山区公路沿线地质灾害分布与环境影响关系研究——以汶川-茂县公路为例

汶茂公路地处我国地质灾害高易发区,是汶川地震发生后重要的"生命通道"。为深入探究该类区域崩滑灾害的发育规律,并据此对公路选线和设计提供依据,通过对灾害最新遥感解译、现场调查和资料搜集,运用Arc GIS平台,分析了汶茂公路走廊带的地表坡度、坡向、工程地质岩组、断层、水系、道路影响共6个环境因子与地质灾害之间的关系。结果表明:(1)研究区共计崩塌258个,滑坡127个,其在30°~60°的坡度范围内分布最广,E、W、SW、NW坡向范围内坡体稳定性较差,灾害频发。(2)地层及岩性在宏观上对灾害发生起着控制作用。(3)距断层越远,其受到的影响越小。(4)走廊带内崩滑灾害受区域水系的控制。(5)距道路400 m的范围内灾害点密度最大,在道路修建时,应重点考虑边坡、路基的的影响因素。

Study on relationship between distribution of geological disaster and environmental impacts along mountain road:case of Wenchuan to Maoxian Highway

Wenchuan-Maoxian road, located in a China′s high-incidence area of geological disasters, which is an important life passage after the Wenchuan earthquake. In order to deeper explore the development laws of landslides and rockfalls in this kindsuch of area, and accordingly to provide basis for highway route selection and design. According to the most recent remote sensing interpretation , filed disaster site investigation and data collection, we analyzed the relationship between geological hazards and six environmental factors using the ArcGIS platform, including slope grade, slope direction, engineering geological rock group, faults, water system and road. The results show that: ① there are 258 rockfalls and 127 landslides in the study area, which are most distributed in the slope grade of 30°-60°. The slopes are lack of stability in the directions of East, West, Southwest, and Northwest, so the disasters frequently occur. ② The strata and lithology play important roles in controlling the occurrence of disasters. ③ The farther away from the fault, the less influences. ④ The landslide and rockfall disasters in the corridor are controlled by the regional water system. ⑤ The density of disaster points is the largest within the range of 400 metres away from the road, so the influential factors of slope and subgrade should be mainly considered in the construction of road.