5 Applications
We have highlighted three applications, based on the framework of the stream connectivity indicator, that can provide supplementary information to decision makers.
5.1 Culvert resistance potential
The Culvert Resistance Potential (CRP) metric is a decision support tool aimed to help users identify culverts that can have a disproportionately large impact on the stream connectivity indicator. The CRP metric is based on the same methodology as the the stream connectivity indicator Diebel et al. (2014) and is calculated as the change in stream connectivity (SC) between when a focal culvert is completely blocked (\(SC_{b}\)) or passable (\(SC_{p}\)).
\(SC_{p} - SC_{b} = CRP\)
The CRP metric is dependent on four properties: 1) The location of the culvert within the stream network; 2) The types and amounts of surrounding habitat (Strahler order, stream length); 3) The scale of analysis (e.g., HUC-2 vs. HUC-6) as it impacts a culverts relative position within the stream network; and 4) the current degree of fragmentation (current SC) within the stream network. The resistance potential metric can be used to prioritize surveys at locations which are predicted to have the largest impacts on stream connectivity if they become blocked and inform how often revisits should occur.
5.2 Culvert prioritization
Until a complete inventory of stream crossings is available throughout Alberta, we can use the culvert passability model to identify predicted road-stream intersections that are currently at high risk of being, or becoming, hanging. This information can be used to direct surveys to locations where we suspect hanging culverts to be occurring. All predictions from the model are masked based on the criteria identified in Culvert Passability Model subsection.
5.3 Subregional studies
This indicator was develop with the intent to be regional in scope. However, this indicator can be calculated at smaller spatial scales (e.g., HUC-8), incorporate measures of habitat quality (e.g., sedimentation, water temperature), and species specific dispersal distances (e.g., Westslope Cutthroat Trout, Athabasca Rainbow Trout, Bull Trout). In collaboration with the Watercourse Crossing Program, we have developed a subregional case study to help inform culvert reclamation priorities in the Berland, Wildhay, and Swan River watersheds. Detailed maps of the stream network can be created to help identify stream segments that have low connectivity, providing another tool to help identify and prioritize restoration efforts within the watershed.
The stream connectivity (red = 0, blue = 1) of each stream segment and location of road-stream intersections (black dots) within the Swan River watershed.