Study on highway debris flow hazard assessment in Wenchuan County

Based on remote sensing and geographic information system technology, and hazard assessment methodologies, this paper focus on the study of debris flow hazard assessment in Wenchuan Count, and Yingxiu-Wenchuan highway, which is the part of National Highway No. 213 and No.317, and the lifeline for 5.12 Wenchuan Earthquake. Considering topography, geology, vegetation and land use patterns and etc, the synthetic evaluation factors for debris flow hazard assessment were operated by different layers and overlay analysis in GIS. Through comprehensive analysis of multi-factor, the debris flow hazard areas in Wenchuan County were identified, and then the hazard regions along Yingxiu-Wenchuan highway were divided as well. The results show that debris flow hazard areas in Wenchuan County mainly distribute along National Highway No.213, and No.317. Furthermore, debris flow hazard areas distribute along Yingxiu-Wenchuan highway, and mainly locate in five towns: covers 4.5 km in Yingxiu Town, 10.5 km in Yinxing Town, 11 km in Caopo Town, 14 km in Mianchi Town, and 8 km in Weizhou Town. This paper provides technical support to the prevention of debris flow hazard for road construction and operation, to mitigation its harm on the highway in the study area. And it will lay the foundation for further study, the practical application and dissemination of assessment techniques.