Quantifying the impact of climate variables on reference evapotranspiration in Pearl River Basin,China |
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Authors: | Tao Zhang Kyaw Tha Paw U |
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Institution: | 1. School of Geography and Planning, Sun Yat-Sen University, Guangzhou, China;2. Department of Land, Air and Water Resources, University of California, Davis, California, USAhttps://orcid.org/0000-0002-2510-5453;3. Department of Land, Air and Water Resources, University of California, Davis, California, USA;4. Joint Program on the Science and Policy of Global Change, Massachusetts Institute of Technology, Cambridge, Massachusetts, USAhttps://orcid.org/0000-0002-4284-5373 |
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Abstract: | ABSTRACTThe impact of climate variables on monthly reference evapotranspiration (ETo) is a critical issue in water resources management and irrigation planning. The spatio-temporal contribution of climate variables to ETo in the Pearl River Basin (PRB), China, from 1960 to 2016 were calculated based on sensitivity and relative change of each climatic variable. The results show that annual ETo total decreased by 1.64% and diminished in magnitude from the southeast to the northwest. Sunshine duration, wind speed and relative humidity decreased by 15.5%, 7.4%, and 4.0%, respectively, while average temperature increased by 4.25%. The ETo showed a positive sensitivity to all variables except relative humidity, which showed a negative sensitivity. Sunshine duration had the highest contribution of ?4.26%, and the overall decrease in ETo was mainly caused by the declines in sunshine duration and wind speed, which offset the positive impact of rises in average temperature and reduction in relative humidity. |
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Keywords: | evapotranspiration spatio-temporal climate variable sunshine duration Pearl River Basin |
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