Landslide Risk Assessment

The multi-criteria evaluation was able to separate Vancouver Island into areas of high, medium and low risk for landslides. While no areas were at risk due to all of the different factors (which makes sense considering few roads are built on high slope areas, for example), there were many areas that could potentially be very hazardous.

Figure 1: Landslide Risk Assessment based on weighted MCE. 

Figure 2: Landslide Risk Assessment based on non-weighted MCE. 

Limitations

         These maps are limited by the data that was inputted; any errors or areas lacking data diminish the overall quality of the MCE. Furthermore, it is important to remember that this is a manipulation and representation of data, and is therefore not necessarily the truth.

We spent the majority of our time on this project struggling with 5.5 million data points, which meant that all file exports, manipulations, etc. took an excessively long time. Resorting to increasing the cell size to speed up the analysis was very disheartening, and also meant a loss of accuracy in the assessment.

 
Figure 3: Areas at high risk for landslide are shown overlain on population density; certain west coast communities appear to be most at risk. 

    We were hoping to use this final map to demonstrate areas of Vancouver Island that are highly populated and at risk for landslides. However, when attempting to calculate population density from the DA data, values became incredibly skewed and no longer represented real population densities. After several attempts at manipulation, it was determined that the Dissemination Area data was missing information for nearly a quarter of the island. We were unable to find alternative population data for Vancouver Island, and were therefore left with no choice but to present the above map. However, the population data displayed is hardly accurate, and not visually indicative of actual population density.