High-Resolution Monitoring of Nearshore Morphologic Change

$30-$50 MILLION POTENTIAL SAVINGS PER YEAR

The Corps’ mission to maintain the U.S. coastline and protect valuable coastal infrastructure from storm damage is costly. Recent data from Western Carolina University notes the total cost of nourishing beaches is nearly $10 billion in the U.S. alone. However, reliable predictive capabilities for nearshore hydrodynamics and morphology changes are needed to optimize project designs, extend project lifecycles and promote more resilient coastlines. Corps research focuses on using novel, high-resolution oceanographic field datasets collected at the ERDC Field Research Facility in Duck, North Carolina, to directly inform development and validation of improved predictive methods for sediment transport and morphology evolution in sandy beach environments. This work has led to improvements in the capabilities and skill of the Corps-developed numerical modeling suite, CSHORE, which can be used to simulate beach nourishment evolution, with particular emphasis on coastline response to extreme storms. Continued advancements through investment in nearshore processes research will enable the Corps to predict morphology change at time scales of relevance for managing coastal sediment resources and optimal sand placement.

PROBLEM: Understanding and predicting how the coastline evolves over time from days to decades are critical to coastal resiliency planning and infrastructure protection. Coastal change results from complex interactions and feedback between ocean processes, such as waves and currents, and the constantly evolving shape of the seafloor and coastline. The most dramatic changes often happen rapidly during extreme storms when very little data are available to inform model development and improvement.

SOLUTION: ERDC modelers and field data scientists developed a plan to collect a targeted field dataset that would improve Corps modeling capabilities. Using state-of-theart instrumentation and data collection techniques, Corps researchers are collecting a continuous multi-year data set that quantifies how numerous tropical storms and large Nor’easters impact the coastline.

IMPACT: This research led to development of new algorithms and improved model skill, allowing better predictions of coastal evolution on sandy shorelines. Corps district engineers can now more effectively optimize beach fill placements, leading to a more economical design process. Given the growing cost of nourishing our Nation’s coastlines, improving the ability to more efficiently design and place sediment along our coasts by 3 to 5 percent will lead to $30 to $50 million in savings to the Nation per year.