The Road Impacts on the River Landscape in a Typical Valley in Yunnnan Province

Roads are ubiquitous features in the valleys; however the road impact on the river landscapes across the valley has not been systematically studied. This study collects the vector data of the road and river systems and data of the erosion of soil across Lan-cang River Valley, then we use GIS analysis to indicate the impacts between roads and river networks in four broad categories: (i) road and river network density, (ii) intersections of different grades of road layers, (iii) buffer analysis of road layers and (iv) the analysis of the road crossings and the erosion of the soil. The results show that the spatial differentiation of road and river density is obvious and the distribution of the roads intersections is similar to the road density. The buffer analysis of roads indicates that high level roads impact rivers more than other levels. Also, the road crossing impact is relevant to the soil erosion nearby.