Assignment 3: Site suitability analysis for wind power subsidies

ESM 263 (Frew), Winter 2017

Due at 8am on Tuesday, 28 February 2017

NOTE: This is a complicated assignment! (The next one will be even more so.) Read it through, carefully, all the way to the end, before you start working on it!


  1. Work through tutorials.
  2. Perform a suitability analysis, and produce a model and results data.
  3. Design a map to communicate your results.
  4. Submit your work to course website.


This assignment is worth 15 points—5 points each for your map, model, and data, awarded according to the evaluation rubric.


The Energy Division from the Planning & Development office of Santa Barbara County seeks your advice on wind energy. They have received a grant to seed small-scale wind energy production by subsidizing WES 250 kW turbines for installation within mainland Santa Barbara County. These turbines operate at 30 to 50 meters in height, and require minimum wind speeds of 6 m sec-1 for optimal power generation (roughly, 300 W m-2 in wind power density). They want a ranked list of 10 potential sites, each with at least 4 contiguous hectares, that meet their suitability requirements, written as follows:

Available data

The following data come from a variety of sources, and are available in the HW3.gdb geodatabase. Except where indicated, we've projected these data into NAD83 California (Teale) Albers and clipped them to the Santa Barbara County mainland.

Remember, once you've added a layer to ArcMap, you can view its metadata by right-clicking on the layer in the table of contents and selecting Data→View Item Description....

Task 1: Tutorials

Work through Law & Collins Chapters 8 (Classifying features) and 18d (Running tools in a model).

Work through the online ModelBuilder tutorial.

Optionally, you may work through the ArcGIS Spatial Analyst tutorial. It walks through a suitability analysis using Model Builder in "Exercise 3: Finding a site for a new school."

Task 2:  Suitability analysis

Use Model Builder and ArcToolbox to implement a binary model that produces a suitability raster where each cell indicates whether that area satisfies all the provided constraints. Use the masking technique for your rasters—that is, 1 = "included in solution" and NoData = "excluded from solution."

Figures 1–6 show the specific ArcToolbox tools and data flow necessary at each step to implement your model. These figures are separate for clarity purposes only. You will implement all steps together in a single model.

Figure 1: Computing Wind mask using Reclassify.

Figure 2: Computing the Roads mask using Project, Euclidean Distance and Reclassify.

Figure 3: Computing the Airports mask using Euclidean Distance and Reclassify.

Figure 4: Computing the Urban mask using Union, Euclidean Distance, and Reclassify.

Figure 5: Computing the Fire mask using Select, Union, and Erase.

Figure 6: Computing the Public mask using Select, Project, and Erase.

Figure 7: Computing the suitability raster using Extract by Mask

Set your model properties as follows:

When working in Model Builder, you should build your model using an iterative process; i.e., one tool at a time:

  1. Find the tool you need in ArcToolbox.
  2. Drag the tool into your model to add it (Yellow box).
  3. Rename the tool's output data as appropriate (Green bubbles).
  4. Drag any data you need for the tool into your model (Blue bubbles).
  5. Connect the tool to the required input data as appropriate.
  6. Configure the tool as appropriate.
  7. Run the tool.
  8. Mark the output data with "Add to display" to view in ArcMap. Did it work as expected?
  9. Repeat until all steps are in your model.

Once your suitability raster is ready, your final step is to interpret your results by identifying the 10 most suitable sites, ranked by most contiguous area.

Task 3: Map results

Design a map that communicates your results, and clearly identifies your 10 most suitable sites.

Task 4: Turn in your work

You will upload three files: your map, your model, and your results data:

  1.  Map: Export your map as a PNG image (use options of 300dpi and 8-bit color palette), and name it HW3Lastname_map.png
  2. Model: organize and name your processes and data to clearly describe your model—assume that your model graphic will be an important figure in a technical report. Export your model as a graphic: in the Model Builder editor, select the Model→Export→To Graphic... menu item. Use the following options:

    Figure 8: Exporting Model Builder model to graphic as PNG file.
    Don't worry if your height and width are different than the ones shown here (lower right, greyed out).

  3. Results Data:
    1. Create a new File Geodatabase (using the Create File GDB tool) to hold your results data. Name it Results.gdb
    2. Export your suitability raster into your Results.gdb geodatabase as a raster named Suitable. You needn't include any attributes for these data—the raster itself is sufficient. (The Example.gdb geodatabase is an example of how to do this.)
    3. Use ArcCatalog to enter appropriate metadata for the Summary (Purpose), Description (Abstract), and Credits fields in the Overview→Item Description section.
    4. Create a 7-Zip file of your geodatabase named Results.gdb.7z
      • In Windows Explorer, right-click on your Results.gdb folder, then select 7-Zip→Add to "Results.gdb.7z"
    5. Rename your 7z file to HW3Lastname.gdb.7z
      • NOTE: This naming convention is different from that used in HW1 and HW2!
  4. Upload your three files to the course website:
    1. HW3Lastname_map.png
    2. HW3Lastname_model.png
    3. HW3Lastname.gdb.7z

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