Abstract:
Analysis of the characteristics and evolution of extreme precipitation is of great importance for basin disaster prevention and mitigation.Based on the long-term daily high-resolution satellite precipitation data, the undirected and directed complex network are constructed with the techniques of statistical significance tests, encoding the connection and propagation of extreme precipitation respectively.Taking the Pearl River basin as an example, the aim of this study is to investigate the spatial characteristics and temporal regime of extreme precipitation. The results show that the Xijiang River basin has the largest extreme precipitation divergence and convergence sources; degree centrality higher than 0.5 are observed in the junction of Hongshui River, Qianxun River and Zuojiang River basins; in the meantime, the Hanjiang River and Dongjiang River basins exhibit mean propagation distance larger than 400 km; the strongest 5% of the clustering coefficient identify the five major basin extreme precipitation centers. In terms of the spatial characteristics, the existence of the Hanjiang River Center, Dongjiang River Center, and Pearl River Delta Centers are verified, the Chang'an-Guilin Event Center is originated from the Liujiang River Center, and the Hainan Island Center is discovered to be an extreme precipitation influx source of the Pearl River basin. In terms of the temporal regime, from late May to early June extreme precipitation mainly propagates from the whole Pearl River basin to the Hanjiang River Center, Dongjiang River Center and Pearl River Delta Center, while from early to mid-June extreme precipitation mainly propagates from Hanjiang River Center, Dongjiang River Center, Pearl River Delta Center and Liujiang River Center to the junction of Hongshui River, Liujiang River, Qianxun River and Zuojiang River basins.