长三角空气质量区域预报准确性评估方法研究

根据长三角空气质量区域预报工作的实际需要,对分区文字预报和落区图预报两种方式分别制定了不同的空气质量指数级别预报准确性评估方法。分区文字预报根据设定的预报准确性判定方法计算预报评分,落区图预报按区域内预报准确城市占比进行准确率统计。分区文字预报结果显示,2017年长三角区域的预报准确天数占比为62.2%,预报评分为70.2,区域预报评估效果良好。落区图预报评估结果显示,预报级别偏差具有地域性差异,安徽北部、江苏北部和江西中北部预报等级偏高,长三角中南部沿海城市预报等级偏低。该套评估方法可为区域空气质量预报偏差成因分析提供依据,为区域预报工作的改进提供定量参考。

Accuracy Evaluation Methods of Regional Air Quality Forecast in Yangtze River Delta

In order to analyze the air quality forecast deviation in the Yangtze River Delta(YRD)region and improve the forecast accuracy,an estimating method was designed based on the content of YRD region s daily forecast.For the text part,the judgment basis and scoring rules of the accuracy for forecast were set according to the sub-region of YRD.For the air qualily index(AQI)level distribution,the accurate ratio of the 52 cities was calculated.The results showed that the text forecast assessment score of the YRD region s air quality forecast in 2017 was 70.2,and the accurate days accounted for 62.2%,the overall effect of regional forecast was good.The accurate ratio was smaller in northern Anhui,northern Jiangsu and most part of Jiangxi because of the forecast AQI level was higher than the observation,which was the opposite of the central and southern coastal areas of the YRD region.The evaluation method provided a quantitative reference for the improvement of regional forecasting work.