Hazard Assessment Of Mountain Torrent Disaster For Town Field Mountians Area

Mountain floods are the natural disasters widely distributed in mountain areas,Its outbreak suddenly, movement speed and has a huge impact, It serious damage to the transportation,land resources utilization,agricultural production,water conservancy and hydropower,urban construction and other economic activities and the safety of human life and property, mountain torrent has caused great disasters around the world.It occurs frequently in our country because of the influence of complex landform,strong rainfall and human activities,caused by rainfall in flood season of a year of mountain floods will be caused heavy casualties and property losses. Global changes will make our country extreme weather caused by high intensity rainfall frequency, intensity and regional distribution become more complicated and difficult to grasp in the future,as a result of disasters will be more serious.Natural science fund project in Chongqing "mountain area highway mountain torrent disaster fine comprehensive hazard assessment research" is the project background by article. Anlan town and Tiaoshi town in Banan district of Chongqing as the research scope, ArcGIS is the main technical support,evaluation on the research from two aspects of mountain torrent disaster subsquently environment partition and hazard assessment division.Through the study on the field survey and a large number of literature review,according to the mountain floods risk evaluation index selection principle,selecting main mountain floods of disaster-pregnant environment index and risk evaluation index,through the analysis of indicator elements, build a complete mountain floods of pregnant environment partition and risk evaluation index system,using analytic hierarchy process (AHP) to calculate the weight of each evaluation index value,meanwhile, taking powerful spatial analysis and mapping function of GIS technology, impact on the various indicators of digital processing, the data needed to obtain the index of single elements, so as to establish mountain torrent disaster of pregnant environment disasters based database partition and hazard assessment.Impact on the various indicators of digital processing, the data needed to obtain the index of single elements, so as to establish mountain floods of pregnant environment disasters based database partition and hazard assessment.From the results of the study,mountain floods in Anlan and Tiaoshi towns of pregnant environment was divided into the danger zone, high rock, rock and low rock four partition,their corresponding area ratio of9.65%,19.93%,34.92%and35.50%,the partition of two towns are mainly to rock and low rock.From the mountain floods hazard assessment results,the study area is divided into four threat level areas,there are high-risk area, moderate area, low risk area and dangerous area, their proportion of the total area in the study area is20.45%,16.05%,31.89%and16.05%in turn.In addition,through the use of settlement data and dangerous overlay analysis of partitioned data,statistics of3094190.41m2house buildings are located in the high-risk area, moderate areas account for33%of the total area.Therefore the study area of mountain floods task are heavy when the flood season comes.Research results provide decision-making basis for mountain torrent disaster prevention and mitigation in Anlan town and Tiaoshi town,meanwhile also provide reference for mountain floods risk zoning in mountain towns.