Data Acquisition
Greater Vancouver Regional District 2001 Census Data
- Acquired from: Canadian Census Analyser @ CHASS (http://datacentre.chass.utoronto.ca/census/) Enumeration Area (old representation)/Dissemination Area (2001 representation)
- Data fields extracted:
- Income.dbf
- Population.dbf
DMTI Datasets
- Acquired From: DMTI Spatial
- Data field extracted:
- BCrds.shp from: DMTI CanMap Street files Version 7.2 2003/CanMap/BC/Streets/
- BCmnwtr.shp and BCmjwtr.shp from: DMTI CanMap Water Version 1.2 2003/CanWater/BC/Water/
Greater Vancouver Regional District 2001 Census Shape File (Census2001_da.shp)
- Acquired from: SFU GIS lab S-drive GEOG255 lab data
Downtown Eastside Map
Data Manipulation
Manipulations done in ArcMap
Census shape file (Census2001_da.shp)
- Convert projection to NAD83 UTM 10N
- Add new field to calculate area of each enumeration area within the shape file
- Using MS Visual Basics code to calculate area of each polygon:
Dim dblArea as Double
Dim pArea as lArea
Set pArea = [shape]
dblArea = pArea.area
Census Base Raster Map (census_raster)
- Convert feature (Census2001_da.shp) into raster format
- Convert again into ASCII format for manipulation in IDRISI
Income (census2001_da_income.shp)
- Attach income.dbf to census shapefile (Census2001_da.shp)
- Export as shape file (income.shp)
Population Density (census2001_da_popdens.shp)
- Attach population.dbf to census shapefile (Census2001_da.shp)
- Create new field in attribute table
- Use calculator to divide population by area
- Export as shape file (popdens.shp)
Downtown Eastside Polygon (DowntownEastside.shp)
- Create Personal Geodatabase with shape layer
- Heads up digitized using editor toolbar
Major and Minor Waterbodies (BCmjwtr.shp & BCmnwtr.shp)
- Convert projection to NAD83 UTM 10N
- Manual selection and created new layer of significant waterbodies to the GVRD
- Export as shape files (Van_mjwaterp.shp & Van_mnwaterp.shp)
DMTI Road Data (bcrds.shp)
- Convert projection to NAD83 UTM 10N
- Clipped with Census shape file
- Merged within ArcMap Editor to decrease unique values
- Export as shape file (van_roads.shp)
Manipulations done in IDRISI
Census Base Raster Map (census_base.rst)
- Convert from ArcInfo raster ASCII format to IDRISI
Income (income.vct), Population Density (populationdensity.vct), DMTI Road Data (Van_roads.vct)
- Convert from shape file to IDRISI
- Open database file .MDB with MS Excel and delete all attributes except for unique ID and Average Family Income
- Save as .CSV file and open in MS Word to replace all commas with spaces and save as .TXT file
- Open .TXT file in IDRISI and save as .AVL file
Downtown Eastside Polygon (DowntownEastside.vct)
- Convert from shape file to IDRISI
Major and Minor Waterbodies (mjwtr.vct & mnwtr.vct)
- Convert from shape file to IDRISI
Further Manipulation by IDRISI Macro Modeler
Three main models were used to prepare the data for analyis
Batdata Model: Rasterization and preparation of data imported from ArcMap for spatial analyis:
- Census Base Raster Map (census_base.rst) is used as the defining image.
- Initial module is used to prepare blanks for each vector file
- Lineras module was used to rasterize line data from the arc based road shape file van_roads.vct
- Polyras module was used to rasterize polygon data from polygon shape income.vct, populationdensity.vct, DowntownEastside.vct, mjwtr.vct & mnwtr.vct
- For data with attributes, the assign module was used to attach prepared corresponding .AVL files to the new raster files to produce Roads.rst, popdens.rst and income.rst.
- The two water layers mjwtr.vct & mnwtr.vct were overlayed and combined to form one raster layer water.rst
MCE Model: Preperation of data for use in the MCE definition wizard
- Census Base Raster Map (census_base.rst) was reclassed to a Boolean image (landcon.rst) to be used as a constraint in the MCE
- The boolean raster image (waterways.rst) of the major waterways was produced using raster file of major waterbodies (raw_mjwater.rst)
- A water cost distance raster image (water_costdist.rst) was made where land closer to the water were given higher values than land further away
- Another cost distance raster image (dtes_costdist.rst) was made where the closer an area was to the Downtown Eastside were the larger the values it has
Least Cost Pathway Models: Used to determine the least cost pathways from the resulting optimal areas to Downtown Eastside. Several identical models were made for each area.
- Data manipulation and anaylsis were done within this model please refer to Spatial Analysis page for analytical steps.
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