Time Scales of Land Use Change and Export of N and P from Coastal Plain Basins to the Coastal Zone

Changing land use frequently leads to enhanced N and P export to lakes, rivers, estuaries, and the coastal zone, resulting in eutrophication. Estuaries such as Chesapeake Bay have been especially impacted due to efficient utilization and retention of these fertilizing elements. In two coastal plain basins within the Chesapeake Bay drainage (Choptank and Chester River basins), landuse and soils are the primary controls on nutrient export, and we have calibrated a hydrochemical model which can predict water flow and NP export with accuracies of 15-30%. The goal of our research is to link our model of N and P export with historical landuse patterns derived from LANDSAT imagery, aerial photographs, and maps. Changes in landuse will be used to estimate export of N and P, and we will also use these watersheds as field verification sites for extrapolation over a larger region of the coastal zone under current conditions.