The City of Vancouver’s maps, from archives to internet

In anticipation of International Map Year (August 2015–December 2016), the City of Vancouver Archives (CVA) has been digitizing its cartographic collection and making it available online, with the help of a grant from the BC History Digitization Program. In a talk at a fundraising event for the archives, digital conservator Sue Bigelow gave us a peek into the digitization process, and digital archivist Sharon Walz talked about the cartographic material they keep at the archives.

Map digitization at CVA

To digitize CVA’s map collection, Bigelow uses a rolling scanner that can accommodate material 54 inches wide. Before feeding the maps into the scanner face-up, she cleans the maps, repairs tears that might catch on the scanner, and flattens out folds as much as possible. She will sometimes use a plastic sleeve for especially delicate documents, but she showed us examples of scanning artifacts that can come from light reflecting off the sleeve and told us that “scanning is best done naked.”

A major milestone in this digitization project was the scanning of the 1912 Goad’s Atlas of the City of Vancouver and Surrounding Municipalities—a fire insurance plan that codes properties by their fire risk. “Digitization produces only an image,” said Bigelow, but researchers often need more. CVA, partnering with a geographic information system (GIS) company, stitched all 98 pages of the atlas together into a mosaic and rectified it so that the components all used the same geo-coordinate system. The Goad’s Atlas, along with other maps in the public domain or under City of Vancouver copyright, is available for viewing using VanMap, which provides hundreds of layers of detail, including zoning information and the location of sewer and water mains. The Goad’s files are also available in the city’s Open Data catalogue.

After the Goad’s Atlas was completed in May, the BC Developers’ Exchange helped convert the files into the Web Map Service standard so that it could be uploaded onto the Open Historical Map project, which aims to offer a publicly accessible history of the world via maps.

In November 2014, CVA was the only archives—and the only Canadians—to attend the international Moving Historical Geodata to the Web meeting. (Bigelow wrote about the meeting on the CVA blog.) That meeting showcased the potential of Map Warper, an web-based application the public can use to rectify and share maps. CVA will provide access to Map Warper; in exchange, researchers will do the work of rectifying, and the results will be made freely available. This arrangement is mutually beneficial, as the City of Vancouver doesn’t usually need rectified images.

For more information about the project, see Bigelow’s blog post about the digitization process and John Mackie’s article about the digitized Goad’s Atlas in the Vancouver Sun.

Cartographic holdings at CVA

The cartographic material at CVA, said Walz, is a mix of city records (~60%) and non-city records (~40%). Most of the maps are non-published manuscript maps—not like the maps you’d find at a map library. City-created cartographic records come from such departments as engineering or community services, and non-city records come from several different industries, including tourism, mapmaking, and resource extraction. Although CVA is now more selective and accepts only cartographic material about Vancouver, its holdings include a lot of maps from surrounding municipalities, because the city’s first archivist, Major J.S. Matthews, accepted a lot of non-Vancouver maps.

CVA’s cartographic holdings include more than just maps. They also include profiles, such as those produced in surveys, and aerial photographs (especially those on which map information has been overlain). Walz showed us the myriad functions maps can have—in promotional material or as business documents. People would often take existing printed maps and repurpose them to depict zoning, say, or electoral boundaries, and these maps, said Walz, “are fundamentally different from the base map.” CVA may have thousands of maps called “City of Vancouver,” but they all depict different things.

On the rhetorical power of the map, Walz explained that when looking at maps, we have to remember “the fourth dimension: the intention of the person who made it.” She quoted Mark Monmonier, author of How to Lie with Maps, saying, “Every map is a lie.” As projections of three-dimensional reality onto a two-dimensional surface, all maps distort reality in some way. Mapmakers will also impose their perspectives onto their maps, and many historical maps depict plans or aspirations that never came to fruition. But because they look scientific, people assume what’s on the map is (or was) what’s on the ground. “We try to take information from historical maps, but it’s not necessarily the information the map was trying to depict,” said Walz.

“Knowing why a map was made helps us understand the contents,” she said. “Knowing how a map was made can tell you if you should believe it.”