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中国沙漠 ›› 2009, Vol. 29 ›› Issue (5): 960-966.

• 天气与气候 • 上一篇    下一篇

近40 a江河源区潜在蒸散量变化特征及影响因子分析

王素萍   

  1. 中国气象局 兰州干旱气象研究所, 甘肃省(中国气象局)干旱气候变化与减灾重点(开放)实验室, 甘肃 兰州 730020
  • 收稿日期:2008-04-18 修回日期:2008-07-24 出版日期:2009-09-07 发布日期:2009-09-07

Trend of Potential Evapotranspiration and Its Main Impact Factors in the Source Regions of Yangtze and Yellow Rivers

WANG Su-ping   

  1. Lanzhou Institute of Arid Meteorology, China Meteorological Administration, Key Laboratory of Arid Climate Change and Reducing Disaster of Gansu Province & Open Key Laboratory of Arid Climate Change and Reducing Disaster of China Meteorological Administration, Lanzhou 730020, China
  • Received:2008-04-18 Revised:2008-07-24 Online:2009-09-07 Published:2009-09-07

摘要: 利用1966—2005年江河源区8个气象站的逐月气候资料,采用Penman-Monteith公式,对源区近40 a潜在蒸散量的时空分布特征和变化趋势进行了分析,并对造成潜在蒸散量变化的主要气候影响因子进行了探讨。结果表明:①江河源区年潜在蒸散量平均为977 mm,高值区位于西北部,低值区位于东南部;潜在蒸散量在空间上可以划分为源区北部、长江源区南部和黄河源区南部3个不同的区域;②近40 a来,江河源区年及四季潜在蒸散量均呈减少趋势,且长江源区南部比其他区域下降显著,夏季比其他季节下降显著,年潜在蒸散量的变化主要以21 a左右和7 a左右的周期振荡为主,且在1985年左右发生均值突变;③源区年和四季潜在蒸散量与风速、净辐射和饱和差关系密切,40 a来风速的明显减小是导致源区潜在蒸散量减小的主要原因。

关键词: 江河源区, 潜在蒸散量, 变化趋势, 影响因子

Abstract: Based on the climatic data from 8 stations throughout the source regions of the Yangtze and Yellow rivers during 1966 and 2005, the potentia1 evapotranspirations (ET0) are calculated by the use of the Penman-Monteith Method recommended by FAO. Besides, the spatia1 and tempora1 distributions of the ET0 over the regions as well as their impact factors have been analyzed. Major results are as follows: ①The average annual ET0 in the source regions is 977 mm. The high value is in the northwest part of the area, and the low is in the southeast part. Classified by ET0 value the source regions can be divided into three climate parts, they are the northern part and the southern part of the Yangtze river source region, and the southern part of the Yellow river source region. ②The annua1 and seasonal ET0 variations show declining tendency during the past 40 years, 21-year and 7-year are the main fluctuation periods of the annual ET0. An abrupt change of the annual ET0 happened in 1985. ③Generally, wind speed, net solar radiation and saturation deficit have great impact on the ET0, above all the decline tendency of wind speed appears to be the major cause for the negative trend of the ET0 in the areas.

Key words: source regions of the Yangtze and Yellow rivers, potential evapotranspiration, trend, impact factors

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