Urban patterns and environmental performance: What do we know?

This paper reviews che empirical evidence on the relationships between urba n patterns and various dimensions of environmental quality and performance. I first examine approaches to measuring urban environmental performance, d rawing on dhe concepts of carrying capacity, ecological footprint, environm ental space, and appropriated ecosystem area. Since cities affect and are a ffected by ecological systems far beyond their physical boundaries, I propo se including interactions at the local, regional, and global scales in the definition of environmental performance. I then systematically review the c urrent literature on the relationship between four structural variables typ ically used to describe urban patterns-form, density, grain, and connectivi ty-and four dimensions of environmental performance-sources, sinks, ecologi cal 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 environmenta l performance.