Byrd, B. (2014) Using desktop hydrologic data to predict fish presence in streams in northern British Columbia. [USQ Project]
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Abstract
Identification of fish-bearing streams is a key part of many environmental assessments in
Canada in general, and specifically in British Columbia (BC), where fish and fish habitat are 
highly valued components of the natural environment.  Pre-field identification of likely 
fish-bearing and non-fish-bearing streams has the potential to reduce cost and effort related to 
field inventories, and to expedite the project design process.
Previous research has considered desktop level hydrologic, geologic and land-use data from single 
catchments with  good results, but in some  cases did not maintain simi- lar predictive success for 
distant catchments. This research drew from three distinct catchments, with the aim of developing a 
model that will be more generally applicable. Data on fish presence/absence, watershed area, and 
mean and maximum monthly flows was collected from 2055 stream crossing points as part of the 
environmental assessment for the Prince Rupert Gas Transmission (PRGT) project. Canadian Digital 
Elevation Data was used to identify the elevation and derive the slope for each site. Parameters 
derived from this data were assessed using logistic regression to develop a model for predicting 
fish-bearing status.
The final model included the following parameters:  watershed area, field gradient (as a proxy for 
higher-quality desktop slope values), number of months per year with maxi- mum flow ≥ the 80th 
percentile of maximum monthly flows, and latitude.  The model achieved good predictive success for 
non-fish-bearing streams (79% to 91% correctly identified) but performed  less well for 
fish-bearing streams (65% to 66% correctly iden- tified).  The contrast between levels of 
predictive success was thought to be strongly influenced by the quality  of the  underlying  data, 
where, for regulatory reasons, the actual status of streams classified as non-fish-bearing  was 
likely far more certain than
the status of streams classified as fish-bearing.
|   | Statistics for this ePrint Item | 
| Item Type: | USQ Project | 
|---|---|
| Item Status: | Live Archive | 
| Additional Information: | Bachelor of Engineering - Honours (Environmental Engineering) project. | 
| Faculty/School / Institute/Centre: | Historic - Faculty of Health, Engineering and Sciences - School of Civil Engineering and Surveying (1 Jul 2013 - 31 Dec 2021) | 
| Supervisors: | Brodie, Ian; Ottenbreit, Kirby | 
| Date Deposited: | 21 Aug 2015 04:52 | 
| Last Modified: | 21 Aug 2015 04:55 | 
| Uncontrolled Keywords: | fish, stream crossing, presence/absence, hydrology, terrain mapping, logistic regression. | 
| Fields of Research (2008): | 09 Engineering > 0907 Environmental Engineering > 090799 Environmental Engineering not elsewhere classified | 
| Fields of Research (2020): | 40 ENGINEERING > 4011 Environmental engineering > 401199 Environmental engineering not elsewhere classified | 
| URI: | https://sear.unisq.edu.au/id/eprint/27284 | 
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