ABSTRACT
ABSTRACT: Based on the Standardized Precipitation Index (SPI) and circulation parameters, in consideration of the nonlinear relationship between the regional drought and drought-formation factors, circulation parameters were selected as predictors to meet different linetypes by the correlation analysis. Then, four autumn droughts forecasting models for the southwest of China have been established, using multiple linear regression method. The results show that, in the calibration period from 1961 to 2004, all models pass the F test and the simulation effect of the exponential type regression model is the best. Nonlinear models hindcast the autumn droughts in the southwest of China in 2005, 2007, 2009 successfully and perform better than the linear model for hindcasting droughts in the validation period from 2005 to 2012, with a forecast period of 6 months. The nonlinear method for predictors is suitable for drought forecasting in the southwest of China, which has potential practical application in prospect.
