GIS 5103 Participation Assignment 1: GIS, Archaeology, and Human Movement Modeling

Fig. 2. The location of the Missaukee Earthworks (20MA11-12) and the twenty-nine contemporary, significant Late Prehistoric (AD 1200-1600) sites used as the focal node input for Circuitscape resistance analysis. (From Howey, 2011)

The article I read as an example of GIS used in the real world was “Multiple pathways across past landscapes: circuit theory as a complementary geospatial method to least cost path for modeling past movement” by Meghan C. L. Howey (Journal of Archaeological Science, 38 (2011), 2523-2535).  Howey uses the topic of population movement among the peoples of northern Michigan between 1200 and 1600 AD to test least cost path modeling and circuit modeling of this movement.  Specifically, she looks at the movement to and from the Missaukee Earthworks site, an important trade and ritual center.  Howey’s circuit model is run by an ArcGIS tool called Circuitscape.

The simplest version of least cost path modeling would consider only distance and topography, which, according to Howey, some researchers still do.  However, Howey also included water routes and land cover in her original least cost path analysis.  The output of a least cost path model is a single route that, based on the input parameters, represents the route of least resistance between two points.  A circuit model, on the other hand, considers the presence of multiple routes between two points in its analysis of the relative ease or difficulty of travel.  In other words, if site A and site B have a single route of medium resistance connecting them while site A and site C have five possible connecting routes of the same resistance, travel between sites A and C will be rated as easier than travel between sites A and B.  While distance is a factor, this may hold true even if site C is significantly further away than site B. 

The article’s tables and figures show an interesting comparison between the results of the two modelling strategies, but Howey concludes by emphasizing each tool has its strengths and weaknesses.  Circuit modelling is clearly useful in considering a larger portion of the landscape as potential routes of travel; humans are not perfect optimizers of their energies and surroundings, after all.  However, circuit modelling can overlook cases in which a single route is overwhelmingly preferred (such as water routes).  In the latter case, least cost path modelling would provide a more useful picture. 

The article may be a bit dry, I suppose, but I followed the suggestion to explore UWF’s library databases and went with a topic aligning with the archaeology track.  The article can be accessed at: http://dx.doi.org.ezproxy.lib.uwf.edu/10.1016/j.jas.2011.03.024. 

GIS 5265 Module 3: Ethics in Archaeological GIS

This week's assignment aimed to place GIS data and research within a discussion of ethics in archaeological research.  How do we conduct research that includes (or is primarily) spatial data when site location is a sensitive issue?  The assignment began with an exploration of the Middle Eastern Geodatabase for Antiquities (MEGA, http://www.megajordan.org/Map), an online geodatabase of archaeological sites in Jordan.  With different levels of access depending on user category, the project aims to facilitate academic research as well as provide information for conservationists and the public to aid in protecting the sites.

The actual lab portion of this week's assignment was largely a review of how to create and use a geodatabase in ArcMap, but it added a discussion of the security benefits of geodatabases over isolated shapefiles in multiple folders.  By collecting all data files in a single database, one has more control over who has access to the data therein.  It is much more difficult to control and protect data spread over multiple locations.

This module also explored methods of creating new point feature classes in our geodatabase.  In the map above, Petra was added as its own layer by directly entering its latitude and longitude coordinates in an ArcMap edit session.  The other sites were imported from an Excel spreadsheet containing each site's name, description, and coordinates.  In completing the above map, my main creative contribution was converting all site labels to annotations stored in the map (after setting the font and halo) for better placement.  I also created a definition query to remove the Petra location that was included in the Excel spreadsheet.

The ethics of sharing archaeological data is a big topic without clear answers.  On the one hand, we would like to educate the public as much as possible, hoping that through education we can minimize the desire to engage in activities that will damage sites.  Unfortunately, there will likely always be a small number of people willing to irreparably damage sites for potential financial gain (or simply to damage sites through inconsiderate land use).  That is why I think the route taken by the State Historic Preservation Offices (at least the ones I am familiar with) in restricting access to detailed location data is prudent.

