基于小时分辨率的降水过程辨识方法研究

强降水极易造成暴雨灾害,尤其是突发性强的短时强降水,动态监测、影响评估和风险预估是灾害防御的重要手段。但目前气象服务业务中,强降水的定量评估和风险预估还是以天为单位,现代气象服务精细化的需求迫切要将时间分辨率提升至小时尺度。本文利用1951—2018年国家气象观测站小时降水观测资料,从小时尺度界定站点、大区域、小区域降水过程的辨识方法。基于改进的降水过程综合强度评估方法,在概率密度分布的基础上,重新划分了极端、特强、强、较强、中等五个等级的降水过程综合强度指数。检验论证显示,基于小时分辨率降水过程的自动提取和评估方法合理,具有可操作性,能够对过程性降水、短时降水过程动态评估和预评估,可实时支撑气象服务业务,提升气象防灾减灾能力,也为后续开展短时强降水影响评估和风险预估建立基础。

Research on precipitation process identification method based on hourly resolution

Heavy rainfall is easy to cause rainstorm disaster,especially the sudden short-time heavy precipitation.Dynamic monitoring,impact assessment and risk estimation are important means of disaster prevention.However,in the current meteorological services,the quantitative assessment and risk estimation of heavy precipitation are still based on days,so the refined needs of modern meteorological services urgently need to improve the time resolution to the order of hours.This paper,by using 1951-2018 national meteorological observation station hour rainfall observation data,defines the sites,large area,small area precipitation process identification method from the hour scale.Based on the improved comprehensive strength evaluation method of precipitation process and using the probability density distribution,the comprehensive intensity index of precipitation process is reclassified into five grades:extreme,extra heavy,strong,relatively strong and medium.Inspection result display that automatic extraction of precipitation process based on hourly resolution and evaluation method are reasonable and operable,can support real-time meteorological services by dynamic evaluation and pre-evaluation of precipitation process and short-term rainfall,improve the capacity of meteorological disaster prevention and reduction,and also establish the foundation for the impact assessment and risk estimation of short-time heavy precipitation in the future.