德昌县宽裕地区岩石坚固程度对泥石流发生的影响

The Degree of Rock Solid in the Formation of Gully Type Debris in Kuanyu Region in Dechang

德昌县2004年发生的群发性泥石流,给当地居民的生活和生产造成了严重的干扰与损失。此次泥石流灾害区域较集中,地形和水文条件也比较接近,却只有部分沟道发生泥石流。为了研究影响泥石流发生的原因,重点对形成条件中地质因子的岩石坚固程度进行分析;发现造成该区域泥石流发生情况不一的原因是受各流域白云岩、碳质千枚岩及砂岩、强风化的花岗岩的坚固程度不同的影响。在前人的基础上以现场实际情况为主,对部分沟的坚固系数值进行校正,最终得到坚固系数G=5.56为该地区泥石流发生与否的分界线。再结合地形因子、水文因子对该地区进行泥石流的预警预报验证,适用情况较好。该方法可作为某一区域内影响泥石流暴发地质条件中岩性条件的评价指标。

Group-occurring debris flow disasters on 2004 in Dechang country caused serious interference and harm to local residents and production. The debris flow disaster area is concentrated and topographical and hydro- logical conditions is the similar. In order to study the causes of debris flow, the degree of rock solid of geological factors on forming condition is focus on analyzing. Finding the cause of the different occurrence conditions of debris flow in this region is affected by degree of rock solid on dolomite, carbonaceous phyllite, sandstone and strongly weathered granite to each basin. Correction of the firmness coefficient values on the basis of predecessors＇research. Finally geting coefficient values G = 5.5 is the dividing line between debris flow occur or not in this area. Combi- ning the terrain factor, hydrological factor of gully in this region to forecast the occurrence conditions of debris flow and applicable situation is better. This method can be used as evaluation index on lithology conditions of geological condition which influence debris flow in a region.