Grey Model of Calamity Forecast and its Application to the Calamity Forecast

The grey system is a incomplete system of information.A new concept of \!grey number\" etc.is developed.A new analysis method is provided for the research of information and incomplete data.It is dealing with discrete raw data by using iteration addition generator method and converting to ordered sequence of number,namely grey method.A grey forecasting model for the calamity forecast is established in this paper by using duplex difference,and the application of this model is expounded by the forecast of drought and flood.At last,the fitting precision ofgrey for ecasting model is discussed.