A Study of the Influence of Environmental Factors on Water–Heat Exchange Process in Alpine Wetlands

Abstract

Wetlands, which are composed of soil, vegetation and water, have sufficient water supply and are sensitive to climate change. This study analyzes the coupling degree between wetlands and atmosphere and discusses the influence of environmental factors (solar radiation and water vapor pressure deficit) on latent heat flux by using the experimental data from the Maduo Observatory of Climate and Environment of the Northwest Institute of Eco-Environment and Resource, CAS and WRF models. The results showed that, during the vegetation growing season, the average value of Ω (decoupling factor) is 0.38 in alpine wetlands, indicating that the coupling between wetlands and atmosphere is poor. Solar radiation is the main factor influencing the latent heat flux in the results of both observation data analysis and model simulation, and solar radiation and water vapor pressure deficit still have the opposite reaction to latent heat flux; when solar radiation increased by 30%, the average daily amount of latent heat flux increased from 5.57 MJ·m−2 to 7.50 MJ·m−2; when water vapor pressure deficit increased by 30%, the average daily amount of latent heat flux decreased to 5.17 MJ·m−2. This study provides a new research approach for the study of the parameterization of latent heat flux and evapotranspiration in the context of global climate change

Keywords

• source region of the Yellow River
• WRF
• latent heat flux
• decoupling coefficient (<i>Ω</i>)
• solar radiation
• water vapor pressure deficit