Application evaluation of GPM and CMORPH satellite products during rainstorms in Chongqing
Based on the ground-level high-spatiotemporal-resolution encrypted rainfall observation data during three consecutive regional rainstorm processes in Chongqing in June 2020,the estimation accuracies of two mainstream satellite precipitation products,IMERG(GPM)and CMORPH,for heavy rainfall in Chongqing was evaluated.The results show that IMERG and CMORPH can generally capture the temporal and spatial distribution characteristics of heavy rainfall in Chongqing.However,both satellite products overestimate the total precipitation during the rainstorm processes,with the relative error(RB)of IMERG ranging from 0.7%to 41.6%,and the RB of CMORPH ranging from 23.7%to 82.8%,and the overestimation of CMORPH is more significant than that of IMERG.At the same time,the two satellite products have significant systematic errors in the estimation accuracy of precipitation with rainfall intensity less than 20 mm·h-1,which is manifested as underestimation of rainfall intensity less than 2.0 mm·h-1 and overestimation of rainfall with rainfall intensity of 4.0～19.9 mm·h-1,and the estimation accuracy of IMERG is better than that of CMORPH.For extreme precipitation with a rainfall intensity exceeding 20 mm·h-1,both satellite products show great instability,the detection rate(POD)and the critical success index(CSI)are less than 0.1,and the false alarm rate(FAR)is greater than 0.85,which means the estimation ability is limited,and further improvement of the algorithm is needed.
国家科技期刊平台
NSTL
万方数据
