Changes in reference evapotranspiration over Northwest China from 1957 to 2018: Variation characteristics, cause analysis and relationships with atmospheric circulation

Journal Article · Sat Jan 11 00:00:00 EST 2020 · Agricultural Water Management

DOI:https://doi.org/10.1016/j.agwat.2019.105958· OSTI ID:1592410

Zhao, Ziyang ^[1]; Wang, Hongrui ^[1]; Wang, Cheng ^[2]; Li, Wangcheng ^[3]; Chen, Hao ^[1]; Deng, Caiyun ^[1]

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1. Beijing Normal Univ., Beijing (China)
2. Argonne National Lab. (ANL), Lemont, IL (United States)
3. Ningxia Univ., Yinchuan (China)

The Ningxia Hui Autonomous (NX) in Northwestern China has been challenged by water scarcity and drought for decades. These problems will remain or even worse in the following decades, threatening regional eco-environmental quality and socio-economic development. Potential evapotranspiration (ET₀) is a key component of water cycle and a main factor to water resources assessment, especially in arid regions. Analysis of ET₀ is significant in understanding the climate change and agricultural water management. In this study, to understand the spatio-temporal variation, cause analysis and relationship with atmospheric circulation of ET₀ in Ningxia, ET₀ and other climate factors at 20 national climate stations from 1957 to 2018 were analyzed. Results showed that the temperature (T_mean, Tmax and Tmin) showed an increasing trend, while other factors (RH, U2 and SD) were the opposite in the past 62 years. ET₀ in NX, NYR and SMA had increased significantly at annual, seasonal and growth period scale, whilst the CAZ was the opposite trend, and the ET₀ had a trend of first rise and then decline from north to south in spatial distribution. ET₀ was most sensitive to RH and T_max at annual and seasonal scale in Ningxia, while the greatest contribution rates were Tmax and SD. Ningxia was becoming drier in the past decades. The abrupt change points of ET₀ was approximately 1990, and it’s long and short period were 25a(15a) and 10a(5a) at annual and seasonal scale, respectively. The four teleconnection indices could be used to predict changes in ET₀ at annual and seasonal scale. With this study, our understanding of spatio-temporal variation and cause analysis of ET₀ could be expanded from climate aspects to teleconnection pattern, which is quite important for crop water demand and agricultural irrigation management.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: National Natural Science Foundation of China (NSFC); USDOE
• Grant/Contract Number: AC02-06CH11357; 51879010; 51479003; 2018YFC0407900; B18006
• OSTI ID: 1592410
• Journal Information: Agricultural Water Management, Vol. 231, Issue C; ISSN 0378-3774
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
Climate change
Dominant factors
Ningxia
Reference evapotranspiration
Spatio-temporal distribution
Teleconnection indices