Simulating urban growth on the US-Mexico border: Nogales, Arizona, and Nogales, Sonora

The paired US–Mexico border cities of Nogales, Arizona, and Nogales, Sonora (known as Ambos Nogales), are the largest and most rapidly growing cities on the Arizona–Sonora border. The growing urban population is producing extensive land-use and land-cover change in the region. The continued expansion of paired cities presents many environmental management and urban planning challenges. This research employs a cellular automata model to examine the difference between the patterns and rates of urban growth and land-use change under different environmental and planning strategies in the two cities over the next 20 years (2004–2025). A series of Landsat Thematic Mapper (TM) images acquired over different time periods (October 1985, July 1991, February 1995, September 2000, and July 2004) were used to simulate urban growth using four planning scenarios, namely business as usual, environmental protection, road network, and antigrowth strategy. The study reveals that the unchecked urban growth trend in the business as usual, environmental protection, and road network scenarios simulates significant (99.5%) edge developments or organic growth throughout the region. In contrast, the antigrowth scenario, which emphasizes environmental protection, allows for more green and open space and is therefore considered the most desirable for planning future urban land use and development.