Spatiotemporal variation and driving forces of reference evapotranspiration in Jing River Basin,northwest China |
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| Authors: | Lihong Xu Zhongjie Shi Shulan Zhang Xinzheng Chu Pengtao Yu Wei Xiong Haijun Zuo Yunni Wang |
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| Affiliation: | 1. Key Laboratory of Forest Ecology and Environment of the State Forestry Ministry, Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, China;2. Institute of Desertification Studies, Chinese Academy of Forestry, Beijing, China;3. College of Science of Geography and Tourism, Xinjiang Normal University, Urumqi, Xinjiang, China |
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| Abstract: | Evapotranspiration is an important component of the hydrological cycle, which integrates atmospheric demands and surface conditions. Research on spatial and temporal variations of reference evapotranspiration (ETo) enables understanding of climate change and its effects on hydrological processes and water resources. In this study, ETo was estimated by the FAO‐56 Penman–Monteith method in the Jing River Basin in China, based on daily data from 37 meteorological stations from 1960 to 2005. ETo trends were detected by the Mann–Kendall test in annual, seasonal, and monthly timescales. Sensitivity coefficients were used to examine the contribution of important meteorological variables to ETo. The influence of agricultural activities, especially irrigation on ETo was also analyzed. We found that ETo showed a decreasing trend in most of the basin in all seasons, except for autumn, which showed an increasing trend. Mean maximum temperature was generally the most sensitive parameter for ETo, followed by relative humidity, solar radiation, mean minimum temperature, and wind speed. Wind speed was the most dominant factor for the declining trend in ETo. The more significant decrease in ETo for agricultural and irrigation stations was mainly because of the more significant decrease in wind speed and sunshine hours, a mitigation in climate warming, and more significant increase in relative humidity compared with natural stations and non‐irrigation stations. Changes in ETo and the sensitivity coefficient of meteorological variables in relation to ETo were also affected by topography. Better understanding of ETo response to climate change will enable efficient use of agricultural production and water resources, which could improve the ecological environment in Jing River Basin. Copyright © 2015 John Wiley & Sons, Ltd. |
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| Keywords: | reference evapotranspiration Penman– Monteith equation sensitivity analysis Mann– Kendall test irrigation Jing River Basin |
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