Over 170,000 acres in the Twin Cities have converted to urban uses in the last 20 years according to interpretations of satellite imagery. This represents a 38 percent increase in urban land and a significant increase in impervious surface. These figures are part of recent study by University of Minnesota researchers Steven Manson and Marvin Bauer. The study was published in the Fall 2006 issue of the CURA Reporter; see www.cura.umn.edu/reporter/06-Fall/Manson&Bauer.pdf.
The article goes on to describe the use of sophisticated modeling techniques to explain the location of this land conversion. Using spatial regression modeling, the authors document the value of agricultural protection programs, the Metropolitan Urban Services Area (MUSA), and exclusion areas for protecting land from development. An alternative technique, cellular modeling, does a good job of showing where growth will occur, especially when constrained by good estimates of total land consumed by urban growth.
Urban Growth in the Twin Cities Metropolitan Area, 1986 to 2002