Surface imperviousness is a useful indicator of urban development. It describes the amount of concrete and other impermeable surfaces through which water cannot filter, one effect of which is urban runoff. This map shows the percentage of developed surface per pixel in 2019. Each pixel represents the average across an area of 1 square kilometer. Areas of the map without data are those where no impervious surface was detected.
Data layer derived from: Dewitz, J., and U.S. Geological Survey, 2021, National Land Cover Database (NLCD) 2019 Products (ver. 2.0, June 2021): U.S. Geological Survey data release, https://doi.org/10.5066/P9KZCM54.