基于地理探测器的元阳梯田地质灾害影响因素及滑坡成因分析

Analysis on the influencing factors of geological disasters and causes of landslide in Yuanyang terraced fields based on geographical detectors

元阳梯田受其特殊的地理位置、地表植被和农耕文化影响,表生地质灾害频发,对其生态价值和文化价值造成极大损害,梯田区域的地质灾害防治显得尤为关键。在详细野外调查基础上,结合元阳梯田区15 m分辨率遥感影像数据,利用空间叠加分析和地理探测器模型对研究区地质灾害影响因素开展了详细研究。结果表明:元阳梯田区地质灾害(隐患)点中滑坡灾害(隐患)点数量占比为93.39%,小型规模灾害(隐患)点数量占比为87.69%,总体表现为以滑坡性质的小型灾害为主;地质灾害分布的影响因素主要为地形坡度,其次为地质构造,受地貌单元影响最弱;滑坡灾害形成的影响因素具有复合性特点,其中强烈的河流侵蚀作用、地壳抬升作用和活跃的断裂构造活动是其成灾的主要地质环境背景,丰富的降雨量和人类工程活动是其成灾的主要触发因素。通过研究可进一步认识元阳梯田地质灾害影响因素及形成条件,可更好地助力于地方防灾减灾体系提升,也可为区域地质灾害风险分析提供一定的参考。

Due to its unique geographical location,surface vegetation,and agricultural culture,Yuanyang terraced fields have been frequently affected by surface geological disasters,causing great damage to their ecological and cultural value.Therefore,the prevention and control of geological disasters in the terraced areas is particularly crucial.On the basis of detailed field investigations,combined with 15 m resolution remote sensing image data from Yuanyang terraced fields,the authors conducted a detailed study on the factors affecting geological disasters in this area using ArcGIS spatial overlay analysis and geographic detectors.The results show that the amount of landslides accounts for 93.39%and the amount of small-scale disasters accounts for 87.69%in Yuanyang terrace fields.Overall,it is mainly characterized by small-scale disasters with landslide as the main type.The main influencing factors of geological disaster points in the study area are topographic slope,followed by geological structure and the geomorphic unit.The influencing factors of geological disasters are complex,and strong river erosion,crustal uplift,active fault tectonic activity are the main geological environment factors.Besides,abundant rainfall and human engineering activities are the main inducing factors.The influencing factors and causes of geological disasters in Yuanyang terraced fields were identified through this research,which could better promote improving the local disaster prevention and reduction system,and also provide certain references for regional geological disaster risk analysis,investigation and evaluation projects.