基于GAM模型的3种降雨因子对贵州地质灾害危险性预测的对比分析

Comparative Analysis of Three Kinds of Rainfall Factor for Geological Hazard Risk Prediction Based on GAM in Guizhou Province

针对贵州省地质灾害的发生特征,笔者选取连续降雨日数、连续无雨日数以及前期累计降雨量等进行主成分分析得到降雨主成分,与10天累计雨量、有效雨量2个单一的降雨因子在贵州省地形条件下分别采用广义加性模型(GAM)构建贵州省地质灾害危险性预测模型。通过检验对比分析,得出以下结论:(1)降雨主成分较客观地解释了降水对贵州省地质灾害危险性的影响,贵州省地质灾害主要发生在前期出现持续性降水或前期连续无雨时的突发性降水这2种情况。(2)在相同的地形地貌下垫面下,降雨主成分对地质灾害危险性的预测检验结果明显优于其余2种降雨因子,对地质灾害预测的精细化程度更接近实际发生情况。(3)不同降雨因子的选择对影响地质灾害的重要性有差异,选择降雨主成分时降水对地质灾害危险性的贡献更突出,其他影响地质灾害的地形地貌因子重要性依次为曲率、高程、坡向、坡度和剖面曲率。

Aimed at the characteristics of the geological hazard in Guizhou Province,the author chose thecontinuous rainy days,continuous non-rainy days and the early accumulative rainfall to calculate the rainfallprincipal component with the method of principal component analysis.Then the risk prediction model ofgeological disaster was built by the generalized additive models（GAM） under the topography in GuizhouProvince respectively with the 10-day cumulative rainfall and the 10-day effective rainfall this 2 singlerainfall factors.Through inspection and analysis,the results showed that：（1） rainfall principal component couldexplain the effect of rainfall on the geological hazards risk objectively,the geological hazards happened mostlyin cases of early continuous rainfall or the sudden rain after the early continuous non-rain;（2） under the sameunderlying surface,the method of the rainfall principal component was better than the other 2 rainfall factors,and the refinement of geologic hazard was more close to actual situation;（3） the choice of different rainfallfactors affected the importance of geological hazard differently,the rainfall made the most contribution to the risk of geological hazard with the method of rainfall principal component,and the other factors to the geologicalhazard followed the order of curvature,altitude,aspect,gradient and profile curvature.