不同降雨强度下红色村干沟泥石流数值研究

Numerical Study on Debris Flow Under Different Rainfall Intensities at Gangou in Hongse Village， Dujiangyan

摘要:

结合实测资料分析了四川省都江堰市红色村干沟泥石流的运动规律，并运用DEBRIS2D软件建立了二维泥石流运动数学模型，利用该模型模拟得到的龙头标高、平均堆积厚度及沟口流速都与实测基本吻合.通过改变雨强进行定量分析得到：当物源充足时，雨强减小会导致泥石流运动减缓，并停止于地势较高处；以150 mm·h-1为参考雨强，当雨强减小为100 mm·h-1和50 mm·h-1时，泥石流运动的龙头标高分别增加25 m和75 m，平均堆积厚度分别减小0.06 m和0.14 m.

Abstract:

The movement of debris flow occurred at Gangou in Hongse Village of Dujiangyan City of Sichuan Province was analyzed with field measurements. A two dimension numerical model of the debris flow was set up with DEBRIS 2D software to simulate the debris flow in the region. It is shown that computational results and on site observations are in good agreement. Different scenarios of the debris flow spreading caused by different rainfall intensities were also simulated. The results quantitatively reveal that with abundant debris source, the reduction of rainfall intensity leads to a slower movement and a higher stop position of debris flow. Taking the rainfall intensity of 150 mm·h-1 as a reference, if the rainfall intensity reduces to 100 mm·h-1 and 50 mm·h-1, the increase on final front position will be 25 m and 75 m respectively and the reduction on average deposit thickness will be 0.06 m and 0.14 m respectively.