中国长短历时暴雨时空变化格局及其对总暴雨贡献的研究(1951—2010)

Long and short duration heavy rainfall spatio-temporal patterns change and its contribution to total heavy rainfall in China(1951-2010)

采用中国1951—2010年659个站点的日值降水数据,以暴雨持续长短为标准对短和长历时暴雨计算,结果表明:在空间上,中国短历时暴雨量从1951到2010年呈现出由东南沿海向西北内陆梯次减少的现象,而长历时暴雨量则主要集中在广东、广西、海南等东南沿海地区。在时间上,中国年际和年代际短和长历时暴雨均呈现增加趋势。在降水贡献率占比上,1951—2010年中国总暴雨量占总降雨量以及总暴雨日占总降雨日的比例分别为6.1%—27.7%和0.6%—2.5%;同期中国短历时暴雨量在总暴雨量和短历时暴雨日在总暴雨日中的比例分别为75.9%—89.4%和75.6%—89.2%,短历时暴雨占主导地位;而长历时暴雨量在总暴雨量和长历时暴雨日在总暴雨日中的比例分别只占10.6%—24.1%和10.8%—24.4%。在降水贡献率变化趋势上,在1951—2010年间,中国总暴雨对总降雨的贡献率呈增加趋势,其雨量和雨日的贡献率趋势分别为2.1%/10a和0.2%/10a;短历时暴雨对总暴雨的贡献率也呈增加趋势,其雨量和雨日的贡献率趋势分别为0.5%/10a和0.4%/10a;而长历时暴雨对总暴雨的贡献率呈减少趋势,其雨量和雨日的贡献率趋势分别为-0.5%/10a和-0.4%/10a。以上结果表明中国降水在朝着极端化方向变化,短历时暴雨增多显著。

Here we use daily rainfall data from 1951 to 2010 of 659 meteorological stations in China and on the basis of duration days defined long duration heavy rainfall. Results indicate that: on the spatial distribution,short duration heavy rainfall shows gradually decreasing phenomenon from the southeast coastal to northwest inland in China from 1951 to 2010.And long duration heavy rainfall is concentrated in the southeast coastal areas,such as Guangdong,Guangxi and Hainan.On the temporal change,the interannual and interdecadal short and long duration heavy rainfall both show increasing trend. In precipitation contribution ratio,the proportion of total heavy rainfall amounts to total rainfall amounts and total heavy rainfall days to total rainfall days are 6.1%-27.7% and 0.6%-27.7% respectively from 1951 to 2010 in China.Short duration storm to occupy the dominant position that the proportion of short duration heavy rainfall amounts to total heavy rainfall amounts and short duration heavy rainfall days to total heavy rainfall days are 75. 9%-89. 4% and75.6%-89.4% respectively in the same period.Long duration heavy rainfall occupy a secondary position that the proportion of long duration heavy rainfall amounts to total heavy rainfall amounts and short duration heavy rainfall days to total heavy rainfall days are only 10.6%-24.1% and 10.8%-24.4% respectively.On the trend of precipitation contribution,China's the contribution rate of total heavy rainfall to the total rainfall show increasing trend with contribution of rainfall amounts and rainfall days trend are 2.1%/10 a and 0.2%/10 a respectively.The contribution rate of short duration heavy rainfall to the total heavy rainfall show increasing trend with contribution of rainfall amounts and rainfall days trend are 0.5%/10 a and 0.4%/10 a respectively.On the contrary,the contribution rate of long duration heavy rainfall to the total heavy rainfall show decreasing trend with contribution of rainfall amounts and rainfall days trend are-0.5%/10 a and-0.4%/10 a respectively.The results suggest that the precipitation in China are changing to extremely accompanied by short duration storm increased significantly.