Comment:

As the plume passes through the vegetation, particles deposit on its leaves, resulting in pollutant reduction. To incorporate particle deposition in the multi-region model, the emission source term in the Gaussian equations needs to be modified, otherwise the model will overestimate pollutant concentration downwind of the barrier. To account for particle deposition, a mass balance was conducted before and after the vegetation to evaluate the particle reduction due to deposition for each of the training cases. When fitting the concentration reduction, in addition to using the five parameters in the fitting process, the particle deposition velocity was also included as it is highly correlated to particle deposition.