Bathymetric Maps of Surveyed Lakes

Published by the Ministry of Environment and Climate Change Strategy - Knowledge Management
Licensed under Access Only

Lakes represented in this layer are those which have georeferenced digital bathymetric (depth) data available for them. Each lake depicted in this bathymetric map layer has been digitized and georeferenced and has intelligent contour polygons created for it. These polygons depict contour depths - with each polygon representing the extent of a horizontal ‘slice’ though the lake at a particular depth. These contour polygons include the lake surface (value 0 metres) with additional depth polygons representing increasing water depths.

This layer is different from the Lake Bathymetric Maps layer WHSE_FISH.BATH_SURVEY_MAP_SHEETS_SVW in that the lakes shown in the Lake Bathymetric Maps layer are ones which have had a (typically hand-drafted) hardcopy bathymetric created for them. Those maps have then been scanned and are presented in that layer as PDF files which are linked to the BC Freshwater Atlas polygon for the corresponding lake.

Data and Resources

Dataset Extent

Latitude: 48.0° to 60.0°
Longitude: -139.5° to -113.5°

Additional Information

Purpose

To better visualize a lake’s morphology through the use of color filled depth contour polygons, to facilitate angling, fisheries survey planning, lake area/volume calculations and to present these bathymetric maps as features georeferenced to the 20K BC Freshwater Atlas Lakes layer. These maps are NOT INTENDED FOR NAVIGATIONAL PURPOSES. They may not reflect current conditions and uncharted hazards may exist.

Data Quality

These digital bathymetric maps are derived from two sources which have different data quality factors;

  1. Hand-digitized maps derived from pdf images are scans of the original hand-drawn bathymetric maps; The technology used for the original surveys for these maps is probably the largest data quality consideration. The earliest maps were generated from spot soundings – literally using a weighted line. Subsequent surveys were done using early echo sounding technology and were typically limited to a few transects per lake. The density and accuracy of the sounding points affected the precision and accuracy of the final product. The contours were also hand interpolated by the draftsperson which is another potential data quality influence. Finally, the scanning, digitizing and georectification processes for these map conversions are also all potential error sources. As a result, the digitized versions of original hand-drawn bathy maps tend to be less detailed and potentially of lower accuracy.

  2. Digitally acquired and derived maps are ‘modern’ maps which have been generated using digital X,Y,Z co-ordinates collected with a GPS / depth sounder. The logger collects this data continually while the boat is travelling around the lake. As a result, this data stream tends to be much more dense and widespread. The location and depth data also tends to be of higher accuracy. The data points are interpolated using digital surface (DEM) generating software. This surface can then be used to generate bathymetric contours. In short, these types of maps can be expected to be of a higher quality - transcription, projection, interpolation and human drawing errors are reduced or eliminated.

More information on the updated Bathymetric Standard and the digital methodology can be found here:

https://www.for.gov.bc.ca/hts/risc/pubs/aquatic/bathymetric/assets/bathymetric_standards_v3.pdf

Lineage Statement

Refer to Data Quality

More Information

Contact Information

NameDon Philip (businessExpert)
Emaildon.philip@gov.bc.ca
OrganizationMinistry of Environment and Climate Change Strategy
Sub-OrganizationKnowledge Management
NameRobin Munro (pointOfContact)
Emailrobin.munro@gov.bc.ca
OrganizationMinistry of Environment and Climate Change Strategy
Sub-OrganizationKnowledge Management

Access & Security

Who can view this dataset? Public
Who can download this dataset?Public

Metadata Information

Record Published 2017-03-21
Record Last Modified 2017-04-02
Resource Status completed

Object Description

Object Name: WHSE_FISH.BATH_LAKE_BATHYMETRIC_SP

Short Name: BATH_LAKES
Comments: Digital Lake Bathymetric Maps georeferenced to the provincial 1:20,000 BC Freshwater Atlas Lakes spatial layer. Each lake depth contour is represented by a polygon feature.

