2. Modeling Sea-Level Rise and Surge in Low-Lying Urban Areas Using Spatial Data, Geographic Information Systems, and Animation Methods

Spatial datasets including elevation, land cover, and population of urban areas provide a basis for modeling and animating sea-level rise and surges resulting from storms and other catastrophic events. With a geographic information system (GIS), elevation data can be used to determine urban areas with large population numbers and densities in low-lying areas subject to inundation from rising water. This chapter provides details of the analysis and modeling procedure, as well as animations for specific areas of the world that are at risk from inundation from moderate rises or surges of sea level. The work is not an attempt to predict sea-level rise, but rather a methodological study of how to use GIS data layers to create the models and animations. Whereas global sea level rise is currently measured by millimeters per year, this work examines theoretical rise measured in meters as well as coastal threats posed by tsunamis, such as occurred in the Indian Ocean in 2004. Global, regional, and local animations can be created using widely available elevation, land cover, and population data. The models and animations provide a basis for determining areas with large population numbers in relatively low-lying areas and potentially subject to inundation risk, as was the case when Hurricane Katrina devastated New Orleans. This determination can provide a basis for more detailed modeling and policy planning such as development and evacuation.