早稻叶瘟灰色灾变长期预测模型

Long period forecasting model on grey catastrophe of rice blast

利用灰色系统理论的灾变预测方法,以广东省化州市1978～1990年早稻叶瘟发生程度为例,拟定用发生程度≥4级为灾变阈值,建立了早稻叶瘟灰色系统GM(1 1)长期灾变预测模型:X∧(k+1)=1 571 212 511e0 001 259 508k-1 569 234 511。后验差和小误差概率检验达"一级"的精度。应用该模型对1991～2002年进行预测,除1998年报而未出成为空报外,其它各年份的预测结果与实况吻合,预报准确率达91 7%。

The grey systematic theory was adapted to predict the calamity change.Based on the data occurrence degree of leaf blast of early rice during 1978-1990 in Huazhou city,Guangdong province,and the degree higher than or equal to 4 grade was used as a changeful value of calamity,the model of X∧=(k+1)-1571212.511e^(0.001259508k)-1569234.511 has been established.The model can predict the calamity change in a long term.The difference and little probability of error reached the 'first class'precision.This model was used to make a forecast during 1991-2002.Except forecasting for 1998 didn't really occur,other predicted reports were in accordance with the occurrence degree of calamity.The accurate rate of prediction reached 91.7%.