Research on the Application of Non-stationary Model in Analyzing the Evolution Law of Reference Evapotranspiration

Bin Gao, Baodeng Hou, Weihua Xiao, Xianglin Lyu, Hao Cui, Hao Cui, Wei Xue

2021

Abstract

The Three Gorges Reservoir area (TGRA) is a typical ecological sensitive area in China. It is of great significance to clarify the non-stationary evolution law of evaporation under changing environment, which is the foundation to the study of water cycle, agricultural drought and irrigation etc. In this study, three models (Model 0, Model 1, Model 2) have been established to compare and analyze the non-stationary evolution laws and driving factors of reference evapotranspiration (ET0) in TGRA. The results are as follows: (1) the annual ET0 of stations with a ratio of ten twelfths shows a decreasing trend from -24.7 to -1.5 mm (10a)-1; among them, the ET0 of Badong, Zigui and Changshou stations decreased significantly (P < 0.05), and the decreasing amount was mainly contributed by autumn and summer; the significant decrease is caused by the combined effect of the decrease of sunshine hours (S), wind speed (U), relative humidity (RH) and the increase of average temperature (T), and the contribution rates of these factors are 80.38%, 48.32%, -23.21% and -5.48%, respectively. (2) The stationary model (Model 0) obviously is hard to explain the characteristics of ET0 trend and mutation; the non-stationary model (Model 1) with time as the covariate can explain that the ET0 sequence has a sudden change in 1979, and the ET0 before and after the mutation point shows a sharp decline and a slow rise trend; even if the model fits well, the Model 1 lacks physical meaning and it is difficult to analyze the future evolution of ET0; meteorological factors are used as covariates, the non-stationary model (Model 2) can better capture the distribution of ET0 scattered points, and the AIC value is also significantly reduced, which verifies that the main contributors to the annual ET0 change are S, U, which has certain physical significance.

Paper Citation

in Harvard Style

Gao B., Hou B., Xiao W., Lyu X., Cui H. and Xue W. (2021). Research on the Application of Non-stationary Model in Analyzing the Evolution Law of Reference Evapotranspiration. In Proceedings of the 7th International Conference on Water Resource and Environment - Volume 1: WRE, ISBN 978-989-758-560-9, pages 28-36

in Bibtex Style

@conference{wre21,
author={Bin Gao and Baodeng Hou and Weihua Xiao and Xianglin Lyu and Hao Cui and Wei Xue},
title={Research on the Application of Non-stationary Model in Analyzing the Evolution Law of Reference Evapotranspiration},
booktitle={Proceedings of the 7th International Conference on Water Resource and Environment - Volume 1: WRE,},
year={2021},
pages={28-36},
publisher={SciTePress},
organization={INSTICC},
doi={},
isbn={978-989-758-560-9},
}

in EndNote Style

TY - CONF

JO - Proceedings of the 7th International Conference on Water Resource and Environment - Volume 1: WRE,
TI - Research on the Application of Non-stationary Model in Analyzing the Evolution Law of Reference Evapotranspiration
SN - 978-989-758-560-9
AU - Gao B.
AU - Hou B.
AU - Xiao W.
AU - Lyu X.
AU - Cui H.
AU - Xue W.
PY - 2021
SP - 28
EP - 36
DO -