摘要
以中国气象局发布的逐小时网格降水数据集(CMPA)为降水参考,采用多种极端降水指数系统地评估了GSMaP(NRT、MVK、Gauge)和IMERG(Early、Late、Final)共6种GPM时代卫星降水数据对四川极端降水的监测精度。结论如下:①四川多发生局部短历时强降水,降水空间异质性强,在盆地和盆地周边的极端降水频率和强度明显大于其他地区,在盆地与川西高原接壤地区形成一条明显的极端降水分界线。②IMERG能够较为精确地探测到暴雨、持续性降水事件和干旱事件,其中Final产品精度最高,IMERG产品的极端降水指数精度明显优于GSMaP。③IMERG-F的降水概率密度函数(PDF)与CMPA的PDF特征最为相似,其次为GSMaP-Guage,但经过站点校正的GSMaP-Gauge产品完全改变了NRT和MVK的PDF特征,忽略掉了较多大雨、暴雨事件,将极不利于对极端降水的监测。总体上,GPM降水产品对极端降水的探测精度存在较大的地域性差异,IMERG较GSMaP表现出更高的极端降水探测精度,在地形复杂的川西高原地区IMERG和GSMaP均存在较大的降水误差。
Sichuan is one of the regions with frequent extreme precipitation in China.Based on the grid precipita⁃tion dataset(CMPA)provided by China Meteorological Administration as the reference of surface precipitation.We systematically evaluated the accuracy of extreme precipitation monitoring in Sichuan province by using a va⁃riety of extreme precipitation index including GSMaP(NRT,MVK,Gauge)and IMERG(Early,Late,Fi⁃nal)satellite precipitation products.The results are as follows:(1)The frequency and intensity of extreme pre⁃cipitation in the basin and its surrounding areas are significantly higher than those in other areas.There is an ob⁃vious boundary line of extreme precipitation along the basin and the plateau.(2)IMERG products can detect rainstorm,continuous precipitation events and drought events more accurately,of which Final product have the highest precision,and the precision of extreme precipitation index of IMERG products is significantly better than GSMaP.(3)The results of probability density distribution function(PDF)show that the PDF characteris⁃tics of IMERG-Final products and CMPA are the most similar,followed by GSMaP-Guage,However,the Gauge product corrected by the site completely changed the PDF characteristics of NRT and MVK,ignoring many heavy rain and rainstorm events,which will be extremely unfavorable to the monitoring of extreme precip⁃itation.In general,the detection accuracy of GPM products for extreme precipitation has great regional differ⁃ences.IMERG products show higher extreme precipitation detection accuracy than GSMaP.We also found that there are large precipitation errors in IMERG and GSMaP products in the Western Sichuan Plateau with com⁃plex terrain.
作者
杨晓瑞
曾岁康
林志鹏
YANG Xiaorui;ZENG Suikang;LIN Zhipeng(Sichuan Electric Power Design and Consulting Limited Liability Company,Chengdu 610041,China)
出处
《遥感技术与应用》
CSCD
北大核心
2023年第6期1496-1508,共13页
Remote Sensing Technology and Application
