GIS – Digital Maps, Space and Place

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For those who have the know-how on using it effectively (or the patience to figure it out), QGIS can be an extraordinarily useful tool for combining layers of data, geographic information, and images. Although the map below presents a clean, simple combination of all three, the process in making it was by no means easy.

In the example below, the base layer is geographic data contained in the shape files of buildings in Mecklenburg County (marked Davidson_buildings on the legend) to which I have added a georeferenced map of Davidson College’s campus dating from 1974. These two layers are interesting juxtapositions in of themselves especially for those who wish to conduct a historical comparison of a certain space. However, in this example, the map stretches beyond mere historical comparison and the combination of building shape files and the map of Davidson College’s campus becomes the background for the shape file data on the number of international students’ currently living in the dorms.

PA #3 Final MAP — QGIS Output Map: Background features a 1974 map of Davidson College campus. Data displays the number of international students’ housed in dorm.

While this QGIS map does not present a unique or insightful comment about the history of Davidson College or the composition of its student body, the map does exhibit the capabilities of the QGIS software and also provides insight into the difficulties that can arise when using this tool.

First, using QGIS, the user can georeference (i.e. embed geographic data points in the image) images and the latitude and longitude lines to align images, shape files and data. In the map above, I aligned the 1974 map of Davidson College visually with the building shape files; however, the latitude and longitude points were useful it that they connected the location of buildings with the data about dorms. Second, I combined the geographic information of the dorm data with the previous layers and formed a new shape file layer that is seen in the green/blue tinged dorms. Here, the shade of the color of the building represents how densely each dorm is populated with international students. As can be seen on the legend, the more international students living the dorm, the darker the shade; thus, the viewer is easily able to see that Sentelle has the most international students.

Although I stumbled a few times in the process of getting to this finished product (as can been seen in the wonky orientation of Knox’s polygon shape file and the frustrated file name “Output Hopeful”), the ultimate outcome is a clean, visually simplistic representation of both historical and numerical data and a testament to the useful possibilities of QGIS.

As you walk around the main quad of Davidson College it’s hard to distinguish which buildings are old, and which are new. The continuity of the architecture, with red bricks and white facing, gives the college a consistently quaint feel. Although it seems like each building has been here from the beginning, GIS can help determine which buildings actually have historical value, and which do not. Because historical value isn’t the only measure of value, I have also included my own personal value in this analysis (measured by weather or not I have been to the building).

To measure value I have georeferenced a map of Davidson College in 1915 with Mecklenburg county buildings data. I then clipped the shape file so only Davidson buildings were included. I assigned each building a value from 1-4 depending on their combined historical and personal value. Buildings with a value of 4 have been there since 1915 and I have visited them. Buildings with a value of 3 have not been there since 1915 but I have visited them. Buildings with a value of 2 have been there since 1915 and I have not visited them. Finally, buildings with a value of 1 have not been there since 1915 and I have not visited them.

The above image shows the effectiveness of Davidson College planning. Of all of the buildings, only two have no historical value or value to me. Although I do not accurately represent all Davidson Students, I have been here for four years, so hopefully visited more buildings than not. Using GIS I show that the main campus of Davidson College is highly populated and contains many buildings with high levels of value. It would be interesting to compare this map to a similar map of the newly acquired areas of Davidson’s campus. It would also be interesting to map these measures of value of different students involved in different areas around campus. These maps might show us weather or not Davidson is designed effectively for the diversity of students. The historical map demonstrates how Davidson has managed to keep numerous buildings that are frequently visited (renovated or not) for 100 years.

Here is the map with google maps as a background

Tag: GIS

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Assigning Value to Davidson Buildings