Description: The within lake subbasins are based on the USGS Great Lakes Aquatic GAP aquatic lake units (ALUs) (McKenna and Castiglione, 2010) with modifications made to Lake Superior based on input from the GLAHF classification working group. The subbasins were based on dominate summer circulation patterns and lake bathymetry. For each subbasin, the upstream catchments for the contributing rivermouths were aggregated to create the land contributions areas.
Service Item Id: d2917bcabead4e249c361b4ceb2a307e
Copyright Text: The Great Lakes Aquatic Habitat Framework (GLAHF) project has been funded by the Great Lakes Fishery Trust and led by Dr. Catherine Riseng at the University of Michigan School of Natural Resources and Environment, with partners from Michigan Department of Natural Resources-Institute for Fisheries Research, NOAA Great Lakes Environmental Research Laboratory, International Joint Commission, Michigan State University, The Nature Conservancy, Ontario Ministry of Natural Resources, University of Minnesota-Duluth, U.S. Fish & Wildlife Service, U.S. Geological Survey and many collaborating partners in both the USA and Canada. More information about this project can be found at http://ifr.snre.umich.edu/projects/glahf/.
Description: The basin outlines for each Great Lake were derived from 30m flow direction grids from the Great Lakes Aquatic Habitat Framework (GLAHF) watersheds product, 2014. Input data to the basin delineation includes the USGS National Hydrography Dataset (NHD) Plus version 2, 2012 and the Ontario Integrated Hydrology Dataset (OIHD), 2012.
Service Item Id: d2917bcabead4e249c361b4ceb2a307e
Copyright Text: The Great Lakes Aquatic Habitat Framework (GLAHF) project has been funded by the Great Lakes Fishery Trust and lead by the University of Michigan School of Natural Resources and Environment, with partners from Michigan Department of Natural Resources-Institute for Fisheries Research, NOAA Great Lakes Environmental Research Laboratory, International Joint Commission, Michigan State University, The Nature Conservancy, Ontario Ministry of Natural Resources, University of Minnesota-Duluth, U.S. Fish & Wildlife Service, U.S. Geological Survey and many collaborating partners in both the USA and Canada. More information about this project can be found at http://ifr.snre.umich.edu/projects/glahf/.
Description: The GLAHF Great Lakes Hydrology Data Package Version 1 (2014) was created as a part of the GLAHF project, a geospatial database and framework for the aquatic environment of the Great Lakes. This data package contains a consistent, basin-wide watershed and interfluve layer and supporting datasets, including modified vector layers from official hydrology base datasets, and intermediate reference layers created during delineation of the watersheds and interfluves. Several base hydrology sources were utilized, including the National Hydrography Dataset Plus (NHD+) Version 2, the Ontario Integrated Hydrology Data Version 1 (OIHDV1), the National Hydrography Dataset (NHD), and the National Elevation Dataset (NED). An ArcHydro process flow was used that began with flow direction grids from base datasets and delineated a synthetic drainage network, associated reach-catchments, aggregated reach catchments, and basin-wide, consistent tributary catchments boundaries. Coastal interfluves, the area between the delineated aggregated reach catchments and the shoreline, were also delineated basin-wide in a secondary processing step. Watersheds and interfluves were developed following the stream interfluves delineation methods outlined in Hollenhorst et al. (2007) using ArcHydro processing guidance from Merwade (2010). The final watersheds and interfluves layers and pour point layers, all synthetic reference layers, and modified official hydrology layers were packaged by entire Great Lakes Basin and by each Great Lake basin. Connecting channels are included with the downstream lake. A few pre-processing steps were performed to prepare the base flow direction grids for delienation: 1) the Great Lakes shoreline was enforced into the OIHDV1 flow direction grids; 2) EPA identified bays were used to enforce additional embayments into the shoreline to create a more detailed shoreline; 3) connecting channels were enforced at the shoreline for the NHD+V2 grids, and 4) the original hydrology datasets were modified to reflect these changes in the shoreline.This layer was created as part of the ArcHydro processing flow to create watershed boundaries. This layer contains the final, post processed watershed pour points, the point where the entire area of each watershed empties into the Great Lakes or the connecting channels. A copy was made of the WatershedPoint_Original layer, interfluves were added, and pour points that no longer corresponded to a watershed in Watershed_Interfluve_Altered_Attributed were removed. Attributes from the nearest downstream reach from the OIHDV1, NHD+V2 or NHD (and names from the National Hydro Network (NHN) and the Geographic Extent Layer (GEL) for Canadian watershds) were attributed to each watershed point, as long as the reach was within 200 meters. This data was then attributed to watershed polygon that corresponded to every point. Since attributes were added from the hydrology source used to delineate data for that watershed, each watershed or watershed point is linked to only the NHD+V2, OIHDV1, or NHD; therefore no watershed polygon or point will have attributes for all fields associated from the original hydrology. Please see the Fields section of this metadata record for more details.
