{"id":14,"date":"2021-12-08T17:23:41","date_gmt":"2021-12-09T00:23:41","guid":{"rendered":"https:\/\/blogs.ubc.ca\/mappingfloodriskinfraser\/?page_id=14"},"modified":"2021-12-15T23:37:43","modified_gmt":"2021-12-16T06:37:43","slug":"results","status":"publish","type":"page","link":"https:\/\/blogs.ubc.ca\/mappingfloodriskinfraser\/results\/","title":{"rendered":"Results"},"content":{"rendered":"
\"\"<\/a>
Figure 4.1 Flood extent of 1m and 2m increases in water elevation in rivers of Metro Vancouver Area (Figure 4.1 Full Resolution<\/a>)<\/figcaption><\/figure>\n
\"\"<\/a>
Figure 4.2 Flood extent of 1m and 2m increases in water elevation in rivers of the area from Abbotsford to Hope (Figure 4.2 Full Resolution<\/a>)<\/figcaption><\/figure>\n

The final maps produced above were created using our model approximating the extent of flooding from a 1m and 2m increase in water elevation in rivers. The maps show the predicted extent of flooding along the Fraser River.<\/p>\n

The results from our overlay analysis using the maps we created are as follows:<\/span><\/h5>\n

Table 2. Summarizes total area, population, and length of roads affected.<\/span><\/p>\n\n\n\n\n\n\n\n
<\/td>\n1m increase\u00a0<\/span><\/td>\n2m increase\u00a0<\/span><\/td>\n<\/tr>\n
Total Area flooded\u00a0<\/span><\/td>\n221 km\u00b2<\/span><\/td>\n416 km\u00b2<\/span><\/td>\n<\/tr>\n
Population affected\u00a0<\/span><\/td>\n480,690<\/span><\/td>\n 611,464<\/span><\/td>\n<\/tr>\n
Length of roads flooded\u00a0<\/span><\/td>\n1,508 km<\/span><\/td>\n2,271 km<\/span><\/td>\n<\/tr>\n
Length of highways flooded <\/span>(Hwy 1, 7, 10, 15, 17, 91, 99)<\/span><\/td>\n140 km<\/span><\/td>\n174 km<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
Flooded roads:<\/span><\/h5>\n

A layer of all road classes were intersected with our flooded area layer. This produced a layer of all the roads that would be flooded by a specific increase in the Fraser river level. Looking at the statistics for the road length field of this layer, the total distance of roads flooded can be revealed. To see the flooding extent for highways, Hwys 1, 7, 10, 15, 91, and 99 were selected as those were the major highways that ran across the Fraser Valley. Using the select by attribute function, and searching for those names with the OR operation, the flooded highways were selected. A new layer was created using the selected highways and was placed on our final map. Only the 4 major highways were selected to be shown on the final map to increase visual clarity and prevent all other road classes from cluttering the map. Closer inspection revealed that our DEM layer did not take the elevation of bridges into account. Therefore the final map would show that a bridge is \u201cflooded\u201d but in reality, this would not be the case, at least for the increments posed in this project. Updated DEM data would result in bridges to have a much higher elevation than the body of water it crosses.\u00a0<\/span><\/p>\n

Population affected:<\/span><\/h5>\n

A DA Census layer from 2016 was intersected with the flooded areas to produce a layer of census data that was directly affected by the flood. The statistics for the population then told the number of people affected by the flood. It should be noted that this number can be much higher as nearby areas could also evacuate. However, it is unknown what precautions would be suitable, but if known, a buffer could be used to increase the affected population\u2019s area on the census layer.<\/span><\/p>\n

Flooded area:<\/span><\/h5>\n

Map 2 and 3 shows the potential flooded area and as was mentioned earlier, also includes the water bodies. Therefore, the total area of land flooded was calculated by taking the difference in area between the waterbody layer and the total area flooded layer. A better option would be to clip the flooded layer with the waterbody layer, however when doing so, an error appears on ArcPro that prevents the attribute table from opening. This step was therefore omitted.<\/span><\/p>\n

