摘要
基于1960—2012年珠江流域42个气象站点逐日降水量资料,利用线性趋势法、主成分分析法、重标极差(rescaled range analysis method,R/S)分析法及相关分析法,对选取的11种极端降水指标时间变化趋势和空间分布规律进行探讨,并在此基础上分析了该区域极端降水与大气环流之间的关系。结果表明:近53 a以来,珠江流域湿天降水总量以-7.2 mm·10 a-1的趋势呈下降趋势,最大1 d降水量、连续5天最大降水量、非常湿天降水量和极端湿天降水量分别以1.1、0.8、5.3和3.9 mm·10 a-1的趋势增加,降水强度以0.2 mm·d-1·10 a-1趋势呈增加趋势;中雨日数和持续湿润日数以-0.4和-0.2 d·10a-1的不显著减少趋势,大雨日数、强降水日数和持续干燥日数以0.05、0.1和1.1 d·10a-1的趋势增加;空间分布上,极端降水指数表现出明显的区域差异,除持续干燥日数外,其他指数均在云贵高原区呈下降趋势,在广东丘陵和广西丘陵区呈轻微的上升趋势;R/S分析结果显示,极端降水事件未来变化趋势与过去一致;相关性分析结果表明,除持续干燥日数外,各极端降水指数之间均呈现较高的相关性;美国环境预报中心(NCEP)和国家大气研究中心(NCAR)联合推出的(NCEP/NCAR)再分析资料大气环流表明,欧亚大陆冬季反气旋势力增强和东亚夏季风减弱可能是引起珠江流域极端降水事件增加的原因之一。
Based on daily precipitation data at 42 meteorological stations over Pearl River Basin observed by the China Meteorological Administration during 1960-2012, the methods of linear regression, correlation analysis and rescaled range analysis method （R/S） were employed to analyze the temporal variability and spatial distribution of extreme precipitation, and its extreme climatic variation in future was predicted. Eleven indices of extreme precipitation were studied. The results showed that wet day precipitation had decreased by -7.2 mm· 10 a-1, while the maximum 1-day precipitation, maximum 5-day precipitation, very wet day precipitation and extremely wet day precipitation showed statistically increasing trends at rates of 1. 1, 0.8, 5.3 and 3.9 mm· 10 a-1, respectively. Meanwhile, simple daily intensity index also showed an increasing trend by 0.2 mm · d-1 · 10 a-1. The number of heavy precipitation （ 10 ram） days had an insignificant decreasing trend at the rate of -0.40 d · 10 a-1 , while heavier （20 ram） and heaviest （25 mm） precipitation days had a weak increasing trend at the rates of 0. 05 and 0.1 d · 10 a-1 , respectively. Consecutive dry days had an increasing trend and consecutive wet days had a decreasing trend at the rates of 1.1, -0.2 d · 10 a-1, respectively. Spatial variations of precipitati- on extreme indices showed obvious differences, and they were not clustered either. On the whole, the number of rainy days had decreased over the Yunnan-Guizhou Plateau and hilly Guan- gxi, and the spatial distribution reflects the regional climatic complexity. R/S analysis showed that the future trends of extreme precipitation events were consistent with the past. In addition, except for consecutive dry days, the other extreme precipitation indices have significant correla- tions with annual precipitation. Large scale atmospheric circulation changes derived from NCEP/ NCAR reanalysis reveal that strengthening anticyclonic circulation over the Eurasian continent and weakening East Asian summer monsoon have contributed to the increase in precipitation extremes in the Pearl River Basin.
出处
《生态学杂志》
CAS
CSCD
北大核心
2014年第9期2528-2537,共10页
Chinese Journal of Ecology
基金
国家基础科学人才培养基金项目(J1103408)资助
关键词
极端降水
大气循环
珠江流域
precipitation extremes
atmospheric circulation
Pearl River Basin.