Service Item Id: d2917bcabead4e249c361b4ceb2a307e
Copyright Text: 1) The National Hydrography Dataset Plus Version 2 (1:100,000), 2012; 2) Ontario Integrated Hydrology Data Version 1, 2012; 3) The National Elevation Dataset; 4) The National Hydrography Dataset (1:24,000); 5) Hollenhorst, T.P., Brown, T.N., Johnson, L.B., Ciborowski, J.H. and Host, G.E. 2007. Methods for generating multi-scale watershed delineations for indicator development in Great Lakes coastal ecosystems. Journal of Great Lakes Research 33 (Special Issue 3):13-26; and 6) Merwade, Venkatesh. 2010. Watershed and Stream Network Delineation using ArcHydro Tools. . 7) The Great Lakes Aquatic Habitat Framework (GLAHF) project has been funded by the Great Lakes Fishery Trust and lead by the University of Michigan School of Natural Resources and Environment, with partners from Michigan Department of Natural Resources-Institute for Fisheries Research, NOAA Great Lakes Environmental Research Laboratory, International Joint Commission, Michigan State University, The Nature Conservancy, Ontario Ministry of Natural Resources, University of Minnesota-Duluth, U.S. Fish & Wildlife Service, U.S. Geological Survey and many collaborating partners in both the USA and Canada. More information about this project can be found at http://ifr.snre.umich.edu/projects/glahf/.
Description: The GLAHF Great Lakes Hydrology Data Package Version 1 (2014) was created as a part of the GLAHF project, a geospatial database and framework for the aquatic environment of the Great Lakes. This data package contains a consistent, basin-wide watershed and interfluve layer and supporting datasets, including modified vector layers from official hydrology base datasets, and intermediate reference layers created during delineation of the watersheds and interfluves. Several base hydrology sources were utilized, including the National Hydrography Dataset Plus (NHD+) Version 2, the Ontario Integrated Hydrology Data Version 1 (OIHDV1), the National Hydrography Dataset (NHD), and the National Elevation Dataset (NED). An ArcHydro process flow was used that began with flow direction grids from base datasets and delineated a synthetic drainage network, associated reach-catchments, aggregated reach catchments, and basin-wide, consistent tributary catchments boundaries. Coastal interfluves, the area between the delineated aggregated reach catchments and the shoreline, were also delineated basin-wide in a secondary processing step. Watersheds and interfluves were developed following the stream interfluves delineation methods outlined in Hollenhorst et al. (2007) using ArcHydro processing guidance from Merwade (2010). The final watersheds and interfluves layers and pour point layers, all synthetic reference layers, and modified official hydrology layers were packaged by entire Great Lakes Basin and by each Great Lake basin. Connecting channels are included with the downstream lake. A few pre-processing steps were performed to prepare the base flow direction grids for delienation: 1) the Great Lakes shoreline was enforced into the OIHDV1 flow direction grids; 2) EPA identified bays were used to enforce additional embayments into the shoreline to create a more detailed shoreline; 3) connecting channels were enforced at the shoreline for the NHD+V2 grids, and 4) the original hydrology datasets were modified to reflect these changes in the shoreline.This layer was created as part of the ArcHydro processing flow to create watershed boundaries. This layer contains the final, post processed watershed boundaries along with the interfluves, the areas between the watershed boundaries and the shoreline that correspond to small coastal streams, that were added in a secondary processing step outside of ArcHydro. A copy was made of the Watershed_Original layer, interfluves were added, and some watershed and interfluve polygons were then edited based upon specified criteria. Attributes from the nearest downstream reach from the OIHDV1, NHD+V2 or NHD (and names from the National Hydro Network (NHN) and the Geographic Extent Layer (GEL) for Canadian watershds) were attributed to each watershed point, as long as the reach was within 200 meters. This data was then attributed to watershed polygon that corresponded to every point. Since attributes were added from the hydrology source used to delineate data for that watershed, each watershed or watershed point is linked to only the NHD+V2, OIHDV1, or NHD; therefore no watershed polygon or point will have attributes for all fields associated from the original hydrology. Please see the Fields section of this metadata record for more details.
Service Item Id: d2917bcabead4e249c361b4ceb2a307e
Copyright Text: 1) The National Hydrography Dataset Plus Version 2 (1:100,000), 2012; 2) Ontario Integrated Hydrology Data Version 1, 2012; 3) The National Elevation Dataset; 4) The National Hydrography Dataset (1:24,000); 5) Hollenhorst, T.P., Brown, T.N., Johnson, L.B., Ciborowski, J.H. and Host, G.E. 2007. Methods for generating multi-scale watershed delineations for indicator development in Great Lakes coastal ecosystems. Journal of Great Lakes Research 33 (Special Issue 3):13-26; and 6) Merwade, Venkatesh. 2010. Watershed and Stream Network Delineation using ArcHydro Tools. . 7) The Great Lakes Aquatic Habitat Framework (GLAHF) project has been funded by the Great Lakes Fishery Trust and lead by the University of Michigan School of Natural Resources and Environment, with partners from Michigan Department of Natural Resources-Institute for Fisheries Research, NOAA Great Lakes Environmental Research Laboratory, International Joint Commission, Michigan State University, The Nature Conservancy, Ontario Ministry of Natural Resources, University of Minnesota-Duluth, U.S. Fish & Wildlife Service, U.S. Geological Survey and many collaborating partners in both the USA and Canada. More information about this project can be found at http://ifr.snre.umich.edu/projects/glahf/.