01/13/2015

Methodologies for Estimating Coastal Infrastructure Risks Under Rising Flood Potential

Summary

Climate change brings increasing sea surface temperature, which is the engine of tropical storms, allowing them to grow in intensity and destructive power. At the same time, sea levels are predicted to rise. Further adding to the risk, some areas are sinking as the result of natural processes or because of removal of subsurface water or fossil fuels. Combining all these factors, the risk of excessive flood damage to coastal infrastructure increases. Department of Energy (DOE)-supported researchers at the Massachusetts Institute of Technology developed a novel, science-driven analysis framework that reveals insights into complex systems interactions that can be used to inform adaptation decisions for coastal infrastructure. This methodology was demonstrated for a facility in Galveston Bay at 5 feet above sea level. Using results from multiple climate models, the researchers modeled changes in hurricane activity and applied the results to a surge model to project the change in frequency and magnitude of storm surge heights. They then coupled the projections with estimates of the uncertainty in the magnitude of sea level rise and subsidence, producing a detailed projection of flood risk in 2100. For the Galveston Bay facility, the researchers assumed that the long-term adaptation path is to protect the facility through the construction of a levee, but that decision options should consider building in phases in response to the rising risk. The analytic framework, using advanced dynamic programming, explores the construction path that minimizes present value of the aggregate costs of damage and protection. The framework links methods and models to characterize flood risk uncertainty and, ultimately, real options analysis to produce time-dependent risk profiles through time. Work was supported through funding from DOE’s Integrated Assessment Research Program.

References

Lickley, M. J., N. Lin, and H. D. Jacoby. 2014. “Analysis of Coastal Protection Under Rising Flood Risk,” Climate Risk Management 6, 18–26. DOI: 10.1016/j.crm.2015.01.001