Lab 10

(undergraduates only)

You work for an environmental nonprofit that is interested in how the Healthy Forests Restoration Act is being implemented. Specifically, they want to know if forest thinning projects are actually located near at-risk communities. Your director heard you are taking a GIS course and has asked you to come up with some preliminary information about which Oregon counties and cities are most at risk from forest fires, and who manages the forests that are most prone to fire. You have the following datasets that are available to the public:

City Limits

Counties

Land Management

Vegetation

Oregon Fires

The dataset for fires only covers the years 1988 through 1992. Although it is not up to date, it will have to do for preliminary analysis.

Specifically, you need to answer the following questions.

1. Create a forests layer from the vegetation layer. (In the vegetation layer the field DOM_CODE contains general codes for vegetation types. Consider the following codes forest land: 4, 45, 47, 49, 50-59, 60-66). List the top five forest types by area.

2. Now find the five forest types that had the largest sum total of acres burned from 1988-1992. (In the Oregon Fires dataset, the field FINAL_SIZE tells you how many acres were burned in each fire.) Call these at-risk forest types.

3. Use the land management layer to find out who manages the most area of the at-risk forest types. Who manages the second-most? (the field OWNER tells you who manages each feature.) Approximately what percentage of the at-risk forest types is managed by these two owners.

4. Find which cities are within 5 miles of the at-risk forest types. Call these at-risk cities and report them in a table.

5. Find which county has the most at-risk cities.

6. Finally, make a multivariate map that shows both the frequency (count) and the total (sum) final size of fires for each county on the same map. You can do this by copying the layer you are interested in mapping and pasting it into the same dataframe. This gives you two layers to symbolize at the same time.

Start by downloading the file Lab10.zip and unzip it. Start ArcMap, open a new empty map, and add all the datasets. Use the following analysis techniques/tools (not necessarily in this order): Select by Attributes, Select by Location, Spatial Join, Export Data, Calculate Areas, Dissolve, Intersect, Identity. Make sure you write a description of what tool(s) you used to answer each question.

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