Basemap Layers



Basemap Layers
Development of a Detailed
Basemap and Model Surface to
Support Sediment Remediation of
Esquimalt Harbour
Challenges of Reconciling Datasets with Multiple Users
Presentation Outline
1.  Project Background
EHRP Project Team
Project Setting
Project Sites
Mapping Resources
Basemap Definition
Basemap Objectives
Data Management
Elevation Model
•  Part of the Esquimalt Harbour Remediation Project (EHRP)
•  Complex multi-year project to address sediment contamination
within one of Canada’s oldest Naval ports.
•  Current in Options Analysis phase, base map required to
generate cost estimates.
•  SNC-Lavalin tasked to provide and maintain project basemap
EHRP Project Team
•  EHRP client team:
Department of National Defence (DND);
Defence Construction Canada (DCC);
Public Works and Government Services Canada (PWGSC);
•  EHRP consultant groups and engineers:
SNC-Lavalin Inc., E&W
Anchor QEA, LLC.
SLR Consulting Canada Ltd.
Klohn Crippen Berger Ltd.
Golder Associates Ltd.
F&M Management Ltd.
Project Setting
Esquimalt Harbour is home to the
Canadian Forces Pacific Naval Fleet
and has been used as a Navy facility
since 1855.
CFB Esquimalt has 5 properties
bordering Esquimalt Harbour
(Dockyard, Signal Hill, Yarrows,
Naden, Colwood).
Also bordering the harbour are
first nations reserves,
residential, commercial, and
parkland properties.
Project Setting (Cont’d)
•  The harbour is a naturally sheltered body of water
covering 354 hectares.
•  The harbour ranges in depth up to 16 m and the
shoreline generally consists of a rocky shoreline.
•  The harbour is home to many marine species of
flora and fuana and is a busy port with vessel
•  Numerous jetties, wharves, and docks are present
•  Ship maintenance has been conducted at the dry
docks and shipyards for since before 1893.
Project Sites
F/G Jetty
D Jetty
Lang Cove
A/B Jetty
Y Jetty
C Jetty / ML Floats
Mapping Resources
•  Mapping data and resources for Esquimalt Harbour:
•  DND Geomatics Department and Base Engineering
•  Previous projects and reports (provided by DND)
•  Canadian Hydrographic Service – Bathymetry and Nautical
•  Capital Regional District – Regional Community Atlas
•  Aerial Photographs
•  NRC National Topographic System for upland areas
•  Esquimalt Harbour Sediment Quality Database
Basemap Definition
What is the basemap?
“A series of data packages containing various data layers that
can be used as a base template for engineering and design
purposes.” Designed for use by any of the EHRP team at any
The basemap is not,
“Just a map.” It cannot be viewed as a whole and should be
viewed as data, not a single document.
Basemap Objectives
•  To present the most accurate graphical data, as possible,
according to project objectives
•  Basemap data designed to allow users to confidently use
graphical data for the planning, design, and engineering of
sediment remediation.
•  The basemap must be kept up-to-date and available to all users
at a central location.
•  Basemap data designed for all EHRP user groups including
federal government clients, consultants, and engineers.
•  Basemap must be compatible for other DND departments, for
other future DND projects, and to other consultants or
Whenever multiple parties are working on a project, there arise
issues of version control, accuracy, reliability and management of
documents and data between the parties.
Basemap Challenges
•  To start, a number of files were collected,
which included a number of different
layers. Some of the layers were obviously
different, whereas some were only subtly
different (slightly different versions)
•  There are a variety of approaches to
managing different data-sets between
multiple parties. Some larger systems are
based on complex database interactions.
Documents Vs. Data
Document Document Data Data Standalone presenta1on Can be mul1ple “correct” versions Not intended for presenta1on Not typically “styled” for presenta1on Final Version O=en includes data representa1on No “final” version Doesn’t need to look good Easily edited Only one “correct” version Building the Basemap
•  The common platform required by the team was AutoCAD Map/
Civil3D 2012, which use the AutoCAD 2010 *.dwg format.
•  The Basemap layers are intended for use in each of the team
members respective figures, rather than as a stand alone figure.
In this respect, they are treated more like data than documents.
•  To keep the file sizes to reasonable levels, and make it easier to
find/work with, the requisite data, the layers were split into
different packages.
•  DND CAD/BIM Standards (CETO C-98-002-CAD) compliant
layer names, line types etc. should make it relatively seamless
to insert these data packages into existing figures and
Basemap Layers
•  The basemap is separated out into separate CAD files, which
contain groups of layers:
Property and Lease
•  Currently Elevation data is stored as *.las files and shape files
as *.dwg was found to be an inefficient format for the volume of
data. Elevation data is discussed near the end.
Maintaining the Basemap
Error Discovered New Data Received Other Reason to Update Base? Files Uploaded as Needed Layer Note Updated AND/OR Document Note Modified Change Made and Note and Document Updated Shoreline
P_H_Shoreline Probably the “best”, but limited in extent Canadian Hydrographic Services Low Water Mark Source File with mul1ple shorelines that don’t match, and don’t even cover the same area. Canadian Hydrographic Services High Water Mark ELEVATION MODEL
One of the risks identified to project planning is related to the
accuracy and quality of surfaces used to estimate volumes of
material needing to be managed. With modern side-scan sonar,
and LiDAR technologies, this risk could be mitigated with an
increase in data quality.
A Question of Datum
The vertical datum used on the project was decided to be “Chart Datum”. Which
represents the approximate average low tide level. Typical geodetic elevation
represents approximate mean sea level. The agreed upon Chart Datum 0
elevation for the project is equivalent to -1.89m for the project area.
Chart Datum Eleva1on 1.89m Chart Datum Eleva1on 0m CVD28 (Geode1c) Eleva1on 0m CVD28 (Geode1c) Eleva1on -­‐1.89m New Data Collection
•  New bathymetry and elevation data was collected by two
Multibeam side scan sonar – by PWGSC
Aerial LiDAR survey at low tide – by Terra Remote Sensing
Data Results
•  High resolution LiDAR and Side
Scan Sonar data has created a
data-rich elevation model.
•  Compared to soundings and
topographic surveys the data
rich, sensor driven data
provides for a reduced risk.
Graphical Presentation
Combined Elevation Surface Layer
Upland Surface
Data Noise
Bathymetry Surface
Graphical Presentation
Combined Elevation Surface Layer
Non-Ground Class
Water Class Data
Ground Class Data
Data Comparison
•  There is a fairly dramatic difference in the resolution of historical
sounding data, and the side-scan sonar data.
•  The diffence in resolution can cause substantial under/over
estimations of volume, as what appears to be a subtly rise or dip
between data points may be a substantial volume.
Data Gaps
Airphoto Draped over Ground Elevations
Surface Elevation Data Gaps:
NonGround Points over Ground Surface
•  A small data gap remains in the surface elevation layer between
Data the bathymetry and the upland surface in the intertidal zone
•  The results indicate that the slope between the available data
points is negligable
•  No new data collection is recommended and future data
collection would mostly be required to monitor changes due to
season and erosion/deposition, or to confirm remediation
What’s Next
•  Describe what the next steps would be for the basemap
Continue to update layers with as data becomes available
Add elevation data into feature layers (to create a better 3D model
of structures)
Help consultant teams use basemap to develop remediation design
Evaluate CVD2013 datum and it’s comparison to the agreed upon
Chart Datum
Consider using data to support management approaches (i.e. leave
it and monitor the sediment elevations to ensure that there is a net
accumulation to limit bio-availability)
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