A numerical model was developed to calculate wind flow and temperature distribution around a shelterbelt. The calculated wind flow and temperature distribution were compared with observed data.
The wind flow model consists of the continuity equation, the Reynolds equation, and the k-ε turbulence model that includes the effects of plant-atmosphere interaction. The calculated flow pattern and wind speed agreed with the observed data.
The temperature distribution model consists of the heat transport equation with the heat balance equation for the ground surface boundary condition and the heat diffusion equation in the ground. The thermodynamic process in the canopy is not included in the model because it is assumed that the air temperature around the shelterbelt depends mainly on the air flow structure, but the effect on the ground surface shaded by the canopy in the shelterbelt is taken into consideration in the heat balance equation. The calculated air temperature pattern in the daytime showed that air temperature rising leeward of the shelterbelt could be calculated by only knowing the air flow disteribution. The air temperature calculated with consideration given to the shady effect closely agreed with the observed data. The increasing rate of temperature leeward of the shelterbelt was larger on the ground surface than in the air. The calculated and observed air temperature patterns at nighttime were consistent leeward of the shelterbelt, but contrary inside the shelterbelt.