Method

The suitable areas for emergency evacuation and emergency facilities can be determined by Multi Critrea Evaluation (MCE) on IDRISI. To perfome the MCE, raster files of 2 constraints and 5 factors are conducted beforehand.

- Constraints:

  1. The suitable site must not be located in areas prone to any kind of natural hazard.
  2. The suitable site should be located in well-known institutional lands, such as community centers, libraries, parks, and schools to increase efficiency and decrease construction cost.

- Factors:

  1. Distance to emergency response route
  2. Slope of the area
  3. Distance to natrual hazard areas
  4. Population density
  5. Land use type

In the MCE analysis, every factor will be stadardized to a rating scale of 0-255 according to certain mathmatical functions, so that every cell on the final raster file will be given a value and ranked. The impotance of every factor is determined by Order Weighted Averaging (OWA) method. An area with the highest cell value will be the most suitable location.

Data

Data Sources:

- District of North Vancouver GeoWeb Open Datasets: shape files of natural hazard areas and emergency response route. ASCII file of population density.

- U.S. Geological Survey: Digital Elevation Model (DEM) of North Vancouver.

- Simon Fraser University SIS Lab: shape file of land use plan of North Vancouver.

Data Preparetion:

  1. All shape files are first transformed into raster file in ArcGIS (polygon/polyline to raster tool) and then thansformed into ASCII files in ArcGIS.
  2. Import all ASCII files into IDRISI and transform into IDRISI raster files.
  3. Open DEM file in IDRISI and obtain the DEM file of North Vancouver by projection module.

Data Manipulation:

  1. Use "projection" module in IDRISI to uniform all raster files to the same North Vancouver area with same reference system, US83_TM_10N, and same cell size, 30 pixels.
  2. Use "distance" and "slope" module to conduct slope raster file of North Vancouver.
  3. Use "assign" and "reclass" modules to transform those raster files from step 1 into 2 constraint raster files and 5 factor boolean raster files (Picture 2.1-2.8).

Picture 2.1 Areas with No Natrual Hazards

Picture 2.2 Institutional Lands

Picture 2.3 Slope Degrees

Picture 2.4 Population Density

Picture 2.5 Distance to Emergency Response Route

Picture 2.6 Land Use Rating

Picture 2.7 Distance to Natural Hazard Areas

 

Back to Top