Using MOVES in Support of Hawaii's Regional Haze Rule FIP Development

摘要

The regional haze rule is intended to restore natural visibility conditions at the 156 Class Ⅰ areas identified in the 1977 Clean Air Act Amendments. Natural conditions are defined as "includ[ing] naturally occurring phenomena that reduce visibility as measured in terms of light extinction, visual range, contrast, or coloration." The unique conditions in Hawaii, both in terms of emission inventory and state of modeling data, required a somewhat different approach from EPA in development of the regional haze FIP and metrics for "reasonable progress" toward reducing anthropogenic emissions that cause haze. This paper has presented a discussion of a methodology derived to determine the effects of on-road, mobile source emissions on the two Class Ⅰ visibility areas in Hawaii and a discussion of the resulting emissions in both recent and future years. These emission trends indicate that statewide VMT, emissions, and on-road influence on visibility at Haleakala are dominated by Honolulu County, as expected given its urbanization. However, the relative isolation of Hawaii Volcanoes Park ensures that only emissions within Hawaii County bear significant impacts there. Although VMT is expected to increase, predicted statewide emissions of visibility-relevant species show a dramatic reduction in future years. A comparison to prior analyses conducted with different models and data sources indicates that use of MOVES leads to significantly larger emission inventory values for particulates and moderately larger values for nitrogen oxides for recent years. In future years, significantly lower inventory values are predicted with MOVES for volatile organic compounds than with other methods. On-road mobile sources in Hawaii County attribute about 35% of the total anthropogenic NOx and less than 1% of total SO_2 emissions in 2005, and each share is predicted to reduce by 2018. Each of these elements is expected to contribute to the understanding of motor vehicle contribution to visibility reductions in Hawaii's National Parks and, more generally, will help guide future analyses of visibility and other particulate issues related to current and future motor vehicle activity. This utility is illustrated by a conclusive overview of use of these results in development of Hawaii's Regional Haze Program and Long Term Strategy.