基于日值和小时降水数据诊断中国暴雨时空变化差异的研究（1991－2010）

摘要

日值和小时观测降水数据在反映中国暴雨时空格局方面的差异还未有明确结论，因此，亟需通过不同时间分辨率的降水观测数据来深入研究中国暴雨的时空变化特征。该文采用观测的长时间序列（1991－2010年）的小时降水数据和日值降水数据对中国暴雨雨量和暴雨雨日的年际和年代际时空变化特征进行研究。结果表明，在时间变化上，1991－2010年期间小时降水数据和日值降水数据计算的暴雨雨量和暴雨雨日在逐年变化上没有本质上的差异，暴雨雨量和暴雨雨日的年累计值在波动中呈现出明显的增加趋势，但日值降水数据所反映的暴雨雨量和暴雨雨日的波动要大于小时降水数据。在空间格局上，小时降水数据和日值降水数据所反映的中国暴雨雨量和暴雨雨日的空间分布格局没有较大差别，但小时降雨数据反映的更详细，空间分布格局的破碎程度更高。在年代际小时暴雨和日值暴雨两者之间的对比方面，小时降水数据和日值降水数据有较大差异，小时降水数据反映的暴雨雨量和暴雨雨日在长江流域偏少，而在其它地区有不同程度的偏高。在小时暴雨和日值暴雨的各自年代际变化方面，小时降水数据和日值降水数据反映的年代际暴雨空间变化表现出相同的变化趋势，但小时降水数据反映的空间分布特点更加破碎。因此，小时降水数据和日值降水数据在反映中国年代际暴雨时空高低分布方面具有一致性，但量级在不同地区具有不同程度的差异，且在揭示中国年代际暴雨变动方面具有一致性，应根据研究目的选择适当数据。%Whether the daily precipitation dataset and hourly precipitation dataset from observation can reflect the spatiotemporal patterns of heavy rainfall in China with consistency or not,which need to deepen research heavy rainfall with different temporal resolution precipitation dataset.Therefore,the precipitation dataset with high tempo-ral resolution is desperately needed to advance the research in the field of the heavy rainfall in China.In this re-search,hourly heavy rainfall amounts and heavy rainfall hours as well as daily heavy rainfall amounts and daily heavy rainfall days are derived as a whole through China,based on the hourly precipitation dataset and daily pre-cipitation dataset during the period of 1991 through 2010.Results show that both heavy rainfall amounts and heavy rainfall days from the hourly precipitation dataset and daily precipitation dataset exhibit obviously consistent increase trends despite some fluctuation during the period investigated.However,heavy rainfall amounts and heavy rainfall days from daily precipitation dataset show higher fluctuation than hourly precipitation dataset.In the aspects of the spatial pattern of decadal heavy rainfall,hourly precipitation dataset and daily precipitation dataset have no signifi-cance difference.However,hourly precipitation dataset can reflect more details of the heavy rainfall.In the aspects of the spatial variation of decadal heavy rainfall,the daily precipitation dataset and the hourly precipitation dataset have great differences.Decadal heavy rainfall amounts and heavy rainfall days form the hourly precipitation dataset is lower than daily precipitation dataset in Yangtze River Basin,but higher in other regions with varying degrees. Decadal heavy rainfall amounts and heavy rainfall days change from daily precipitation dataset as well as hourly pre-cipitation dataset showed the same trend,but hourly precipitation data reflect spatial distribution characteristics more broken.Our results shown that hourly precipitation dataset and daily precipitation dataset consist reflect the spatial and temporal distribution of heavy rainfall in China,but there is a big difference in the order of magnitude. And there is a great difference in the aspects of China’s heavy rainfall changes.Appropriate dataset should be cho-sen according to research purpose.