The hierarchy and definition of the precipitation-concentration degree and precipitation- concentration period of annual precipitation have been proposed by using the so-called vector method of annual distribution of ...The hierarchy and definition of the precipitation-concentration degree and precipitation- concentration period of annual precipitation have been proposed by using the so-called vector method of annual distribution of precipitation,so that the two relevant parameters can represent the annual distribution of total precipitation correctly and indeed accurately.The relationship between the spatial and temporal distribution patterns and variations of the two parameters and the annual precipitation amount in China has been further investigated.Results demonstrate that the precipitation-concentration degree and the precipitation-concentration period increase from southeast to northwest gradually.Moreover there obviously exists a belt pattern:the largest variability of the precipitation-concentration degree and the precipitation-concentration period occurs in the Yellow River Valley and the middle and lower reaches of the Yangtze River, corresponding to the significant zones in which flood and drought take place frequently.It is found that there exist high correlations between the precipitation-concentration degree and precipitation- concentration period and the annual precipitation amount in Northeast China,North China,the middle and lower reaches of the Yangtze River. Furthermore,8-year and 22-year periodic oscillations in the precipitation-concentration degree and 6-year and 12-year cycles in the precipitation-concentration period are identified by use of their Morlet wavelet analysis.展开更多
Based on 740 stations of daily precipitation datasets in China, the precipitationconcentration degree （PCD） and precipitation-concentration period （PCP） of different intensity durative precipitation events were ca...Based on 740 stations of daily precipitation datasets in China, the precipitationconcentration degree （PCD） and precipitation-concentration period （PCP） of different intensity durative precipitation events were calculated to analyze their statistical characteristics, mainly including spatial and temporal distributions, variations and climatic trends of the two parameters of the durative heavy precipitation events in China. It is proved that these two parameters of heavy rainfall can display the temporal inhomogeneity in the precipitation field. And it is also found that there is a good positive relationship between the precipitation-concentration degree and annual rainfall amount in the Eastern and Central China. This method can be anolied in flood assessment and climate change fields.展开更多
In this study, we investigated the spatial and temporal characteristics of precipitation heterogeneity and meteorological drought/flood in China based on the precipitation-concentration degree （PCD） and the inte- gr...In this study, we investigated the spatial and temporal characteristics of precipitation heterogeneity and meteorological drought/flood in China based on the precipitation-concentration degree （PCD） and the inte- grated meteorological drought index. We also studied the corresponding relationship between precipitation heterogeneity and meteorological drought/flood in China by using Spearman correlation analysis and canon- ical correlation analysis. The results show that： （1） The severity of meteorological drought/flood exhibited a spatial pattern of gradual change from Northwest to Southeast China. （2） With a higher PCD and a delayed precipitation-concentration period （PCP）, the drought severity was higher but the flood severity was lower. In contrast, with a lower PCD and an early PCP, the drought severity was lower and the flood severity was higher. （3） The correlation between meteorological drought/flood and PCD was significant. The higher the PCD, the longer the duration of drought and more frequently, the droughts occurred, and vice versa. It is concluded that PCD and PCP were significantly correlated with meteorological drought/flood in China.展开更多
利用宁夏气象台站1961-2010年逐侯降水量序列资料,研究了表征降水量时间分配特征的降水集中度(PCD)和集中期(PCP)的空间分布与年际变化特征。结果表明:宁夏降水PCP与PCD空间分布特征明显,中北部PCP比南部山区偏早1候,PCD自北向南逐渐减...利用宁夏气象台站1961-2010年逐侯降水量序列资料,研究了表征降水量时间分配特征的降水集中度(PCD)和集中期(PCP)的空间分布与年际变化特征。结果表明:宁夏降水PCP与PCD空间分布特征明显,中北部PCP比南部山区偏早1候,PCD自北向南逐渐减小,北部1年中最大降水出现的时间变率较大,且出现极端降水的可能性比中南部大;1961-2010年全区PCD与PCP呈微弱的下降趋势,但近20 a PCD明显增大,PCP显著推迟;PCD与PCP显著正相关,PCP出现得越晚,PCD集中度越高;各地的PCD与年降水量、汛期降水量以及年日最大降水量都有非常好的正相关性,正相关中心区位于北部的惠农、陶乐、中卫,中部的盐池、麻黄山和南部山区的大部,上述地区降水越集中,年降水量、汛期降水量以及年日最大降水量越大,导致洪涝灾害发生的可能性将越大;宁夏汛期降水多雨年各地降水更集中,且大降水中北部大部易出现得早,南部出现得晚;中高纬的北极涛动和低纬的南海季风对宁夏降水集中度有着显著的影响,北极涛动偏弱的年份,南海季风爆发偏早的年份,宁夏各地年降水比较集中。展开更多
