甘肃武都区泥石流活动与降雨特征关系

Relationship between debris flow activity and precipitation characteristics in Wudu area,Gansu province

收集了武都区近30年的降雨资料,分析了泥石流发生前后的降雨资料,探讨了泥石流的发生与降雨之间的关系.结果显示:近30年来,每年7,8,9月降雨量有一定减少趋势,但是当物源比较丰富,泥石流发生次数不会有明显的减少,当物源不丰富时,泥石流的发生次数会比原来有所减少.诱发泥石流灾害的前15天累积降雨量与泥石流关系较为密切,可以用来评估泥石流临界降雨量,作为武都区泥石流的预报因子.

Wudu area rainfall data for about 30 years were collected and analyzed and a special focus has been laid on the rainfall fata during the occurrence of debris flow hazards,especially on the relationship between the debris flow and the precipitation.The result suggests that the annual rainfull in the 7,8,9 month in the recent 30 years has showed a decline trend,but the potential of debris flow occurrence would not decline when the material source is abundant.However,when the material source is inadequate,the chances of debris flow occurrence would be greatly reduced.It was also found that the pre-15-day accumulated precipitation has a closer relationship with a debris flow hazard.Therefore the result can be used to assess a critical rainfull and predict a possible debris flow hazard.