干旱区研究 ›› 2025, Vol. 42 ›› Issue (7): 1159-1172.doi: 10.13866/j.azr.2025.07.01 cstr: 32277.14.AZR.20250701

• 天气与气候 • 上一篇    下一篇

1981—2024年雅鲁藏布江流域降水集中度与特征量季节性变化

杜军1,2,3(), 高佳佳2,3,4, 陈涛1,2, 次旺1, 巴果卓玛2,5   

  1. 1.西藏自治区气候中心,西藏 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/墨脱大气水分循环西藏自治区野外科学观测研究站,西藏 墨脱 860700
    3.中国气象局日喀则国家气候观象台,西藏 日喀则 857000
    4.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,西藏 拉萨 850001
    5.西藏自治区林芝市气象局,西藏 林芝 860000
  • 收稿日期:2025-03-03 修回日期:2025-04-24 出版日期:2025-07-15 发布日期:2025-07-07
  • 作者简介:杜军(1969-),男,正研级高级工程师,主要从事高原气候与气候变化研究. E-mail: dujun0891@163.com
  • 基金资助:
    西藏自治区科技计划项目揭榜挂帅专项(XZ202303ZY0002G);中国气象科学研究院青藏高原气象科学研究院开放课题(CAMS/ITPM2024K02);西藏自治区科技创新基地建设项目(XZ202401YD0008)

Spatiotemporal variations of the precipitation concentration index and seasonal precipitation characteristics in the Yalung Zangbo River Basin from 1981 to 2024

DU Jun1,2,3(), GAO Jiajia2,3,4, CHEN Tao1,2, Tsewang 1, Pakgordolma 2,5   

  1. 1. Xizang Autonomous Region Climate Centre, Lhasa 850001, Xizang, China
    2. Field Science Experiment Base for Comprehensive Observation of Atmospheric Water Cycle in Mêdog, CMA/Mêdog National Climate Observatory/Xizang Mêdog Field Scientific Observation and Research Station for Atmospheric Water Cycle, Mêdog 860700, Xizang, China
    3. Xizagê National Climate Observatory, CMA, Xizagê 857000, Xizang, China
    4. Xizang Institute of Plateau Atmospheric and Environmental Sciences/Xizang Open Laboratory for Plateau Atmospheric Environment, Lhasa 850001, Xizang, China
    5. Nyingchi Meteorological Service of Xizang Autonomous Region, Nyinchi 860000, Xizang, China
  • Received:2025-03-03 Revised:2025-04-24 Published:2025-07-15 Online:2025-07-07

摘要: 降水集中指数(Precipitation Concentration Index, PCI)能很好地表征降水年内的集中度,在相关研究中被广泛应用。本文基于1981—2024年雅鲁藏布江(以下简称雅江)流域15个气象站逐月降水和平均气温观测资料,采用线性方程、Pearson系数及Mann-Kendall、Cramer等5种突变检验方法,分析近44 a雅江流域PCI、季节降水量、降水频率和降水强度的时空变化特征以及PCI变化原因。结果表明:(1) 雅江流域PCI自东向西递增,年降水量、降水频率和降水强度由东向西递减。(2) 近44 a雅江流域PCI平均每10 a减小0.26,降水在年内的分配趋于均匀;1—7月和10月降水量呈增加趋势(7月增速最快),其他月份降水量为减少趋势(9月减少的最多);2月、4—7月降水量占年降水量的比例(MPAP)表现为增加趋势(5月最大),其余月份MPAP趋于减小(9月减幅最大)。(3) 雅江流域因春、夏、冬三季和全年降水强度增大,致使其降水量增多;秋季降水频率减少导致降水量减少。年降水强度的增加是由于西藏高原-1指数和西太平洋暖池强度指数显著增加造成的。PCI下降与增暖背景下季节性差异减小有关。(4) PCI仅在2000s偏低,其他3个年代均偏高,并在20世纪90年代初期发生了突变;年降水量、频率和强度的突变时间分别出现在21世纪前10 a初期和20世纪90年代中后期。

关键词: 降水集中度, 降水特征量, 变化特征, 大气环流指数, 海温指数, 雅鲁藏布江

Abstract:

The precipitation concentration index (PCI) is a measure of precipitation during the year. Based on the monthly precipitation data of 15 meteorological stations in the Yarlung Zangbo River Basin (YZRB) from 1981 to 2024, the spatiotemporal variation characteristics of PCI, the amount of seasonal precipitation, its frequency and intensity over the last 44 years, and the reasons for a change in PCI were analyzed using a linear equation, Person coefficient, and five mutation tests, including the Mann-Kendall and Cramer tests. The results indicated that (1) The PCI increased from east to west in YZRB, whereas annual precipitation, precipitation frequency, and precipitation intensity decreased from east to west. (2) Over the past 44 years, the PCI decreased at a rate of -0.26 per decade, indicating a trend toward more evenly distributed monthly precipitation throughout the year. Precipitation exhibited an increasing trend from January to July and October (the fastest increase in July), and it decreased in other months (the most in September). Monthly precipitation accounted for the proportion of annual precipitation (MPAP), which increased in February and April-July (the largest in May). MPAP was decreased in other months (the largest decrease in September). (3) The increase of precipitation in spring, summer, and winter was primarily due to the increase in precipitation intensity, whereas the decrease of precipitation frequency played a major role in the decreased amount of precipitation during autumn. Furthermore, the increase in annual precipitation intensity resulted from the significant increase of the Tibetan Plateau-1 index and the western Pacific warm pool intensity index. The decrease in the PCI was related to a decrease in the seasonal difference under the background of warming. (4) The PCI was lower only in the 2000s, but was higher in the other three decades, although there was a sudden change in the early 1990s. The abrupt changes in annual precipitation, frequency, and intensity occurred during the first 10 years of the 2000s and the middle and late 1990s.

Key words: precipitation concentration, precipitation characteristic quantity, variation characteristics, atmospheric circulation index, SST index, Yalung Zangbo River Basin