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

Abstract

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, NO 2, O 3, PM10, and SO 2 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 NO 2 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.