拟建猴子岩水电站移民安置点位于江口沟泥石流堆积扇上，通过现场调查泥石流形成条件和运动特征，获得了1958年发生的50 a一遇泥石流危险区范围，根据雨洪法计算确定了泥石流的相关运动学参数。使用基于有限体积法的CFX软件，选择Bingham流变模型对江口沟泥石流流动过程的液面分布情况和速度场进行了三维数值模拟，得出了泥石流危险区范围和速度场分布情况。模拟结果显示，江口沟50 a一遇泥石流流过堆积区的平均速度为5.76 m/s，其中最大速度为13.59 m/s。数值模拟计算得出的危险范围较1958年扩大，是因为早期泥石流堆积物将原有地面特别是沟道附近地面抬高，使得现状条件下泥石流更容易向两侧漫流泛滥而扩大。上述结果为泥石流防治工程设计及危险区范围划定提供了一种新的方法，对工程实践具有重要的指导意义。

The immigrants from Houziyan hydropower station are resettled on the accumulation fan of Jiangkou gully debris flow. Based on field investigation on the formation conditions and motion characteristics of the debris flow, the hazard scope of debris flow occurred in 1958 with a frequency of 50-year return period is obtained, and the motion parameters of debris flow are determined with the rain-flood method. The fluid level distribution and velocity field are simulated, and the hazard scope and the velocity field of Jiangkou gully debris flow are obtained by using CFX software, based on Bingham rheological model. The simulation results show that the average velocity of a 50-year return period debris flow passed through the accumulation fan is 5.76 m/s, while the maximum velocity is 13.59 m/s. The hazard zone obtained by the numerical simulation is larger than that occurred in 1958, since the deposit of early debris flow filled up the original ground, especially the ground near the channel, making the debris flow flood and expand more easily toward both the flanks of the channel. This research provides a new approach to designing prevention project and delineation of hazard zone of debris flow.