Component-based development and sensitivity analyses of an air pollutant dry deposition model

The Urban Forest Effects-Deposition model (UFORE-D) was developed with a component-based modeling approach. Functions of the model were separated into components that are responsible for user interface, data input/output, and core model functions. Taking advantage of the component-based approach, three UFORE-D applications were developed: a base application to estimate dry deposition at an hourly time step, and two sensitivity analyses based on Monte Carlo simulations with a Latin hypercube sampling (LHS-MC) and a Morris one-at-a-time (MOAT) sensitivity test. With the base application, dry deposition of CO, NO2, O3, PM10, and SO2 in the city of Baltimore was estimated for 2005. The sensitivity applications were performed to examine UFORE-D model parameter sensitivity. In general, dry deposition velocity was sensitive to temperature and leaf area index (LAI). Temperature had a non-linear effect on all pollutants, while LAI was important to NO2 deposition with a nearly linear effect. PAR and wind speed had limited effects on dry deposition of all pollutants; dry deposition was affected by PAR and wind speed only up to their threshold values. The component-based approach allows for seamless integration of new model elements, and provides model developers with a platform to easily interchange model components.

Research highlights
► A component-based Urban Forest Effects-Deposition model (UFORE-D) was developed.
► Dry deposition of CO, NO2, O3, PM10, and SO2 in Baltimore was estimated for 2005.
► Sensitivity of the model to its parameters and inputs was analyzed.
► Dry deposition velocity was most sensitive to temperature and leaf area index (LAI).
► Dry deposition velocity was largely affected by soil and mesophyll resistances.