Topographic maps on a scale of 1/20,000

**Note that topographic maps at a scale of 1/20,000 are no longer updated. For the latest update date, see the [metadata] (ftp://transfert.mern.gouv.qc.ca/public/diffusion/RGQ/Documentation/BDTQ/Metadonnees_Topo-20K.xls). The reference cartographic data is now constituted according to a continuous information layer approach: **

• [AQNetwork+] (https://www.donneesquebec.ca/recherche/fr/dataset/adresses-quebec)

• [Quebec Hydrographic Network Geobase (GRHQ)] (https://www.donneesquebec.ca/recherche/dataset/grhq)

• [Administrative divisions on a scale of 1/20,000 (SDA)] (https://www.donneesquebec.ca/recherche/fr/dataset/decoupages-administratifs)

• [Regional Coherent Hydro Digital Terrain Models (RTM)] (https://www.donneesquebec.ca/recherche/fr/dataset/modeles-numerique-de-terrain-hydro-coherents-a-l-echelle-regionale)

• [Quebec framework for buildings] (https://www.donneesquebec.ca/recherche/dataset/referentiel_bati)

Topographic maps at a scale of 1/20,000 are the official cartographic base of the Government of Quebec.

They cover almost all of the territory south of the 52nd parallel.

The data is extracted from aerial photographs at a scale of 1:40,000 taken at an altitude of 6,300 meters.

They offer an accuracy of approximately four meters in planimetry. In hypsometry, it is about two meters for dimensional points and about five meters for level curves.

Each file covers an area of approximately 250 km2.

The main components are:

• Hydrography (lakes, rivers, streams, swamps, etc.).

• Vegetation (forests, peatlands, nurseries, orchards, etc.).

• The constructions of man:

• transport infrastructure (roads, bridges, airports, etc.);

• buildings (mobile homes, silos, greenhouses, etc.);

• equipment (docks, electrical power transmission lines, surface tanks, etc.);

• designated areas (golf courses, loan benches, etc.)

• The relief (the level curves are generally at an equidistance of ten meters and, in some cases, they can vary between eight and twenty meters).This third party metadata element was translated using an automated translation tool (Amazon Translate).