| A coupled model of GM(1,1) and BP neural network is established and applied in groundwater dynamic
simulation and prediction of Minqin basin using data of well 64, well 65 and well 84 as representatives. Accuracy test of this model indicates that the average relative errors of these three wells are 0.45%，0.93% and 0.62% respectively, which are all less than 1% and meet the accuracy requirements. Compared with GM(1,1)，the predicted average rela-tive errors of this coupled model are all less than that of GM(1,1) model. And when compared with BP model, the aver-age absolute error of predicted groundwater depth of 1998~2001 reduced greatly from 0.32 m to 0.07 m. The results show that this coupled model considers the certainty and uncertainty of groundwater depth time series，with high accuracy of possessing prediction，and can be used for short term prediction. |