Evaluation Of Monitoring Capability Of Various Satellite Precipitation Products For Extreme Precipitation In Mainland China

Extreme precipitation has caused huge losses to the economic activities and development of human society.It is of great significance to study the temporal and spatial changes of extreme precipitation in order to prevent disasters caused by extreme weather.Precipitation has a high degree of spatio-temporal heterogeneity.Compared with traditional observations based on ground-based weather stations,satellite precipitation observations have the characteristics of all-time and all-weather,and are considered to be the most effective way to obtain information on the temporal and spatial distribution characteristics and changes of precipitation on a regional and even global scale.It has become a research frontier and hotspot in the field of hydrological remote sensing.So far,a series of satellite precipitation products have been released and widely used in meteorology,hydrology,ecology,environment and other fields.In order to enable data users to apply data more effectively,a large number of studies have evaluated the uncertainty of satellite precipitation products in estimating precipitation,and achieved fruitful results.However,precipitation has severe skewed distribution characteristics,and extreme precipitation has attracted much attention because of its huge destructiveness.Whether and to what extent satellite precipitation observations can identify extreme precipitation is not yet fully clear.The main purpose of this study is to explore the ability of satellite precipitation products to monitor extreme precipitation.Taking mainland China as the research area and 2001-2018 as the research period,12 extreme precipitation indicators were selected from the three aspects of extreme precipitation duration,frequency and intensity,and 13 kinds of satellite precipitation data monitoring extremes were comprehensively explored on multi-temporal and spatial scales.Precision and accuracy of precipitation.The main conclusions of this study are as follows:(1)There are large differences in the monitoring precision and accuracy of satellite precipitation products for different extreme precipitation indices.Generally,the monitoring accuracy of most products for the cumulative precipitation index above the percentile threshold(RTop series index)is better than other indices,and for the precipitation day index(Rnn series index),the maximum continuous multi-day precipitation index(Rxnday series index)The monitoring accuracy of the maximum continuous wet days index(CWD)is the worst.In addition,they have the best monitoring accuracy for the maximum consecutive drought days index(CDD),followed by the monitoring accuracy for the Rnn series index and RTop series index,and the worst monitoring accuracy for the maximum single-day precipitation index(Rx1day).(2)There are significant differences in the monitoring capabilities of different satellite precipitation products for extreme precipitation.Overall,CMHBLD(CMORPH-BLD),IMERGF(IMERG Final),3B42(TRMM 3B42),and MSWEP have the best monitoring precision and accuracy for extreme precipitation indices;CMHCRT(CMORPH-CRT),GSMNG(GSMa P＿Gauge＿NRT),IMERGE(IMERG Early),3B42RT(TRMM 3B42RT),GSMN(GSMa P＿NRT)followed by;PSNCDR(PERSIANN-CDR),PSN(PERSIANN),CHIRPS,CHIRP worst.Compared with the pre-correction products,the corrected precipitation products usually have better monitoring precision and accuracy,and the ability of the corrected products to monitor extreme precipitation is more stable in different time periods and different spatial scales.Compared with satellite precipitation products using multi-sensor data,products relying solely on infrared sensor data are less capable of monitoring extreme precipitation.(3)The monitoring ability of satellite precipitation products for extreme precipitation shows significant time differences,and the time distribution of monitoring ability for different types of extreme precipitation indices is different.From a seasonal point of view,the monitoring accuracy of satellite precipitation products on the duration index is the best in winter and the worst in spring;while the accuracy is highest in summer and lowest in winter.For the frequency index,both monitoring precision and accuracy are highest in summer and lowest in winter.For the intensity index,the monitoring precision and accuracy are best in autumn and worst in winter;however,the monitoring accuracy for the mean daily precipitation intensity index(SDII)is best in summer and worst in winter.In addition,the monitoring capabilities of satellite precipitation products for extreme precipitation indices also vary from month to month.Their ability to monitor the duration index is the best in October,and the worst in January and December;but their accuracy time distribution for CWD and CDD in each month is opposite.In January,December,they are better than other months for CDD,but worst for CWD;in June,they are better for CWD than other months,but worst for CDD.For the strength index,most products achieve the best monitoring precision and monitoring accuracy in October,but the accuracy for SDII reaches the best in July.For the frequency index,the product’s monitoring capability and accuracy in July was better than other months.(4)The monitoring precision and accuracy of satellite precipitation products for extreme precipitation have significant spatial differences,and the overall trend is gradually decreasing from the east to the west of the Chinese mainland.The monitoring capability of satellite precipitation products is the best in Southeast China(SE),Yangtze River Plain(CJ),North China(NN),and Northeast China(NE),followed by Yunnan-Guizhou Region(YG)and Northwest China(NW),the worst in Qinghai-Tibet Plateau(QT)and Xinjiang region(XJ).The seasonal and monthly differences in the monitoring precision and accuracy of satellite precipitation products for extreme precipitation in the eastern part of the Chinese mainland are smaller than those in the western part of the Chinese mainland.(5)Although some products have a better ability to monitor extreme precipitation in general,at a specific time and in a specific area,the monitoring accuracy and accuracy ranking of satellite precipitation products for extreme precipitation will change.No one product is best for monitoring extreme precipitation in all conditions.When selecting satellite precipitation products for hydrological and other related research,it is necessary to select the most appropriate data according to the selected time period and research area.