• 西部地理环境 •

### 西藏羊卓雍湖流域近45 年气温和降水的变化趋势

1. 1. 西藏自治区气候中心拉萨850001;
2. 拉萨市气象局, 拉萨850001;
3. 西藏自治区水文水资源勘测局, 拉萨850000;
4. 西藏自治区气象信息网络中心, 拉萨850001
• 收稿日期:2008-01-13 修回日期:2008-07-20 出版日期:2008-11-25 发布日期:2008-11-25
• 作者简介:杜军(1969-), 男, 贵州绥阳人, 正研高工, 主要从事气候变化和农业气候研究。E-mail: dujun0891@163.com
• 基金资助:

国家自然科学基金项目(40565002)

### Climatic Variations of Temperature and Precipitation in the Yamzho Yumco Lake Basin of Tibet from 1961 to 2005

DU Jun1, HU Jun2, TANG Shujun3, BAO Jianhua4, LHAK Pa1

1. 1. The Climatic Center of Tibet, Lhasa 850001, China;
2. Lhasa Meteorological Bureau, Lhasa 850001, China;
3. Water Resources Survey and Hydrology Bureau of Tibet, Lhasa 850000, China;
4. Meteorological Information & Network Center of Tibet, Lhasa 850001, China
• Received:2008-01-13 Revised:2008-07-20 Online:2008-11-25 Published:2008-11-25
• Supported by:

National Natural Science Foundation of China, No.40565002

Abstract:

The interannual, interdecadal variations and anomalous years of the annual and seasonal mean temperature and precipitation are investigated in the context of the monthly data at 9 meteorological and hydrological stations in the Yamzho Yumco Lake basin of Tibet from 1961 to 2005 by using modern statistical diagnostic methods such as the linear trend, and the relationship between lake level and precipitation is discussed. The results show that the annual temperature presented a significant increasing trend and the rate of increase is about 0.25 oC/10a during recent 46 years, indicating that the warming trend is obvious in autumn and winter. In recent 25 years (1981-2005), the precipitation presents a decreasing trend in winter, while the increasing trend is apparent in other seasons with a rate of (11.4-30.0) mm/10a, especially in summer. Finally, the annual precipitation shows an obviously increasing trend and the rate is 54.2 mm/10a. In terms of interdecadal variations, the mean temperature increases apparently in most seasons, except in summer. The summer precipitation is less in the 1980s, more in the other three decades. On the contrary, in winter the precipitation is more in the 1980s, less in the other three decades. Also, the warm anomalous years of annual mean temperature occurred three times in the end of the 1990s and the early 2100s. The more precipitation anomalous years occurred in the end of the 1960s and the early 1970s. Since generation of electricity with the water of the Yamzho Yumco Lake in 1997, the trend of annual precipitation has increased. The mean precipitation is about 409.7 mm in the basin, which is higher than the balanced rainfall, and presents an obvious increasing trend of the lake level. The water level rise is directly correlated with precipitation increase and sunshine decrease, while the apparent rise of temperature and the increase of snowmelt are also important factors.