Flood Evacuation Function

Overview

Unique Identifier: Flood Evacuation Function

Author: AIFDR

Rating: 4

Title: Need evacuation

Synopsis: To assess the impacts of (flood or tsunami) inundation in raster format on population.

Actions: Provide details about how many people would likely need to be evacuated, where they are located and what resources would be required to support them.

Hazard Input: A hazard raster layer where each cell represents flood depth (in meters).

Exposure Input: An exposure raster layer where each cell represent population count.

Output: Raster layer contains population affected and the minimum needs based on the population affected.

Limitation: The default threshold of 1 meter was selected based on consensus, not hard evidence.

Details

The population subject to inundation exceeding a threshold (default 1m) is calculated and returned as a raster layer. In addition the total number and the required needs in terms of the BNPB (Perka 7) are reported. The threshold can be changed and even contain multiple numbers in which case evacuation and needs are calculated using the largest number with population breakdowns provided for the smaller numbers. The population raster is resampled to the resolution of the hazard raster and is rescaled so that the resampled population counts reflect estimates of population count per resampled cell. The resulting impact layer has the same resolution and reflects population count per cell which are affected by inundation.

Docstring

Impact function for flood evacuation

:author AIFDR :rating 4 :param requires category==’hazard’ and subcategory in [‘flood’, ‘tsunami’] and layertype==’raster’ and unit==’m’

:param requires category==’exposure’ and subcategory==’population’ and layertype==’raster’


Contact info@inasafe.org for more information. Source code available on GitHub! Please file a ticket if you have discovered an issue.
This document is licensed under a Creative Commons Attribution 3.0 Australia License.
CCByA, Copyright 2013, BNPB/AusAID/World Bank.