A continuum modeling approach to the interactions of land use, transport and the environment for a polycentric city

Abstract

Air pollution has become a pressing issue, and the transport sector is an important source of emissions. For example, global warming has become one of the most acute problems of our time, and it is reported that the transport sector is responsible for about a quarter of global CO2 emissions. On the other hand, other pollutants, such as nitrogen oxides, sulfur oxides, particulates, affect people’s quality of life and health. Because of the strong interactions between land use and transport, it is useful to develop an integrated model for the land use, transport, and the environment (ILUTE), which helps to devise sustainable land use and transport policies that are environmentally compatible. The prediction of housing location choices is important for making decisions on how to allocate resources for land use developments, and the spatial analysis of air pollution and housing location choice in urban cities becomes an interesting but challenging problem. Traditionally, this problem is studied using a discrete modeling approach, in which a detailed network is constructed, and linked to an environmental sub-model to estimate the environmental impacts. In this study, we adopt an alternative continuum modeling approach, which focuses on the general trends and patterns of distribution and the travel choices of road users at the macroscopic rather than microscopic level. In this approach, we consider a city with several central business districts (CBDs) serving several classes of road users. The road network is relatively dense and can be approximated as a continuum. Transport demand and housing provision are continuously distributed outwards from the CBDs, and the commercial activities are concentrated in the CBDs. We establish a bi-level model to determine the transport demand, traffic intensity, and CO2 emissions with an optimized housing development pattern that minimizes total greenhouse gas emissions. In addition, we also attempt to develop a model that takes explicit account of the dispersion pattern of pollutants in the city, and the effect of air quality on housing location choice.