| Cite this article: | 赵众,周密,张刘东,等.顾及“蒸发悖论”的洱海灌区逐日参考作物蒸散发预测[J].灌溉排水学报,0,():-. |
| zhaozhong,zhoumi,zhangliudong,et al.顾及“蒸发悖论”的洱海灌区逐日参考作物蒸散发预测[J].灌溉排水学报,0,():-. |
|
| |
|
|
| This article has been：Browse 2363Times Download 0Times |
|
|
|
| DOI： |
|
| Prediction of daily reference evapotranspiration considering evaporation paradox phenomena in Erhai irrigated district |
|
zhaozhong1, zhoumi2, zhangliudong1, gushixiang3, lijing1
|
|
1.Yunnan Agricultural University;2.Yunnan Institute for Investigation. Design and Research of Water Resources & Hydropower Engineering,;3.Yunnan Institute for Investigation. Design and Research of Water Resources & Hydropower Engineerin
|
| Abstract: |
| 【Objective】Evapotranspiration (ET) is one of the most important hydrological processes in the regional water cycle, which is of great practical significance for the estimation or accurate measurement of short-term reference crop evapotranspiration (ET0). 【Method】This paper takes Dali meteorological station in the upper Erhai Lake Irrigation Area of the central Yunnan Plateau as an example to analyze the period of "evaporation paradox" phenomenon, and uses conventional conceptual statistical models such as linear regression of meteorological factors, the pan conversion coefficient Kp model, the meteorological factor plus pan multiple regression model, and the normal copula model of the random method are used to predict and compare the daily ET0, and the ET0 calculated by penman Monteith formula is used as the standard value for comparative analysis. 【Result】(1) in the long time series from 1954 to 2018, the evaporation capacity of ET0 and 20cm evaporating dish all shows a downward trend, but the downward trend of ET0 is more gently, and the temperature shows an upward trend. Although the evaporation capacity of ET0 and evaporating dish has the same change trend in the long time series, there are different ages in the short time series, and "evaporation paradox" appears in the whole year and the four seasons of 1960s and 2000s.In 1970s, “evaporation paradox” appeared in the whole year, summer, autumn and winter, in 1990s, only in summer, and in 2010s, in autumn; (2) In the period of no "evaporation paradox", the error between daily ET0 prediction result and standard value is the smallest by adding Epan's multiple regression model (ET0, Epan + metr), followed by simple meteorological factor's multiple linear regression model (ET0, metr), and the worst is the pan conversion coefficient Kp model(ET0, Kp).Used to predict daily ET0 by adding Epan (ET0, EPAn + metr). the relative error ERR is less than 15%, 20%, 25% of the sample number is 79.18% - 90.16%, 89.32% - 97.23%, 94.79% - 98.36%;【Conclusion】When the "evaporation paradox" occurs, the change trend of evaporation plate is opposite to that of ET0, only copula joint distribution function model can be used to predict and build two-dimensional normal The accuracy of copula model is higher. The number of samples with err less than 15%, 20%, 25% is 73.70% - 86.56%, 82.51% - 92.95%, 89.89% - 98.52%. |
| Key words: reference crop evapotranspiration（ET0）；pan evaporation（Epan）；Mann-Kendall test; Multi- linear regression; high-dimensional Copula function；Real –time forecast; Erhai irrigated district |
|
|
|
|
|
|
