Weight Analysis And Risk Assessment On Influence Factors Of Debris Flow Main Gully In Shuimo

Referring to previous studies and field investigation,this paper determined the regional geological environment conditions and the debris flow basic characteristics of the main gully in the study area.According to the basic characteristics of the main gully,this paper calculated debris flow basic characteristic value of main gull and two branch gully consisted of Sanwangmiao gully and Liansanpo gully in the study area,including heavy debris flow fluid,peak flow,the maximum debris of one time,and so on.Then,based on AHP-PCA,the author calculated weights and comprehensive weights of evaluation factor in the main gully area.At first confirm influencing factors to construct the hierarchical structure model.Then,construct judgment matrix and judgment matrix calculated by using MATLAB's largest eigenvectors.Finally calculate the weight value of each refers to the impact factors and comprehensive weight value and corresponding eigenvectors.The results of impact factor weights as follow: relative height>rainfall> Slope height > surface runoff of the main rivers > landform type> the intensity of earthquakes> unreasonable slope cutting >engineering geological lithology > Construction diverted rivers > the distance from the fault zone >slope farming.These achievements will provide a very important idea and direction for the prevention and control of debris flow in the study area.In addition,according to the basic characteristics of the main gully debris flow,debris flow type and the outbreak frequency to assessment the main gully debris flow in the study area,the study area belongs to the debris flow prone areas,the affected body in the study area is more dangerous,the probability of landslides caused by geological disaster loss is very large,and governance very urgent.Finally,the application of FLAC3 D model under storm conditions in the study area the main debris flow numerical simulation analysis,obtained the most dangerous place for location of the slope angle,the maximum displacement is about 5.6×102m,there is a big risk,the possibility of a great slip.Slip surface is also similar to the arc shape,if there is a heavy rain in the study area,there is a great possibility of debris flow.Therefore,we should pay more attention to the debris flow in the main channel of the study area,we must take measures as soon as possible to protect the safety of the local residents and avoid the loss of property.