Based on the property of entropy,a new index Q was defined to measure the temporal concentration property of summertime daily rainfall in China,based on daily precipitation data collected at 553 observation stations i...Based on the property of entropy,a new index Q was defined to measure the temporal concentration property of summertime daily rainfall in China,based on daily precipitation data collected at 553 observation stations in China during 1961–2010.Furthermore,changes in the temporal concentration property of summer precipitation in China were investigated.The results indicate that the regions with larger Q values were located in most parts of Northwest China and the north of the Yellow River,where daily precipitation tended to become temporally concentrated during the study period.On the contrary,smaller Q values were found in eastern Tibetan Plateau,southeastern Northwest China,and most parts of Southwest and South China.The most obvious increasing trend of Q index was found in South China and most parts of Southwest China,where precipitation showed a temporal concentration trend.However,a decreasing trend of Q index was found in Northwest China,the Tibetan Plateau,and the north of the Huaihe River.Variations of the Q index and the summer rainfall total during 1961–2010 in China both exhibited an increasing trend,implying larger temporal variability in rainfall attributes.It is illustrated that the summer precipitation in general became more temporally concentrated with more intense rainfall events and wetter days.展开更多
基金the National Natural Science Foundation of China projects"Studies on interaction between the South Asia high and the Asian monsoon and its mechanisms"(40175021)"Interannual and interdecadal variations of Meiyu in the Yangtze-Huaihe River Basins and their mechanisms"(40233037)
文摘The hierarchy and definition of the precipitation-concentration degree and precipitation- concentration period of annual precipitation have been proposed by using the so-called vector method of annual distribution of precipitation,so that the two relevant parameters can represent the annual distribution of total precipitation correctly and indeed accurately.The relationship between the spatial and temporal distribution patterns and variations of the two parameters and the annual precipitation amount in China has been further investigated.Results demonstrate that the precipitation-concentration degree and the precipitation-concentration period increase from southeast to northwest gradually.Moreover there obviously exists a belt pattern:the largest variability of the precipitation-concentration degree and the precipitation-concentration period occurs in the Yellow River Valley and the middle and lower reaches of the Yangtze River, corresponding to the significant zones in which flood and drought take place frequently.It is found that there exist high correlations between the precipitation-concentration degree and precipitation- concentration period and the annual precipitation amount in Northeast China,North China,the middle and lower reaches of the Yangtze River. Furthermore,8-year and 22-year periodic oscillations in the precipitation-concentration degree and 6-year and 12-year cycles in the precipitation-concentration period are identified by use of their Morlet wavelet analysis.
基金Concentrated fund item of nationalscience and technology foundation work,No.2001DEA30029-0604Jiangsunaturalsciencefoundation,No.BK2005163
文摘Based on 740 stations of daily precipitation datasets in China, the precipitationconcentration degree （PCD） and precipitation-concentration period （PCP） of different intensity durative precipitation events were calculated to analyze their statistical characteristics, mainly including spatial and temporal distributions, variations and climatic trends of the two parameters of the durative heavy precipitation events in China. It is proved that these two parameters of heavy rainfall can display the temporal inhomogeneity in the precipitation field. And it is also found that there is a good positive relationship between the precipitation-concentration degree and annual rainfall amount in the Eastern and Central China. This method can be anolied in flood assessment and climate change fields.
