National Fish Habitat Action Plan (NFHAP) 2010 HCI Scores for the Conterminous United States - by EDU

This shapefile contains summaries of habitat condition indices (HCI scores) from the National Fish Habitat Action Plan (NFHAP) 2010 assessment for Ecological Drainage Units (EDUs) in the Conterminous United States. Initial HCI scores were developed using landscape factors representing human disturbances summarized to local and network catchments of river reaches throughout the Conterminous United States. Habitat condition scores were based on responsiveness of biological metrics to anthropogenic landscape disturbances throughout ecoregions. Separate scores were created by considering disturbances within local catchments, network catchments, and a cumulative score that accounted for the most limiting disturbance operating on a given biological metric in either local or network catchments. More information on the NFHAP 2010 assessment of the Conterminous United States can be found at the following links: http://dx.doi.org/doi:10.5066/F7B56GN1 . To summarize data into EDUs a length-weighted average was used (i.e. the cumulative HCI value for each river reach within an EDU was weighted by the reach length with the formula (H1*L1+H2*L2...+HX*LX)/(H1+H2...+HX) where H = reach HCI score, L = reach length).