Lens

LAYERS

Hotspots

Background

The Fire Monitoring, Mapping, and Modeling (Fire M3) System, an initiative by Natural Resources Canada, uses infrared satellite imagery provided by US National Oceanic and Atmospheric Administration (NOAA), the US National Atmospheric and Space Administration (NASA), and various other organizations to identify fires burning on the landscape. After some post-processing they publicly release daily hotspot maps for all of Canada. The Canadian Wildland Fire Information System (CWFIS) also provides the hotspots data through their datamart.

Interpretation

The hotspots are visualized in two ways. As coloured points on the map and as a histogram timeline. The colour profile uses D3's YlOrRd sequential interpolation. A sequential colour scheme is a continuous colour profile that transitions smoothly through shades between two colours, in our case yellow to red. We're using it to represent time within the selection window. So the deep red represents the most recent hotspot and yellow represents the oldest hotspot in the selection window. This means it's a relative value and does not represent an absolute fire intensity.

Fire M3 hotspot data © Canadian Forest Service. 2022. Canadian Wildland Fire Information System, Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, Alberta. http://cwfis.cfs.nrcan.gc.ca

Fire Perimeter Estimates

Background

The perimeter estimates are a secondary product that Natural Resources Canada creates using the M3 hotspots. The polygons approximate a fire perimeter using the outer bounds of the year-to-date hotspot data. These are separate from the official fire perimeters released by the BCWS.

Interpretation

The fire perimeters are an estimation only and therefore are less accurate than the official perimeters released by the BCWS. However, we do not have official fire perimeters for other provinces so these act as the best guess approximation for the rest of the country.

Fire perimeter estimate data © Canadian Forest Service. 2022. Canadian Wildland Fire Information System, Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, Alberta. http://cwfis.cfs.nrcan.gc.ca

Fire Perimeters

Background

The fire perimeters are created and released by BCWS (BC Wildfire Service) and represent the status of the current fire season. They include both active and inactive fires. They come from many operational sources and may vary in their update frequency. For this reason they may not represent the most up-to-date information given. However, they still roughly represent the current official status of a fire.

Interpretation

If you hover of the polygon it will give you some general purpose information about the fire

• Fire Number
• Status: Out of Control, Being Held, Under Control, Out
• Estimated fire size in hectares
• Track Date

The Track Date represents the date that the perimeter was initially tracked via GPS. It is not the same as the Last Updated or Discovered On attributes, which you'll find in the BCWS mobile app. The data source may get updated without the track itself changing.

Current fire perimeter data sourced from the BC Wildfire Service of the Government of British Columbia under terms of the Open Government License - British Columbia. Historical fire perimeters, pre-2023, contains information licensed under the Open Government License - Canada.

Evacuations

Background

The Evacuation Orders and Alerts produced by GeoBC is an aggregate of active orders and alerts issued by the Local Governments or First Nations. There are many different event types represented, not just for wildfire. For example you may also see alerts or orders for floods, landslides, infrastructure damage, avalanche, and many more.

Interpretation

The data that is presented on hover is, in order of appearance:

• ORDER_ALERT_STATUS: the current status of the even, e.g., Order, Alert, All Clear.
• ISSUING_AGENCY: The name of the agency that issued the event
• EVENT_NAME: the name assigned to the event
• DATE_MODIFIED: the date the record was last updated

Evacuation data sourced from GeoBC Branch of the Government of British Columbia under the terms of the Open Government License - British Columbia

Burn Severity

Background

The Burn Severity data is a combination of two datasets: Same Year and Historical. The Same Year data is actually considered an interim product of the Historical dataset. The Same Year data represents the most recent finished fire season. They are produced by the Inventory Branch (FAIB) using either Landsat-8, Landsat-9, or Sentinel-2 satellite imagery. It uses pre-season and post-season imagery to calculate the difference in reflectance. A higher change in reflectance indicates a greater degree of burn occurred. It classifies fires greater than 100 hectares into four severity classes: Unburned, Low, Medium, and High. Read a detailed description of the methodology.

Interpretation

The burn severity layer uses a categorical colour palette to clearly differentiate between classes, that has clear contrast with the hotspot palette.

* Unknown is a classification set by FAIB and there is no explicit information explaining what it means.

Burn severity data is sourced from the BC Data Catalogue under terms of the Open Government License - British Columbia.

INTERACTIONS

Hotspot Histogram

Year Selector

The year selection is primarily used to change the hotspot data.

• The Evacuations and Perimeter Estimates layers not bound to the year selection. They will ALWAYS show current data.
• The Burn Severity data is produced once a year at the end of the fire season. Therefore it will ALWAYS show the data from 2023.
• The Fire Perimeters are bound to the year selection, however, we currently only have data available for 2024.

Calendar Slider

This helps shrink or expand the date range. The right side of the X-axis is fixed to today. By using the slider you change the start date of the X-axis.

Show/hide past hotspots

The default behaviour is to only show the hotspots that are selected by the scrubber window. If you toggle this on then all the hotspots from the beginning of the year to the end date of your scrubber will be visible, however, all the hotspots outside of the selection window will be grey.

Timeline scrubber

The Y axis of histogram is an aggregation of all the hotspot counts in the visible map window per day. As you scrub across the timeline the hotspots visible on the map will update to reflect the fire state during that block of time.

