Description: Map index point data are centroids (points) of the map index polygons. Map index polygons are spatial boundaries that define sub-areas in kelp bed mapping. The purpose of the sub-areas is to subdivide the study area into smaller units for analysis. Boundaries are primarily based on geographic features, such as headlands. Map index areas are used to track the abundance, species composition and distribution of of floating kelp beds (Nereocystis luetkeana and Macrocystis pyrifera) along the Strait of Juan de Fuca and outer coast of Washington State. These data are part of a long term monitoring effort that surveys kelp canopies in this area annually. The entire data set is comprised of the following components: yearly inventories (feature classes) starting in 1989, excluding 1993 (kelpYYYY), a combined inventory from all years (kelp_all_years), a combined inventory of kelp observations from the five most recent years (kelp_recent_5yr), a spatial index (polygon and point feature classes) delineating the geographic extent of monitoring sub-areas (map_index, map_index_pts), and tabular data describing kelp characteristics for each year that link to the spatial index (summary_kelp_stats). Users who wish to use the most precise inventory estimates and compare area over multiple years should use the tabular summary tables which summarize area by map_index. The tabular estimates are more precise because they are based on the source imagery. The area estimates in the feature classes reflect subsequent processing. Methods of subsequent processing have varied with changes in technology since 1989, resulting in noticeable differences among years in the spatial data that preclude detailed comparison of spatial data across years. Major methodological changes include: 1) a format change from vector (CAD) in 1989 to raster (20 m cell size) in 1994; 2) In 2010, the resolution changed from 20 meter to 4 meter resolution.
Service Item Id: f914128b696c4dcfbbe063972c7e63c9
Copyright Text: This dataset is primarily funded and managed by Washington State Department of Natural Resources, through the Nearshore Habitat Program. Other supporters and collaborators include: NOAA's Olympic Coast National Marine Sanctuary, Washington State Department of Transportation, Washington State Department of Ecology's Coastal Zone Management Act, and Washington State Coastal Protection Fund.
Description: These data describe the extent of floating kelp beds (Nereocystis luetkeana and Macrocystis pyrifera) along the Strait of Juan de Fuca and outer coast of Washington State. Annual surveys describe conditions between 1989 and 2019. Data are derived from photo interpretation of low tide aerial photography in the late summer, the season of maximum extent. Polygons represent bed extent or planimeter, which include the kelp canopy floating on the surface and small gaps between plants (25 meter threshold for delineating discrete beds). These data are part of a long term monitoring effort that surveys the kelp canopies annually. The entire data set is comprised of the following components: yearly inventories (feature classes), excluding 1993 (kelpYYYY) a combined inventory from all years (kelp_all_years), a combined inventory of kelp observations from the five most recent years (kelp_recent_5yr), a spatial index delineating the geographic extent of monitoring sub-areas (map_index) and tabular data describing kelp characteristics for each year that link to the spatial index (summary_kelps_stats).It was necessary to generalize the polygons in kelp_all_years in order to produce a dataset that did not exceed the maximum number of vertices allowed for the feature class. Users who wish to use the most precise inventory estimates and compare area over multiple years should use the tabular summary tables which summarize area by map_index. The tabular estimates are more precise because they are based on the source imagery, while the area estimates in the feature classes reflect subsequent processing. Methods of subsequent processing have varied with changes in technology since 1989, resulting in noticeable differences among years in the spatial data that preclude detailed comparison of spatial data across years. Major methodological changes include: 1) a format change from vector (CAD) in 1989 to raster (20 m cell size) in 1994; 2) In 2010, the resolution changed from 20 meter to 4 meter resolution.
Service Item Id: f914128b696c4dcfbbe063972c7e63c9
Copyright Text: This dataset is primarily funded and managed by Washington State Department of Natural Resources, through the Nearshore Habitat Program. Other supporters and collaborators include: NOAA's Olympic Coast National Marine Sancutary, Washington State Department of Transportation, Washington State Department of Ecology's Coastal Zone Management Act, and Washington State Coastal Protection Fund.
Description: These data describe the spatial boundaries that define sub-areas in kelp bed mapping. The purpose of the sub-areas is to subdivide the study area into smaller units for analysis. Boundaries are primarily based on geographic features, such as headlands. Map index areas are used to track the abundance, species composition and distribution of of floating kelp beds (Nereocystis luetkeana and Macrocystis pyrifera) along the Strait of Juan de Fuca and outer coast of Washington State. These data are part of a long term monitoring effort that surveys kelp canopies in this area annually. The entire data set is comprised of the following components: yearly inventory feature classes from 1989 through 2014, excluding 1993 (kelpYYYY), a combined inventory from all years (kelp1989_2014), a spatial index delineating the geographic extent of monitoring sub-areas (map_index) and tabular data describing kelp characteristics for each year that link to the spatial index (summary_kelp_stats). Polygons represent bed extent or planimeter, which include the kelp canopy floating on the surface and small gaps between plants (25 meter threshold for delineating discrete beds). Users who wish to use the most precise inventory estimates should use the tables (summary_kelp_stats) which summarize kelp canopy area by map_index. The tabular estimates are more precise because they are based on the source imagery, while the area estimates in the feature classes reflect subsequent processing. While the tabular data provides more detailed attribute information, it is limited in that the attributes are summarized for each map_index number (which corresponds to a stretch of shoreline). The tabular data is related to the spatial data using the map_index column. The total planimeter area of a kelp bed as calculated directly in the kelp polygon feature classes (kelpYYYY) is slightly different from the total planimeter area reported in the summary tables (summary_kelp_stats). These differences are expected because the area estimates in the shape files reflect subsequent processing. Methods of subsequent processing have varied with changes in technology since 1989, resultsing in noticeable differences among years in the spatial data that preclude detailed comparison of spatial data across years. Major methodological changes include: 1) a format change from vector (CAD) in 1989 to raster (20 m cell size) in 1994; 2) In 2010, the resolution changed form 20 meter to 4 meter resolution.
Service Item Id: f914128b696c4dcfbbe063972c7e63c9
Copyright Text: This dataset is primarily funded and managed by Washington State Department of Natural Resources, through the Nearshore Habitat Program. Other supporters and collaborators include: NOAA's Olympic Coast National Marine Sancutary, Washington State Department of Transportation, Washington State Department of Ecology's Coastal Zone Management Act, and Washington State Coastal Protection Fund.