海河流域极端降水事件时空变化特征分析

为研究气候变化背景下海河流域的极端降水事件变化规律,基于流域内30个气象台站1960~2008年的逐日降水资料,选取不同的降水指标,应用M-K趋势检验和滑动t检验方法分析了海河流域极端降水的时空变化特征。结果表明,海河流域的极端降水事件的发生频率和强度在年际变化中均呈减小趋势;在空间大部分范围内,降水频率和强度指标也均呈负趋势,仅滦河上游山区、子牙河山区和胶东沿海部分地区呈微弱上升趋势,但趋势并不显著。总体而言,海河流域趋向于干旱化,流域内洪涝灾害发生的概率有所减小。

Temporal and Spatial Variation Characteristics of Extreme Precipitation Events in Haihe Basin

To study the variability of extreme precipitation in Haihe Basin under the background of climate change, based on the daily precipitation data of 30 meteorological stations during 1960 2008 years and different indicators, the spatiotemporal variation characteristics of extreme precipitation are analyzed with M K trend test and sliding t test methods. The results show that both of frequency and intensity for extreme precipitation events of Haihe Basin appear downward trend in inter annual variation characteristics; in the majority space range, the rainfall frequency and intensity indicators appear negative trend, only the mountain area of the upper reaches of the Luanhe River, the mountain area of Ziya River and part of the Jiaodong coastal area appear a slight upward trend, but the trend is not significant. Overall, the Haihe Basin tends to drought development stage and the occurrence probability of flood is reduced.