北京地区极端降水事件的变化规律探讨

Study on Changes of Precipitation Extremes in Beijing

摘要: 利用 1961~2010 年 15 个常规气象站逐日降水数据分析了北京地区极端降水变化趋势。结果表明，在1961~2010 年期间，北京地区大部分站点的极端降水量呈现下降趋势，极端降水频数与之相似，但极端降水强度与降水量和降水频数的变化趋势有明显不同。超过第 95 个百分位极端降水阈值的极端降水量、降水频数和降水强度均呈下降趋势，并均通过了 0.05 的显著性检验。同时，北京地区超过第 99 个百分位降水阈值的极端降水量、降水频数也呈现显著下降趋势，但极端降水强度的变化并不明显。

Abstract: Daily precipitation data of 15 national stations in Beijing area during 1961-2010 are used to study the extreme precipitation exceeding relative thresholds. The results show that the decreasing trend of extreme precipitation frequency is similar to extreme precipitation amount, while the extreme intensity shows a different trend compared with precipitation amount and precipitation frequency during 1961-2010. Our analysis also indicates the decreasing trend of extreme precipitation amount, frequency and intensity based on the relative threshold of 95% in the same period (statistically significant at 0.05-level). Meanwhile, the extreme precipitation amount and frequency based on the relative threshold of 99% also show obvious declining trend (statistically significant at 0.05-level) in Beijing area, but the change of extreme precipitation intensity is not obvious.