Abstract

Land Cover and Pollutant Estimation in the Chesapeake Bay Watershed
Track: Water, Wastewater, and Stormwater
Authors: Pamela Cowher, Weston Young

The Total Maximum Daily Load (TMDL) regulations for the Chesapeake Bay watershed have left many wondering how they are going to meet the standards set by the US EPA for stormwater runoff, and how they are going to pay for costly retrofits. Land cover data created by EPA using Landsat data were outdated and coarse, not accurately reflecting the ground condition and sometimes increasing nutrient loadings. A methodology was created to classify Virginia one-foot aerial photography into six land cover classes to more accurately assess baseline nutrient loading. Once the initial image classification was completed, data refinement and analysis were preformed in ArcGIS Desktop. Spatial analysis techniques were used to break the land cover data into measurable areas to determine nutrient loading rates. As an added benefit, the impervious class was used to generate additional municipal revenue by updating stormwater utility billing records per parcel with more accurate impervious areas.