GIS Data Layers

Different themes are often organized in geospatial mapping software as distinct layers of geographic information – buildings, water and electric lines, land use, hydrography, zoning, ecoregions, transportation, elevation, climate, and more. As shown in the graphic below, these layers can be overlaid in geospatial mapping software to discover overlapping features and complex relationships.

Source: Ontario County NY and USGS, public domain.

To explore some overlay maps, visit the Geography 224 (Cartography) course project gallery and find the poster presentation titled “Growing Pains”. Can you find examples of countries in Africa whose GDP seems to have grown with growing urbanization across the years mapped in this poster? Are there others where GDP seems to have stagnated or shrunk with growing urbanization?

Now visit the Vassar research project gallery and find the poster presentation about air quality in Poughkeepsie. Does there appear to be a relationship between the air quality metrics displayed and neighborhoods with higher proportions of young children or whose annual income is between $15,000 and $50,000?

The authors of the air quality poster explain in the discussion/conclusion section that they expected to find more poor air quality on the north side of Poughkeepsie due to its land use and vegetative cover. See if you can find these maps in the Poughkeepsie Natural Resource Inventory maps. Do you notice a difference in the pattern of land use and vegetative cover between the north and south sides of Poughkeepsie? Do the authors’ expectations make sense? How do you think land use and vegetative cover affect air quality?

>> 5) Earth-Based Reference Systems