| Using the precipitation and evaporation data for 12 representative stations in Hedong region in Gansu province during 1958 to 2003, this paper gives the numeration expressions and estimation criterion for early spring drought index and spring drought index. It is indicated that these methods can be used for determining early spring drought years, spring drought years and rainy years easily, and are valuable for drought monitoring. By analyzing the spatio-temporal drought characters in 46 years, the paper presents the circumfluence characters of meridional wind and geopotential height. It is discovered that the anomaly of north wind runs through all convection layer over west China from mid-winter; with the increase of height, the geopotential height over east Asia tends to weaken and incline to the west, and the east Asia groove and the Europe ridge is relatively strong. The circumfluence condition and wavelet distribution is not beneficial to rainfall and cause drought easily in Hedong region in Gansu province. A forecast model for early spring drought and spring drought is proposed. |