FloodVulnerabilityStudy: Flood Vulnerability Study

In essatech/MNAI.CPBT: Municipal Natural Assets Initiative - Coastal Protection Benefit Toolbox

Flood Vulnerability Study

Description

Calculates the number of flooded structures, median flood depth and total structural damage across a range of water level elevations.

Usage

FloodVulnerabilityStudy(
  Bldgs = NA,
  group_col = NA,
  TopoBathy = NA,
  start_elevation = 2,
  end_elevation = 10,
  step_size = 0.2,
  simulation_name = "My Simulation",
  dir_output = getwd()
)

Arguments

Bldgs	Spatial polygon of building footprints of class sf and dataframe. See data(Bldgs) for an example input format.
group_col	(Optional) Column name of group column name in building data frame. If used results will be summarized by region.
TopoBathy	TopoBathy digital elevation model of class RasterLayer.
start_elevation	Starting lower water level elevation for sequence.
end_elevation	Ending upper level elevation for sequence.
step_size	Water level elevation step size for sequence.
simulation_name	Character. Simulation name for export.
dir_output	Local output directory for CPBT simulation results.

Details

The flood vulnerability is a computationally intensive yet simple tool to allow communities to better understand the vulnerability of their communities to coastal flooding. The function works by gradually raising the water level by a fixed amount and then recalculating the structural damage cost of a flood at that water level. Users define a range of elevation e.g., 0 – 5 meters above chart datum and a step size e.g., 0.15 m and then the function calculates to total damage cost at each 0.15 interval. A html report is exported with three plots showing the depth-damage curves used in the assessment, the number of affected structures at each water level and the total damage cost at each water level. The intent of this tool is to look at overall damage cost to different storms. If the number of affected structures and total damage costs quickly climb upwards at low water levels, then users can assume that the area is highly vulnerable to coastal flooding. Conversely, if damage costs do not show any significantly values until the water level reaches extreme levels, then users can conclude that the community is naturally resilient to flooding. Users can also evaluate tipping points at which the damage cost climbs significantly for a given water level. For example, if a community is expect to have no structural damage below flood water levels of 2.1 m CD, but then experience millions of dollars in damages between water levels of 2.1 – 2.5m then users can conclude that any forces pushing the water levels above 2 m represent a significant concern for their communities.

Value

Exports results to a specified folder file path.

essatech/MNAI.CPBT documentation built on July 1, 2023, 12:34 p.m.