基于数值模拟的小流域泥石流危险性评价研究

通过重点研究岷江小流域内6条泥石流沟，采用野外实地调查和遥感影像解译，以及在同实际降雨频率相同的条件下运用FLO 2D进行的数值模拟，重现了泥石流暴发现状，得出其堆积扇危险特征，与实际作出对比验证，计算出其堆积扇面积的误差比率在-25%~12%之间，冲出量的误差比率在-16%~-1%之间，模拟结果较好。并同时对研究区内高、中、低3种危险类型的面积及特征进行分析，得出小流域内的泥石流堆积扇危险面积所占比例。根据相同参数设计模拟5%、1%降雨频率下泥石流结果，得出3种不同频率下的堆积扇平均堆积深度、堆积扇面积和冲出量，可为研究区的泥石流风险评估、预警预报、工程治理和危险范围分区提供有效的参考依据

Hazard Assessment of Debris Flow in Small Watershed Based on Numerical Simulation

This paper focuses on 6 debris flow gullies in the small watershed. Based on field investigation and remote sensing image interpretation, the numerical simulation of debris flow process in the actual rainfall frenquency was made by FLO 2D. It shows the deviation ratio in fan area is between -25%-12%, in run out amount is between -16%--1%, which shows the simulation results are bettercompared with the actual situation.Meanwhile, we carried out the debris flow hazard analysis and the outcome shows the area proportion of high hazard,medium hazard and low hazard accumulation zone of the total area. In addition, according to the debris flow simulated results of 5% and 1% rainfall frequency under the same parameters, average deposition depth ofalluvial fan , alluvial fan area and the run out amount under three different frequencies, it can provide reference for debris flow hazard assessment, disaster forecasting, engineering treatment and hazard zone partition in study area.