长江上游流域数值降雨预报产品精度评估

Accuracy Evaluation of Numerical Rainfall Forecast Products in the Upper of the Yangtze River Basin

根据实测站点降雨数据和ECMWF、梯调降雨预报数据,评估两种降雨预报产品在长江上游流域51个降雨分区的面雨量预报精度。各分区面雨量预报值采用网格算术平均法计算,观测值采用泰森多边形法计算。相关系数、平均绝对误差和ROC曲线的AUC数值指标的计算结果表明,两种产品在长江上游流域均具有较好的预报效果,其中梯调降雨预报数据在预见期较长时相对精度更高,质量更为稳定;梯调降雨预报数据相较于ECMWF数据更适用于流域的上游和下游区间,中游区间ECMWF数据的预报效果更好。

According to the measured rainfall data of stations and ECMWF and rainfall forecast data in cascade dispatch center,the area rainfall forecast accuracy of two kinds of rainfall forecast products in 51 rainfall zones in the upper reaches of the Yangtze River Basin was evaluated.The forecast area rainfall of each region was calculated by the grid arithmetic mean method,and the observed rainfall was calculated by the Thiessen polygon method.Correlation coefficient,mean absolute error and AUC value of ROC curve were calculated.The results show that the two products have good forecasting effect in the upper reaches of the Yangtze River Basin.The rainfall forecast data in cascade dispatch center is more accurate and stable when the forecast period is longer.Compared with ECMWF data,the rainfall forecast data in cascade dispatch center is more suitable for the upper and lower reaches of the basin,and ECMWF data in the middle reaches has better forecast effect.