Prediction of Coastal Flooding and Evacuation Demand Estimation Considering Climate Change

Climate change consequences such as sea level rise have put residents and transportation systems in the Tri-State coastal regions around New York at a risk for catastrophic flooding events, and it has become urgently needed to develop capabilities to predict the impact of such events. In this paper, the authors propose an approach to predict coastal flooding and analyze its impact on transportation systems and population in the region. In particular, the three-dimensional finite volume coastal ocean model (FVCM) is coupled with a two-dimensional shallow water model to simulate hydrodynamic flooding with resolution desired to resolve traffic systems such as streets at an affordable expense. A hydrological method is also proposed to estimate flooding resulting from overland runoff. The hydrodynamic and hydrological methods are combined to determine the entire flooded region. On the basis of the predicted areas of flooding, the demand to be evacuated may be estimated. To demonstrate its capabilities and performance, the proposed approach is applied to flooding along Cape May coastlines in the Delaware Bay under projected sea level and storm conditions. Simulations indicate that sea level rise indeed leads to a substantial increase in the total flooded area. Transportation facilities and local population will be significantly impacted in this region as discussed in the results of the case study.