Using an Urban Growth Model Framework to Project the Impacts of Future Flooding on Coastal Populations

Abstract

Urbanization in coastal areas of the United States is increasing as simultaneously the East and Gulf coasts of the United States face increasing threats from climate change from hurricanes and storm surge inundation. This study will evaluate urban growth using a cellular automata model to analyze the trends in urbanization between 1996 and 2019 and predict how it will continue until 2050. The study uses historical trends in land use and urbanization, as well as spatial and environmental data, to evaluate the likelihood of urban growth in two modeled scenarios: one that accounts for flood risk and one that does not. The study evaluates trends over the entire coastal buffer area, including the 150-kilometers adjacent to the East and Gulf coasts as well as targeted areas of New Orleans, Louisiana and Houston, Texas to determine growth at the scale of a metropolitan area. Both the scenarios have an overall prediction accuracy of 93% in determining the projected land use of a cell on the gridded map; however, the two models have different strengths. The scenario excluding storm surge impacts better predicts urban growth across the entire study area categorically, while the scenario accounting for the suitability of growth in areas at risk of storm surge inundation is more reliable in showing the specific areas urban growth occurred. The comparison of the strengths and weaknesses of the models will help determine if urbanization and population shifts are impacted by threats of storm surge and hurricanes in the study area. The outcome of the model analysis can be used to influence how communities burdened by climate change can strategically grow to limit the impacts of flooding on their residents and infrastructure.