User guide
This guide explains how to use the Flood Map Viewer.
Prerequisites
To access the Flood Map Viewer, you should use the latest version of one of the following browsers:
Optionally, if you want to open the downloaded files (full or clipped), a Geographic Information System (GIS) processing software should be used. The recommended software is the free, open-source Quantum GIS (QGIS):
Landing page
The landing page will show the main options of the Flood Map Viewer:
- Maps: Visualization of flood and complementary maps
- Learn more: Methodology used to produce the flood maps
- Download: Download page for the maps and other files
- User guide: This document
Explore the maps
The initial page will show a map of Canada using Google Imagery (a hybrid satellite and Google streets maps) as the base layer, similar to the following figure.
The main map page has the following controls that you can use:
General and Current and Future Conditions Flood maps
When you open the Map page (Explore the maps menu item), three categories of overlaying maps are available:
Each of the overlay maps categories is briefly described as follows:
1. General maps
This option presents the following overlay maps that are available for selection and briefly described:- Canada DEM: Digital Elevation Model (DEM) for Canada
- Canada High Res DEM: A higher resolution DEM of Canada
- Drainage basin Drainage basins of Canada
- Postal Codes: Boundaries of the Postal Codes of Canada
Multiple layers can be selected to be overlayed with the flood maps. To add a layer to the map, click and select the desired option, and to remove the layer from the map, click again to unselect the layer.
2. Current conditions
This option allows you to select one of the flood maps created based on current conditions. Only one flood map can be selected at a time. To remove the selected layer from the map, choose the None option from the list.
The available map options are the following:
Please review the Methodology section of the "Learn more" menu for a detailed explanation of map versions. Hovering over the map number shows a reference to the map type. When you select a map, for example, H25 (25 yr, 1980 – 2019 CMIP6 ensemble), the flood water depth information is presented on the screen as one layer.
The corresponding Legend menus explain the colour shades of the flood maps and DEMs. In addition to the visual information, the user can obtain detailed information by selecting a location on the map. The Info box (as shown below) provides geographic coordinates of the chosen location; surface elevation (if DEM layer is loaded); and flood map and water depth (if the flood map layer is loaded).
3. Future conditions flood maps
This option allows you to select one of the flood maps created based on future conditions (considering climate change). Only one flood map can be viewed at a time. To remove a flood map, select the None option from the menu.
The available map options are the following:
For information on the map version, please check the Methodology section under Learn more.
Hovering over the map number will also show a map type.
Base maps and transparency
There are two options of base maps to choose from:
Open Street Maps
OpenStreetMap is a map of the world, created by volunteers and free to use under an open licence. https://www.openstreetmap.org/.
Google Imagery
Google hybrid satellite and streets static tiled layer.
The base map selection can be made from the Base layer box at the bottom-right corner. Your selection will be highlighted in blue, and the base maps will reflect the selection.
One additional functionality is provided by the transparency bar. It allows you to set the level of transparency for the overlaying maps (from 0: no transparency to 100: fully transparent).
Legends
The Legend helps to understand the colour shades for the two main types of layers:
Water Level: each colour represents a flood depth from a light blue for lower levels to a darker shade of blue for higher levels.
DEM: the terrain elevation is represented by a colour-ramp version from orange (minimum value) to blue (maximum value) and green (in between).
Exporting, clipping and downloading
These functionalities allow you to export visible areas of the map, define a clipping area and download full and clipped maps.
Exporting and downloading
The following buttons allow the export (create a screenshot of the visible map area and all visible layers, and access the download page, respectively).
Clipping
The clipping functionality allows you to select a region of interest to zoom in and download reduced (clipped) map layers. The buttons located on the top right are:
- Rectangle button: create the clipping region
- Edit button: edit, change and move the existing clipping area
- Delete button: remove the clipping area
The list of buttons described is shown on the Map page as follows
Once a clipping area has been selected, a region (rectangle) is displayed to indicate your selection.
When editing a clipping area, dashed lines are shown, and the corners and center point are highlighted.
The Delete button allows removing an existing clipping area by using the Clear all option or clicking on the selected area. Save will confirm the removal and Cancel will undo your action.
Downloading files
The download button will take you to a list of files available for download. The first option is a complete file of each layer (Full file) that is compressed with 7-Zip (.7z extension) and, if a clipping area was defined on the map, a Clipped file option will be available.
We recommend installing 7-Zip to decompress and open the Full files. 7-Zip is free open-source software. You can use 7-Zip on any computer, including computers in commercial organizations without registration or payment.