Good or Bad of Greening Effects on High-Density Urban Housing Air Quality

Abstract

Green city initiatives are expected to continue growing as a strategic issue of urban development in Indonesia. This spirit is motivated by several factors that are namely, a rapid urban growth which ignores the ecological functions; followed by floods and landslide disasters; and is also strengthened by global warming issues and climate change. These aforementioned factors encourage cities to become clean and enter the race of the greening movement. With various species of flowers and shrubs planted, the urban housing in Malang City has become more beautiful and cooler. Through photosynthesis in daylight, plants absorb CO₂ and release O₂. On the other hand, plant respiration, in the night, absorbs O₂ and releases CO₂. This study aims to understand the relation of vegetation presence to CO₂ concentrations in dense urban housing. Through regression analysis, urban canyon ratio and vegetation densities are positioned as independent variables to find out how strong their contribution is to the level of CO₂ concentration during the day and nighttime. The research result show that at daytime, urban canyon ratio and vegetation density, collectively, give no significant contribution to CO₂ concentration flux. If we eliminate urban canyon ratio from the regression model, vegetation density has a significant effect (partially) on decreasing CO₂ concentration in the dense urban housing at day time. However it’s not too high compared with the intercept factor (another variable that isn’t examined in this research). At nighttime, urban canyon ratio and vegetation density, collectively, give significant contributions to CO₂ concentration flux. The urban canyon ratio has the most significant role in the regression model. Meanwhile, vegetation density has weak significance, but it doesn’t undermine the regression model confidence. Therefore, we could determine that urban canyon ratio and vegetation, together, bring a significant effect to CO₂ concentration in dense urban housing at nighttime.