威远县地质灾害生成特点与防治措施

威远县位于四川盆地中部红层丘陵区,近年来,地质灾害频繁,直接经济损失90.65万元。截至2006年5月,县域内共发现地质灾害隐患点189处,灾害类型有滑坡、崩塌(危岩)、潜在不稳定斜坡、采空塌陷和泥石流等1]。地质灾害分布在高陡且节理较发育的边坡、有软弱层分布的地层、海拔高程在320~700 m的低山、深中丘区、威远背斜南东翼,及人类工程活动如矿山开采、公路建设较频繁的地段。灾害规模小,险情小,危害程度为轻到中等2],发生时间主要集中在每年5-9月份的暴雨期。针对县域内地质灾害的分布特点及形成特征,采取的防治措施主要有避险搬迁、工程治理、监测预警等3],共确定62处受灾害威胁需避险搬迁的农户183户计710人,灾害点治理13处、监测预警114处。

Formation characteristic of geological disaster in Weiyuan County and prevention measures

Weiyuan County is located in the red-soil hilly area of the middle of Sichuan Basin.In recent years,the geological disaster has frequently occurred and caused direct economic loss of 906 500 Yuan.Until May 2006,there were the amount of 189 points which were found to have geological disaster in the county.The disaster types include the landslides,the collapse,the latent unstable slopes,the collapses of caved goaf,debris flow and so on.These geological disasters are located at steep and fissuringing-developing slope,flabby soil layer distributive stratum.The altitude of disaster places is about 320 to 700 meters of the lower hill and deep hillock in the south-eastern part of the Weiyuan.The geological disaster is on the increase due to mankind activities such as mining and highway construction,the disasters are mainly concentrated in the rainstorm period,from May to September of each year.According to the characteristic of distribution and formation of the geological disaster,the main prevention and control measures include removal to avoid danger,engineering harnessing,monitoring and pre-warning etc.Migration involves 183 households,710 persons,13 disaster points,114 mornitoring and pre-warning places.