City of Apple Valley, Minnesota
The city needed accurate and up-to-date citywide impervious surface data for planning needs. Traditional methods of digitizing impervious layers are labor-intensive and cost prohibitive. Furthermore, maintenance of these datasets is time consuming and requires diligence.
Bolton & Menk used high-resolution imagery along with powerful spatial and spectral analytical methodologies to produce a highly accurate impervious layer that classified pervious, impervious, and water land-cover. Using Python scripts, we developed a custom toolbox to provide QA/QC checks and manage the dataset with new development. We also provided training and reference guides to help facilitate the city’s workflow for data management.
We produced a layer with an accuracy above 96 percent at a fraction of the cost it would take to manually digitize data with comparable accuracy. The data is being used by the city’s community development/planning department to evaluate neighborhood impervious surface values to ensure the ordinance meets what has been constructed. It is also being used by the engineering department to help update the surface water section of the 2040 Comprehensive Plan Update. The addition of the custom toolbox provides an easy way for the city to keep data current and useful for future projects.