基于信息量-层次分析耦合模型的泗水县地质灾害易发性评价

Susceptibility assessment of geological disasters in Sishui County based on the coupling model of Information Content and Analytic Hierarchy Process method

以泗水县为研究区,选取区域地貌、地质构造、地层岩性及人类工程活动等9个评价因子,基于GIS数据分析功能,运用信息量法及层次分析法确定各评价因子信息量及权重,进行地质灾害易发性评价。研究表明:区域地貌低山区,坡度28°~65°,坡向西和西北,较坚硬的中厚层状碎屑岩、页岩、砂岩夹灰岩岩组,降雨量700~730 mm及地震加速度0.10 g的区域内信息量最大;各评价因子权重从大到小依次为区域地貌(0.21)、降水(0.16)、坡度(0.14)、地层岩性及人类工程活动(0.10)、坡向(0.09)、地质构造及地震(0.07)、水系(0.06);研究区高易发区面积为294.26 km^(2),面积占比26.30%,灾害点数量占比84.62%,中易发区面积为66.28 km^(2),面积占比5.92%,灾害点数量占比15.38%,低易发区面积为758.42 km^(2),面积占比67.78%。对易发性评价过程的合理性进行检验,3个构造矩阵的随机一致性比率CR分别为0.000、0.013、0.020,均小于0.1,表明易发性研究结果具有合理性,能够为研究区地质灾害防治、土地利用规划及地质环境保护提供基础依据。

Taking Sishui County as the study area,the researchers in this paper selected 9 evaluation factors,such as regional landforms,geological structure,lithology and engineering activity.Based on GIS data analysis function,the information value and weight of each factor were identified by Information Content and Analytic Hierarchy Process method to evaluate geological disasters susceptibility.The results show that the biggest information content located in low mountainous area,with slope of 28°-65°,west and northwest slope aspect,hard medium-thick layered clastic rock,shale and sandstone with limestone rock group,700-730 mm rainfall and 0.10 g ground motion acceleration.The comprehensive weight value of each factor in descending order is 0.21 for regional landform,0.16 for rainfall,0.14 for slope,0.10 for lithologic character and engineering activities,0.09 for slope aspect,0.07 for geological structure and earthquake,and 0.06 for river systems.The high-prone area is 294.26 km^(2),accounting for 26.30%of area proportion and 84.62%of disaster points proportion.The medium-prone area is 66.28 km^(2),accounting for 5.92%of area proportion and 15.38%of disaster points proportion.The low-prone area is 758.42 km^(2),accounting for 67.78%of area proportion.The rationality test of the susceptibility assessment shows that the CR of the three constructed matrices is 0.000,0.013 and 0.020,which are all less than 0.100,indicating that the susceptibility evaluation is reasonable.This research results can provide theoretical basis for geological disaster prevention,land use planning and geological environment protection in the study area.