暴雨沟谷型泥石流冲出量和冲出范围研究

摘要

不同类型泥石流一次性冲出量和冲出范围的影响因子和权重存在差异。“5·12”汶川地震后，震区沟谷流域内的大量松散物质在强降雨作用下形成了很多规模较大的降雨型泥石流，选取汶川震区20条暴雨沟谷型泥石流沟，对其被一次降雨过程的一次性冲出量、最大冲出长度、最大冲出宽度的预测方法进行了研究，应用多元统计方法建立了泥石流一次性冲出量和冲出范围预测模型。结果表明：影响泥石流一次性冲出量和冲出范围的因素除了总物源量、动储量总量、流域面积、沟道纵向长度、相对高差等自然因素外，还有筑坝、矿产开采、泥石流流域内边坡开挖等人为因素；所建立的模型适用于汶川震区暴雨沟谷型泥石流一次性冲出量和冲出范围的预测。%It is quite different that the influence factors and weights vary of different kinds of a one⁃time runout volume and runout zones of rainstorm and channelized debris flows. Rainstorm⁃induced debris flows were remobilized from large amounts of loose material triggered by Wenchuan earthquake. This paper selected the 20 rainstorms and channelized debris flows which had an entire alluvial fans and a single type as a typical case. And researched a one⁃time runout volume and the maximum runout distance and depositional width of rainstorm and channelized debris flows after a one⁃time rainfall. Applying the multivariate regression analysis, a mathematical model was established to estimate a one⁃time runout volume and the maximum runout distance and depositional width. The validation shows that affecting a one⁃time runout volume and runout zones of rainstorm and channelized debris flows is not only including the total amount of material source, dynamic reserve, drainage area, the longitudinal length of the channel and relative height difference of natural factor, but also damming, minerals exploitation and slope excavation in debris flows valley of anthropogenic factor. The new model is suitable for predicting a one⁃time runout volume and hazardous zones of rainstorm and channelized debris flow in the Wenchuan earthquake areas.