GIS 5103 Module 2: Geoprocessing in ArcGIS

This week continued our introduction to Python programming.  Unlike last week, however, this time we used Python script to utilize ArcGIS tools to produce output data.  The first step was to create a model using ModelBuilder to produce the layer pictured above.  This model needed to clip a layer representing a large area of soils to a small layer representing a basin, then to select from the soil layer all areas classified as "not prime farmland," and finally to remove from the basin layer areas that coincided with this soil selection.  The model was then exported as a Python script for further exploration and editing.

It was at this point that I experienced an issue.  Prior to exporting the model as a Python script, we were required to set our model variables as model parameters.  Because my model had five variables, the instructions' reference to four variables led me to not set the final variable as a model parameter.  I proceeded with the assignment, following the instructions to make the script operational outside of ArcMap by entering the file paths for the soils and basin layers and including the line of code to allow data overwriting.  However, I kept getting a "Parameters are not valid" error when I ran the script.  I eventually stumbled upon my simple mistake of not setting my final variable as a model parameter; the script ran smoothly afterward.

I enjoyed this introduction to using Python script for geoprocessing.  Even my little error described above taught me how important it is to pay attention to detail when programming.  I am looking forward to learning more in the next module.

GIS 5265 Module 2: Chicago Fire of 1871, Queries and Clipping

The first lab of GIS Applications in Archaeology used the topic of the Chicago fire of 1871 to review ArcMap tools that will be important for future projects.  The map above, while relatively simple, conveys multiple layers of information.  We see the geographic footprint of Chicago in 1871 and 1890, thus getting a sense of how quickly the city grew.  We also see the origin and extent of the fire; from this we can see the effects of the wind on the spread of the fire.  Finally, the location of currently extent landmarks built before and after the fire are depicted, showing the destruction caused by the fire as well as the rapid rebuilding in its aftermath.  To produce the final map, the 'clipping' and 'select by attributes' tools were used and the layer selections exported as new layers.  While an inset map was not required, I added one to focus on the landmarks built before the fire; that they are clustered together makes them fit well in an inset map and allows for the main map to remain uncluttered from their labels.

This module was a good refresher and introduction to the course.  The simple tools and techniques of this module could be used for a wide variety of research questions.  I look forward to the next modules and learning more of how to apply GIS to archaeological research.

GIS 5103 Module 1: Introducing Python

Thus begins our journey into the world of Python programming for GIS.  The screenshot above is the result of running a provided Python script to create the folders we will use for our assignments for the course.  In addition, we were initiated into Python programming by creating our "Hello world" script, a nearly-universal first line of code for the novice programmer.  And novice I surely am; the last formal instruction in any form of programming was with BASIC eons ago in an intro to computer science course.  Other than some fiddling with HTML here and there, this will be the first time I expect to be able to accomplish anything useful with coding.  I am looking forward to progressing through the course and learning more of Python.

GIS 4043 Final Project: The Bobwhite-Manatee Transmission Line Project

This was one of the most challenging yet rewarding projects I have worked on for a college course.  Our task was to consider multiple categories of impact on the human and natural environment as a result of the Bobwhite-Manatee Transmission Line Project.  For each of these potential impact categories, we were required to conduct analyses on the amount of land or number of locations affected.  In addition to the data resulting from our analyses and our maps produced to communicate the data, we were required to construct a Powerpoint presentation communicating our results to a lay audience.  We were also required to write a slide-by-slide commentary to accompany our presentation.  Below are the links to my contributions.  While I would have welcomed more time to spend on certain maps, I believe the final product is a success.  I look forward to continuing my GIS education with the next round of courses.

Presentation:
http://students.uwf.edu/tae12/TyEvans_project_presentation.pptx
Presentation slide commentary:
http://students.uwf.edu/tae12/TyEvans_project_slidecommentary.pdf