Column Name Short Name Data Type Data Precision Comments
LAKE_BATHYMETRIC_ID LK_BTHY_ID NUMBER 10 LAKE_BATHYMETRIC_ID is a system generated unique identification number.
CONTOUR_DEPTH_M CTRDPTHM NUMBER 19 CONTOUR_DEPTH_M is the depth of the depth contour polygon in metres, e.g., 12.345
CONTOUR_DEPTH_AREA_SQM CTRDPTHAR NUMBER 19 CONTOUR_DEPTH_AREA_SQM is area of the depth contour polygon in square metres, e.g., 123.456
CONTOUR_DEPTH_PERIMETER_M CTRDPTPRM NUMBER 19 CONTOUR_DEPTH_PERIMETER_M is the perimeter of the depth contour polygon in metres, e.g., 1234.567
CONTOUR_DEPTH_LABEL CTRDPTLBL VARCHAR2 8 CONTOUR_DEPTH_LABEL is the label for the depth contour polygon, e.g., 8.5m
LAKE_REGION_NAME LKRGNNM VARCHAR2 15 LAKE_REGION_NAME is the BC Ministry of Environment Region Name, e.g., Okanagan
LAKE_REGION_NUMBER LKRGNNO VARCHAR2 2 LAKE_REGION_NUMBER is the Ministry of Environment Region Number, e.g., 4
LAKE_FWA_WATERSHED_CODE LKFWAWSC VARCHAR2 143 LAKE_FWA_WATERSHED_CODE is the Fresh Water Atlas watershed code associated with the lake, e.g., 100-000200-000300-000400-000000-…
LAKE_FWA_WATERBODY_KEY LKFWAWBKY NUMBER 12 LAKE_FWA_WATERBODY_KEY is the Fresh Water Altas waterbody key associated with the lake, e.g., 123456789
LAKE_WSA_WATERSHED_CODE LKWSAWSC VARCHAR2 56 LAKE_WSA_WATERSHED_CODE is the 1:50000 Watershed Atlas watershed code associated with the lake, e.g., 200-123456-12345-1234-0000-…
LAKE_WSA_WATERBODY_IDENTIFIER LKWSAWBID VARCHAR2 9 LAKE_WSA_WATERBODY_IDENTIFIER is the 1:50000 Watershed Atlas waterbody identifier associated with the lake, e.g., 00418OKAN
LAKE_GAZETTED_NAME LKGZTDNM VARCHAR2 50 LAKE_GAZETTED_NAME is the official BC gazetted name for the lake, e.g., Wood Lake
LAKE_ALIAS_1 LKNMALS1 VARCHAR2 50 LAKE_ALIAS_1 is the first alias name for the lake, if applicable, e.g., Blue Lake
LAKE_ALIAS_2 LKNMALS2 VARCHAR2 50 LAKE_ALIAS_2 is the second alias name for the lake, if applicable, e.g., Muddy Lake #2
BATHYMAP_SOURCE BTHMAPSRC VARCHAR2 150 BATHYMAP_SOURCE is the source of the bathymetry information, e.g., Digital Bathymetric Mapping as part a standard BC lake inventory survey
BATHYMAP_PDF_URL_1 BTHPDFURL1 VARCHAR2 200 BATHYMAP_PDF_URL_1 is a web link to a PDF image of the lake bathymetric map sheet #1.
BATHYMAP_PDF_URL_2 BTHPDFURL2 VARCHAR2 200 BATHYMAP_PDF_URL_2 is a web link to a PDF image of the lake bathymetric map sheet #2.
BATHYMAP_PDF_URL_3 BTHPDFURL3 VARCHAR2 200 BATHYMAP_PDF_URL_3 is a web link to a PDF image of the lake bathymetric map sheet #3.
BATHYMAP_PDF_URL_4 BTHPDFURL4 VARCHAR2 200 BATHYMAP_PDF_URL_4 is a web link to a PDF image of the lake bathymetric map sheet #4.
LAKE_SURVEY_DATE LKSRYDT DATE 7 LAKE_SURVEY_DATE is the date the lake was surveyed.
LAKE_SURVEY_AGENCY LKSRYAGNY VARCHAR2 100 LAKE_SURVEY_AGENCY is the name of the agency responsible for the lake survey, e.g., BC Ministry of Environment, Knowledge Management Branch
LAKE_SURFACE_ELEVATION_M LKSFELEM NUMBER 19 LAKE_SURFACE_ELEVATION_M is the elevation of the lake in metres, e.g., 123.456
LAKE_SURFACE_AREA_SQM LKSFARSAQM NUMBER 19 LAKE_SURFACE_AREA_SQM is the surface area of the lake in square metres, e.g., 12345.678
LAKE_VOLUME_CUBM LKVMCUBM NUMBER 19 LAKE_VOLUME_CUBM is the volume of the lake in cubic metres, e.g., 1233456.788
LAKE_MEAN_DEPTH_M LKMNDPTM NUMBER 19 LAKE_MEAN_DEPTH_M is the mean lake depth in metres, e.g., 12.345
