泥石流起动的突变学特征

泥石流起动是泥石流发生、发展、成灾全过程中的关键环节,起动规律是泥石流预测预报和灾害防治的理论基础。对建立在实验基础上的泥石流起动条件进行适当变换,得到泥石流起动势函数,它符合尖点突变模型。进一步分析,发现准泥石流体起动时具有突变、缓慢和过渡状态等多条路径,并在起动临界点附近具有发散性和模态软化等性质。根据这些起动特性提出的单沟泥石流预测方法以及通过调控准泥石流体起动条件使之不起动,达到泥石流灾害治理防患于未然的新途径,已在泥石流防治中取得了实效。

THE SUDDEN CHANGE PROPERTIES OF DEBRIS FLOW INITIATION

Among the whole process from debris flow generating and developing to it causing disasters,initi-atal process is the key.The theory of debris flow initiation is a foundation for forecasting and control-ling debris flow.Through transforming initiation condition of debris flow based on the experiments,thepotential function of debris flow initiation was obtained,which is consistent with the model of pointsudden change.By further analyzing,some properties of debris flow initiation were found,those are:1)when a quasi-debris flow initiates,it goes by one of the three courses:sudden change,gradualchange and interim situation;2)as a quasi-debris flow is located by the critical point of initiation,quasi-debris flow has the properties of diverge and softened matrix.According to these properties,threemethods for forecasting dibris flow in a given dully as well as the new way of debris flow controlthrough regulating and controlling the initiation conditions and hence preventing the quasi-debris flowfrom initiation had set up.The practical benefits have been obtained by applying those achievements inthe works of debris flow control.