GIS II: Lab 8- Raster Modeling

Goal and Background

The purpose of this lab was to learn various raster geoprocessing tools in order to build models for sand mining sustainability and sand mining impacts of environmental and culturals risks.  The modeling took place in Trempealeau County, Wisconsin.  The main outcomes of this project include:

• Building a sand mine suitability model
• Build a sand mining risk model
• Overlay the results of the two models to find the best locations for sand mining with minimal environmental and community impact.

Methods

Suitability for mining

1. Generate a spatial data layer to meet geologic criteria 

2. Generate a spatial data layer to meet land use land cover criteria 

3. Generate a spatial data layer to meet distance to railroads criteria 

4. Generate a spatial data layer to meet the slope criteria 

5. Generate a spatial data layer to meet the water-table depth criteria 

6. Combine the five criteria into a suitability index model 

7. Exclude the non-suitable land cover types 

The first part of the lab had us create a mine suitability model based on watershed, land cover, distance to railroad, geology, and slope of Trempeaulau county.  Below in Figure 1 is my model I created in order to produce the results in Figure 2.  Each of these required me to reclass and project the rasters.  This was a difficult process, but ultimately helped me better understand model builder and these tools I used many times throughout the lab.

Figure 1: Model used to create Mine suitability model.

Figure 2: Mine Suitability model.

I also created a table  below in Figure 3 of the layers I mapped in order to give a better understanding of the map.

Figure 3: Suitability layer descriptions.

Risk for mining

8. Generate a spatial data layer to measure impact to streams
9. Generate a spatial data layer to measure impact to prime farmland
10. Generate a spatial data layer to measure impact to residential or populated areas
11. Generate a spatial data layer to measure impact to schools
12. Generate a spatial data layer to measure impact on one variable of your choice
13. Combine the factors into a risk model
14. Examine the results in proximity to prime recreational areas

The second part of this lab required us to create a suiltability risk model for these potential new mines.  I once again created the individual layers using model builder.  The risk factors that were mapped were farmland, residential areas, school areas, wildlife areas, and streams.  I ran into less problems in this section but that doesn't mean I didn't have any.  Below in Figure 4 is my model that created my mine impact model in Figure 5.

Figure 4: Model to create mine impact model.

Figure 5: Mine Impact model.

I created another table in Figure 6 in order to give a better understanding of how I mapped these layers.

Figure 6: Mine risk layer descriptions.

Results and Discussion

The optimal locations for these potential mines have to take a lot into consideration.  There are environmental and health risks that many don't realize.  I think it would be interesting to see what the true suitability model looks like of this area or a different area.