Mapping

GDES-396 spring 2019 (David Ramos, American University Design)
ramos@american.edu · office hours

Create a map that shows either storm surge risk areas or historic district boundaries in context. This project offers an introduction to spatial data, GISes, and cartographic tasks.

Work in QGIS, though you can (and perhaps should) move to Illustrator for typography and labels. For geography, look at a coastal city—preferably the District of Columbia, though you might be able to examine another city, with instructor permission.

First, create a base map, using data from DC Open Data, OpenStreetMap, or USGS. The map should show cultural and natural features, enough to let a reader understand the city—you have a choice about what to show, and what to emphasize, but you must provide several different layers.

Next, add either data showing the extent of Storm Surge Risk Areas or Historic Districts. (FEMA floodplain maps are also available, but they are more difficult to use and to interpret.)

Adjust the scale and size of your map, and the display of map features so that the floodplains or historic districts can coexist with the base map.

Specifications:

Data sources for the base map

OpenStreetMap

OpenStreetMap is a collaboratively-edited map of the world, with good accuracy and detail. The most usable data format, if you’re starting out, is probably the Geofabrik OSM data extracts. Features are coded; see the list of map Features on the OSM Wiki.

DC Open Data

The simplest approach involves pulling spatial data from DC Open Data. Highlights:

USGS

If you’re ambitious, you could incorporate data from the USGS via the National Map interface.

Aside about filter syntax

QGIS lets you filter features using SQL syntax. You don’t need to know SQL, though. Here are two examples of simple filters; the text would go into the “Specific filter expression” field of the Query Builder.

Let’s assume you’re working with OSM data via Geofabrik’s extracts. This code would select the roadways that are coded as “cycleway”:

"fclass" = 'cycleway'

And this would select the roadways that are coded as highways or main roads.

"fclass" IN ('motorway','primary','secondary')