Using CanVec from Natural Resources Canada?

Question

It has now been a little over 3 years since Natural Resources Canada released CanVec, a national coast to coast to coast spatial dataset at 1:50,000 or better nominal scale. In the interverning time there have been several updates, we now sit at Edition 6, and there are scheduled updates every 6 months, indefinitely.

Canvec replaces the National Topographic Database (NTDB) which was both expensive, ~$240 per NTS tile if memory serves, and definitely not libre. With the NTDB we had to pay royalties for every map that went to another party, even if we gave it away. The royalty was reasonable, on the order of 25 cents each, but we had to pay in advance, in $5,000 chunks, with a minimum of $8,000.

Canvec is a well modelled internally consistent dataset of good quality, better than the NTDB, and it's FREE, both libre and gratis. What puzzles me, greatly, is the virtual silence online* about this fantastic resource. There is little chatter about Canvec. Perhaps this scale of data just not that relevant south of 60°N and you're using something different. Perhaps the naming conventions are so opaque that people just can't drum up the energy to figuring out what's what.

Where are the resources and tools to make using this stuff easier (or even possible)?

Answer 1

I use the CanVec offerings somewhat regularly in building teaching assignments for profs, but the data require a good amount of work to go from what's provided to what a novice GIS user (who may or may not actually be interested in GIS) can handle.

As an example, if I want to supply a layer of fire station points in our region as part of an assignment, the process is as follows:

• Download and extract the zip file for each of the 4 tiles that intersect our region (not CanVec's fault, the boundaries between tiles have to go somewhere)
• Look up in the documentation what the number is for the buildings and structures layer, and what the code is for fire stations
• Isolate the 8 shapefiles that have the information I need (1 polygon and 1 point layer for each tile)
• Merge the 4 polygon layers and the 4 point layers
• Select and export the features I need in each
• Convert the selected polygons to points
• Merge the two point layers I now have
• Remove the duplicated points, if any (there are sometimes features in the polygon and point layers that represent the same feature on the ground, this tends to bug me more than anything else)

That's a decent amount of processing to get what I need, but it's not hard and probably not more than what the average GIS professional has to do to wrangle their data.

That said, maybe the complexity of the data model scares people off (particularly the naming conventions, as the question mentioned). I think you can usually find what you're looking for in CanVec, as long as you know how to look and are willing to read the documentation.

The other (more anecdotal) thing is that in my experience, compared to NTDB, there are a lot more features categorized as "unknown" in CanVec. This sometimes includes features that were properly categorized in NTDB, but then became unknown in CanVec.

Answer 2

The CanVec dataset will be merged into the OpenStreetMap database, over the next 2 years (i estimate on how long it should take) http://wiki.openstreetmap.org/wiki/CanVec

For those interested im helping out, feel free to just ask on the OSM mailing list. (this link can be found on the CanVec wiki page) this website does not allow for more than 1 link.

And BTW the CanVec dataset is derived from multiple datasources, including GeoBase.

Answer 3

We use the Canvec WMS server on a regular basis for localized mapping, and love it. Simple to use, easy to access, free, well rendered and consistent (well free if you ignore the fact that it is supported by the taxpayer).

It works well in ArcGIS but I am having difficulties connecting to the data using the AutoCAD Map 2001 3D FDO.

Answer 4

I appreciate the link to CanVec. It's nice to know such a resource exists for Canada.

Nevertheless, there many unsung geographic data sources. For instance, while I love US NAIP, I rarely express my appreciation. Rather, I celebrate every once in a while when the government makes its periodic update.

The GIS world is developing into a community rather than simply a user base. As part of the that evolution, celebrated datasets facilitate two-way communication and data flows. Vast governmental data sets remain invaluable, but they are unlikely to capture the imagination. If you would like a community to develop around a data source, package an associated visualization, create a few tools, and set up a forum. Leverage the two-way nature of the Internet and geospatial mindshare is much more likely to flow your direction.

Answer 5

My big problem with using CanVec was always the size of the data set, its structure and my lack of resources as an amateur/student. It's getting cheaper to get access to powerful computing facilities though (via Amazon, etc.)

Plus I built a little program that will efficiently extract one or more feature sets into PostGIS sql by matching the feature ID.

https://github.com/rskelly/canvecj

The next minor step is to allow piping the output directly into PostGIS.

Answer 6

Where are the resources and tools to make using this stuff easier (or even possible)?

Geogratis from Natural Resources Canada now has a web based data extraction tool @ http://geogratis.gc.ca/site/eng/extraction

It's really easy, I tried it the other day.

First you can just select your Clipping Area by either:

• Current map extent
• Predefined clipping area
  • NTS sheets
  • drainage areas
  • landsat footprints
• Custom Clipping Area
  • Draw a rectangle
  • Draw a polygon
  • Enter coordinates (two corner coords in DD)

Once you've got your area of interest, you can Select the Data but... You won't be able to select CanVec or "Topographic Data" until you are zoomed in close enough (it's scale based and greyed out until you zoom in).

If that limitation becomes a problem, they have a neatly (finally) organized site of the canvec themes for each province and theme at http://geogratis.gc.ca/site/eng/download available as either FileGDB (don't know what version, but I couldn't open them with gdal) or GML.

But the FileGDB you get from the data extraction tool does work in gdal - they are >= version 10 FileGDBs.

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There's a new QGIS plugin called NTS Data Download/MapSheetDownload that should help too. Now I can retire some of my scripts.

Answer 7

I have used CanVec, but also you might be competing in a sense with Geobase, which has a different focus obviously but still some overlap in the dataset. Especially if someone just wants roads and hydro features, Geobase data is laid out a bit more user-friendly, by province and hydrographic region, not on a tile basis for those features. DEMs of course are tiled in GeoBase.

Answer 8

I just started using CanVec 7 for a project, but seems like a great resource. I download the entire province in 11 thematically separated geodatabases,pretty easy. ftp://ftp2.cits.rncan.gc.ca/pub/canvec/province_fgdb/

However, figuring out what was actually in each geodatases was another issue. I end up finding a CanVec Symbolization Utility 1.1

Now my only issue is order the layers in the table of contents in an appropriate manner.

Answer 9

From a quick browse, it seems each zip file provides all data for a fairly small area. I'd much rather have access to files containing a single datatype (e.g. rail lines) for a larger area. (I'm looking purely for Shape files).

Answer 10

The reason that they are tiled is because it's a more modern version of the raster product - which is like the USGS quads in the US. Tiling is nice if you want to quickly get some data for an area. But a WMS server will give you the bounds you want, and the Canada fgdb or gml will give you all of it. I like this product. It'd be nice if the US did the same.

Answer 11

I find the CanVec Data to be extremely out of date, especially with airport/aeronautical information. This is the main reason why I haven't been using it.