基金Supported by the National Nature Science Foundation of China(41171090)National Social Science Foundation of China(14AZD094 and 14XSK019)
文摘In this study, we investigated the spatial and temporal characteristics of precipitation heterogeneity and meteorological drought/flood in China based on the precipitation-concentration degree （PCD） and the inte- grated meteorological drought index. We also studied the corresponding relationship between precipitation heterogeneity and meteorological drought/flood in China by using Spearman correlation analysis and canon- ical correlation analysis. The results show that： （1） The severity of meteorological drought/flood exhibited a spatial pattern of gradual change from Northwest to Southeast China. （2） With a higher PCD and a delayed precipitation-concentration period （PCP）, the drought severity was higher but the flood severity was lower. In contrast, with a lower PCD and an early PCP, the drought severity was lower and the flood severity was higher. （3） The correlation between meteorological drought/flood and PCD was significant. The higher the PCD, the longer the duration of drought and more frequently, the droughts occurred, and vice versa. It is concluded that PCD and PCP were significantly correlated with meteorological drought/flood in China.
文摘利用宁夏气象台站1961-2010年逐侯降水量序列资料,研究了表征降水量时间分配特征的降水集中度(PCD)和集中期(PCP)的空间分布与年际变化特征。结果表明:宁夏降水PCP与PCD空间分布特征明显,中北部PCP比南部山区偏早1候,PCD自北向南逐渐减小,北部1年中最大降水出现的时间变率较大,且出现极端降水的可能性比中南部大;1961-2010年全区PCD与PCP呈微弱的下降趋势,但近20 a PCD明显增大,PCP显著推迟;PCD与PCP显著正相关,PCP出现得越晚,PCD集中度越高;各地的PCD与年降水量、汛期降水量以及年日最大降水量都有非常好的正相关性,正相关中心区位于北部的惠农、陶乐、中卫,中部的盐池、麻黄山和南部山区的大部,上述地区降水越集中,年降水量、汛期降水量以及年日最大降水量越大,导致洪涝灾害发生的可能性将越大;宁夏汛期降水多雨年各地降水更集中,且大降水中北部大部易出现得早,南部出现得晚;中高纬的北极涛动和低纬的南海季风对宁夏降水集中度有着显著的影响,北极涛动偏弱的年份,南海季风爆发偏早的年份,宁夏各地年降水比较集中。
基金Supported by the National Natural Science Foundation of China(41575094 and 41275092)Project for Postgraduate Scientific Research and Innovation of Jiangsu Province(KYLX_0842 and CXZZ12-0485)Innovation Program of the State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences(2015LASW-A03)
文摘Based on the property of entropy,a new index Q was defined to measure the temporal concentration property of summertime daily rainfall in China,based on daily precipitation data collected at 553 observation stations in China during 1961–2010.Furthermore,changes in the temporal concentration property of summer precipitation in China were investigated.The results indicate that the regions with larger Q values were located in most parts of Northwest China and the north of the Yellow River,where daily precipitation tended to become temporally concentrated during the study period.On the contrary,smaller Q values were found in eastern Tibetan Plateau,southeastern Northwest China,and most parts of Southwest and South China.The most obvious increasing trend of Q index was found in South China and most parts of Southwest China,where precipitation showed a temporal concentration trend.However,a decreasing trend of Q index was found in Northwest China,the Tibetan Plateau,and the north of the Huaihe River.Variations of the Q index and the summer rainfall total during 1961–2010 in China both exhibited an increasing trend,implying larger temporal variability in rainfall attributes.It is illustrated that the summer precipitation in general became more temporally concentrated with more intense rainfall events and wetter days.
