泥石流预报是泥石流减灾的重要手段之一，然而泥石流形成的复杂性使泥石流预报准确度低，误报和漏报率较高。泥石流误报和漏报都会造成损失，但二者造成的损失有很大的差别。为了减少泥石流误报或漏报造成的损失，应当考虑两种错报造成损失的不同。根据使总平均损失达到最小的原则，建立了不同损失条件下的泥石流预报模型，并将该模型应用到云南东川蒋家沟。

Debris flow forecasting is one of the important methods of debris flow mitigation. However, the accuracy of debris flow forecasting is low because of the complexity of debris flow formation. Both the missing forecasting and misdeclaration will cause economic loss. But the loss from them is different. In order to decrease the loss from the missing forecasting and misdeclaration, the loss from them must be considered in the debris flow missing forecasting and misdeclaration, the model of debris flow forecasting under different loss factors in set up as follow based on the minimal principle of the loss. {R_1 = {X: W(X) ≥ d} R_2 = {X: W(X) < d} The probabilities of missing forecasting and misdeclaration are p(2|1) = phi[(d-lambda/2)/lambda~(1/2)] and p(1|2) = 1 - phi[(d+lambda/2)/lambda~(1/2)] The model is applied in Jiangjiagou, a debris flow valley located in Donchuan, Yunnan Province.