2.2.1 Data Compilation |
Data sources used for all aspects of the assessment are summarized in Table 3. A description of how this information is used is described in Sections 2.2.2, 2.2.3, and 2.2.4. All data were georeferenced and assembled into a comprehensive geographical information system (GIS) using ArcView 3.2. This was accomplished in two primary ways: 1) data were initially collected and/or distributed in a geographic file format; or 2) the geographic location of data were estimated from maps or aerial photographs, and the data were then added as an attribute for the reach with which it was associated. Data and GIS files are available by request from the City of Bainbridge Island.
Table 3. Categories of Data and Data Sources Used in Assessment Approach
| Data Category | Definition | Assessment Use | Data Source |
| Drift Cell | Direction of nearshore sediment transport. | Spatial scale (Defines “Management Area”) | Taggart 1984, Schwartz et al. 1991; WA Dept. Ecology 2001 |
| ShoreZone Unit | Areas of relatively homogeneous beach geomorphology. | Spatial scale (Defines “Reach”) | ShoreZone Inventory (WDNR 2001); Oblique photos (WDOE 1977, 1992, 2000) |
| Geomorphology | Shape of land surface forms and processes producing them | Geomorphic class | Visual interpretation of oblique photos (WDOE 1977, 1992, 2000) |
| Sediment source | Predominant source of shoreline sediment (e.g. fluvial, backshore) | Geomorphic class; Controlling Factor: Sediment Supply | ShoreZone Inventory (WDNR 2001); |
| Substrate class | Predominant shoreline substrate | Geomorphic class | ShoreZone Inventory (WDNR 2001); |
| Slope | Angle of beach/backshore | Geomorphic class | LiDAR data (Puget Sound LiDAR Consortium 2000; Hardy and Berghoff 2000) |
| Slope stability maps, Feeder bluff locations | Location of eroding backshore landforms (an incomplete inventory) | Geomorphic class, Controlling Factor: Sediment Supply | Small 2001 |
| Historic Geomorphology | Records of land surface forms before substantial human development | Geomorphic class | Topographic sheets (T-sheets) from U.S. Coast and Geodetic Survey; Puget Sound River History Project, UW |
| Wave Exposure | Relative protection of shore from wave energy | Controlling Factor: Wave Energy | ShoreZone Inventory (WDNR 2001) |
| % Armoring | Linear percentage of shoreline with armoring structures (e.g., rip-rap, bulkheads) | Controlling Factors: Wave Energy, Sediment Supply, Substrate Type, Depth-Slope | COBI Nearshore Structure Inventory (COBI 2002, Best 2003) |
| Armor Material Composition | Armor material (e.g., concrete, rock, wood) | Controlling Factor: Wave Energy | COBI Nearshore Structure Inventory (COBI 2002, Best 2003) |
| % Armoring Encroachment | Linear percentage of shoreline with armoring that encroaches into the intertidal zone | Controlling Factor: Wave Energy, Depth-Slope, Hydrology | COBI Nearshore Structure Inventory (COBI 2002, Best 2003) |
| % Overhanging Vegetation | Linear percentage of shoreline with vegetation overhanging the beach | Controlling Factor: Natural Shade Ecological Function |
COBI Nearshore Structure Inventory (COBI 2002, Best 2003) |
| Overwater Structure Density | Density of shade causing structures, (docks, piers, boats, buoys, and other overwater structures) | Controlling Factor: Artificial Shade | COBI Nearshore Structure Inventory (COBI 2002, Best 2003) |
| Marinas | Piers and floats with more than 5 mooring slips | Controlling Factor: Artificial Shade, Pollution | Oblique photos (WDOE 2000) |
| Groins | Structure built at angle to shore to intercept alongshore drift | Controlling Factor: Sediment Supply | COBI Nearshore Structure Inventory (COBI 2002, Best 2003) |
| Ramps | Sloping platform used as a launch for small watercraft | Controlling Factor: Sediment Supply, Physical Disturbance | COBI Nearshore Structure Inventory (COBI 2002, Best 2003) |
| Point Modification Density | Density of all nearshore structures composed of unnatural materials | Controlling Factor: Substrate Type | COBI Nearshore Structure Inventory (COBI 2002, Best 2003) |
| Dredged Areas | Areas where substrate has been removed to provide/maintain depth for vessels | Controlling Factor: Depth-Slope | COBI (unpublished) |
| Areas of Shellfish Closures | Known sources of chemical or biological pollution | Controlling Factor: Pollution | Kitsap County Health District 2003; U.S. EPA 303(d) listed sites |
| % Total Impervious Area | Percent of land cover classified as impervious surfaces in marine riparian zone | Controlling Factor: Pollution, Hydrology | Kitsap County Aerial Imagery (2001) |
| Pipe Outfall Density | Density of discharging pipes greater than 8” in diameter | Controlling Factor: Pollution, Hydrology | COBI Nearshore Structure Inventory (COBI 2002, Best 2003) |
| Artificial Tidal Constrictions | Tide gates, barriers, or culverts | Controlling Factor: Hydrology | COBI (unpublished); Oblique photos (WDOE 2000) |
| Urban waterfront | Areas with commercial shipping activity or ferry use | Controlling Factor: Physical Disturbance | COBI (unpublished); Oblique photos (WDOE 2000) |
| Floating / Grounding Structure Density | Density of floating docks, boats, and buoys, and boat ramps | Controlling Factor: Physical Disturbance | COBI Nearshore Structure Inventory (COBI 2002, Best 2003) |
| % Total Forested Area | Percent of land cover classified as coniferous, deciduous, meadow-shrub, and wetland in marine riparian zone | Controlling Factor: Physical Disturbance | Kitsap County Aerial Imagery (2001) |
| Salmon-bearing streams | Streams with documented populations of salmonids | Ecological Function | WRIA 15 Salmon Limiting Factors Analysis (Haring 2000); Kitsap Refugia Study (May and Peterson 2003) |
| Herring spawning | Documented herring spawning areas | Ecological Function | Priority Habitats and Species (WDFW 2001) |
| Sandlance spawning | Documented sandlance spawning beaches | Ecological Function | Priority Habitats and Species (WDFW 2001) |
| Surf smelt spawning | Documented surf smelt spawning beaches | Ecological Function | Priority Habitats and Species (WDFW 2001) |
| Geoduck presence | Distribution of geoduck beds | Ecological Function | Priority Habitats and Species (WDFW 2001) |
| Eelgrass | Eelgrass distribution (patchy and continuous) | Ecological Function | Bio-Band Code ZOS from ShoreZone Inventory (WDNR 2001) |
| Salt marsh | Distribution of salt-tolerant vascular plants | Ecological Function | Bio-Band Codes SAL and TRI from ShoreZone Inventory (WDNR 2001) |
| Bull kelp | Distribution of canopy forming kelp Nereocystis | Ecological Function | Bio-Band Code NER from ShoreZone Inventory (WDNR 2001) |
| Intertidal seaweed | Distribution of Intertidal Algae | Ecological Function | Bio-Band Codes FUC, LAM, SAR, and LAM from ShoreZone Inventory (WDNR 2001) |
| << 2.2 Methods |