人民长江2024，Vol.55Issue(1)：97-104,134,9.DOI:10.16232/j.cnki.1001-4179.2024.01.014
光流法雷达外推产品在突发强降水预报中的应用
Application of optical flow radar extrapolation precipitation products for forecasting sudden heavy rainfall
摘要
Abstract
The floods occurring in small and medium-sized rivers in complex hills are strong suddenness and short confluence time.The precipitation short-term proximity prediction product with high accuracy and long-term timeliness is particularly cru-cial for flood forecasting models.Taking the 1000-year return period catastrophic flood of Yahekou Reservoir in Henan Province in September 2021 as an example,the TS score and forecast deviation of radar extrapolated precipitation prediction products based on the improved optical flow method are examined for the 0～1 h and 0～3 h precipitation forecasts during this flood using the three source fusion grid point real precipitation data provided by the National Meteorological Information Center.The results showed that:① The improved optical flow method is more accurate in 0～1 h hourly precipitation forecast.When the accumulated rainfall is below 50 mm,the TS score ranges from 0.45 to 0.85;when the rainfall is between 50 mm and 70 mm,the TS score is between 0.35 and 0.70,when the rainfall is above 70 mm,the TS score is between 0.25 and 0.35.The high TS score of rainfall above 50 mm shows the superiority of the improved optical flow method in extreme heavy rainfall prediction.②In 0～3 h precipi-tation forecast,when the accumulated rainfall is less than 50 mm,the TS score is 0.55 to 0.85,when it is above 50 mm,the TS score is between 0.35 and 0.75.This precipitation forecast product not only has good prediction effect on extreme precipitation,but also has a prediction time up to 3 hours,providing a longer decision-making time for flood control scheduling.③ Compared with the grid point precipitation of the fusion real situation,the precipitation forecast product of the improved optical flow method in 0～3 h is relatively close to the precipitation below 20 mm,and the average absolute error is within 10 mm.The error gradually increases when the rainfall exceeds 20 mm;with the increase of rainfall,the average error,average absolute error and root mean square error increase gradually.④The improved precipitation prediction products of optical flow method in 0～3 h have good pre-diction performance for extreme heavy precipitation of small influence range,large precipitation intensity,long duration and large accumulated precipitation.The research results can provide a more reliable precipitation input forecast for flood forecasting model.关键词
极端强降水/降水预报产品/临近预报/光流法/雷达外推/鸭河口水库Key words
extreme heavy rainfall/precipitation forecast product/nowcast/optical flow method/radar extrapolation product/Ya-hekou Reservoir分类
天文与地球科学引用本文复制引用
魏凡,田刚,徐卫立,李春龙..光流法雷达外推产品在突发强降水预报中的应用[J].人民长江,2024,55(1):97-104,134,9.基金项目
中国气象局创新发展专项项目"长江流域大洪水天气识别及预报关键技术研究"(CXFZ2022J018) （CXFZ2022J018）
中国长江电力股份有限公司项目"基于大数据的长江流域强降水过程分析及应用"(2421020002) （2421020002）
国家自然科学基金项目"极端天气视阈下长江中游通航环境风险的演变机理研究"(51709218) （51709218）