LAKE_MAX_DEPTH_M LKMXDPTM NUMBER 19 LAKE_MAX_DEPTH_M is the maximum lake depth in metres, e.g., 123.45
LAKE_SHORELINE_PERIMETER_M LKSHLPRTM NUMBER 19 LAKE_SHORELINE_PERIMETER_M is the perimeter of the lake shoreline in metres, e.g., 12345.678
LAKE_ISLANDS_PERIMETER_M LKISLPRTM NUMBER 19 LAKE_ISLANDS_PERIMETER_M is the perimeter of all islands in the lake in metres, e.g., 1234.567
LAKE_LITTORAL_AREA_SQM LKLTLARSQM NUMBER 19 LAKE_LITTORAL_AREA_SQM is the littoral area of the lake in square metres, e.g., 1234.567
LAKE_BENCHMARK_HEIGHT_M LKBNMKHTM NUMBER 19 LAKE_BENCHMARK_HEIGHT_M is the benchmark height for the lake in metres, e.g., 123.456
LAKE_MAP_SCALE LKMAPSCL VARCHAR2 12 LAKE_MAP_SCALE is the map scale for the lake images, e.g., 1:6000
LAKE_NTS50K_MAPSHEET LKN50KMPST VARCHAR2 10 LAKE_NTS50K_MAPSHEET is the National Topographic Series 1:50,000 map sheet number for the lake, e.g., 103F14
REASON_CREATED RSNCRTD VARCHAR2 500 REASON_CREATED is the reason this bathymetric map survey was conducted, e.g., Digital Bathymetric Mapping as part a standard BC lake inventory survey.
CREATION_PROCESS CRTNPRCS VARCHAR2 500 CREATION_PROCESS is how this bathymetric map was created, e.g., DualBeam Sonar/Chartplotter (Humminbird 798) with ReefMaster Bathymetry Mapping Software. A total of 68 East-West profiles were made, and an additional 28 East-West profiles at vicinity of Middle Vernon Creek. Oyama Canal consisted of 2 North-South profiles.
METHODOLOGY_REFERENCE_URL MTHREFURL VARCHAR2 200 METHODOLOGY_REFERENCE_URL is the web link to the methodology reference.
LAKE_STATISTICS_COMMENTS LKSTCCMNT VARCHAR2 600 LAKE_STATISTICS_COMMENTS are any comments on file for this lake survey, e.g., The values for the Lake Statistics fields were derived from post-processing digitally captured georeferenced echo sounding point locations.
KNOWN_LIMITATIONS KNNLIMITS VARCHAR2 600 KNOWN_LIMITATIONS are any known limitations to the survey information, e.g., This digital bathymetric map is not an exact representation of the source hardcopy bathymetric map from which it was derived. Some source depth contours may have been omitted to produce a more simplified or generalized version for specific fisheries management objectives. The source bathymap lake surface area and perimeter values may differ from the corresponding values calculated from the derivative digital product.
DISCLAIMER DSCLMR VARCHAR2 500 DISCLAIMER is the standard bathymetric map disclaimer, e.g., DO NOT USE THIS MAP FOR NAVIGATIONAL PURPOSES. This map may not reflect current conditions. Uncharted hazards may exist.
FEATURE_AREA_SQM FEAT_AREA NUMBER 19 FEATURE_AREA_SQM is the system calculated area of a two-dimensional polygon in square meters.
FEATURE_LENGTH_M FEAT_LEN NUMBER 19 FEATURE_LENGTH_M is the system calculated length or perimeter of a geometry in meters.
SHAPE SHAPE SDO_GEOMETRY 1 SHAPE is the column used to reference the spatial coordinates defining the feature.
OBJECTID OBJECTID NUMBER 38 OBJECTID is a column required by spatial layers that interact with ESRI ArcSDE. It is populated with unique values automatically by SDE.
SE_ANNO_CAD_DATA ANNO_CAD BLOB 4000 SE_ANNO_CAD_DATA is a binary column used by spatial tools to store annotation, curve features and CAD data when using the SDO_GEOMETRY storage data type.

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