摘要
利用江西省17个国家级台站1960～2008年逐日降水量资料,对日降水量超过绝对阈值(25mm和50mm)和百分位数阈值(95%和99%)的极端降水变化情况进行了分析。结果表明,江西省近50年极端降水频率和强度均呈波动上升趋势,大雨和强降水频率的增加最为迅速,暴雨和极端强降水事件强度增加最大;夏季各种极端降水事件频率均有明显升高;冬季大雨和强降水事件频率也有显著增加;春季和秋季极端降水强度有明显增加,特别是暴雨和极端强降水事件强度增加迅速;夏季暴雨和极端强降水强度有所降低或略有增加;江西省极端降水的频率和强度变化趋势较为一致,特别是1990年代;极端降水的增加以发生频数的增加为主,降水强度的增加并不显著;近50年江西省大部分地区的极端降水事件频率和强度均有增加,但高值区的分布有较大的差异。极端强降水事件强度在鄱阳湖平原附近减小,而在周边的大部分地区呈增长趋势。进一步的分析发现,极端降水强度的变化与地形有显著的正相关关系。
Daily precipitation data of 17 national stations in Jiangxi Province during 1960-2008 are used to study the extreme precipitation exceeding absolute thresholds （25 mm and 50 mm） and relative thresholds （95% and 99%）. The results show that the frequency and intensity of the extreme precipitation during recent 50 years undergone a fluctuant increasing trend in most parts of the province. The trends of the frequencies exceeding 25 mm and 95%,and the intensities exceeding 50 mm or 99% show significant increase. The frequencies of the extreme precipitation in summer,and that exceeding 25 mm and 95% percentile in winter increase more rapidly than the others. The intensities of the extreme precipitation in spring and autumn increase more rapidly than in summer and winter,especially that exceeding 50 mm and 99%. There is a superposition between high frequency and high intensity of the extreme precipitation events,especially during the 1990s. In recent 50 years,most parts of Jiangxi Province show increase of the intensity and frequency of the extreme precipitation,but the distributions of the highest value are inconsistent. The strength of the extreme precipitation reduced in and around the Poyang Lake Plain,while an enhancement in the most other parts. Extreme precipitation in the province is positively related to the altitudes of the stations. Frequency of the extreme precipitation in the Wuhe watershed and that in the Ganjiang watershed show coherent variations.
出处
《气候与环境研究》
CSCD
北大核心
2010年第4期462-469,共8页
Climatic and Environmental Research
基金
国家科技支撑项目课题2007BAC03A01
关键词
极端降水
气候变化
江西省
extreme precipitation
climate change
Jiangxi Province
