| Study of main meteorological factors affecting evapotranspiration based on gravimetric method |
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| DOI：10.7606/j.issn.1000-7601.2020.03.06 |
| Key Words: evapotranspiration time scale meteorological factor temperature and humidity nonlinear fitting |
| Author Name | Affiliation | | SU Yanyin | Institution of Soil and Water Conservation, Chinese Academy of Science, Yangling, Shaanxi 712100, China
University of Chinese Academy of Sciences, Beijing 100049, China | | FAN Xingke | Institution of Soil and Water Conservation, Chinese Academy of Science, Yangling, Shaanxi 712100, China
Institution of Soil and Water Conservation, Northwest Agriculture and Forestry University, Yangling, Shaanxi 712100, China |
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| Abstract: |
| In order to construct a simple calculation model for transpiration and evaporation of farmland, obtain the water consumption and the water demand of crops quickly, and to obtain the status of water deficit in a timely manner, this study used a gravimetric method to measure the evaporation of water from an evaporation pan at different time scales, and measure the transpiration water consumption of plants under the condition of sufficient irrigation, while the meteorological factors that affect transpiration in the corresponding period were monitored. The correlation between evapotranspiration and meteorological factors was analyzed by Pearson correlation analysis method and partial correlation test. The correlations of volume change and several major meteorological factors with high correlation with surface water evaporation and potential plant evapotranspiration were analyzed with multivariate non\|linear fitting. Thus, a simple calculation equation of potential evapotranspiration was constructed and tested. The results showed that (1) the main meteorological factors that affect water surface evaporation and plant transpiration were temperature, net solar radiation, and relative humidity; (2) net solar radiation had a high correlation with changes in temperature and humidity (r=0.718, r=-0.639); (3) the evaporation and transpiration were well simulated by using temperature and humidity (R2=0.743). For small irrigation areas (points) that lacked solar net radiation data, an approximate crop evaporation water consumption model was constructed using temperature, humidity, and crop parameters. Based on real\|time temperature and humidity data, it is possible to calculate the crop’s evapotranspiration water consumption for the corresponding period to quickly obtain the crop’s water consumption and their water demand, so this could help to obtain the real\|time farmland water deficit status and provide timely supplemental irrigation. |
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