The proper definition of the factors and appropriate rankings are critical to carrying out the analysis. When considering how to decide on the level of protection for a given land area in the Greenbelt, ecological, hydrological and agricultural components were considered and applied spatially. Achieving this objective required consulting the literature on areas of importance for each aspect of the environment.
Ecological biodiversity was measured by species richness and species diversity (Why Measure Biodiversity, 2009). It is often measured because it is synonymous with ecosystem health. To achieve the goal of ranking certain factors, understanding what factors affect the biodiversity was important. In order to decipher whether the land was more ecologically important, it was imperative to look at protection data of flora and fauna, ecologically significant land, areas with or without vegetation, species patterns, size of the species community and their location. This data was useful to look at when considering theories of ecology like edge effects, dynamic forest mosaics, forest “islands” and fragmentation (Hunter, 1999) and how to figure out what cells would be assigned values on a common scale.
When working with environmental data the connectedness of different disciplines, varying scales, and open-system operations can be inherently complex to work with. Keeping factors separate (ecology and hydrology) was a major assumption that helped with the comparison between different categories in the environment. Within a watershed, protected areas with a concern of degradation and contamination are often surface water sources like lakes, river, and streams (Ruso, 2008). Protecting the connectivity of these features ensured that water resources were maintained. The size of the feature determined the streams ability to react to an impactful change in the hydrology and connectivity of an area. Larger first order streams were able to have development closer to them due to their resiliency (Westman, 1978) while a small tributary may be significant in the connectivity of a system but not able to handle the quickly altered landscape following development. Natural spring water from groundwater sources coming to surface, feed and contribute to many surface water processes. Emphasizing the importance of groundwater-surface water interactions (Chapman, 2007).
The last of the considerations when looking at what areas to prioritize for protection was agricultural land. A dominant driver in the initial process of creating the Greenbelt Act was to help preserve the uniquely productive farmland of the area and help moderate the goods and services of farmers in a rapidly expanding urban environment. In the agricultural aspects of ranking land importance, there was not a lot of variances. Agricultural land is considered extremely valuable to the purpose of the Greenbelt (Greenbelt Act, 2009) but the highest-ranking factor of farmland was the ability to produce specialty crops. The specialty crops are considered particularly important because they are unique in the sense that they are the only agricultural land in the region able to produce that particular crop, like peaches or grapes (Government of Ontario, 2015). These lands are important to protect because once they are lost, they cannot be restored. The loss also has large economic impacts to Ontario farmers adding an extra layer of significance.