Urban patterns and environmental performance: What do we know?

This paper reviews che empirical evidence on the relationships between urban patterns and various dimensions of environmental quality and performance. I first examine approaches to measuring urban environmental performance, drawing on dhe concepts of carrying capacity, ecological footprint, environmental space, and appropriated ecosystem area. Since cities affect and are affected by ecological systems far beyond their physical boundaries, I propose including interactions at the local, regional, and global scales in the definition of environmental performance. I then systematically review the current literature on the relationship between four structural variables typically used to describe urban patterns-form, density, grain, and connectivity-and four dimensions of environmental performance-sources, sinks, ecological support systems, and human well-being. I conclude that what we measure and the scale of analysis affect the direction of observable urban impacts. We must consider these factors as we select measures of urban environmental performance.