Understanding Future Non-stationary Exposure Climate for U.S. Regions: Storm Power, Sea Level Change, and Topographic Thresholds

Sea level change can be viewed as a foundational mechanism for hydrodynamic processes, combining with waves and other water level components that range from low to high frequency. For the US Army Corps of Engineers (USACE), multiple mission areas have stability and performance functions that will respond to future nonstationary conditions differently. The identification of thresholds and the timing of the future exceedance of those thresholds is important. Hydrodynamic parameters and combinations may vary significantly for different USACE regions, and, in addition, the topographic layout and characteristics of the project receiving area may take various forms. The importance of the range, frequency and duration of loading will depend on the topography, type of impacted resources, and the consequence of exposure. For this analysis, storm power comparisons by region are developed using wave data from the National Data Buoy Center around the U.S. coastline. Storm power can be viewed in a variety of formats including individual storms, successive storms, storm seasons, and annual power. A better understanding of what drives regional loading can influence the data, tools, and methods that are most effective in quantifying risk and project performance. Water level comparisons (including sea level change) are made and contrasted for regional explanations of the potential impacts of future nonstationary on expected consequences and how those may change over time.