温州群发性坡面泥石流临界雨量研究

温州地处浙江东南沿海,降雨充沛。台风等极端气候灾害引起的强降雨次数繁多,并可能引发地区周边泥石流等地质灾害。收集相关地区、时段的气象、水文资料,并对研究区降雨数据进行处理,在野外实地调查、遥感解译的基础上,根据研究区地质灾害调查结果,总结群发性坡面泥石流特征,分析其形成的地质环境条件。针对致灾因子降雨量与温州地区群发性泥石流灾害的因果关系,获取坡面泥石流发生周期内的各时段降雨量,并利用相关性分析确定最大1h、3h雨强为研究变量,在二维坐标平面上投影近百个案例点,拟合得出临界雨量方程,并根据泥石流发生与否划分区域计算超越概率和误报概率,得出温州地区泥石流爆发前期雨强满足"两倍关系"的经验结论,寻求解决温州地区实际泥石流地质灾害预警问题的可行性。

Study on critical rainfall of grouped slope debris flows in Wenzhou

Wenzhou is located on the southeast coast of Zhejiang Province with abundant rainfall. Heavy rains caused by extreme weather disasters such as typhoons are numerous and may cause geologic hazards such as debris flows. Collecting meteorological and hydrological data of relevant regions and time periods and processing the rainfall data in the study area are done firstly. Based on the field investigation and remote sensing interpretation,summarizing the characteristics of the grouped debris flows and analyzing its forming geological environmental conditions are done according to the result of the geologic hazard investigation in the study area. Aiming at the causal relationship between the hazard factor,rainfall,and the grouped debris flows in Wenzhou area,the rainfall at certain time in the cycle occurrence of slope debris flows is obtained. With the help of correlation analysis,rainfall intensity maximum of 1 h、3 h are regraded as studied variables and more than one hundred case points are put into two-dimensional coordinate plane to obtain critical rainfall equations for the debris flows. Areas are divided by the judgement of whether debris flow happened or not and the probability of exceeding and the probability of false positives are calculated. As an empirical conclusion,the rainfall intensity in the early breaking stage of debris flow in Wenzhou area satisfies "twice relationship",which explores the feasibility of solving the early warning problems of actual debris flows geological disasters.