results show that, road network accessibility of Danfeng County varies from region to region. Regions with high level economic development, better land use condition an high level of road network construction have high level of proximity to road; Regions with closely distributed administrative villages and high level of road network construction have high level of inner accessibility within townships; Regions along and near the trunk roads have high level of connectivity to trunk road. Regions that are remote, undeveloped and with complicated topography have low level of nearly all the indexes of road network accessibility Based on the evaluation results of proximity to road, inner accessibility within townships and connectivity to trunk road, the comprehensive road network accessibility of each township has been analyzed. The results show that, the comprehensive road network accessibility of Danfeng County has an obvious spatial pattern of "core-periphery" and the characteristics of "distance-decay" along the direction away from the truck roads.The improvement approaches of road network accessibility in different regions are as follows:In valley-plain regions, the land is relatively flat, the population and industries are concentrated and large scale urban and rural settlements with planar distribution are very common. The road network accessibility in these regions is relatively high, yet still needs an overall optimization and improvement; In low mountain-hill regions, the population and industries have low level of concentration because of the topography, and rural settlements with liner or radial distribution in river confluence reaches are very representative. Proximity to road needs to be enhanced by improvement of roads in villages. Inner accessibility within townships needs to be improved through rural residential land consolidation and improvement of roads that connect administrative villages. Connectivity to trunk road needs to be improved by the improvement of roads that connect townships with trunk road; The topography is irregular and complicated in medium high mountainous regions. The townships there have remote location and slow social and economic development. Rural settlements with liner or radial distribution along rivers and settlements with point shaped distribution in medium high mountain regions, especially in remote medium high, ecological fragile and geological hazard threatened regions, are very common. The road network accessibility problems in these regions are various and complicated, where comprehensive measures such as road network construction and optimization, immigration moving, rural residential land consolidation and special industry development need to be carried out to improve the overall road network accessibility and the standard of production and living of the local people.