Study on drought prediction technology of winter wheat in Hebei province
Based on the drought monitoring model of winter wheat in Hebei province,the drought prediction model was established to predict the soil relative moisture index,crop water deficit anomaly index and precipitation anomaly index for the next 10 days.With the meteorological and soil moisture data at the eight stations in Tangshan,Zhuozhou,Dingzhou,Huanghua,Shenxian,Luancheng,Nancheng and Feixiang in Hebei province in 2001 and from 1981 to 2010,and based on the soil water balance principle,the predicted soil relative moisture in 0～50 cm and 0～20 cm depth and the simulated results of drought prediction model of winter wheat were tested.The results showed that,as for the soil relative moisture in 0～50 cm depth,the cases with the relative error lower than 10% was 73% of the total,the cases with the relative error within 10%～15% was 12% of the total,and the cases with relative error higher than 15% was 15% of the total.As for the soil relative moisture in 0～20 cm depth,the cases with the relative error lower than 10% was 68.4% of the total,the cases with the relative error within 10%～15% was 13.7% of the total,and the cases with relative error higher than 15% was 17.9% of the total.The general accuracy of drought prediction model was 77.8%.If the prediction was thought to be correct when the difference between predicted results and monitored results was within a drought level,these two kinds of results were wholly identical with each other. The drought prediction model could meet the needs of business application,but the prediction accuracy was dependent on the accuracy of precipitation forecast.