Green wall design to mitigate highway pollution

Abstract

Recent studies showed that Baghdad City suffers from highly polluted environment. The enormous traffic congestion and highly number of vehicles, especially during peak hours, is the main source of this pollution. This study is focused on stopping this deterioration by suggesting a green infrastructure to the one of main arterial road of the city (Mohamed Al-Qasim Expressway). The amount of pollutants resulted from traffic fleet have been estimated. It was found that the level of pollution is exceeded the acceptable levels. A combination of vegetation (trees) and green wall (shrubs) has been proposed for designing the green infrastructure for a selected section. Three types of trees namely: Neem tree, Ficus benjamina and Conocarpus have been selected after review many types that can be used for this purpose and resist the extreme hot weather. Two types of shrubs: Myrtus communis and Dodonaea viscosa were proposed due to their suitability for this function of filtering the particulate matters. The maximum ideal annual amount of CO₂ sequestration for 1km of trees planted on road sides and median was about 43.2, 10.5, and 9.25 Tonne for the Neem tree, Ficus benjamina, and Conocarpus, respectively.