Command Palette

A Command Palette is a user interface found in many software applications that allows users to quickly execute commands by typing them, without needing to use your mouse to navigate. It is triggered by typing ⌘K (on MacOS) or CTRL-K (on Windows). You can then type a command which will filter the available options. Once the command you want is highlighted you can hit Return or Enter to execute it. The up and down arrows can also be used to navigate. If you want to close the Command Palette hit Esc or re-execute ⌘K or CTRL-K.

The Command Palette is broken up into three different sections: Layers, Features, and User.

Under the Layers you find a list of the possible data you can display on the map.

The Features are additional interaction that can be performed. Show/hide past hotspots achieves the same outcome as the toggle button on the Hotspot Histogram. The Copy embed code will add a iframe html tag to your clipboard. The same functionality can be achieved using the Share button on the main map view.

The User section will display different things depending on whether you are logged in. Some of our layers require you to be a paid user. If you are not logged in then you will see Sign up for Lens Pro and Log in to Lens Pro. If you are logged in then you will see a Log out button.

If you click on the sign up option you will be redirected, in a new window tab, to a form you can complete to notify us that you would like to sign up for Lens Pro. Shortly after which a member of our team will reach out to you for further information. If you've already signed up but are not logged in you can click on the log in button and you will redirected to the login modal.

Layer Indicator

The layer indicators at the left side of the map view is another way to turn on and off the map data. This is a mouse-forward way of accomplishing the same effect as provided by the Command Palette. It is collapsed by default and only shows the layer icons. If you hover an individual icon the full layer name will unroll. If you want all the layer names to be fixed visible then you can click on the top layer icon. If you click on it again it will fold back to it's collapsed state.

Share

An html iframe tag is used to embed a document into another document. Use this code to render Lens directly in your web page! Click on the Share button to see the iframe code. Click COPY to copy it to your clipboard and then paste it directly into your own site.

Credits

To learn where we've sources our data and find licensing information you can click on Credits and Info in the footer. It will list the information relevant to the currently visible data. So if you're looking for a specific reference make sure you've toggled on that layer.

URL

Our URL is pretty long and ugly but it serves an important purpose. We've built Lens so that all the vital information is encoded in the URL. Practically what this means is that when you link to Lens you can ensure that your readers will be taken to the exact view you want. The selection window, the year, which layers are visible, the map extent and zoom level are all encoded in the URL ensuring view replicability.

How this works: the base url is https://lens.pathandfocus.com and then the rest of the information is in the query parameters, key-value pairs attached at the end of the URL following the ? symbol. The following are the keys we use and how to structure them if you want to adjust them manually. A note on the date time string: they are in ISO date time format using the UTF-8 character set. That being said, the dates are extremely forgiving. In UTF-8 %3A represents a colon :. However, if you create the URL yourself you can use a colon instead and then when you paste it into the browser, the colons will be automatically converted for you. If you want, you can actually take the time out entirely. In that case, it will be treat as the start of the day. The benefit of all of this is that you can greatly reduce the length of the URL and make it a lot more human-readable if you wish.

(A similar thing exists for the comma-separately lists used for the layers. In UTF-8 %2C represents a comma, so either you use %2C or you use a comma. Either way it will also be automatically converted for you).

This might sound a bit confusing but keep in mind you do not need to interact with these directly. The URL is updated automatically as you navigate and toggle things on and off within the site.

Query Parameters

startDate

This sets the oldest date (the left-hand side) of the selection window of the timeline scrubber.

Format: An ISO date-time string, eg. endDate=2023-09-20T21%3A59%3A59.999Z

endDate

This marks the most recent date (the right-hand side) of the selection window of the timeline scrubber.

Format: An ISO date-time string, eg. startDate=2023-08-20T06%3A00%3A00.021Z

minDate

This controls the calendar slider so the date that sets position 0 on the x-axis.

Format: An ISO date-time string, eg. minDate=2023-05-01T00%3A00%3A00.000Z

latitude

Represents the latitude of the centre point of the map view.

Latitude refers to how far north or south a point is from the Equator. Ranging from -90.0 to +90.0. Positive values indicate locations north of the Equator, while negative values indicate locations south of the Equator. For Canada we range from 41 in Southern Ontario to 83 in Northern Nunavut.

Format: Decimal degrees, eg. latitude=50.6745

longitude

Represents the longitude of the centre point of the map view.

Longitude refers to far east or west a point is from the Prime Meridian (an imaginary line running from the North Pole to the South Pole through Greenwich, England). It ranges from -180.0 to +180.0 where positive values indicate locations east of the Prime Meridian and negative values indicate locations west of the Prime Meridian. For Canada we range from approximately -141 to -52.

Format: Decimal degrees, eg. longitude=-120.3273

zoom

The smaller the number the more zoomed out you are. For instance 3 is approximately the zoom level of Canada, whereas 20 would be the zoom level of an individual house.

Format: Decimal number from 0 to 20, eg. zoom=3.5

layers

Indicates which layers an visible; if they are included in the list they are visible on the maps. The options are: hotspots, burn-severity, evacuations, fire-corridors, fire-perimeters, and perimeter-estimates.

Format: Comma-separated list, eg. layers=hotspots%2Cperimeters

pastHotspots

0 to have them turned off and 1 to have them turned on.

Format: Binary, eg. pastHotspots=1