Impervious Surface Area and Residential Housing Density: A Satellite Perspective

A correlation between housing lot size and impervious surface area (ISA), previously published by the Soil Conservation Service (SCS), is re‐examined using satellite (Landsat 5 Thematic Mapper) image data and a new method for determining ISA from remote measurements. ISA is determined for each pixel using two criteria: an image classification and the fractional vegetation cover. Reworking part of a previous study of Chester County, Pennsylvania, we use satellite images to calculate ISA in Uwchlan Township, a rapidly urbanizing municipality located west of Philadelphia. Results show a similarity with the SCS values in which ISA decreases with increasing lot size. In our study, however, the values were higher (8 ‐ 20%), possibly because we included sidewalks and roads.