1981-2020年西藏植物生长季昼夜降水量变化特征  

Variation Characteristics of Daytime and Nighttime Precipitation during the Growing Season of Plants in Xizang from 1981 to 2020

作　　者：杜军 普布桑姆 平措桑旦 索朗 王挺 DU Jun;Phurbusangmo;Phuntsoksamten;Sonam;WANG Ting(Xizang Institute of Plateau Atmospheric and Environmental Science Research/Plateau Atmospheric and Environment Open Laboratory of Xizang,Lhasa 850001,China;Field Science Experiment Base for Comprehensive Observation of Atmospheric Water Cycle in Mêdog,China Meteorological Administration/Mêdog National Climate Observatory,Mêdog 860700;Nyingchi Meteorological Bureau of Xizang,Bayip 860000)

机构地区：[1]西藏高原大气环境科学研究所/西藏高原大气环境开放实验室,拉萨850001 [2]中国气象局墨脱大气水分循环综合观测野外科学试验基地/墨脱国家气候观象台,墨脱860700 [3]西藏自治区林芝市气象局,巴宜860000

出　　处：《中国农业气象》2025年第2期133-144,共12页Chinese Journal of Agrometeorology

基　　金：第二次青藏高原综合科学考察研究项目(2019QZKK0106);中国气象科学研究院青藏高原与极地气象科学研究所开放课题(ITPP2021K03)。

摘　　要：利用1981-2020年西藏38个气象站点5-9月逐小时降水量资料,采用气候倾向率、Pearson相关、线性回归方法以及Mann-Kendall、Cramer等5种突变检验方法,分析近40a西藏植物生长季昼(P_(d))、夜(P_(n))降水量时空分布以及变化趋势、突变和周期等气候特征。结果表明:(1)P1时段(1981-2010年)西藏各地平均生长季P_(d)为21.3~240.5mm,总体上呈自东北向西南递减分布规律;P_(n)为36.3~430.7mm,表现为以拉萨市东北部、那曲市南部为中心向四周减少的分布特征。P_(n)与P_(d)比较,除隆子站偏少6.8%外,各站偏多1.7%~436.0%。P2时段(1991-2020年)与P1时段比较,P_(d)和P_(n)空间分布基本一致,不同的是昼降水量200mm等值线偏南,夜降水量400mm等值线范围略有扩大。(2)近40a林芝市大部、洛隆和聂拉木生长季P_(d)和P_(n)均呈减少趋势,其他大部区域P_(d)和P_(n)趋于增加。其中,63.2%站点P_(n)变幅大于P_(d);P_(d)与P_(n)同增型占63.2%,P_(d)与P_(n)同减型占13.1%,P_(d)增P_(n)减型占7.9%、P_(d)减P_(n)增型占15.8%。影响P_(d)和P_(n)气候倾向率空间分布的主导因子为海拔高度,并随海拔升高而增大。(3)20世纪80年代西藏大部分站点生长季P_(d)和P_(n)偏少,90年代东南部偏多、西北部偏少,21世纪前10a东部和西部偏少、北部偏多,21世纪10年代与20世纪90年代正好相反。(4)近40a,西藏38站平均P_(d)和P_(n)均趋于增加,分别为3.4mm·10a^(-1)和6.9mm·10a^(-1),两者都存在显著的3a周期,且在2004年、2005年发生突变。Based on the hourly precipitation data of May to September at 38 meteorological stations in Xizang from 1981 to 2020,the spatial and temporal distribution,variation trend,mutation and period of daytime precipitation(P_(d))and nighttime precipitation(P_(n))during the growing season of plants in Xizang in recent 40 years were analyzed using the methods of the climatic propensity rate,Pearson coefficient,linear regression method,and five mutation tests including the Mann-Kendall,Cramer,etc.Results showed that:(1)the annual day and night precipitation in Xizang varied greatly in different regions.During the P1 period(1981−2010),the average P_(d) in the growing season in Xizang ranged from 21.3 to 240.5mm,generally characterized by a decreasing distribution pattern from the northeast to the southwest,and the Pn ranged from 36.3 to 430.7mm,showing a distribution pattern decreasing from the northeastern part of Lhasa and the southern part of Nagchu city to the surroundings.The Pn was 1.7%to 436.0%more than P_(d) for all stations except the Lhünzêstation,which was 6.8%less than P_(d).Among them,that were the most obvious in the middle reaches of the Yarlung Zangbo river,with an excess of 1.0−4.4 times.Compared with the P1 period,the spatial distribution of P_(d) and Pn was basically unchanged in the P2 period(1991−2020),except for a southward shift of the 200mm isoline of P_(d) and a slight expansion of the 400mm isoline of Pn.The highest and lowest values of P_(d) and Pn were more of 1.8%−2.4%and 8.3%−8.9%respectively,especially the lowest values.In addition,the Pd and Pn during the growing season were mainly affected by longitude.(2)In the past 40 years,both the Pd and Pn decreased in most of Lyingchi city,Lhorong and Nyalam stations during the growing season,and increased in most other areas,but the trends were not significant.Moreover,the trend of Pn was greater than that of Pd at 63.2%stations.The Pd and Pn co-increasing type accounted for 63.2%,the Pd and Pn co-decreasing type accounted for 13.1%,the ca

关 键 词：生长季 昼夜降水 变化趋势 年代际变化 气候突变 周期 

分 类 号：Q948.112[生物学—植物学]