Estimation of Elemental Carbon Emission and Spatial Distribution of Atmospheric Concentration in Kansai Area

Abstract

In this study emission amount of elemental carbon (EC) was estimated for the assessment of human health impacts in Kansai area. The emission inventory consists of two parts, one is emission from mobile sources and the other is stationary sources. Mobile sources were divided in that from roads, which is included not only trunk roads but branchy roads, and that from ships. Emission from stationary sources was reconstructed from the national emission database of soot and dusts. This emission inventory was developed mainly by the statistics in 2000. In Kansai area including 6 prefectures (Shiga, Kyoto, Osaka, Hyogo, Nara, and Wakayama), annual amount of EC emission was estimated at 6.62×10³ (t). According to the analysis of source contribution, emission intensity in holidays is higher than that in weekdays. And it was also shown that the emission from roads is occupied 92% in total EC emission, especially trucks are the major source of EC emission.
Moreover, with this inventory, some transport simulations in Kansai area by MM5 and CMAQ models were also conducted episodically in four seasons. Meteorological fields by MM5 had good performance in the comparisons with observed data. In summer simulation by CMAQ, comparably good agreement was shown in the comparison with time-averaged observed data, however, some underestimated points were found. In other seasons calculated values showed underestimated in the comparison with observed values, because air mass was mainly coming from main land of China and Korean peninsula. Therefore, future formation of modeling system, such in the determination of domains and the height of stationary sources, should be refined and other compounds would be included to be a integrated tool for the assessment of human health impacts.