Welcome to Chinese Agricultural Science Bulletin,

Chinese Agricultural Science Bulletin ›› 2008, Vol. 24 ›› Issue (9): 480-484.

• 农业工程科学 • Previous Articles     Next Articles

Long-term Trend of Reference Evapotranspiration in Liuyuankou Irrigation System
and its Impacts on Irrigation Water Requirements

Luo Yufeng, Jiao Xiyun, Peng Shizhang   

  • Received:2008-07-01 Revised:2008-07-08 Online:2008-09-05 Published:2008-09-05

Abstract: The long-term trend of reference evapotranspiration (ET0) and it’s relationships with weather parameters and irrigation water use were analyzed, and the reasons and impacts of ET0 trend were investigated. Daily meteorological data for the years of 1983-2003 of Liuyuankou Irrigation Area, Henan Province from Huibei Irrigation Experiment Station were collected, then daily, monthly and annual ET0 were calculated using the FAO-56 Penman-Montieth model. Mann-Kendall tests were conducted to detect trends in ET0 and corresponding meteorological parameters. The results show that in Liuyuankou Irrigation System, ET0 decreased 50mm/a in the last two decades; decreasing ET0 was caused mainly by decreasing sunshine hour firstly and wind speed secondly, increasing air temperature was not enough to counteract the impacts of the former two; annual ET0 decrease was contributed by decrease in April, June, July and August; when there was no significant trend in rainfall, decreasing ET0 resulted in decreasing trend in irrigation requirement, which was confirmed by reduced diverted irrigation water from Yellow River. Therefore, besides dissemination of water-saving irrigation techniques, reduced diverted irrigation water from Yellow River was partially contributed from the decreasing irrigation water requirements due to climate change.

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