Learning GIS with Colby Davidson: DEM's: Making Maps from Elevation Data!

This week was my favorite project because for the first time we got to work with 3D modeling using elevation/topographic data--also known as DEMs (Digital Elevation Models). I chose to use data from the San Francisco Bay Area because as a Northern California native I know how interesting the terrain is due to the large amounts of geologic activity there. At first using/making DEM's seemed like a daunting task, but the most difficult part of the entire lab was simply downloading the information from the USGS website. ArcMap/ArcScene were very user friendly and allowed for a lot of creative expression by being able to change the different elevation color schemes and backgrounds for the map. I used ArcMap to create several maps including the Shaded relief model which displays various elevation areas using a scale of light to dark purples. The slope model shows that there is a steep slope in the area as almost the entire map is colored in with the magenta representing the steepest grade of slope. The aspect model demonstrates which direction areas of the map are facing and shades them a certain color (indicated by the legend). Finally, the 3D model demonstrates how the area would look if one were looking in reality from a birds eye perspective. Below I've included the Raster Download Information which includes the decimal and geographic coordinates of the area in the Bay I mapped.

Raster Download Information for this portion of the San Francisco Bay Area:

Number of columns: 3707

Number of rows: 6427

Resolution in x direction: 0.000277777777796473 Degree

Resolution in y direction: 0.000277777777796473 Degree

Coordinate system ID Native: 4269

Top edge Native: 38.5024999993735 Degree

Bottom edge Native: 36.7172222214756 Degree

Left edge Native: -123.098611111054 Degree

Right edge Native: -122.068888888763 Degree

Coordinate system ID WGS84: 4326

Top edge WGS84: 38.5024999993735 Degree