Impervious surface mapping using satellite remote sensing

Landsat TM data have been used to map the percentage of impervious surface area of the seven-county Twin Cities Metropolitan Area in 1991, 1998 and 2000. Following classification of land cover types, a regression model relating percent impervious surface area to "tasseled cap" greenness was used to estimate the percent impervious surface area for pixels classified as urban or developed. Eighty to 90 percent of the variation in imperviousness is accounted for by greenness. Classification of the Landsat TM data provides a means to map and quantify the degree of impervious surface area, an indicator of environmental quality, over large areas and over time at modest cost.