Jul 27, 2015

Increasing risk of compound flooding from storm surge and rainfall for major US cities

Thomas Wahl, Shaleen Jain, Jens Bender, Steven D. Meyers, Mark E. Luther
Nature Climate Change
  • States that when storm surge and heavy precipitation co-occur, the potential for flooding in low-lying coastal areas is often much greater than from either in isolation
  • Determines the likelihood of joint occurrence of these two phenomena for the contiguous United States (US) and show that the risk of compound flooding is higher for the Atlantic/Gulf coast relative to the Pacific coast
  • Provides evidence that the number of compound events has increased significantly over the past century at many of the major coastal cities
  • Finds that long-term sea-level rise is the main driver for accelerated flooding along the US coastline; however, under otherwise stationary conditions (no trends in individual records), changes in the joint distributions of storm surge and precipitation associated with climate variability and change also augment flood potential
  • Looks at New York City (NYC)—as an example—and finds the observed increase in compound events is attributed to a shift towards storm surge weather patterns that also favor high precipitation