Simulating Urban Expansion Dynamics via the Cellular-Automata-based SLEUTH model: A Case Study in Auckland Metropolitan Area

Abstract

Since the Anthropocene, the rapid population growth has caused urban areas to expand towards the surrounding environments, which brings up the importance of sustainable urban development and management under scientific guidance. As urbanisation is composed of complex factors across different disciplines throughout spatiotemporal scales, urban models are then usually utilised to function as planning systems that can simplify urban complexity by combining multi-disciplinary approaches. The cellular automata (CA) has become a successful urban model, which is able to replicate urban complexity under simple processes. Auckland is the largest city of New Zealand that has the highest population. In order to promote sustainable urban development in Auckland, simulating future urban expansion dynamics can be a method to help urban planners to formulate efficient urban planning policies. The CA-based SLEUTH model can thus be utilised as it is an urban model that can simulate future urban expansion dynamics.

In this master’s thesis, four historical land cover datasets from 1996 to 2018, and datasets related to the digital elevation model, traffic roads, natural protection areas and fundamental facilities were acquired to analyse future urban expansion dynamics of the Auckland Metropolitan Area via the SLEUTH model under three different simulation scenarios. Three stages of the model calibration step were initially sequentially processed based on the required input layers of the model, which produced the best growth coefficient combinations of each simulation scenario. After the accuracy assessment proved adequate results from scenario-based historical urban expansion simulations, three future urban expansion maps in 2050 were then simulated as outputs with regards to formulated scenarios. Overall, based on previous research of the SLEUTH model, this thesis research added up the possibility of applying the SLEUTH model into coastal urban areas, which also filled the vacancy of implementing various urban models into simulating the future urban expansion dynamics of the Auckland Metropolitan Area through achieving objectives with regards to potential influences of traffic roads and schools on future urban patterns, especially for reducing the consumption on surrounding farmlands. Future work should explore the possibility of adopting more social and economic factors into the SLEUTH model under finer scales.