In the mid-2000s the Great Lakes Commission convened the Great Lakes Coastal Wetland Consortium (GLCWC) to identify hydrologically connected coastal wetlands across the entire Great Lakes Basin. The final data set identifies the areas and hydrogeomorphic wetland types the coastal wetlands. We have enhance the data set by aggregating the wetlands into 3 major types (open, protected, and delta) and creating data layers that describe the distance and direction to these 3 wetland types. Michigan Tech Research Institute (MTRI) created an updated wetlands and land use data within 10 km of the Great Lakes shoreline, which have also been incorporated into the GLAHF database.
Fish access to Great Lakes
Fish tributary access in the Great Lakes Basin was determine using the National Hydrography Dataset (NHD) Plus Version 2 and the Ontario Integrated Hydrology Dataset (2012). The tributary barriers included the USGS National Anthropogenic Barrier Dataset for the U.S. and the Ontario Ministry of Natural Resources and Forestry dams and barriers. The fish access data set identifies stream segments between the shoreline of the Great Lakes and first major barrier identified.
While developing the Great Lakes Hydrology Dataset (GLHD) we compiled a high-resolution shoreline of the Great Lakes using best available digitized shorelines for the U.S. and Canada.
Watersheds & tributaries
Tributaries are the most dominating link between the landscape and the open waters of the Great Lakes. We have tried to capture this link, consistently, by creating a set of watersheds and interfluves in the Great Lakes Hydrology Dataset (GLHD). Tributaries mouths are identified as pour points in the GLHD and contain attributes of common name and stream order. Data layers were created to calculated distance, direction, and river mouth density to all pour points in the GLHD and to only those pour points of Strahler stream order 5 and greater. Tributaries and land adjacent to the coastal and nearshore areas of the Great Lakes are known to influence the water and aquatic habitats. This is a very dynamic system that GLAHF tried to capture by spatially and mathematically modeling the zone most likely to be impacted by tributary and surface water runoff. The tributary influence data layer is weighted by watershed and interfluve area, decayed by distance and water depth, the layer is then broken into 3 classes based on stream order.