The consequence of scale: process and policy implications of modelling urban sustainability using the conceptual framework of GIS‐MCDA

We live in a world that is dominated by humans. New paradigms that blend socioeconomic development with the preservation of our natural systems are required for future generations to thrive. Conceivably, scientists know what is needed to implement sustainable growth, with extensive research completed on urban biodiversity, ecological functions and land use practices. Connections between urban processes and global conservation efforts have been made, alongside a growing acceptance of the importance of nature to the well-being of an individual. However, broad societal issues, divisive politics, and an increasingly complicated network of human and ecological systems, present significant challenges to developing and maintaining sustainable cities. Arguably, the road to success is rooted in evidence-based policy decisions that rely on data and scientific findings, since science articulates what is happening. Yet it is policy that dictates how we address it.

This research investigates the theoretical foundation of multi-criteria decision analysis within geographic information systems (GIS-MCDA) as a composite indexing tool to assess relative measures of urban sustainability. This exploratory research uses scientific principles and rational frameworks to spatially structure, understand, and evaluate changing socioeconomic and environmental conditions in order to support policy and decision making practices. To accomplish this goal, a series of area-based composite indices are developed to model specific urban conditions pertaining to smart growth or sustainable planning practices for the City of Toronto, Canada. Model parameters are tested to assess index validity. Inherent uncertainties associated with modelling urban sustainability are systematically quantified and the ambiguities associated with aggregate data identified. Finally, this composite indexing approach is applied to a broader framework that links underlying social and ecological processes. The strengths and limitations of GIS-MCDA as a tool for policymakers is couched in policy and process implications throughout this research.

Multi-disciplinary approaches are imperative in pursuing sustainable cities and in understanding the association between socioeconomic patterns, physical processes, and urban infrastructure. In an increasingly complex and divided society, the conceptual framework of GIS-MCDA offers a pragmatic tool that allows decision-makers to appreciate issues from a variety of perspectives, enacting novel solutions that are driven by data, science, and the public.