建立暴雨山洪水动力学数值模型.基本控制方程采用二维浅水方程,并考虑降雨和下渗;在空间上采用能有效捕捉激波的WAF TVD二阶格式;在时间上采用一阶龙格库塔法,并采用自适应时间步长满足数值稳定性要求,使模型对复杂地形也能保持高计算效率.基于该模型,提出新的方法确定山洪灾害的临界降雨条件,并应用于典型山洪易发区的暴雨山洪预报.计算结果表明该研究方法具有理论先进性和实际可操作性,为有效防御山洪灾害提供了新的技术. A numerical model of storm flood dynamics was established.The two-dimensional shallow water equation was adopted for the basic control equations, and rainfall and infiltration were taken into account. The WAF TVD second-order format which could capture the shock waves was adopted spatially. Tower method and the adaptive time step to meet the numerical stability requirements so that the model can maintain high computational efficiency for complex terrain.Based on the model, a new method is proposed to determine the critical rainfall conditions of mountain torrent disasters, and applied to a typical flood easy Rainstorm and flash flood forecast in this area.The calculation results show that this research method has theoretical advancedness and practicability and provides a new technology for effective prevention of mountain torrent disaster.