Modelling urban growth and landscape changes in the Atlanta metropolitan area

We use an urban growth model, closely coupled with a land transition model, to simulate future urban growth in the Atlanta metropolitan area, one of the fastest growing metropolises in the United States during the past three decades. We calibrate the model with historical data that are extracted from a time series of satellite images. We design three specific scenarios to simulate the spatial consequences of urban growth under different environmental conditions. The first scenario is to simulate the continued growth trend by maintaining unchanged the current conditions. The second scenario is to project the growth trend by taking into consideration road development and environmental protection. The third scenario is to simulate the development trend by slowing down growth and changing growth pattern. The first two scenarios demonstrate that unchecked urban growth would result in the displacement of almost the entire natural vegetation and all of the open space in the metro area. In contrast, the result from the third scenario shows that much more greenness and open space, including buffer zones of large streams and lakes, could be preserved. Accordingly, the last scenario should be the most desirable for the future urban growth of Atlanta. We also examine the model's effectiveness as applied to the Atlanta area and suggest future research directions for more accurate simulations.