Community Modeling and Analysis System


In collaboration with the EPA, we are developing a series of community tools to study local air quality due to various sources. Each community tool is a modeling and visualization system that accesses inputs, performs calculations, visualizes results, provides options to manipulate input variables, and performs basic data analysis - all through an easy-to-use web-based interface. The community tools based upon existing algorithms for dispersion are intended to inform the community user of local air quality due to various source types in their region of interest using a reduced-form modeling approach. The models are intended to be used by local government, city planners and community groups.

The community tools access publicly available emissions, traffic and meteorological datasets, and are optimized to use in community-sized areas (100-1,000 km2). The user is not required to provide input data, but can provide their own if desired.


The Community LINE Source Model (C-LINE) is intended to inform the community user of local air quality impacts due to mobile sources in their region of interest using a simplified modeling approach. As has been established in near-road and near-source monitoring studies, busy roadways and large emission sources, respectively, may impact local air quality near the source. Reduced-form air quality modeling is a useful tool for examining what-if scenarios of changes in emissions, such as those due to changes in traffic volume, fleet mix, or vehicle speed. Examining various scenarios of air quality impacts in this way can identify potentially at-risk populations located near roadways and the effects that a change in traffic activity may have on them. C-LINE computes dispersion of primary mobile source pollutants using meteorological conditions for the region of interest and computes air quality concentrations corresponding to these selected conditions. The dispersion routines used are in the analytical version of R-LINE (Snyder, et. al. 2013, also see Specific emissions for each road link are calculated by combining national database information on traffic volume (AADT) and fleet mix with emissions factors from the EPA's MOVES modeling system. The user can modify the emissions for each road link by changing the traffic composition, speed, and/or volume. The air quality impact from a change in emissions due to changes in activity, fleet composition, or representative meteorological conditions can be visually quantified for a select set of criteria pollutants and mobile source air toxic (MSAT) species. This web-tool is currently capable of modeling any region of the United States. C-LINE is a screening-level model and is not intended to replace any regulatory models or be used to make enforcement decisions. Additional information on the overall tool is available in Barzyk et al (Env. Modeling and Software, 2015, 66, pp. 46-56). More Info


The Community modeling system for near-PORT (C-PORT) Tool is intended to provide users with the capability to do screening-level analyses of changes in the concentration of air pollutants associated with emissions from port activities, including terminal operations, ship traffic, vehicle (truck) traffic, and rail operations. Designed primarily to evaluate the local air quality impacts of proposed port expansion or modernization, as well as to identify options for mitigating any impacts, C-PORT provides a flexible and easy-to-use mechanism to modify current sources of emissions and view potential local impacts associated with proposed changes. It is not intended to be used to analyze current air quality within a community as it does not include ambient background pollution from sources other than port activities. It is also not intended to precisely predict the outcome of any permitting or other management decision, but rather to allow an screening-level assessment of decision alternatives by presenting the likely pattern of potential pollutant dispersion and an estimated change in pollutant concentrations for user-designated scenarios. If additional rigor is needed beyond screening-level, EPA recommends the use of other air dispersion models such as AERMOD which is the Agency's regulatory air dispersion model. More Info