Emergency Shelter Allocation Evaluation

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Introduction

FACT: Hawaii is the State most at risk of Tsunami conditions, Getting about one per year, a highly damaging one every 7 years. The biggest tsunami that occurred in Hawaii happened in 1946 when the coast of Hilo was hit with 30 ft waves at 500 mph, 170 fatalities. Click here for more facts of Tsunami Danger.

This project demonstrates how to make a spatial decision that determines the best use of monetary resources when further developing the emergency preparedness framework of a community. Spatial allocation decisions often can not be made most efficiently with consideration of only an independent variable, and scenarios realistically exist as multi-criteria based. This tutorial will demonstrate how this evaluation can be carried out using only Free and Open-Source Software(FOSS), particularly using the Quantum GIS (1.8.0) package and the GRASS Plugin.

Particularly the scenario that outlines what the objectives are for this tutorial involve the expansion of Emergency Shelters in Hawaii. The funding for this expansion has specific criteria which is as follows:

  1. Funds must be concentrated to the area of highest risk to large waves within the State.
  2. Shelter Location must be far away from Evacuation Land.
  3. Shelter Location must be in area of highest population density.
  4. Shelter Location must be far away from existing Shelters.

This tutorial is directed towards someone who has a minimal or basic understanding of GIS. The processes outlined throughout this tutorial may also be applicable in understanding gaps of public safety as a community evolves, or something as simple as determining the best location for a business expansion. The variety of applications are extremely widespread.

Data Collection

For this specific scenario, it was necessary to collect a variety of shapefiles (vector data) that are freely available online. There is a variety of online databases that have appropriate files with access to download freely. Sources of data very much depend on your geographical location and the government availability of free files.In this particular case the data was gathered from a catalog provided by the Hawaii State Government and U.S Census Bureau. The following chart is a specific breakdown of where each file was found and the adequacy of it.

Table 1. Data Collection Breakdown used throughout this Analysis
Shapefile Name Applicability Data Source
Tsunami Evacuation Zones Vector Polygon - Preliminary Analysis/Final Anaysis File Hawaii State Office of Planning Layer: High risk area to Tsunami impact.
Tsunami Wave Heights Vector Point - Preliminary Analysis File Hawaii State Office of Planning Layer: Locations of large wave events along the coast, attributes include year by year breakdown of events.
Emergency Shelters Vector Points Hawaii State Office of Planning Layer: Locations of Shelters, and individual capacity.
Census Tracts Vector Polygon U.S Census Bureau Layer: Total Population by tract, 2009 TIGER/Line Shapefiles for: Hawaii




http://hawaii.gov/dbedt/gis/download.htm

Setup

Install QGIS

Install GRASS Plugin

Preliminary Analysis

Deciding Area of Interest

Quantitative Map Output

Data Processing

Clipping to AOI

Dissolve AOI

Attribute table editing

Calculating Population Density

Deleting Attributes

Data Conversion

ESRI Shapefile to GRASS Vector

GRASS Vector to GRASS Raster with Attributes

Methods

Proximity Tool

Clipper Tool

Reclassify Rasters

Creation of Text files

Executing Tool

Suitability Calculation

Calculation Logic

Performing Calculation

Results

Decision Output

Optimal Resource Allocation Determined

Conclusions

References