Relationship between urban form and changes in carbon dioxide fluxes derived from urban green spaces

Abstract

Carbon dioxide emissions are recognized as a major contributor to climate change, making it crucial to understand the role of urban green spaces in mitigating these emissions. However, the expansion of urban areas often leads to the reduction of these spaces. Therefore, it is essential to enhance our understanding of the environmental and urban dynamics that influence the management of these spaces. Measuring urban form can provide valuable insights into the impact of urbanization on the surrounding environment and the dynamics of an urban area. The objective of this research is to determine the relationship between urban form and carbon dioxide fluxes derived from urban green spaces in two distinct sites: Asuncion and Suwon. To accomplish this, a methodology utilizing multi-source data assimilation was adopted. The study focused on estimating five urban indicators: density, Gini coefficient, Richardson compactness, patch density, and road length for the years 2002 and 2012. In addition, the study incorporated the Enhanced Vegetation Index (EVI) obtained from MODIS, as well as meteorological data and respiration parameters to estimate carbon dioxide fluxes from urban green spaces. The findings of this study demonstrated a significant positive correlation between carbon dioxide fluxes and the Richardson compactness. indicating that higher levels of compactness are associated with increased CO$_2$ emissions. This correlation may be attributed to biodiversity loss and vegetation cover reduction in urban areas. Furthermore, both sites demonstrated a negative correlation with the Gini coefficient, indicating that a more even distribution of households is associated with lower CO$_2$ emissions. Suwon exhibited a stronger negative correlation compared to Asuncion. Additionally, the geographically weighted regression model revealed that the parameter estimates for the variables varied spatially and temporally, highlighting the localized nature of the relationships. Based on these findings, the following policies were recommended: prioritize green space preservation and encourage connected development.