Word to the wise - this lab will take much more time than earlier labs, so plan for it.
Start by working through the first two exercises (45 pages) of the raster 'Quickstart Tutorial' that is available as a pdf on J:\geog303\lab7\. The data for this exercise is in J:\geog303\lab7\spatial\. This will provide you with an introduction to the Spatial Analyst extension - basically, ESRI's raster functionality. As always, copy the data down to your flash drive before working through the exercise.
On to the real work: you are responsible for determining a suitable site for a resort in Washington. The type of resort is up to you - it could be fishing, skiing, wildlife viewing, etc... Given that you have some control, you will have to determine some of the criteria - some basic criteria are detailed later in the lab. Read the entire lab before proceeding with the computer/non-computer work. Go to the J drive to get the data from the geog303\lab7\ras_lab\ folder.
The available datasets include: major cities, major roads, elevation, major rivers, Indian reservations, national parks, national recreation areas, railroads, and water bodies. A state/county boundary file is also included. Note, unless you have at least a gig of free space on your drive, work off the D:\ drive.
For your convenience, I have italicized all questions for which you
must write/hand in answers.
The set criteria include:
Prior to working on the computer, I would like you to hand sketch a flowchart detailing what you will do to ID your suitable sites. A portion of a flowchart is given below to give you some sort of idea what I'm looking for.
OK - you have now figured out what you need to do. Time to do it!
Open a new map in ArcGIS. Be sure the Spatial Analyst extension is checked (under tools, then extensions). Start by adding the county file.
Add the rest of the data.
DEM Questions
1. What is a DEM? (and don't just tell me what the acronym represents)
2. How many rows and columns are in the DEM you imported?
3. What is the cell size?
4. What are the 'pixel type' and 'pixel depth'? (this info can be found in a layer properties - source) What do those terms mean?5. What is the datum, projection, and coordinate system of the DEM
Now back to the design problem.
By now, you should have four well-defined criteria and a plan (flowchart) for analyzing them.
First, you need to select your input layers, identify the operations required and then obtain a result. Boolean operations will be used to determine the final solution.
Implementing a solution to the site selection problem:
1. To meet the basic guidelines, you will have to use the (raster-based) spatial analysis extension. Look at your handout for help performing spatial analysis. Start by setting the options in Spatial Analyst - very important. Very. (the extent will be your state shapefile and your output cell size as 500m. You can use this for all five of your criteria). When calculating straight line distance, do NOT set a max distance. This way, you get a 'distance from' layer which you can then query. Be thankful I just spent some time reprojecting all the layers that were in lat long. You cannot do a straight line distance calculation on a layer that is in a spherical coordinate system.
2. After you have completed the four criteria, recalculate the Reservation refuge distance theme again, but this time choose a cell size of 2000 m. What happens? 3000 m? After answering, delete the two extra wildlife themes (2000 and 3000 m resolutions).
3. You should now have 5 distance themes (for criteria 1,2,3, 4, and your own selection). Now you need to do some calculations.
4. Query the areas. Click the Spatial Analyst dropdown arrow and click 'Raster Calculator'. Double-click the layer you want to make a selection from and add it to the expression box. Use your criteria for selecting your location, be careful with the "<" and ">" symbols. The only time you will be using the "<" will be for finding something close to the roads.
5. Click 'Evaluate' to perform the calculation. The 'Raster Calculator' will be closed and the result displayed. Be sure to put all the criteria in the same equation. Take a look at what you got. The values that meet the equation's specification will be labeled '1', while those that don't will be '0'. Does your output make sense make sense? If not, go back through and look at your equation again. In other words, the results of your calculation should be that areas which meet ALL of your criteria have a value of "1" and all others "0".
6. What type of operation did you just perform?
7. You can see what areas you can potentially build on all the areas that are '1'. To make picking your area easier, make the '1' a bright color and make the '0' transparent in your legend editor. Turn off all of your 'distance to… layers to see the results.
Now you'll work with your DEM - turn off your calculations layer for the time
being.
1. First change the color scheme of your DEM since you will be printing these
out in color. Use one of the two 'Elevation' color schemes, right click on the
color ramp to see which ones are called elevation 1 and 2.
2. Now you need to compute a hillshade. The hillshade function is typically
used to create a shaded relief map from an elevation raster. The default azimuth
and altitude works well for graphical display.
3. Click the 'Spatial Analyst' dropdown arrow, point to 'Surface Analysis',
and click 'hillshade'.
4. Click the Input surface dropdown arrow and click the surface for which you
want to calculate hillshade.
5. Next, use your newly created hillshade to give your DEM theme depth. Click
and drag the DEM raster layer above the hillshade.
6. Click View, point to 'Toolbars' and click 'Effects'.
7. Click the 'Layer' dropdown arrow and click whatever you've named your DEM
file.
8. Click the 'Adjust Transparency button and move the scroll bar up to the desired
lever of transparency. You should now see the hillshade underneath the DEM raster
layer.
9. Now click on your cities shapefile and lakes shapefile, as well as your roads.
Move them around on your table of contents so that you can see them. Turn on
you 'calculations' layer to see the sites that met your four criteria.
10. Choose a site from the acceptable areas that you think would best serve
a suitable site for your resort. Should it be near a city? Lake? Mountains?
It's up to you. Remember, you cannot build in a National Park, or in the middle
of a lake, etc.... Check these sorts of things by zooming in on your potential
areas and turning layers on and off. You can tell what towns/lakes you're near
by going to the layer and labeling them, or use the identify button. Play around
a bit. Write a paragraph or so describing why you chose your final location.
11. Use you Drawing tools (bottom left corner of ArcGis) to select a point and
place it approximately where you'd like to build your resort.
12. Create a layout that details your chosen site and why you selected it. Make
sure your colors are nice - you will be printing your final map in color. Include
in your map both all suitable areas and your final location.
13. When you're happy with everything, export your map as a pdf file and get
it over to Kristen (either put it on the transfer drive or bring her your flash
drive). She'll print your final map in color.
14. Afterthought.... I want two final maps. One with only the hillshade to depict elevation; one with both the colored DEM and the hillshade to depict elevation. Everything else (the whole 'my final resort' bit) on both.
Hand in your final layout maps and the answers to all the questions (go back through this lab and look for italicized text - those are the questions I want answered).
Due date: Monday, 16 November 2009. Worth 6 points.