Development And Case Study Of A Gis-based Attainment Test Tool For Ambient Air Quality Standards

Most of the countries around the world have issued all kinds of air quality standardswith different content or requirements for protecting public health. To prepare attainmentdemonstrations for the National Ambient Air Quality Standards (NAAQS) and the RegionalHaze Rule, U.S. Environmental Protection Agency (USEPA) has developed the ModeledAttainment Test Software (MATS), which is primarily intended as a tool to implement themodeled attainment tests for PM2.5and O3, and perform the uniform rate of progress analysis.With the input observational data and photochemical model data, MATS estimates whetherselected emission reduction will result in ambient concentrations that meet the NAAQS.However, MATS has some disadvantages, such as computational efficiency, GIS visualizationcapability, crash caused by memory limitation and not open-source code, which limit it to befurther used for complex air quality attainment test tasks. To resolve and overcome abovedisadvantages, USEPA provides us the financial and technical support for developing the nextgeneration open-source ambient air quality attainment test tool named as SMAT-CE (Softwarefor Model Attainment Test-Community Edition).This paper describes the functional design, performance evaluation and case study ofSMAT-CE. With the redesigned technical framework, SMAT-CE significantly enhances thecomputational efficiency up ranging from1.5(for O3calculation) to5times (for daily PM2.5calculation) depending on different analysis targets. An open-source GIS component-DotSpatial is integrated to SMAT-CE to improve the visualization and analysis capabilities.The GIS-mapping and other types of results showing are displayed in one integrated “displaywindow” to provide instant and better user experience. Comparison by using the results ofMATS depending on different analysis targets verified the accuracy and reliability of theresults for SMAT-CE with Mean Fractional Bias of <±1%based on the same VoronoiNeighbor Averaging (VNA) algorithm and the same input data after resolving theout-of-memory bug existed in MATS. The case study results demonstrate that SMAT-CE iscapable of performing the attainment tests for the current NAAQS of annual PM2.5and8-hourozone on the continental U.S. domain. SMAT-CE may also be used to perform the attainmenttests for the new PM2.5Ambient Air Quality Standards of China after resolving the problem of insufficient PM2.5speciated monitoring sites. Two different methods of how to use SMAT-CEto perform attainment tests in China are suggested depending on whether there are enoughavailable speciation data.