摘要
滑坡是湘南中低山区最为常见的地质灾害之一,其分布广、危害大。本文以江华县为例,基于RS和GIS探讨滑坡孕灾因子和地质灾害易发性评价。分析认为地形地貌、坡度、地层岩性、人类工程活动、降雨共5类因子与县域内滑坡密切相关,并采用易发程度指数划分出低易发区、中易发区、高易发区。结果显示:江华县往年和新发地质灾害隐患点落入中、高易发区比例均大于90%,研究表明,孕灾因子分析及易发性评价可有效指导野外调查工作,为地质灾害防治管理提供技术支撑。通过进一步分析“6.22”江华强降雨,蔚竹口乡受灾最为严重,其U字形地貌特征使得该区域形成局部暴雨中心,加之河道弯曲,排水不畅,致使滑坡地质灾害和不良地质现象频发。研究认为,中低山区应多分析整体地形对降雨汇流影响,以提高地质灾害预测精准度。
Landslides are one of the most common geological hazards in the middle and low mountainous areas of southern Hunan,with a wide distribution and great harm.Taking Jianghua County as an example,this study explores the landslide risk factors and geological hazard susceptibility evaluation based on RS and GIS.Analysis suggests that five factors,including topography,slope,geological lithology,human engineering activities,and rainfall,are closely related to landslides within the county.The susceptibility index is used to divide the areas into low susceptibility,medium susceptibility,and high susceptibility.The verification results show that in previous years,the proportion of newly developed geological hazard hidden points in Jianghua County falling into medium and high risk areas is greater than 90%.Research has shown that disaster prone factor analysis and susceptibility evaluation can effectively guide field investigation work and provide technical support for geological hazard preven-tion and control management.Further analysis shows that the"6.22"strong rainfall in Jianghua,Weizhukou Town-ship was the most severely affected.Its U-shaped geomorphic features made the area form a local rainstorm center.In addition,the river channel is curved and the drainage is not smooth,resulting in frequent landslide geological disasters and adverse geological phenomena.Research suggests that more analysis should be conducted on the impact of overall terrain on rainfall convergence in low to medium mountainous areas to improve the accuracy of geological hazard prediction.
作者
尹展
郝玉军
卜鹏
杨艳绪
YIN Zhan;HAO Yujun;BU Peng;YANG Yanxu(China Non-ferrous Metals Resource Geological Survey,Beijing 100012,China)
出处
《矿产勘查》
2024年第10期1878-1884,共7页
Mineral Exploration
基金
湖南省地质灾害调查项目“湖南省江华瑶族自治县1∶10000地质灾害调查和风险评价”(湘地调[2022]24)资助。
关键词
滑坡
孕灾因子
易发性评价
江华县
landslide
factors of the geological hazards
susceptibility assessment
Jianghua County
