EarthWorks Geospatial Catalog

Hennepin County Wetland Inventory

Description
The original Hennepin County Wetland Inventory (HCWI) was developed from the remote sensing of multiple years of orthophotograpy in combination with the analysis of related GIS layers and 10 years of Natural Resources Conservation Service slide reviews to identify and include farmed wetlands. The HCWI does not classify wetlands but merely locates them, whereas the NWI classifies wetlands based on the Cowardin methodology utilizing remotely gathered data and photo signature. For more information concerning detail on procedures followed to develop the HCWI contact Hennepin County Dept. of Environmental Services.National Wetland Inventory Metadata:The National Wetland Inventory (NWI) for east-central Minnesota were updated through multi-agency collaborative effort under leadership from the Minnesota DNR. Operational support for wetland mapping and classification was provided by Ducks Unlimited and support for methods development and field validation were provided by the Remote Sensing and Geospatial Analysis Laboratory at the University of Minnesota. Major funding was provided by the Environmental and Natural Resources Trust Fund.The project area consists of 13 counties in east-central Minnesota including: Anoka, Carver, Chisago, Dakota, Goodhue, Hennepin, Isanti, Ramsey, Rice, Scott, Sherburne, Washington, and Wright Counties. The updated wetland inventory area included complete coverage for all USGS quarter quadrangles that intersect any of these counties (about 7,150 square mile). The NWI classification process for east-central Minnesota consisted of three basic steps: 1) creation of image segments (polygons), 2) RandomForest classification of the segments, and 3) photo-interpretation of the classified image segments. The updated NWI also contains a Simplified Plant Community Classification and a Simplified Hydrogemorphic Classification. Quality assurance of the data included a 100% visual inspection, automated checks for attribute validity and topologic consistency, as well as a formal accuracy assessment based on an independent field verified data set. Further details on the methods employed can be found in the technical procedures document for this project (provide URL). The updated NWI data are primarily based on aerial imagery acquired in 2010 and 2011 as well as other modern ancillary data. This data is intended to replace the original NWI data which was based on imagery acquired in the early 1980s. NWI data support effective wetland management, protection, and restoration. The data provide a baseline for assessing the effectiveness of wetland policies and management actions. These data are used at all levels of government, as well as by private industry and non-profit organizations for wetland regulation and management, land use and conservation planning, environmental impact assessment, and natural resource inventories.
Publisher
Hennepin County
Year
2014
Held by
Minnesota