CALCULATING HAZARD PERCENTAGE
Within the attribute table of the public transit layer, I was able to calculate the total length of each transit route by converting 'Shape_Length' from meters to miles in the 'Length_Miles_geom' column. Additionally, I was able to calculate the percentage of each route route affected by severe flooding. To do this, I employed a simple field calculation where I divided the 'Miles_Hazard' column by the 'LengthMiles_geom' column, which resulted in the values contained in the 'Percent_Hazard' column.
IDENTIFYING HAZARD LOCATIONS
With the simplified transit data it became possible to perform an intersect with the transit layer and the flood hazard layer to identify all areas where to the two layers come into contact. The red portions of the transit routes illustrate where the intersections occur. I then performed a join to append this new data to the transit data from which it was derived.
INITIAL ACTIONS
The first step to my analysis was to determine whether Pierce County transit routes and flood hazard areas come in contact. To do this I obtained transit and flood data from Pierce County's Open GeoSpatial Data Portal. Next I clipped the transit routes to Pierce County, and performed a dissolve to make each transit route one continuous line instead of many segments. Looking at the result of these steps validated my hypothesis that transit routes and flood hazards overlap.