Lower Mainland (Richmond, Delta, Surrey):<\/span><\/h5>\n
\"\"
Figure 5: At the mouth of the Fraser, figure 4 shows the extent of both a 1 meter (orange) and 2 meter (red) increase in the Fraser\u2019s and nearby water body\u2019s level.<\/figcaption><\/figure>\n\n\n\n\n\n
Richmond<\/span><\/td>\n\n
    \n
  • Highway 91 eastbound would be flooded by both levels of water increase<\/span><\/li>\n
  • Highway 99 southbound would be flooded by both levels of water increase after crossing the Fraser as northern Delta is completely flooded<\/span><\/li>\n
  • Flooding would also be prevalent into the center of Richmond coming from the south, mostly from a 2m increase<\/span><\/li>\n<\/ul>\n<\/td>\n<\/tr>\n
Delta<\/span><\/td>\n\n
    \n
  • Highway 17 north and southbound would be flooded only by a 2m increase, restricting access to the Tsawwassen ferry and surrounding cities<\/span><\/li>\n
  • Highway 99 north and eastbound would be flooded\u00a0 by both levels of increase, effectively blocking all movement into and out of Delta via highways<\/span><\/li>\n<\/ul>\n<\/td>\n<\/tr>\n
Surrey<\/span><\/td>\n\n
    \n
  • Highway 99 and 15 southbound would be flooded by both levels of increase despite not being due to the Fraser, but by the Nicomekl and Serpentine rivers that protrude deep into South Surrey<\/span><\/li>\n
  • Access to the United States would be severely impacted as highways 99 and 15 both connect to the Interstate 5 that runs along the entire western coast of the United States<\/span><\/li>\n
  • Despite the smaller volume of both Nicomekl and the Serpentine rivers, its flood potential surpasses that of the Fraser for the Lower Mainland<\/span><\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    Upper Fraser Valley (Mission, Chilliwack)<\/span><\/h5>\n
    \"\"
    Figure 6: Extent of both a 1 meter (orange) and 2 meter (red) increase in the Fraser\u2019s and nearby water body\u2019s level<\/figcaption><\/figure>\n\n\n\n\n
    Mission<\/span><\/td>\n\n
      \n
    • Highway 7 eastbound would be flooded at multiple sections, almost entirely due to a 1 meter rise\u00a0<\/span><\/li>\n<\/ul>\n<\/td>\n<\/tr>\n
    Chilliwack<\/span><\/td>\n\n
      \n
    • Highway 1\/Trans Canada Highway would be flooded at multiple sections before, at, and after Chilliwack as it continues northeast towards Hope<\/span><\/li>\n
    • Being a vital pathway that connects the western coast of Canada to the rest of the provinces to the east, this blockage could have adverse implications\u00a0<\/span><\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
      <\/div>\n
      <\/div>\n","protected":false},"excerpt":{"rendered":"

      The final maps produced above were created using our model approximating the extent of flooding from a 1m and 2m…<\/p>\n","protected":false},"author":86841,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-14","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/blogs.ubc.ca\/mappingfloodriskinfraser\/wp-json\/wp\/v2\/pages\/14","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.ubc.ca\/mappingfloodriskinfraser\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/blogs.ubc.ca\/mappingfloodriskinfraser\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.ubc.ca\/mappingfloodriskinfraser\/wp-json\/wp\/v2\/users\/86841"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.ubc.ca\/mappingfloodriskinfraser\/wp-json\/wp\/v2\/comments?post=14"}],"version-history":[{"count":53,"href":"https:\/\/blogs.ubc.ca\/mappingfloodriskinfraser\/wp-json\/wp\/v2\/pages\/14\/revisions"}],"predecessor-version":[{"id":103,"href":"https:\/\/blogs.ubc.ca\/mappingfloodriskinfraser\/wp-json\/wp\/v2\/pages\/14\/revisions\/103"}],"wp:attachment":[{"href":"https:\/\/blogs.ubc.ca\/mappingfloodriskinfraser\/wp-json\/wp\/v2\/media?parent=14"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}