暴雨灾害 (Feb 2024)
Climate characteristics and variation of the Dragon-boat Precipitation in South China in the past 62 years
Abstract
The precipitation reaches its maximum and is most concentrated during the period of the first flood season in South China around the Dragon Boat Festival every year, which is usually referred to as"Dragon-boat Precipitation". The Dragon-boat Precipitation causes serious floods and exerts a serious impact on the production of early rice. It is urgent to study the frequency and intensity of rainstorms during the Dragon-boat Precipitation in South China for disaster prevention and reduction. Using daily precipitation data from 192 national meteorological observation stations in South China from 1961 to 2022, the spatiotemporal characteristics and variation of precipitation during the Dragon-boat Precipitation period in South China were analyzed with different methods, such as EOF analysis, linear trend analysis, and M-K mutation analysis. A comprehensive index representing the intensity of the Dragon-boat Precipitation rainstorm events in South China is constructed. Then, it is used to analyze the characteristics and variations of the number and intensity of the rainstorm events during the Dragon-boat Precipitation period in South China in the recent 62 years, as well as the annual index of the Dragon-boat Precipitation intensity. The results indicate that the consistent increase of the annual intensity index is the main characteristic of the Dragon-boat Precipitation in South China. During the Dragon-boat Precipitation period in the recent 62 years, there were 229 rainstorm events in South China, with an average of 3.7 times per year. In South China, the average precipitation and the number of rainstorm events did not change significantly, but the annual intensity index of Dragon-boat precipitation increased significantly at a rate of 1.2·(10 a)-1. The assessment showed that the strongest Dragon-boat precipitation rainstorm event in South China in the past 62 years would occur during June 4-21, 2022. The annual variation shows that there are four peaks of Dragon-boat Precipitation in South China, which occurred in 2022, 2020, 2008, and 2006.
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