A complementary relationship evaporation model referring to the Granger model and the advection–aridity model |
| |
Authors: | Songjun Han Heping Hu Dawen Yang Fuqiang Tian |
| |
Institution: | 1. State Key Laboratory of Hydro‐science and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China;2. Department of Irrigation and Drainage, China Institute of Water Resources and Hydropower Research, Beijing 100048, China;3. National Center of Efficient Irrigation Engineering and Technology Research, Beijing 100048, China |
| |
Abstract: | A complementary relationship evaporation model has been proposed and verified based on evaluations of the advection–aridity model and the Granger's complementary relationship model (Granger model) in dimensionless forms. Normalized by Penman potential evaporation, the Granger model and the advection–aridity model have been transformed into similar dimensionless forms. Evaporation ratio (ratio of actual evaporation to Penman potential evaporation) has been expressed as a function of dimensionless variable based on radiation and atmospheric conditions. Similar dimensionless variables for the different functions have been used in the two models. By referring to the dimensionless variable from the advection–aridity model and the function from the Granger model, a new model to estimate actual evaporation was proposed. The performance of the new model has been validated by the observed data from four sites under different land covers. The new model is an enhanced Granger model with better evaporation prediction over the aforementioned different land covers. It also offers more stable optimized parameters in a grassland site than the Granger model. The new model somewhat approximates the advection–aridity model under neither too wet nor too dry conditions, but without its system bias. Copyright © 2011 John Wiley & Sons, Ltd. |
| |
Keywords: | evaporation complementary relationship advection– aridity model Penman equation |
|
|