RASTER DATA - SITE SELECTION
Problem
Raster data can be used for site selection purposes. In this exercise, I needed to determine optimal sites in the San Diego area for vineyards. The elements that were necessary to take into account included soil, climate, elevation, slope, and aspect, although there are many other factors contributing to optimal vineyard growing conditions.
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Analysis Procedures
To conduct this analysis, I used the data provided in the ESRI course. This data included elevation, highways, and other layers, which were used to calculate the other required parameters. I first used the elevation raster to calculate aspect using the Aspect tool. Next, I used the Slope tool to calculate the slope from the elevation raster. I used the Euclidean Distance tool to calculate the distance of sites from highways, because vineyard sites should be close to highways for customer convenience. The optimal distance was considered to be within 1 mile of highways. Next, I used the Reclassify tool to reclassify the aspect and distance to highway rasters for ease of analysis. Lastly, I used the Weighted Overlay tool to determine suitable vineyard sites based 30% on optimal slope, 20% on the distance to highways, and 50% on aspect.
Figure 1. Diagram of methods.
Results
Figure 2. Aspect derived from elevation.
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Figure 3. Reclassified aspect.
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Figure 4. Slope raster.
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Figure 5. Distance to highways.
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Application & Reflection
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Problem Description: This procedure for site selection would be extremely applicable to my research, where I am looking for specific conditions under which to induce nutrient deficiencies in crops. For instance, I am looking for well drained land that is relatively flat with sandy soils and low soil nutrient content.
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Data Needed: The data needed for this analysis include soil series data, elevation, and flooding data.
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Analysis Procedures: First, the elevation could be used to derive slope and aspect rasters. Next, the soils series raster could be queried to only include sandy soil types. The flood map could also be reclassified to a scale where low flooding risk is more desirable. Lastly, the Weighted Overlay tool could be used to pick the optimal research site based on the aforementioned criteria.