We update large portions of our aerial imagery every year to keep up with demand for new data, especially in suburban areas where land development is taking place. In the built environment, the imagery will be different every single year, so it’s worth the effort to fly the same areas over and over.
The same is true for many types of “cultural” features such property line boundaries. Not every parcel changes every year, but within our large database covering all of Ontario, enough parcels change to need scheduled updates to maintain the relevance of the information a few times a year.
Not so, however, with other types of mapping. One of our most popular data products is elevation mapping which was produced in 2002. Since our DEM and contour mapping is looking at bare earth topography, and the lay of the land doesn’t generally change, there’s no reason to update the data based solely on its age.
There are a few exceptions. Activities that change the landscape such as mining, dam building, and urban expansion would require an updated map if those activities took place at your area of interest since the DEM was produced in 2002.