Regional precipitation frequency analysis for 24-h duration using GPM and L-moments approach in South China

Abstract

There are little researchers that combined satellite-based products and L-moments methods in frequency analysis. The objective of this study was to explore and evaluate the satellite precipitation data applied in univariate L-moments method. The Shaoguan City of South China was selected as the study area. Annual maximum precipitation (AMP) respectively from observational rainfall and Integrated Multi-satellitE Retrievals for Global Precipitation Mission (IMERG) gridded rainfall was used for the calculation of estimates using regional L-moments analysis (RLMA) method. Then, the quantiles at grids were corrected by mean bias correction (MBC) method with the estimates at sites. The results showed that the number of homogeneous regions as well as the spatial distribution of parameters ({C}_{v}, {C}_{s}, and {C}_{k}) for two data sets are different. When the return periods are larger than 40 years, the estimates at sites are also larger than those at grids and the difference will increase as return period increases. After being modified, the quantiles from IMERG are more reasonable and combine the spatial distribution characteristic of estimates from two cases, which indicates that the estimation calculated by satellite products with L-moments approach is applicable and more reasonable. This study can also provide reference for solving the issues regarding the density and coverage of rain gauges that affect the accuracy of frequency analysis, especially in remote areas of China or most parts of the word.