广东省极端降水事件的变化特征

目的]分析广东省极端降水事件的分布特点并对其未来的变化趋势进行判断,旨在为该省的气候评估预测、生态环境建设及经济可持续发展方面的研究提供科学依据。方法]利用广东省1960—2013年的逐日降水数据,根据百分位方法定义了极端降水事件的阈值,通过采用Mann-Kendall法、小波分析、Hurst指数等方法,对该区的极端降水事件频次和强度的变化特征及其变化趋势进行研究。结果]广东省极端降水事件的发生频次、强度及极端降水量均呈上升的趋势,且极端降水量对总降水量的贡献率在50%以上。在空间上极端降水事件的发生频次呈现出北高南低的规律性,而强度正好相反。在未来的变化预测中,广东省大部分地区极端降水事件的频次和强度与过去变化趋势相一致,呈持续增加的趋势。结论]极端降水事件的频繁发生给广东省造成了严重的损失,应加强极端气候事件的预防工作,针对不同成因的极端降水事件应采取不同的应对措施。

Variation Characteristics of Extreme Precipitation Events in Guangdong Province

Objective] This paper elucidated the distribution characteristics of extreme precipitation events in Guangdong Province and made forecasts about the future trends in order to provide scientific basis for the study of climate assessment, ecological environment construction and sustainable economic development. Methods] Based on daily precipitation data of 24 meteorological stations in Guangdong Province during 1960-2013, the extreme precipitation thresholds were determined for different stations by the centesimal value method, and then, frequency, intensity of extreme precipitation events were analyzed by using Mann-Kendall test method, wavelet analysis, the Hurst index to explore the trend of extreme precipitation events. Results] The frequency, intensity and rainfalls of extreme precipitation events in Guangdong Province were increased. Extreme precipitation accounts for about 50 percent of the total precipitation. In space, the frequency of extreme precipitation events decreased from the north to the south, while the intensity showed opposite distribution. Extreme precipitation frequency and intensity were forested consistent with the ones of the past, showing continually increasing trend. Conclusion] The frequent occurrence of extreme precipitation events caused serious losses to Guangdong Province. The province should strengthen the prevention of extreme events. Corresponding measures should be taken to deal with the extreme precipitation cases resulted from different causes.