地理学报(英文版)

›› 2014, Vol. 24 ›› Issue (1): 93-112.doi: 10.1007/s11442-014-1075-5

• Research Articles • Previous Articles     Next Articles

Quantitative estimation of climate change effects on potential evapotranspiration in Beijing during 1951-2010

LIU Haijun1,4, LI Yan1,2, JOSEF Tanny3, ZHANG Ruihao1, HUANG Guanhua2   

  1. 1. College of Water Sciences, Beijing Normal University, Beijing 100875, China;
    2. College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China;
    3. Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization, The Volcani Center, P. O. Box 6, Bet Dagan 50250, Israel;
    4. State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100048, China
  • Received:2012-11-12 Revised:2013-09-17 Online:2014-02-15 Published:2014-02-15
  • About author:Liu Haijun(1975-), PhD and Associate Professor, specialized in crop evapotranspiration and irrigation scheduling. E-mail：shanxilhj@bnu.edu.cn
  • Supported by:

    Open Research Funds of State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, No.IWHR-SKL-201105; National Natural Science Foundation of China, No.51179005; Fundamental Research Funds for the Central Universities, No.2009SD-10

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Abstract:

Climate change is likely to affect hydrological cycle through precipitation, evapotranspiration, soil moisture etc. In the present study, an attempt has been made to study the climate change and the sensitivity of estimated evapotranspiration to each climatic variable for a semi-arid region of Beijing in North China using data set from 1951 to 2010. Penman-Monteith method was used to calculate reference crop evapotranspiration (ETo). Changes of ETo to each climatic variable was estimated using a sensitivity analysis method proposed in this study. Results show that in the past 60 years, mean temperature and vapor pressure deficit (VPD) were significantly increasing, relative humidity and sunshine hours were significantly decreasing, and wind speed greatly oscillated without a significant trend. Total precipitation was significantly decreasing in corn season (from June to September), but it was increasing in wheat season (from October to next May). The change rates of temperature, relative humidity, VPD, wind speed, annual total precipitation, sunshine hours and solar radiation were 0.42℃, 1.47%, 0.04 kPa, 0.05 m·s-1, 25.0 mm, 74.0 hours and 90.7 MJ·m-2 per decade, respectively. In the past 60 years, yearly ETo was increasing with a rate of 19.5 mm per decade, and total ETos in wheat and corn seasons were increasing with rates of 13.1 and 5.3 mm per decade, respectively. Sensitivity analysis showed that mean air temperature was the first key factor for ETo change in the past 60 years, causing an annual total ETo increase of 7.4%, followed by relative humidity (5.5%) and sunshine hours (-3.1%); the less sensitivity factors were wind speed (0.7%), minimum temperature (-0.3%) and maximum temperature (-0.2%). A greater reduction of total ETo (12.3%) in the past 60 years was found in wheat season, mainly because of mean temperature (8.6%) and relative humidity (5.4%), as compared to a reduction of 6.0% in ETo during corn season due to sunshine hours (-6.9%), relative humidity (4.7%) and temperature (4.5%). Increasing precipitation in the wheat season will improve crop growth, while decreasing precipitation and increasing ETo in the corn season induces a great pressure for local government and farmers to use water more efficiently by widely adopting water-saving technologies in the future.

Key words: climatic variables, reference crop evapotranspiration, Penman-Monteith equation, changing trend, sensitivity analysis