摘要:In this study, the spatial-temporal features of eight extreme precipitation indices selected in the Yangtze-Huaihe River Basin during 1979-2011 are analyzed to assess the reanalysis datasets of ERA-Interim and NCEP/DOE, using the observational data from meteorological stations as a reference.The results are as follows:1) The consecutive wet day (CDD), day of heavy rainfall (R10 mm, R20 mm) and the extreme indices based on percentiles (R95 p, R99 p) are distributed with lowvalues in the north and high values in the south, while the consecutive dry day is distributed with a positive phase. In addition, the intensity indices (Rx1 day, Rx5 day) showhigh values along the coast of Zhejiang.2) The R10 mm and R20 mm showdecreasing trends in most regions, with the exception of the marginal areas of the basin, where weak increasing trends are observed.3) The intensity indices averaged over the basin tend to increase with time.The annual cycles of these indices demonstrate bell-shaped patterns, with peaks in July.In late summer and winter, there is a more obvious trend of increasing with age, while in autumn it decreases with age.4) The two reanalysis datasets showboth advantages and weaknesses when presenting the extreme indices. The ERA-Interim performs better in producing the spatial patterns of R10 mm, CDD and percentile indices, as well as the linear trend of CDD. It also produces better inter-annual variations of intensity and percentile indices. However, its ability to reproduce the trend distribution of CWD is weak. On the other hand, NCEP/DOE is better at presenting the spatial pattern of R20 mm, as well as the linear trends of intensity and percentile indices.However, its ability to express the trend of the duration index is weak.5) The two reanalysis datasets can reasonably reproduce the interannual variation characteristics of R10 mm, R20 mm, CDD and seasonal variation characteristics of intensity indices.%利用淮河流域1979-2011年260个站点观测、ERA-Interim和NCEP/DOE再分析资料的日降水量数据, 选用8个极端降水指数, 从空间分布、发展趋势、时间变化等方面对比分析了我国江淮流域极端降水的变化规律, 研究了再分析数据的适用性, 结果表明:1) 持续湿润指数 (CWD) 、强降水日数 (R10mm, R20mm) 以及百分位指数 (R95p, R99p) 具有一致的北少南多的分布特征, 而持续干燥指数 (CDD) 为北多南少, 且强度指数 (Rx1day, Rx5day) 和百分位指数在浙江沿海均有极大值存在.2) 大部分地区的强降水日数呈减少趋势, 仅在江淮周边地区有弱上升趋势.3) 区域平均的降水强度指数具有上升的趋势变化, 逐月变化具有先增长后减少的结构特征, 5-6月的增长量最大, 峰值出现在7月, 在夏末、冬季有较明显的随年代增加的趋势, 在秋季则随年代减少.4) 再分析资料ERA-Interim和NCEP/DOE对不同指数的再现能力有所不同, ERA-Interim对强降水日数 (R10mm) 、CDD、百分位指数的空间分布以及CDD的变化趋势再现能力较好, 与强度指数和百分位指数年际变化的相关性较高, 但对CWD变化趋势分布特点的再现能力较弱;NCEP/DOE更善于再现较强降水日数 (R20mm) 的空间分布以及强度指数和百分位指数的线性变化趋势.5) 两种再分析资料能合理地再现强降水日数 (R10mm, R20mm) 和CDD年际变化特征和强度指数的季节变化特征.