These data were created as part of the National Oceanic and Atmospheric Administration Office for Coastal Management's efforts to create an online mapping viewer depicting potential water level increase and decrease in the coastal areas of the Great Lakes. The lakes included are: Erie, Huron, Michigan, Ontario, St. Clair, and Superior. The purpose of the mapping viewer is to provide coastal managers and scientists with a preliminary look at lake level change and potential coastal impacts. The viewer is a screening-level tool that uses nationally consistent data sets and analyses to help users examine multiple scenarios and prioritize actions. The Lake Level Viewer may be accessed at: https://coast.noaa.gov/llv

    These data depict the mapping confidence of the associated lake water level data for the water level amounts of -6 feet through +6 feet. The mapping 
    process is designed to give the most accurate picture of water extent possible, but inherent data errors introduce some uncertainty in the exact water 
    extents. The presentation of data confidence only represents the known error in the elevation data and not uncertainty associated with the natural evolution 
    of the coastal landforms (e.g., erosion or bluff failure) or future climate change impacts on lake levels.

    To access the associated data to be used with this data:
    NOAA Office for Coastal Management Lake Level Data: -6 Feet to +6 Feet Water Level Change data may be downloaded at:
    https://coast.noaa.gov/llv

    The NOAA Office for Coastal Management has tentatively adopted an 80 percent rank (as either inundated or not inundated) as the zone of relative confidence.
    The use of 80 percent has no special significance but is a commonly used rule of thumb measure to describe economic systems (Epstein and Axtell, 1996). The 
    method used to determine the confidence data only includes the uncertainty in the lidar derived elevation data (root mean square error, or RMSE). This 
    confidence data shows that the water level depicted in the -6 feet to +6 feet water level change data is not really a hard line, but rather a zone with greater 
    and lesser chances of being wet or dry. Areas that have a high level of confidence that they will be wet, means that there is an 80 percent or greater 
    likelihood that these areas will be covered with water. Conversely, there is a 20 percent or less likelihood that the area will be dry. Areas mapped as wet 
    (inundation) with a high confidence (or low uncertainty) are coded as 2. Areas that have a high level of confidence that they will be dry, means that there is 
    an 80 percent or greater likelihood that these areas will be dry. Conversely, there is a 20 percent or less likelihood that the area will be wet. Areas mapped 
    as dry (no inundation) with a high confidence (or low uncertainty) are coded as 0. Areas that have a low level of confidence, means that there is a 21 - 79 
    percent likelihood of wet or dry conditions. Note that 60 percent of the time, the land-water interface will be within this zone. Areas mapped as dry or wet 
    with a low confidence (or high uncertainty) are coded as 1.

    As with all remotely sensed data, all features should be verified with a site visit. The data are provided as is, without warranty to their performance,
    merchantable state, or fitness for any particular purpose. The entire risk associated with the results and performance of these data is assumed by the user. 
    This data should be used strictly as a planning reference and not for navigation, permitting, or other legal purposes. For a detailed description of the 
    confidence level and its computation, please see the Mapping Inundation Uncertainty document available at: 
    http://www.jcronline.org/doi/abs/10.2112/JCOASTRES-D-13-00118.1