Discussion and Conclusions

Abstract

C e n t r e f o r U r b a n a n d C o m m u n i t y S t u d i e s • U n i v e r s i t y o f T o r o n t o • w w w . u r b a n c e n t r e . u t o r o n t o . c a 2 Gross density is not adequate for comparing densities or measuring intensification over time.The key issue in defining density is the distinction between gross and net density. Measures of gross density are easy to calculate and understand, but may be misleading, because very different types of land use are found in different places. Because some municipalities like Toronto are almost fully built-up and others have large amounts of undeveloped land, the use of gross or net measurements will make a huge difference in the way municipalities appear relative to each other. For example, Figure 2.1 shows that Mississauga has a higher gross population density than Brampton, but Figure 2.2 shows the reverse for net density. The same problem also emerges in the analysis of smaller units such as tracts or dissemination areas and in measuring changes in density over time. Different areas may have exactly the same amount of growth at the same intensity of development, but areas with smaller amounts of unbuilt land will appear to have grown denser than areas with larger amounts of unbuilt land, all else being equal. Clearly defining what should be included in net measures of density is complex and difficult.The various development patterns found throughout the region was shown in the analysis of CTs associated with Urban Growth Centres in Section 3. Ideally, all built-up lands should be included, but it is difficult to obtain consistent, reliable data and to define exactly what "built-up" means. Greenspace and protected lands are especially hard to define. For example, small neighbourhood parks are usually seen as integral to development and defined as part of the built-up area, but large tracts of protected, environmentally sensitive lands are not. In between these extremes are an array of sizes and types of open space protected to different degrees by different levels of government. Roads present a similar problem: local streets are seen as integral to development and are often included as "built-up," but limited-access highways serve regional purposes and do not provide direct access to development. Whether or not the rights-ofway for highways are included can substantially affect measured densities, without affecting the intensity of nearby development. Again, the Province needs to establish consistent criteria in this area.A consistent method of defining the boundaries of measurement units is critical to meaningful density measurement and monitoring. The modifiable areal unit problem (MAUP) complicates the measurement of density. The size of the geographic units used and the location of their boundaries can have enormous impacts on the results. These problems are particularly acute in the analysis of census data. Boundaries and Census DataUsing census data to describe urban form and measure changes in density is subject to several problems. Census data on pop...