Debate on the sustainability of human settlements has recently been focused
primarily on the urban portion of the land use pattern. However, urban
areas rely on suburban, rural, and other less densely settled lands for their
existence. In order to
quantify the impacts of various land patterns on their
supporting resources, these exurban lands must be included in any
sustainability assessment. This need for a regional view has resulted in a
measurement method that enables comparisons of relative sustainability
between various regional land use patterns.