A System Dynamics Model for Urban Sprawl and Its Impact on Sustainability

The exponential population growth and global urbanization have resulted in a surge in the demand for housing, thereby intensifying the demand for construction material resources. Nonetheless, the construction industry continues to be a significant contributor to global pollution, with its annual carbon dioxide emissions exceeding 35% of global emissions. Furthermore, the industry generates substantial construction and demolition (C&D) waste, comprising 20-29% of all US solid waste. To address these environmental concerns, a fundamental understanding of the management of construction resources and C&D wastes is needed. To this end, the goal of this paper is to propose a system dynamics model to simulate the urban environmental management of C&D waste in the construction industry. The model incorporates historical data and established principles from the literature to simulate the emergent behavior of the housing market for the State of Washington as a case study, and simulates the construction material demand, C&D waste generation and handling, and the associated environmental impacts. The findings underscore the superior effectiveness of proactive reuse of C&D waste compared to reactive waste management strategies. Furthermore, the results emphasize the critical role of integrating enhanced reuse practices and alternative waste management methods beyond landfilling. This integration is essential for fostering a sustainable circular economy and mitigating environmental impacts, with the potential to yield significant reductions of over 40% in construction-related greenhouse gas emissions. Ultimately, this model provides valuable insights for construction stakeholders and governmental bodies, informing policies on sustainable circular economy initiatives and urban environmental management strategies.