Advanced GIS. Lab 3

Designing a Raster GIS solution

The goal of this is a basic, raster site selection analysis. In short, you pick a business (anything you want), define location criteria, and then, ultimately, a final location.

Read the whole lab before you get started. Tips abound. If you have questions about spatial analyst, ESRI has some help and a quick tutorial here. I highly recommend you at least read through everything on spatial analyst (left side links get you there).


  1. Decide what sort of business you are going to locate - ski resort, fishing resort, mountain biking, Wal Mart, McDonalds, etc. Anything is cool - you decide.
  2. Pick the area. Make sure the scale you are working at is appropriate for your particular project. One caveat - the area must NOT be in Washington State.
  3. Determine your criteria (as these will be data dependent, steps 3 and 4 should be done simultaneously). I want you to use at least 5 different criteria. They could be things like distance, slope, landuse type, zoning, etc... Note, not all need to be (or should be) distance criteria. Some could be attribute selections, etc (i.e. within a certain property ownership type - private, federal, state - however, you will need to convert anything vector to raster to use it in a raster calculator query. And yes, this is a raster lab, so your analyses must be in raster format. Remember to set your geoprocessing environments every single time you open arcMap to do some work.
  4. Get some data! See the below section for details about grabbing data. No more than 2 datasets may come from the same source (ie - you can get no more than two datasets from the USGS, two from the State DOT, etc). Which means your data must come from at least three different sites.
  5. Create 5 suitability maps - one for each criteria. Make sure they're reclassified such that values of 1 are not suitable, while values of 10 are most suitable. Note, you don't need to use every number between 1 and 10 - it will depend on your particular data.
  6. Determine weights for each of your criteria. Remember, the weights must range between 0 and 1, but sum to 1.
  7. Combine your 5 criteria maps and weights in raster calculator to generate a final suitability map. Pick your final site on this map.
  8. Add some geography to your criteria/suitability maps. Could be roads, rivers, cities... something appropriate to the scale of your area. I do NOT want to see just a bunch of colors - gimme some context!
  9. OK. In the end I want you to hand in
    1. 6 maps (in color) - one of each reclassified criteria map and your final, combined, site suitability map. Be sure to include your final site selection on the suitability map. Make sure you follow all proper cartographic procedures.
    2. A writeup which includes:
      1. a description of what you are trying to site
      2. For each criteria, include the data source and every step you used to get the final reclassified raster layer. Include what each suitability value (1-10) means. For example, a 10 might be slopes <2 degrees, a 5 slopes 2-4 degrees, and a 1 slopes over 4 degrees.
      3. A list of your weights
      4. A final paragraph or two which a) justifies your final site selection and escribes how you could make your analysis better (diff criteria, data, etc...)

Where do you get data? (note, these links may be a bit old - and certainly, this list is NOT exhaustive)

How do I import data?

Well, that depends on the data format. Let me go over a couple of options (once you get the data saved to your drive). First, take a look using Windows Explorer. If the unzip process made a bunch of folders, your data is probably in a ArcInfo Coverage (or GRID) format. If not, look at the filename extensions.

So. Main points to check

  1. importing the data. See above for the most common formats. Remember, Arc can read coverages, grids, shapefiles, and geodatabases. If you are fuzzy on this, refer to your lecture notes when I went over these.
  2. Projections/datums. Easiest thing to do here is to open the file into a blank, new ArcMap window. Then look at the coordinates at the bottom of the page and the properties of the layer. Make sure everything is in the same coordinate system/datum (UTM or State Plane). Bad things will happen if you use Lat/Long.
  3. Before you do anything, use ArcCatalog to make a copy of the data you downloaded. The chances are good you will screw something up, and you will want a nice, clean copy tucked away somewhere you can go back to, rather than having to redownload, import, etc.
  4. Remember that this is a lab. If you can't get a layer to work or can't find exactly what you need, dump it and look for it somewhere else or something different. Don't waste too much time on a single layer.

Generate your final maps in color (8.5x11) and get it to the lab TA to print (check his office hours). Don't forget the appropriate cartographic necessities. Don't forget the writeup either.

Worth 5 points.