This image shows the shortest
distances from roads in black and blue, and the
farthest in green.
Once my data had been prepared in ArcView and Idrisi, as discussed in the Methodology section, I was ready to begin my analysis.
Please keep in mind that the following analyses were for learning purposes only, and do not necessarily present realistic or factual analyses and conclusions. While the spatial questions were valid and of real concern, some of the analyses were based on random or estimated data (for example, that an OSB plant of this size should be located at least 4 km from major water sources) for the simple purpose of querying and...
Using my data layers, I was able to answer my spatial question by specifiying the following requirements:
The OSB plant could be located in an area that is not within a provincial park or government reserve, that is within 500 m of an existing road, that is at least 2000m from significant water bodies, and that is within 4000m of a rail line.
Requirement 1:
Locate outside of a provincial park or government reserve.
The rasterized
park layer had already been reclassed 1=good location and 0=bad location.
It was ready to go.
Requirement 2:
Locate within 500m of an existing road.
I ran
DISTANCE on the rasterized roads layer.
This image shows the shortest
distances from roads in black and blue, and the
farthest in green.
Once distances had been calculated, I reclassed so that 1=within 500m and 0=too far away.
Image showing areas within
500m of roads in black.
Requirement 3:
Locate at least 2000m from significant water bodies.
Again,
I ran DISTANCE on the rasterized river and lake layer. I supposed
that the appropriate distance from water was not linear; 2km was the minimum,
and appropriateness increased with distance up to 6km. After 6km,
I supposed that all distances were of equal appropriateness for the location
of the plant. To reflect this, I ran the sigmoidal function in FUZZY
with control points of 2000 and 6000m on the distance-from-water layer.
This image shows dark green
as the most appropriate area to locate the OSB plant, in terms of distance
from open water. Suitability decreases are shown by color changes,
with black being completely unsuitable.
Requirement 4:
Locate within 4000m of a rail line.
This turned
out to be the most limiting factor. Similar to the roads layer, I
ran DISTANCE and then reclassed so that 1=within 4000m and 0=too far away.
From here, all I had to do was combine the layers. Using OVERLAY, I first multiplied the rail and lake layers. The result:
Image showing most suitable
locations from rail and water for OSB
plant in green, with othercolours
representing decreasing suitability.
Unsuitability is shown in
black.
Next, I multiplied the above image with the road suitability layer. The result:
Image showing most suitable
locations from rail, water, and road for OSB
plant in green, with othercolours
representing decreasing suitability.
Unsuitability is shown in
black.
Finally, I multiplied the above image with the provincial forest/government reserve layer. At the last minute I also decided to create a distance image for the distance from Fort St. John in order to emphasize alternative locations for the OSB plant, and because I unfortunately did not have data representing the human health costs surrounding the city. This, in effect, became Requirement 5: Locate at least 10km from the City of Fort St. John. I used linear FUZZY to create an image from a digitized central point in Fort St. John that permitted no development within 10km of the city, and appropriateness increasing therefrom. It was then overlayed with the fuzzy river and lake image. The results:
Image showing distances from
Fort St. John and from water; black is not an appropriate location
for OSB plant, with brown
as least appropriate and light green as most appropriate.
Once the above image had been overlayed with the boolean provincial forest, road, and rail layers, I had one more step to perform. I ran the final image through SCALAR and divided by 58140 in order to create a more sensible legend that would convey appropriateness of location on a scale of 0 (not appropriate) to 1 (most appropriate). The final image resulted (shown here with the original vector layers):
The map shows Fort St. John
in the south as a collection of roads. The red dot signifies the
proposed
location of the OSB plant;
the airport is shown by the red recangle just east of the plant.
The Alaska Highway
can be seen running northwest
from the city. The BC Rail line is shown in gold, with rivers and
lakes in blue.
The Peace River runs along
the southwest portion of the map.
Conclusion:
Reveiw of criteria for the location of the OSB plant used in analysis:
With my limited criteria,
I have shown that the current location of the proposed Slocan-LP OSB plant
is not appropriate. More suitable locations can be found about 30-40
km north-northwest of Fort St. John. Unfortunately, this does not
take into account other communities' concerns, but it does provide a starting
point for finding an alternative location for the OSB plant.
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1.
Spatial
Question
2.
Data
Collection
3.
Methodology
4.
Spatial
Analysis
5.
Methodological
and Operational Problems