基于FLO-2D与冲量模型的泥石流危险度分区方法及应用

Method and Application of Debris Flow Hazard Zoning Based on FLO-2D and Impulse Model

鉴于正确的泥石流危险度分区对合理规划布局泥石流堆积区经济活动的重要作用,采用FLO-2D模型对泥石流的运动堆积过程进行数值模拟,求得泥石流堆积扇上流速、流深分布及以格网为单位的泥石流体流速和流深的时间变化过程,结合GIS技术对计算所得数据进行空间分析,以泥石流体冲量为分区指标,建立泥石流堆积扇危险度分区模型,并以四川省石棉县马颈子沟泥石流为例,模拟该沟百年一遇泥石流运动堆积过程。结果表明,模拟堆积范围与实际堆积面积吻合度达86.16%;根据格网内泥石流体冲量模长,可将泥石流堆积扇危险度分为极度、重度、中度、轻度危险区四个等级。

In view of the significance of correct risk degree zoning of debris flow in reasonable planning and layout economic activities of the accumulated region of mud-rock flow,this paper simulates the process of debris flow diffusion and deposition by using FLO-2Dmodel.And then we obtain the velocity and flow depth distribution on the debris fan and the change of debris flow velocity and flow depth with time based on the grid unit.Combining with the GIS technology,the calculated spatial data was analyzed.Taking the impulse of debris flow as new zoning index,a new hazard zoning model of debris flow deposition fans is established.Taking the Majingzi debris flow in Shimian county,Sichuan Province for an example,its accumulation process happened once-in-a-century is simulated.The results show that the goodness of fit for simulation scope and the actual area is up to 86.16%;the hazard degree of debris flow deposition fans can be divided into four grade zones based on impulse length.