Based on the statistical information of meteorological and agricultural inundation disaster data from 1951 to 2006, the characteristics of the spatial and temporal distribution of the occurrence frequency of min-waterlogging process (defined as 10-day accumulated rainfall ≥ 250 mm (150 mm in Northwest China) or 20-day accumulated rainfall ≥ 350 mm (250 mm in Northwest China)) in the Yellow River and the Yangtze River basins were analyzed, the results show that rain-waterlogging in the two river basins has continually increased during the last 50 years, especially after the 1980s due to the impact of climate change; inundated cropland areas and economic losses showed increasing trends. The rain-waterlogging range was larger and the occurrence frequency of rain-waterlogging was higher in the Yangtze River basin in comparison with the Yellow Rive basin. Summer was a season in one year when the occurrence frequency of rain-watedogging was the highest and its range was the largest due to the influence of rainstorms. Since the end of the 1980s, rainstorm disaster has distinctively increased in the Yellow Rive basin, and since the early 1980s inundated cropland area has remarkably increased in the Yangtze River basin. The inundation ratios of rain-waterlogging in the two river basins gradually increased from the upper reaches to lower reaches, and the impacts of rain-waterlogging disaster were relatively larger in the middle and lower reaches of the Yangtze River basin.%根据1951-2006年黄河和长江流域雨涝灾害灾情统计资料,分析了两个流域雨涝灾害发生频率的时空分布特征,结果表明:近50 a以来,特别是20世纪80年代以来,受气候变化影响,黄河和长江流域雨涝灾害不断增加,农作物受灾、成灾面积呈增加趋势,损失日趋严重,且长江流域受雨涝灾害影响范围较大,灾害发生频率大于黄河流域.受暴雨影响,夏季两个流域雨涝发生频率最高、范围最广.20世纪80年代末以来,黄河流域雨涝灾害增加趋势较为明显,而长江流域80年代初雨涝受灾面积和成灾面积显著增加.两个流域雨涝灾害的受灾率均自上游至下游逐渐增加,其中长江流域中下游地区受雨涝灾害影响较大.
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