摘要
本文选取云南省1979-2016年125个气象台站秋季逐日降水量资料,利用Mann-Kendall趋势分析和突变检验方法,研究了秋季降水量降水强度趋势变化规律,发现年均降水量及小雨、中雨、大雨等级雨强大部分站点呈下降趋势,少数站点呈上升趋势;暴雨等级降水强度差异较大;年均雨强在较多站点存在显著性突变.应用经验正交函数(EOF)分解方法分析了秋季降水时空分布特征,从第一、二模态发现多年平均降水量从南向北逐渐减少,主要特征是大范围区域降水具有一致性,其次为滇中及以东以南与滇西及滇西北地区反向变化空间分布型态,这与云南省过去几十年天气状况及极端降水现象相符合.而后,分析了降水强度和降水日数对降水量的影响程度及其差异性.以雨强贡献大于雨日贡献为正,发现对于多年小雨、中雨、大雨等级,全局为负且具有一致性.年均降水量主要表现为西南、西北、东南地区为正,滇中及东部东北地区为负.至于暴雨,两者贡献值百分比差异明显且幅度较大,东北为负,西南为正,由东北向西南递增.可以认为雨量等级越大,降水强度对降水量影响越大.本研究在云南省降水研究中具有重要的现实意义.
The daily rainfall data in autumn from 1979 to 2016 at 125 meteorological stations in Yunnan province are analyzed in this paper selects.The Mann-Kendall trend analysis and mutation test are used to study the trend of rainfall and precipitation intensity in autumn.It is found that precipitation intensity of the average annual precipitation and the levels of light rain,small rain and heavy rain at the most stations are on the decline,while at a few stations is on the rise.Precipitation intensity of rainstorm grade varies greatly.There are significant mutations in the average annual rainfall intensity at a large number of stations.Empirical orthogonal function(EOF)decomposition is applied to analyze the spatial-temporal distribution characteristics of precipitation in autumn.From the first and second modes,the average annual rainfall decreases from south to north.The main characteristics is that regional rainfall has consistency in a wide range,and followed by the reverse spatial distribution pattern between the middle with its southern-eastern and the western with its northwest,which conforms to weather condition and extreme precipitation phenomenon in the past few decades.The influence degree and the difference of rainfall intensity and precipitation days on precipitation was also analyzed.When the contribution of rain intensity is greater than that of rain day,the token is specified as the positive value.It can be seen that for the levels of light rain,small rain and heavy rain,the whole is negative with the consistency.The average annual precipitation mainly shows that it is positive in the southwest,northwest,southeast area and negative in the northeast.As for the rainstorm,the percentage difference of contribution value is markedly obvious.The northeast is negative and the southwest is positive,increasing from northeast to southwest.It can be considered that the greater the rainfall grade,the greater the influence of precipitation intensity on precipitation.The above results have important practical significa
作者
渠姗
赵君
徐进超
徐石川
李雪纯
王一燃
QU Shan;ZHAO Jun;XU Jinchao;XU Shichuan;LI Xuechun;WANG Yiran(School of Hydrology&Water Resources,Nanjing Univ.of Information Science&Technology,Nanjing 210044,China;Nanjing Hydraulic Research Institute,Nanjing 210029,China;School of Resource Environment&Earth Science,Yunnan Univ.,Kunming 650504,China)
出处
《三峡大学学报（自然科学版）》
CAS
2021年第5期26-32,共7页
Journal of China Three Gorges University：Natural Sciences
基金
国家重点研发计划项目(2016YFA0601501,2017YFC1502706,2017YFA0605002)
中国博士后科学基金资助项目(2020T130309,2019M651892)
国家自然科学基金面上项目(41671022)
江苏省水利科技项目(2020022,2021024)。
