关键词: 降雨-融水型泥石流;泥石流流量;度日模型;雨热耦合变化;气候变化;帕隆藏布流域;

Abstract: Under the background of global warming,current empirical model for the glacial debris flow discharge calculation cannot quantitatively consider the coupling effect of rainfall water and the snow/ice melting water. We proposed a discharge calculation model that considers coupling effect of both rain and melting water for glacial debris flows by studying ice-snow melt equivalent in the improved degree-day model as well as the current storm flood calculation method for rainfall triggered debris flows. The criteria of return period for the glacial debris flows discharge prediction was established based on the rainfall and temperature change trends fitted by the 51 years long period observation data in the Palong Zangbo watershed. Then this proposed model was verified by the observation data of 2 typical glacial debris flows along the Palong Zangbo River,and the accuracy of the proposed method was significantly improved by comparing to the current empirical model. Afterwards,the discharge estimation of15 glacial debris flow gullies in the Palong Zangbo watershed were analyzed under various climate change scenarios. The results show that the proposed method can quantify the coupling effect of rain-thermal on debris flow and can provide a reference for the calculation and prediction of key parameters for the prevention and control of glacial debris flows.

Key words: rainfall-melting water debris flows; debris flows discharge; degree-day model; rain-thermal coupling changes; climate change; Palong Zangbo watershed;