基于改进突变理论的滑坡危险性评价

Landslide hazard assessment based on improved catastrophe theory

滑坡危险性评价是滑坡风险评估的重要组成部分,对滑坡的预测和防治意义重大。传统滑坡危险性评价在计算指标间重要性时多采用AHP、专家评判法、模糊综合评判等方法,但存在主观性较强,计算较为复杂等问题。研究基于一种改进的突变理论模型对滑坡进行危险性评价,选取坡度、坡向、高程、平面曲率、剖面曲率、距河流距离、地层岩性、土地利用类型、距断层距离、植被覆盖率、24 h降雨以及人类工程活动等12个因子作为滑坡危险性评价的影响因子,采用熵权法判定指标间的相对重要性,并建立滑坡危险性评价体系;然后对指标进行标准化、归一化,计算总突变结果;最后使用拟合函数对总突变结果进行转换,得到新的滑坡危险性评价准则,并以雅安市的20条滑坡对评价准则进行实例验证。结果表明,突变理论得到的评价结果准确率为90%,评价结果更加直观准确。

Landslide hazard assessment is an important part of landslide risk assessment,which is of great significance to landslide prediction and prevention.Analytic Hierarchy Process(AHP),expert evaluation,fuzzy comprehensive evaluation and other methods were often used in traditional landslide hazard evaluation to calculate the importance of inter-index,which were subjective and complicated.This paper introduced an improved model of mutation theory,which overcame the limitation of traditional methods and achieved higher evaluation accuracy.Firstly,according to field investigation and previous studies,12factors including slope,slope direction,elevation,plane curvature,profile curvature,distance from river,stratigraphic lithology,land use type,distance from fault,vegetation coverage rate,24 h rainfall and human engineering activities were selected as influencing factors of landslide risk assessment,and the relative importance of indicators was determined by entropy weight method,and the landslide risk assessment system was established.Then the index was standardized and normalized,and the total mutation result was calculated.Finally,the fitting function was used to transform the total catastrophe result,and a new criterion of landslide risk assessment was obtained.Taking 20 landslides in Ya’an city as an example,the results showed that the accuracy of the evaluation results obtained by the catastrophe theory was 90%,and the improved evaluation results were more intuitive and accurate.