Results

With all of the analysis complete, we needed to create our final map. To do this, we used the spatial analyst raster calculator and added all of the hazard values together. The result was a map which shows the degree of danger one could expect in different areas of the GVRD.

Error and Uncertainty

It is important to remember that all maps are a representation of reality; therefore, there will always be error no matter how good we think our data is.

Digitizing: The map we downloaded off the Natural Resources Canada website was a jpeg image; therefore, we had to use onscreen digitizing to get the data into the GIS. We had 3 people digitizing and everybody digitizes differently. That is, everyone has different ways of drawing boundaries between different categories. Since the thickness of the boundaries differ from one view to another, it is difficult to digitize with solid accuracy.

Coast Buffer: Since tsunami data has never been recorded for the GVRD, it is not known for sure how far inland a tsunami would strike. When we digitized the coast line to create the buffer for the tsunami hazard, we were making assumptions as to the distance inland a tsunami would strike.

Surficial Material Data: The data for the surficial materials does not cover some of our study area in the north shore. Due to the lack of data for those areas, an accurate hazard map could not be created for those locations.

DEM: Elevation is continous data, but the data used to generate the DEM was based on spot heights which are not continous. Therefore, error's can arise in relation to spatial interpolation.