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| DOI：10.13522/j.cnki.ggps.2020303 |
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| Variation of Reference Crop Evapotranspiration and Its Sensitivity Analysis in Ningjin County of Hebei Province under a Changing Climate |
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YANG Li, LIU Haijun*, TANG Xiaopei, GAO Zhuangzhuang, FENG Dongxue
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Beijing Key Laboratory of Urban Hydrological Cycle and Sponge City Technology, College of Water Sciences, Beijing Normal University, Beijing 100875, China
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| Abstract: |
| 【Objective】Agricultural production in Ningjin county of Hebei province relies on irrigation and understanding crops demand for water and its evapotranspiration is essential to improving agricultural water management. The purpose of this paper is to analyze the potential variation in evapotranspiration across the county under a climate projected to change.【Method】Meteorological data measured daily from 1981 to 2018 at the weather station in the county was used to calculate the reference crop evapotranspiration (ET0) using the FAO56 Penman-Monteith formula. We also calculated the extreme climate indexes and how each meteorological factor trended. The impact of each meteorological factor on ET0 was estimated by sensitivity analysis.【Result】The change in precipitation in the county did not show noticeable trends in the studied period, but the average temperature had risen significantly accompanied by a significant decrease in sunshine hours, relative humidity and wind speed. The extreme temperature indexes for high temperature events trended up while the indexes for extreme low temperature events trended down, with extreme precipitation indexes not showing noticeable change. The annual average ET0 was impacted by the relative humidity most, while the monthly average ET0 was most sensitive to net radiation in summer and to relative humidity in other seasons. The decrease in wind speed and radiation appeared to have overwhelmed the positive influence of temperature rise and relative humidity drop on ET0, leading the ET0 to decline although not at significant level.【Conclusion】Most meteorological factors in the county had showed substantial changes from 1981-2018, but, surprisingly, their combination did not lead to a significant change in ET0. |
| Key words: climate change; extreme climates; reference crop evapotranspiration; sensitivity analysis |
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