Final Project and Threats to Validity
This post discusses geographic threats to validity in the final project for GEOG 0323.
The final project on which I am currently working mainly consists of reproducing a QGIS model workflow for a least cost model into R. The workflow was created by Justin Lucas (another Middlebury student) in Summer 2023 to add to an existing project concerning the Makuyuni Wildlife Corridor in Tanzania. This broader project aims to assess the status of this wildlife corridor through GIS, but it is not yet completed. I am working on this class project with Alana Lutz, who is also enrolled in GEOG 0323. The project will involve using functions from both the stars and raster packages to reproduce the functions which are part of the QGIS model. Some commonly used functions include rasterizing, cropping, and reprojecting.
The Makuyuni project has existing data beyond the contributions of Justin Lucas. Professor Joseph Holler worked on an unpublished manuscript for the broader project, and this manuscript gives ideas for how geographic threats to validity may be discussed for this class project. In particular, it would seem that edge effects are one of the most concerning problems for the authors of the manuscript, for they refer to the need to displace start and end regions away from the study area borders when creating an accumulated cost surface. If we are able to progress to reproducing the accumulated cost surface, it stands to reason that we will have to ensure that we also include this step in our R workflow.
In addition, spatial dependency may have been addressed through sampling in transects. I do not believe there would be control sites/transects for the study conducted, so the control/experiment dichotomy mentioned in the class slideshow on this topic may not apply. It also seems that spatial nonstationarity has been addressed through ensuring the inclusion of all habitat types on the ground, but it is noted that one area of the study region was not easily accessed for sampling. I do not believe I would be able to change anything about this aspect of the project, seeing as this process was one which required in-person work.