This week we created a map of possible campsite locations within the De Soto National Forest while being introduced to buffering and overlaying. These tools are commonly used, and are key to the process of answering questions about locations using specific criteria.
Buffering was used to find areas which satisfied two criteria for possible campsites - being within a certain distance from water features and roads. A distance of 300m was set as the buffer for roads, 150m for lakes, and 500m for rivers.
Overlays were used to join layers using one of six possible tools. The "Union" tool was used to join the two buffered layers from the previous step. This created a new layer showing areas which were within both the road buffer area and the water buffer layers.
The next step was to exclude conservation land. This was done by using the overlay tool "Erase", which selected particular areas to remove from the "possible campsites" layer. This was a multipart layer which we converted to a singlepart layer so that individual records could be accessed and manipulated within the Attribute Table. In the lab, we looked at the attribute "Area" to see which possible campsites had the largest and smallest area. The total area in square meters was also calculated.
These two tools are clearly very powerful and useful in a large variety of situations, in many industries and occupations. I'm excited to explore ways in which they are used in archaeology.
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