2003年中国西南山区典型灾害性暴雨泥石流运动堆积特征

Movement and Deposit Characteristics of Typical Catastrophic Debris Flows by Rainstorm in the Mountainous Area of Southwestern China in 2003

2003年发生在中国西南山区的大规模泥石流为典型的灾害性暴雨泥石流,造成了巨大的经济损失和人员伤亡。作者实地考察其中7条造成较大损失的典型泥石流沟,分析得出,这一地区泥石流的流速一般都比较大,流量变化也比较大,流量大小与流域面积相关,总体上流量随流域面积的增大有增加的趋势,但流量与面积并非正相关关系。同时,在这些流域的堆积物的组成中,粗大颗粒极多,最大的颗粒普遍比较大,另外漂石含量很高。粘性泥石流中砾石含量相对于中国西南山区其它粘性泥石流较低,砂砾含量相对较高,大部分泥石流堆积物的有效粒径(d10)。

The debris flows, occurring in the mountainous area of southwestern China in 2003, are of typically destructive, which are trigged by rainstorm. They swallowed many persons and damaged amount of property. To analyze the debris flow＇ s movement and deposit characteristics in the area, the authors chose seven typical debris flows to study, which caused much severe hazards. And then we computed their velocity and discharge by some models and concludes the characteristics of large grain and high concentration by statistic and analysis. The value of the debris flow velocity in the mountainous area of southwestern China is very high and the variation of peak discharge is marked. The peak discharge of these debris flows is correlative to the area of valley and in general it increases with the area of valley, however, the relationship between the discharge and area is not positive correlation. In the composition of these debris, some grains are unbelievably large. But the content of the gravels is comparatively low comparing to other viscous debris flows in the southwestern China.