兰州市区地质灾害发育特征及类型研究

DEVELOPMENT AND TYPES OF THE GEO-HAZARDS IN LANZHOU CITY

根据兰州市区近8年来地质灾害详细调查资料,系统归纳了兰州市区地质灾害主要类型、空间分布规律、发育特征及其危害性,针对不同类型的地质灾害,提出相应的防治对策。研究结果表明:兰州市区地质灾害发育类型主要有滑坡、崩塌、泥石流及不稳定斜坡等4类,总体发育特征具有普遍性、反复性、突发性和周期性。其中,滑坡和泥石流数量多、危害大;崩塌相对发育较少;不稳定斜坡多与滑坡、崩塌相伴生,大多演变为滑坡。兰州市区在每年汛期中的强降雨作用下,均有地质灾害发生,特别是居民建房削坡、加载以及公路切坡地带频繁发生,是区内地质灾害群测群防和减灾防灾关注的重点区域。

This article makes use of detailed geo-hazard investigation data in 5 districts of Lanzhou City in recent 8 years, based on collecting and sorting out main types and spatial distribution characteristics of geologic disasters in Lanzhou City, and analyses the general development characteristics, different development characteristics of various geologic disasters types in Lanzhou City and their impacts. And according to different kinds of geological disasters, the countermeasures are put forward. It is preliminarily revealed that development types of geologic disasters in Lanzhou City mainly include： landslide, collapse, debris flow and unstable slope. These geohazards generally indicate universality, repeatable, unexpected and periodic. Development characteristics among all types of disasters,landslides and debris flow happen most frequently and cause serious damage. Collapse account for relatively rare part. Unstable slopes often occur together with landslide or collapse, and mainly prone to landslide. In each year, the heavy rainfall during rainy season will induce small scale landslides and collapses,especially the landslide and collapse in urban residential area. Landslides and collapses due to slop cutting of mountain roads and slope which occur frequently need to be paid special attention to monitoring,prevention and reduction of geologic disasters in Lanzhou city.