基于通径分析与可拓学的公路泥石流危险性评价

Danger evaluation of debris flow along highway based on path analysis and extension method

利用通径分析,将公路泥石流危险性评价因子进行精简,选取对泥石流危险性影响较大的主沟长度、一次泥石流最大冲出量、流域面积、泥沙补给段长度比、流域最大相对高差、主沟床弯曲系数以及24h最大降雨量等7个因子,并在此基础上利用可拓学方法对泥石流危险性进行评价。选取大西沟地区泥石流沟,根据可拓集合的关联函数计算可得到泥石流沟关于四类危险性级别的关联度分别为K1(p)=-0.2889,K2(p)=0.0344,K3(p)=-0.6265,K4(p)=-0.7504,由此可判断该泥石流沟危险性等级属于中度危险,该评价结果与实际调查时所用的刘希林模型、灰关联度方法评价结果一致,说明本文所选用的评价因子及评价结果具有一定的合理性与可靠性,可为减轻公路泥石流灾害提供依据。

Debris flow is one of the main reasons to destroy highway, so debris flow danger ec = valuation is an important issue in reducing the harm of debris flow to highway. Evaluation factors of debris flow danger were retrenched based on path analysis method, and the factors which greatly influence the debris flow danger evaluation were selected, including the main channel length, the largest volume of once flow, the drainage area, the length ratio of sediment supplement, valley relative height, bending coefficient of major ditch bed and maximum rainfall in 24 h. Then extension method was applied in debris flow danger evaluation. The site of Da-Xi-Gou regional debris fully was selected for this study. Calculation were done according to the correlation functions of extension set about the four types of risk levels of the correlation, which are K1 （p） = -0. 288 9, K2 （p） = 0. 034 4, Ka （p） = -0. 6265, K4 （p） = -0. 750 4 respectively. So the debris flow risk level of the gully is evaluated as moderate risk. The evaluation results are consistent with that of the actual survey Liu Xilin model, and the correlation method. The selection of evaluation factors is reasonable and the proposed evaluation method is feasible, which could provide a basis for mitigating debris flow disasters along highway.