The Debris Flow Risk Assessment Of Xiaohuogou In Huaichang Village

Although there is no record of debris flow in the history of the Xiaohuo gou watershed in Huaichang Village,it has become a potential debris flow geological hazard due to its large longitudinal slope gradient and rich resources.If the critical conditions of rainstorm are met,the debris flow develops and the accumulation will threaten the security of the school buildings and people on the south side of the valley.In this paper,with the qualitative analysis and quantitative analysis of the combination of the method,the study area of debris flow potential development of the law were analyzed and studied.By means of numerical simulation,the potential debris flow movement and accumulation characteristics of the study area are expounded by visualization and quantification and the potential risk of debris flow in this area is analyzed and evaluated,which has certain predictive significance for the study: the study area satisfies the topographic and geomorphological conditions and provenance conditions with debris flow,and the overall debris flow basin status is still developing.In the quantitative analysis,FLO-2D,a two-dimensional flood simulation program,is mainly based on the viscous-plastic-collision rheological model,and the central finite difference numerical algorithm is used to solve the problem.In the ARCGIS,the digital elevation model is established after gridding the elevation map.The model should be introduced into the FLO-2D program in ASC ? format,The n the FLO-2D is run after dividing the boundary,dividing the grid,selecting the water collection point,drawing the flow process curve and selecting the parameters.This study simulates the development process of a debris flow with a burst of 60 minutes and a recurrence period of 20 years.The simulation results include debris flow velocity distribution,accumulation depth and accumulation range.According to the simulation results,the velocity distribution is mainly in the range of 1.2-1.6m/s,the maximum is 2.16m/s,the accumulation area is formed by the accumulation zone,the maximum flow depth is 14.97 m,the maximum accumulation height is 13.36 m,the accumulation area is 1625.3m~3 and the total volume of the deposit is 2115.5m~3.The results show that the error is 21% in the qualitative analysis.According to the above analysis results,the numerical simulation results are introduced into ARCGIS for further analysis and calculation.Taking the mud depth and the product of mud depth and velocity as the two evaluation indexes,the influence intensity range and th e outbreak frequency of the debris flow are delineated by the condition screening,and the dangerous area of debris flow disaster is further obtained.When the debris flow to reproduce the cycle of 20 years,the Buildings of Huaic hangcun primary school are in a high-risk area,once the outbreak of debris flow disaster,there is the possibility of rapid destruction of the building,timely preventive measures,such as the construction stop dam,planting seedlings,drainage dredging and so on are needed.