基于ECMWF和WRF的嘉陵江流域面雨量预报精度评估

将降雨数值预报产品运用到水文预报中已经逐渐成为提高洪水作业预报的预见期的重要手段。为充分了解ECMWF(European Centre for Medium Range Weather Forecasts)和WRF(Weather Research and Forecasting model)2种数值天气预报产品对嘉陵江研究区面雨量预报的预报精度和误差分布,且为增强洪水预报精度的稳健性提供科学支持,采用TS评分、空报率、漏报率、正确率等指标,对嘉陵江地区7个气象分区内的2016年汛期面雨量预报结果进行了检验,分析了不同分区内各检验指标与预报时效的关系。结果表明:ECMWF数值预报产品和WRF数值预报产品均可用于该地区晴雨预报,且2种产品的预报精度随降水等级的增大呈增大趋势,随预报时效的增加呈减小趋势。综合而言,ECMWF数值预报产品对嘉陵江研究区的预报效果更好。

Evaluation of Areal Rainfall Forecast Precision in Jialing River Basin by Using ECMWF and WRF Meteorological Products

Numerical product has been an important means to improve the anticipation period of hydrological forecast. In the purpose of understanding areal rainfall forecast accuracy and error distribution of ECMWF (European Centre for Medium Range Weather Forecasts) and WRF (Weather Research and Forecasting Model) and providing scientific support for improving the robustness of flood forecast accuracy, we verified the forecast results of areal rainfall in flood season of 2016 in seven subareas of Jialing River Basin by examining indexes involving TS score, false alarm rate, point over rate, and success hit rate. Furthermore, we analyzed the relationship between the abovementioned indexes and the period of forecast validity in the subareas. Results suggest that ECMWF product and WRF product could be both applied to the sunny/rainy forecast in the study area. The forecast accuracy improves with the increase of rainfall grade, but reduces with the decrease of forecast validity period. In general, ECMWF has better forecast efficiency in the Jialing river basin.