An Analytical Study on the Air Purification Effect of Urban Openspace - Focusing on Urban Roadside Trees -

도시녹지의 대기정화효과에 대한 분석적 연구 - 도시 가로수를 중심으로 -

The objective of this study is to review and verify whether the functions and effect of roadside trees generally known in theory are actually realized in urban roads and how well they are performed if the function and effect are really realized. The study was conducted with a focus on air purification effect of roadside trees. The m헤r study result is as follows. First, calculation of air purification effect of roadside trees showed that it is minimal. However, 7.4 units of broad-leaved trees is necessary in order to purify $SO_2$ discharged by one passenger car and 1,803.3 trees to purify $NO_2$. Second, regarding pollutant absorption capacity, air pollutant absorption capacity increased as the number of rows planted gets higher (i.e., 2-row plantation absorbs pollutant better than I-row plantation). In particular, "2-row plantation + lower-level shrub + buffer green belt" was as eight times high as "I-row plantation" in absorption capacity. Third, out of 30 roads with over 8 lanes in 15 cities, only 33.3% or a total of ten roads in seven cities had a median strip. Out of these ten roads, nine roads were planted in a double-layer consisting forest trees, shrubs, ground plants (grass). Analysis showed that out of six tree species planted along these roads, about a half of them were weak to air pollution. Also, based on the outcome of this study, charging a "plantation due" when people purchase a new car, improving layout of roadside trees, and reinforcing plantation of air purification tree species when selecting tree species for roadside trees were proposed.