Site Suitability Analysis for Hibernaculum at the Silver City Trap Club
Introduction

Limitations and Assumptions

The West Kootenay region is known for the landscapes and
ecological diversity it holds. With the rapid changing of the
natural environment, susceptible species populations continue
to decline. Reptiles such as the listed rubber boa (Charina
bottae) are becoming subject to habitat loss and degradation,
even here in its native region, West Kootenays.

Working with high grade GPS equipment borrowed from the
Applied Research and Innovation Center was a limiting
factor. The computers at the main Selkirk College campus are
not set up with specific software to work with the devices.

The former layout of the Silver City Trap Club resulted in the
possibility of targets for shooting landing outside of the
property. To stay in operation and to follow the regulations of
a gun range, the club needed to undergo a major land
reconstruction project on its grounds. Losing a large portion
of habitat due to the land reconstruction, the club is now
focusing on creating reptile hibernaculum on the suitable area
that remains.

A previously conducted land survey that was supplied by the
client had contour intervals that were accurate to 1m, but
tools to digitize or export those contour lines from the PDF
did not work. Instead, a DEM was used for the analysis. Even
at 5m contour intervals, there was still slight error in the data
that the DEM provided. Due to the potential error in the
contour data derived from the DEM, it is possible that some
area that was calculated as unsuitable could actually be
suitable.
Timing posed as a limitation to this project. Because the
fieldwork was conducted over the winter, the ground was
covered in snow. This limited the variables that could be
collected to only sightings, road lines and elevation points.

Methods
1. Initial client meeting was done to address their specific
needs and desires. Existing data and information was
collected from client.
2. Training for use of a GPS Trimble R2 paired with the
Trimble Nomad handheld computer were taken. Training
for post processing data on GPS Pathfinder Office was
taken. Both of which were provided by Ian Dennis at the
Applied Research and Innovation Centre
3. Using Trimble R2 and Trimble Nomad, point and line
features were taken across the study area. Collecting data
for physical location of snake sightings, point features for
major changes in elevation (approximately 5m changes),
and a line feature for a newly constructed road. Post
processing was done on these features in the lab to create
shape files.
4. The natural neighbor tool was used to create a newly
interpolated surface using the elevation points that were
collected in the field. This was done to provide base data
for the area of land that had been reconstructed, since
none existed.
5. A Digital Elevation Model that was collected from
Geogratis was used to create layers for contours, aspect
and slope.
6. Aspects were reclassified so that flat, east, southeast,
south and southwest were set to 1 (suitable), and north,
northeast, west and northwest were set to 0 (unsuitable).
7. Areas of high canopy cover, human disturbance and
roads were created into polygons, changed to raster
layers and reclassified. Anything falling inside of the
polygons was set to 0 (unsuitable), anything outside of
polygons was set to 1 (suitable).
8. Raster math was used to calculate the suitable areas
across the site where the construction of hibernaculum
could take place.
9. Maps created to display results of analysis.

https://twitter.com/RichardGreenEco/status/1042516586526072835

Results and Discussion
From mapping the sightings of rubber boa snakes across the
study area, it was clear to see that the sightings recorded were
mostly located in the southwestern corner of the study area,
with a couple lying towards the middle of the study area.
After creating a newly interpolated surface where the land
was reconstructed due to regulations, the land was deemed
unsuitable for habitat construction. The slopes were steep and
the human disturbance in the area was large.
For a visual comparison, rubber boa sightings were overlaid
onto the suitability analysis. Only two locations were found
to be within suitable habitat area. The sightings that are
located within unsuitable area are not far form suitable area.
It is possible that constructing hibernaculum within the
suitable area would lead to a large amount of reptile use.

Citations
Selkirk College O-Drive, I-Drive.
http://geogratis.cgdi.gc.ca/

Project created by: Lindsay Kokolski
Course: IEP271 GIS Applications II