Niche-based cellular automata for sustainable land use planning

Rapid urbanization has brought about a series of ecological and environmental problems. Urban planning based on the concepts of ecology is useful for alleviating some of these problems. This paper proposes a new method by incorporating the ecological concept of "niche" in cellular automata (CA) for planning purposes, and illustrates its application to the simulation of sustainable land use. There have been many applications of CA for simulating urban development, yielding significant progresses in verifying urban theories and assumptions. However, many of them are limited to the simulation and prediction of urban development based on the "business-as-usual" scenario that assumes further development to follow present patterns. There exists a general lack of CA application in urban planning. Land use planning is required to solve complex land use problems in implementing the initiatives of sustainable land use. Complex natural and social systems are the subject of many studies aimed at understanding their characteristic dynamics and functioning. Scenario analysis is a promising and interesting planning tool for investigating future in such a complex environment. In this study, the planning objectives related to sustainable development are embedded in this proposed CA model. It simulates alternative development patterns under different land use policies. Planning authorities can evaluatethese options and choose the best option for implementing the initiative of sustainable development. This model thus provides a powerful exploratory tool for generating alternative development patterns. The novelty of this proposed mode is based on the incorporation of the concept of ecological "niche" in CA. Each cell in cellular automata is assigned with a distinct ecological "niche" such as "agriculture ecological niche", "urban development ecological niche" and sustainable development ecological "niche". The ecological "niche" of each cell will have its own distinct "contribution" to the urban development according to the planning objectives These cells will compete each other according to a biological competition mechanism characterized by selection of the superior and elimination of the inferior for ecological "niche" assuming cells with higher potentials are more competitive. This competition mechanism will result in urban evolution. This paper presents a new method for simulating sustainable land use by the integration of ecological "niche", cellular automata and GIS. This ecological cellular automaton can simulate urban development under different land use policies. It can be used to assist decision makers in searching for alternative land development so that land use conflicts can be minimized. This model has been applied to the simulation of development alternatives for a fast growing city Guangzhou, South China, and produced promising results.