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Northeastern Aquatic Habitat Classification System, Stream Gradient


2014-08-05 19:05:32
Last Update
2017-08-22 23:02:19


U.S. Environmental Protection Agency (USEPA)(Cooperator/Partner), U.S. Geological Survey(Cooperator/Partner), North Atlantic Landscape Conservation Cooperative(administrator), Mark G. Anderson(Principal Investigator), 2014-08-05(creation), 2017-08-22(lastUpdate), Northeastern Aquatic Habitat Classification System, Stream Gradient


The download for this dataset includes TNC’s full Northeastern Aquatic Habitat Classification System: stream size, stream temperature, stream gradient, stream geology, lakes and catchments. This dataset represents the results (9/30/2008) of the Northeastern Aquatic Habitat Classification System (NAHCS) GIS map for streams and rivers. This classification focused on mapping a stream habitat types across 13 northeastern states (ME, NH, VT, MA, CT, RI, NY, NJ, PA, MD, DC, DE, VA, WV). Stream and river centerlines were extracted from the USGS National Hydrography Dataset Plus (NH-Plus) 2006 1:100,000 data. These reaches were attributed and placed into classes representing their biopysical setting in terms of stream size, gradient, and [...]


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Project Goal: The goal of this project was to develop a standard Northeastern Aquatic Habitat Classification (NAHCS) and GIS map for 13 northeastern states (ME, NH, VT, MA, RI, CT, NY, PA, NJ, DE, MD, VA, WV, and DC.) that are part of the Northeast Association of Fish and Wildlife Agencies (NEAFWA). This classification and GIS dataset was designed to consistently represent the expected natural aquatic habitat types across this region in a manner deemed appropriate and useful for conservation planning by the participating states. This product is not intended to override state classifications, but is meant to complement state classifications and provide a means for looking at aquatic biodiversity patterns across the region. Background: With the creation and implementation of State Wildlife Action Plans (SWAP) by state fisheries and wildlife agencies, the need for consistent, current digital habitat maps has grown dramatically. The implementation of the SWAPs within each state and across the Northeast region will be greatly enhanced through the development of current, consistent terrestrial and aquatic habitat geographic information systems (GIS) datasets. These habitat datasets are expected to form the foundation of state and regional conservation in the Northeastern United States. Key anticipated uses include the following: o Provide common definitions and mapping of aquatic habitat types across state lines. This will allow each state to identify aquatic habitats consistently across jurisdictional borders, such as large habitat patches and watersheds that cover multiple jurisdictions. This will also improve the success of state-level actions by assisting jurisdictions that have not yet developed aquatic habitat classification and mapping tools. o Facilitate a new understanding of aquatic biota and populations on a regional scale by linking biological datasets to the regional aquatic habitat types for reporting and analysis. o Create a new opportunity to assess the condition and prioritize habitats at a scale broader than the individual state by linking and reporting information on dams, land use, conservation lands, impaired waters, and other condition metrics by the regional aquatic habitat types Developing an Aquatic Ecosystem Classification: Unlike terrestrial communities, no national standard aquatic community classification for the U.S. currently exists. The comprehensive biological sample data necessary to develop a classification and map of aquatic ecosystems from biological data alone is also lacking across large regions, including the northeast states. The Northeast Aquatic Habitat Classification System thus used the aquatic biophysical classification approach developed by the Nature Conservancy and recommended by the National Fish Habitat Science Panel (Olivero and Anderson 2003, Higgins et al. 2005, Beard et al. 2006). This classification approach can be implemented at regional scales and emphasizes the environmental gradients of climate, elevation, landform, and geology which are known to shape aquatic ecosystems at several spatial scales and influence the physical aquatic habitat diversity (Higgins et al. 2005). The individual variables chosen to define specific aquatic habitat types can vary between regions, and regions are encouraged to refine the classification attributes to better reflect more meaningful ecological breaks and variables within their region (Higgins et al. 2005, Beard and Whelan, 2006). The Northeastern Aquatic Habitat Classification System (NAHCS) workgroup decided to use 4 primary variables to define aquatic habitat types in northeast streams and rivers. These variables include stream size, gradient, geologic buffering capacity, and natural stream temperature regime. Please see the full report for more information on why these variables were chosen and how the classification was applied.


The Nature Conservancy (TNC) compiled this data set from the analysis of publicly available data sources. It is freely distributable without permission from this TNC resource office. This data set must be cited on all electronic and hard copy products using the language of the Data Set Credit.

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Type Scheme Key
File Identifier file identifier 53e12afce4b0beb42bdd78d0

ArcGIS Service Definition Extension

dateUploadedTue Aug 05 12:59:35 MDT 2014
dateUploadedTue Aug 05 12:59:49 MDT 2014

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