The NFHAP Coastal Spatial Framework and Indicator Datasets consist of a geospatial base layer developed in ArcGIS, and associated data fields joined to the spatial framework. The Coastal Spatial Framework is a layer of 612 distinct polygons covering coastal areas of the Continental U.S. Polygons represent either coastal watersheds (land) or coastal waters (estuaries, inshore marine, offshore marine),and are classified into six regions and 22 nested subregions. Each polygon is assigned a unique code (UniqueID) to provide location reference for indicator data, and enable joins to separate data tables.s for information recorded in the Bibliography and Assessment tables. Key indicator data fields attributed to each estuarine polygon include scores for eutrophication, pollutants and contaminants, coastal watershed land use changes, and freshwater inflow and hydrologic alteration over time. In addition, a composite score is calculated as the geometric mean of the four indicator scores.
