Analysis of LiDAR elevation data for improved identification and delineation of lands vulnerable to Sea-Level rise in Nadi, Fiji Islands (14040)
Coastal areas are susceptible to sea level rise due to global climate change. Sea-level rise has the potential to physically displace people and their communities as well as upset the natural ecological balance of the area. Understanding the impacts of rising oceans is especially important as many densely populated urban areas exist in coastal regions. The town of Nadi located on the island on Viti Levu in Fiji Islands is an example of this and has a situation reflective of many Pacific Island countries suffering from sea-level rise. Nadi is also affected by inland flooding due to neighbouring rivers. It is important to determine an accurate representation of the extent of sea level rise, and how the coastal landscapes would be affected together with the addition of the hazards posed by inland flooding.
The first LiDAR (Light Detection and Ranging) data captured for Fiji was in 2012 in the area of Nadi covering 135 km2. LiDAR data are the most accurate remotely sensed digital elevation models available with horizontal and vertical resolutions an order of magnitude better than the alternatives. Using this dataset for Nadi, various maps were created to delineate areas susceptible to flooding due to coastal sea level rise at different elevations. Expanses disposable to inland flooding risks, given different rainfall events and river discharges, were also mapped out. The areas susceptible to flooding hazards were further assessed by evaluating the potential expansion of floodplain in Nadi resulting from inland flooding as well as increases in sea level.