Precipitation and Aerosol Analysis
Looking at the precipitation and aerosol map, a general pattern for the 2001 can be found. For aerosol concentrations, Richmond and Port Moody have the highest values. On the other hand, North Vancouver and northern Burnaby have the lowest aerosol concentration in all of GVRD. This pattern is caused by the density of population, the number of cars on the roads of a city, emission of mechanical machineries (factories), and also wind patterns.
For precipitation, the general trend is that the north shore areas have the highest precipitation values due to orographic uplift caused by the high mountains in that region. The lowest values occur in southern Richmond and Delta. This dryness pattern near the Canada-US border is caused by the pattern of storm movements. Usually, storm tracks in the GVRD area will pass through the Richmond and Vancouver area with a sharp cut-off point of storm clouds right above southern Richmond, southern Surrey, and Delta. Besides, this area has the lowest elevation in the region, as evident by its location at the mouth of the Fraser River delta (Look at DEM Map). Therefore, orographic uplift is a non-factor in the southern part of GVRD. The combination of these two reasons provides answers for the dryness in the south.
As one can see, there is no observable correlation between aerosol concentration and precipitation in the GVRD at present time. This is attributed to the dominant control of mid-latitude storm tracks and orographic uplift at the northern edge of the GVRD. These two features combine to clutter up the signature of aerosol effects to the precipitation pattern in the region. Besides these factors, there are a few technical problems related to this study that one has to take a close look at in order to understand the difficulty of analyzing such a complex precipitation system.
Map 4. Digital Elevation Map of the GVRD
When aerosol concentration is low and precipitation is high, the air pollution level is low since the rain will be able to throughly wash all the aerosol away. When aerosol concentration is high and precipitation is high, the air pollution is still manageable since the rain will still have enough moisture to wash most of the aerosol away from thte atmosphere. It is when aerosol is high and precipitation is low, the condition of air pollution will be the worse and causes photochemical smog generation. The inverse relationship between aerosol and precipitation in this regard is mapped out in Map 4 showing the areas of bad air quality generation.
Map 6. Areas with slopes less than 5 degrees.
Map 2. Aerosol Distribution Map of the GVRD (2001)
Map 3. Precipitation Distribution Map of the GVRD (2001)
Map 5. Areas with
bad air quality (smog) generation.
The higher the index, the stronger the generation.
Topography Analysis
The slope map (Map 6) shows boolean flat areas of the GVRD. The flat areas are classified as less than 5 degrees in slope. This boolean contraint is then overlaid with the bad air quality generation map to see which areas are most in need for non-polluting transit in the GVRD. It is clearly seen in Map 7 that the Richmond and Delta areas are the most needed for a new public transit line.
Map 7. Areas most
in need of public transit line. The higher the suitability value, the
higher the need.
Socio-Geographic Analysis
(Population Density & Avg. Family Income)
Using a visual analysis from the population density map, one can see that the population is most dense in Vancouver and Burnaby, with Richmond following closely behind. The income map on the other hand, shows that patches of Vancouver has the highest average family income. Richmond and Delta has a general middle class income. Thus, aggregating all these socio-geographic factors, one can predict that Richmond is a pretty decent and feasible location for a new rapid transit line since Vancouver Burnaby already have skytrain. However, environmental and topographic factors still have to be included in order to do a final analysis of the optimal areas for the new non-polluting rapid transit line.
Map 8. Population Density Map (GVRD, 2001)
Map 9. Average Family Income Map (GVRD, 2001)
Final Results
(Post MCE results)
Now, all the factors and constraints are evaluated in a visual basis. One can have a rough idea that Richmond is already a good candidate for the new non-polluting rapid transit line. What are the results when an MCE analysis is executed in IDRISI and putting all these factors into different weightings according to importance? It has already been mentioned in the methodology section that both aerosol and precipitation factors are of equal importance, while income and population density is less than them. Also, income is less important than population density when the subject of consideration is building a new transit line. The two dominant constraints for the transit line are water bodies and slope over 5 degrees. When these factors and constraints are put into an MCE, here is the result:
Map 10. Map of suitable areas for having a new non-polluting light rapid transit line.
Now, the result is clearly shown, that the Richmond area in dark purple is most in need of a new, non-polluting rapid transit line. This analysis takes into account the environmental concern of air pollution and population density and income. Richmond is more suitable than the other surrounding areas because, it has got a relatively low precipitation to wash away its high aerosol content compared to others in the GVRD area. Coupled with the fact that Richmond has a high population of middle class, it becomes clear that it is the place that need a non-polluting transport line the most.