A Study On Formation Reasons About Chengkou Country's Mountain Torrent Diasters And Countermeasures

Chengkou Country, in Chongqing, situated in the area of Daba Mountain and influnenced by both physical geographic and socioeconomic factors, belongs to the ecological vulnerable area. Far away from the city of Chongqing, its transporation is blocked, ecnomy backward, human quality low, and the low level of its urbanization cannot promote the development of the less developed rural area. Frequent occurrence of mountain torrents cause serious damage to physical environment, the people s lives and properties, and socioeconomic environment. This hinders the socioecnimic sustainable development. The paper has dicussed comprehensively and systemmaticly the reasons that this local mountain torrent disasters occur frequently in time and space. And it has proposed taking measures against the natural disaters.Based on field investigation and data anaiysis, this paper has summarized the characteristic and its distribution. First, the author take a systemtic study for the local mountain torrent disaters and initially establish the relationship between the outbreak of mountain torrent disaters and geological landforms and vegetation. Chengkou, due to its special geographical location, which causes the southwest monsoon to affect easily. Southwest warm and moist air currents are prevented by Daba Moutain,which produces abundant rainfall on windward slope, and more flash floods,and causes mountain torrent diasters to occur frequently.At the same time the author has set up the quantitative relationship between the different rainfall and the occurrence of mud-rock flow and landslide. For example,the continous rainstorms affect the landslide greatest,the different rainfall causes different types of mud-rock flows to happen.There is close relationship between lothological and the formation and growth of the mountain torrent diasters. Soft and hard strata are main lothological unit which causes the mountain torrent disasters to happen. The former causes more mud-rock flows and landslides the mountain torrent induces primarily, the latter causes more stream- river floods.Besides the natural factor's influence,by using real examples the author explain that the local human activities, including the forest vegetation's destruction, the cultivation on the steep slope, the unreasonable engineering construction and so on,cause more extensive damage the mountain torrent disasters. Nowadays the mountain torrent disasters,which do severe damage, mainly are created by human behaviors.In short, the author has used the full and accurate material to analyze the reason that Chengkou County' s mountain torrent diasters frequently occur:â‘ The intensive rainstorm is the direct reason that cause the local mountain torrent disasters to occur;â‘¡The special terrain topography is the foundation condition which induces the mountain torrent disasters to happan;â‘¢The complex geological structure is to intensify the mountain torrent disasters' damages;â‘£But the human activities then further stimulate and aggravate the mountain torrent disasters.Finally the author,using Arcgis and unflying relative data,has made a zoning map of preventing and controlling local mountain torrent disasters. And the author has proposed concrete measures to prevent and control the diasters.On the basis of quantitative analysis,the paper, unifying the qualitative analysis and considering comprehensively the influences which physical geographic factors and human socioeconomic activitives affect the mountain torrent disasters,is of certain pratical value.