Effect of the Root-Water-Uptake Process Parameterization Schemes on the Land-Surface-Process Simulation in the Qinghai-Tibet Plateau
Received:October 31, 2018  
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KeyWord:Root water uptake  Parameterization scheme  Land surface process  BCC_AVIM model (Beijing Climate Center Land Model)
Author NameAffiliationE-mail
MA Xiangyi Chengdu University of Information Technology, Chengdu 610225  
ZHANG Yu Chengdu University of Information Technology, Chengdu 610225 yuzhang@cuit.edu.cn 
WU Tongwen Nation Climate Center, China Meteorological Administration, Beijing 100081  
SONG Minhong Chengdu University of Information Technology, Chengdu 610225  
WANG Shaoying Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou 730000  
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      The root-water-uptake process plays an important role in maintaining the surface energy balance and water cycle. Currently, the influence of different root-water-uptake parameterization schemes on the simulation of the land surface processes in the Qinghai-Tibet Plateau is unclear. This study intends to explore the influence of these parameterization schemes and provide a reference for establishing root parameterization schemes for the future development of a land-surface-process model. Using the Beijing Climate Center Land Model (BCC_AVIM), we applied different root-water-uptake parameterization schemes and used the meteorological data observed at the Maqu station in the Qinghai-Tibet Plateau from June 1, 2010, to September 30, 2010, as the forcing data to simulate sensible heat flux, latent heat flux, soil temperature, and soil water content at the Maqu station. We subsequently compared the simulation results obtained using different parameterization schemes in case of the Qinghai-Tibet Plateau. We divided the root-water-uptake parameterization scheme into a root distribution model and a soil-water-availability function for roots. Further, we based our root distribution model on the Jackson and Schenk schemes and the soil-water-availability function for roots on the Li, LSM1.0 (Land Surface Model 1.0), and CLM4.5 schemes. A comparison of the results denotes that different parameterization schemes have little impact on the soil temperature and the soil water content but a considerable impact on the sensible and latent heat fluxes, especially with respect to canopy transpiration. We observed that the differences between the simulation results were related to precipitation. During the rainy period, the simulated root distribution model is considerably sensitive, with a large difference being observed between the sensible and latent heat fluxes simulated by the original model. During the less rainy period, the simulated soil-water-availability function for roots is more sensitive, with a large difference being observed between the sensible and latent heat fluxes simulated by the original model.