Partnering to Develop High Quality Land Cover Products in Washington

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The Washington Department of Ecology required up-to-date land cover information and more accurate wetland maps to explore wetland loss and find strategies to avoid future losses. Producing and developing land cover data is expensive and requires technical expertise and time that many agencies don’t always have.


Two programs—the Washington Department of Ecology and the NOAA C-CAP land cover program—worked together on shared goals to update regional land cover data and improve wetland mapping accuracy. The team was able to expedite the C-CAP 2010 land cover update and develop a longer period of trend analysis with historic 1992 data from the coastal portion of Washington State.

The partners worked to improve wetland mapping accuracy using a new method for modeling potential wetlands by combining several data layers, including the National Wetland Inventory, Soil Survey Geographic (SSURGO) data, National Hydrography Dataset, C-CAP, National Elevation Dataset, and Landsat Satellite imagery and modeling. This approach provided a more robust representation of potential wetland features and addressed gaps in coverage or dates.


Because of this partnership, the Washington Department of Ecology was able to quickly obtain 2010 regional land cover data, 1992 data at a lower cost, and wetland maps that were more accurate. These data are useful for wetland mitigation, restoration site evaluation, and assessments. Lessons learned from this effort were used to improve all the regional land cover products produced by NOAA.

The Washington Department of Ecology uses C-CAP Regional Land Cover and Wetland Potential data to improve wetland mapping accuracy of Puget Sound
This map of Puget Sound shows wetland potential overlain on Landsat imagery. Darker shades of blue represent areas that are more likely to be considered wetland.