摘要
文章利用西藏山南市1981-2017年汛期(5-9月)6个气象站逐日降水资料,定义不同等级雨日选取标准,采用线性回归、累积距平、相关系数等统计学方法,分析了山南市雨日时空变化特征。结果表明:山南市汛期各等级雨日空间分布基本一致,自西南-东北呈增加趋势;总雨日数、中雨日数、大雨日数随年代呈增加趋势,小雨日数则呈不明显减少趋势,气候倾向率为-0.06 d/10a;小雨对山南市汛期降水贡献率最大,平均降水贡献率高达89%,小雨为山南汛期主要降水事件,但中雨事件对山南市旱涝分布影响最大;各等级雨日具有明显的年代际变化,存在突变年份。
Based on the daily precipitation data measured at 6 meteorological stations between the years of 1981-2017 during flood season(May-September)in Shannan area,Tibet,the standard of the grades of number of rainy days was defined in this paper.Using the statistical methods of linear regression,cumulative departure,correla-tion coefficient etc.,the characteristics of the spatial and temporal variation of number of rainy days in this area was analyzed.The results show that the spatial distribution of each defined grade during the flood season is basi-cally consistent,with the increasing trend from the southwest to the northeast.And the total numbers of rainy days,moderate rainy days,as well as heavy rainy days show increasing trend,in the meantime,the number of light rainy days show slightly decreasing trend with the climatic trend rate of-0.06d/10a.Moreover,the contribu-tion rate of light rainfall to precipitation in this area during the flood season is the most significant with the aver-age precipitation contribution rate as high as 89%.Light rainfall is the main precipitation event,but the moderate rainfall event has the greatest influence on the drought and flood distribution,and the results also show that there is obvious inter-decadal variation of each grade of number of rainy days and years with abrupt change.
作者
益西拉姆
陈定梅
次仁吉宗
Yeshi-Lhamo;CHEN Ding-mei;Tsering-Kyizom(Meteorological bureau of Shannan Tibet,Shannan 856000,China)
出处
《高原科学研究》
2018年第2期75-82,共8页
Plateau Science Research
基金
西藏自治区山南市科技局项目(SNKJ201817)
关键词
西藏山南市
汛期
雨日时空分布
Shannan
Flood season
Temporal and spatial variation of the number of rainy days
作者简介
益西拉姆,女,藏族,西藏山南人,西藏山南市气象局助理工程师,主要研究方向为长、中、短期天气预报。
