Shorezone Classification

Shorezone data are sourced from the "Physical Shore-Zone Mapping System for British Columbia" dataset.

The shorezone, or the ocean to land transition area, has been classified into various types along with as much physical characteristics that can be extracted from visual assessment. The primary goal of the dataset was to better understand British Columbia's shoreline types and how they may be impacted by various hazards such as oils spills. The information provided is a polyline shapefile with numerous attribute information including type of shoreline, general width of the shoreline, and oil residency potential.

Shorezone information was collected by aerial survey and video classification analysis as detailed in the full metadata report.

Flights for the entire coast were recorded and later brought back to a lab to be analyzed systematically into a geographic information dataset.

The methodology was developed in the late 1970s and provides for the systematic recording of shore morphology, shore-zone substrate and wave exposure characteristics. The system involves the subdivision of the shore zone into alongshore units and across-shore components. The Shore Units are usually represented by line segments on a map and identified with a unique identifier; alternatively, shore units may be represented as polygons or points. Additional information on the unit and on the components are recorded in an associated ShoreZone Database. The system has been used at mapping scales ranging from 1:10,000 to 1:50,000. However, because the information contained within the Shore-Zone Database is more detailed than information portrayed on the map, the effective mapping scale of the system is usually about 1:10,000 to 1:15,000; that is, a map of at least 1:10,000 scale would be required to display all the information recorded within the database.

The concept underlying this mapping system is that the shore zone can be subdivided and described in terms of systematic collection of physical entities. That is, a shoreline can be subdivided into smaller pieces, and the characteristics of each piece described and recorded. The subdivision hierarchy that is used is to first subdivide the shoreline into alongshore units, subdivide the shore units into across-shore components and categorize each of the components into zones.

The concept of a shore unit is fundamental to understanding and using the mapping system. Although the across-shore component is the primary building block of the mapping system, the shore unit is the primary feature portrayed on the maps. The shore unit identifies areas of morpho-dynamic homogeneity. That is, within a unit, the morphology, sediment texture and dynamic physical processes do not vary in the alongshore direction. As a general rule, a change in one or more across-shore components (i.e., a change in either form or texture) or a significant change in processes operating on the shore zone will define a new unit.

Credits: Don Howes BC Ministry of Environment. Lands and Parks Victoria, British Columbia John Harper Coastal and Ocean Resources Inc. Sidney, British Columbia Edward Owens Owens Coastal Consultants Bainbridge, Washington

No edits to the data were performed. Alterations included a re-projection to Web Auxiliary WGS84, clipping to the Central Coast of British Columbia, and cleaning the attribute fields to only include relevant and complete datasets.

Attribute Fields: FID Unique identification code for each polyline section Each shorezone unit has a unique ObjectID created automatically in the creation of the original dataset.

Shape Type / geometry of shapefile being represented. For all records the shapefile is defined as a "Polyline" or line segment.

REP_TYPE Reported Type of shorezone classification (code classification 1-16) Reported as a numbered code - the number is associated with a particular type of beach type and is detailed more in the "REP_TYPE_NAME" attribute. It is calculated by the GIS technician in the creation of the dataset by manually classifying the shorezone type from video footage.

REP_TYPE_NAME Reported shorezone classification (detailed) Reported Type of shorezone classification with a detailed name descriptor of beach type. It is calculated by the GIS technician in the creation of the dataset by manually classifying the shorezone type from video footage.

COASTAL_CLASS_1 Coatal classification details Reported classification providing a more detailed description of the "REP_TYPE_NAME" - giving details for general dimensions of the shore type. Coastal class name is calculated by the GIS technician in the creation of the dataset by manually classifying the shorezone type from video footage.

MAX_DIRECT Maximum direction of the greatest fetch distance. See "MAX_FETCH" attribute. Direction is in degrees eg - 90 = maximum fetch distance is from the east, 270 = maximum fetch distance is from the west. Classified based on the direction for each shorezone that the maximum amount of fetch is achieved.

MAX_FETCH Maximum fetch distance (in kilometres) based on the distance in which waves / wind can collect in a single compass direction and hit the shorezone location. Classified by a fetch GIS analysis.

SHORENA Mean shorezone direction. Each shorezone block has a mean direction it faces in degrees. 90 = east facing shoreline. Calculated in direction GIS analysis.

TIDE_LARGE Maximum tidal change reached (in meters) for each shorezone block. Calculated primarily on the nearest tidal station.

TIDE_MEAN Mean tide for each shorezone block (in meters). Primarily based on mean tides from the nearest tide station.

CHANGE_TYPE_NAME Change or status of the shorezone (stable / accretional / erosional) Three definitions used to describe a sediment based shoreline as stable / accretional / or erosional. Defined by GIS technician manually classifying shoreline from video footage.

SEDIMENT_1 (sediment source) Source of sediment (if known) on the shorezone. Defined as unknown - alongshore - backshore - offshore - fluvial and details the source of sediment for each shorezone section Defined by GIS technician manually classifying shoreline from video footage.

SEDIMENT_2 (Sediment abundance) Abundance or relative amount of available sediment in that shorezone block Defined by GIS technician manually classifying shoreline from video footage.

EXP_FINAL Mean exposure direction (in compass headings) SE = Main exposure for the shorezone unit is to the South East. Calculated within a GIS.

OIL_RESI_1 Oil residency - amount of time an oil spill would likely heavily impact a shorezone unit. Detailed in days / months/ years and is calculated primarily based on the shorezone type (sandy / lagoon / rocky) and exposure.

OIL_RESIDENCY_NAME Oil residency - amount of time an oil spill would likely heavily impact a shorezone unit. Detailed in relative amount of time classified as long / medium / short and is calculated primarily based on the shorezone type (sandy / lagoon / rocky) and exposure.

GEOMETRY_L Length of the line segment / shorezone unit length in meters. Calculated in geometry GIS tools.

Dataset created by: Don Howes, BC Ministry of Environment Lands and Parks John Harper, Coastal and Ocean Resources Inc. Edward Owens, Owens Coastal Consultants P.D. Reimer, P. Lewis, M.J. Miles, D.L. Forbes, N. McFadden and M.Dunn, Government of British Columbia's Corporate Resources Inventory Initiative Hakai Institute, Keith Holmes

Access and Use

Licence: Appropriate credit must be given to Hakai Institute and the authors of the dataset.

Data and Resources

Dates

Metadata Created October 26, 2018, 22:48 (UTC)
Metadata Updated October 26, 2018, 22:48 (UTC)
Reference Date(s) 2015-08-04 (Publication)
1996-04-15 (Creation)
Frequency of Update
Metadata Date April 19, 2016, 16:39 (UTC)

Graphic Preview

Dataset extent

Map data © OpenStreetMap contributors

Additional Info

Field Value
Contact Email data@hakai.org
encoding utf8
metadata-language eng
progress completed
resource-type dataset
Responsible Party Hakai Institute (Point of Contact, Processor)
spatial-reference-system 3857