With 0800 h convenient data and numerical products as input,the element field of a key region is expanded as the Chebyshev orthogonal polynomial,whose coefficients are taken as predictors to be trained with the aid of the B-P neural network,whereupon is established an arti- ficial rainfall fallout region forecasting network for categories 5,10 and 25 mm for 24 h in ad- vance.

The forecast of the air pollutant index in different forecast area in Rizhao City;