In Hurricane Waves and Storm Surge, Prof Sees Threat to Louisiana Coast

Louisiana State professor Q. Jim Chen is working to understand violent storms.

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BATON ROUGE — As Louisiana begins to watch the Gulf of Mexico with a wary eye, it’s hard not to remember hurricane seasons past that produced such storms as Hurricanes Katrina, Rita, Gustav, Ike … the list goes on. Q. Jim Chen, Louisiana State University associate professor of civil and environmental engineering and recipient of one of the National Science Foundation’s most prestigious awards, the NSF Career Grant, leads a research group tasked with helping our coastal communities better prepare for hurricanes and other inevitable events that come with living near the coast.

“More than 50 percent of this country’s population lives within 50 miles of the shoreline,” said Chen. “Human activity has dramatically altered the coastline, impeding its natural ability to protect inlying areas. Because of the weakening of this natural defense system, as well as climate change and accelerated sea-level rise, it is imperative that we take action to mitigate impending coastal hazards and disasters.”

Chen’s group makes use of a novel new coastal modeling technique that combines both hurricane waves and storm surge, producing the most comprehensive modeling system currently available.

“Simulations of storm surges and coastal waves are intrinsically complex owing to the highly variable and non-linear boundary conditions involved, such as sea surface and coastal landscapes,” said Chen. “Traditionally, wind waves and storm surges are treated as two separate hydrodynamic processes, but in fact they interact and influence each other in coastal waters.”

According to Chen, storm surges increase water depth—and, naturally, wave height—near the shore, which causes significant damage to coastal infrastructure and dramatically increases beach erosion. But the breaking of wind waves in shallow water modifies the ocean surface roughness and increases the surge height. Chen’s group is unique because they have found an innovative way to develop models simulating the impacts of both storm surge and wind waves using the high performance computing technology available at LSU.

“We were also among the first to develop an efficient methodology for coupling two high-resolution storm surge and hurricane wave models for coastal areas and applying the technique to solve engineering problems associated with past major storms,” said Chen.

The ultimate goal of Chen’s ongoing research is to improve the fundamental understanding of complex coastal processes and enhance the practical application of advanced technologies for hurricane protection and coastal restoration. To reach this goal, he and his team are busy developing new computer models, perfecting the application of open-source modeling capabilities on complex engineering problems relating to storms and engaging in multi-level education and outreach activities such as the LSU High School Scholarship in Coastal Engineering, the LSU Minority Fellowship in Coastal Engineering and the new graduate program in coastal and ecological engineering, among other projects.

After the impact of Hurricane Katrina, the Chen Group coupled two state-of-the-art computer models simulating storm surge and wind waves generated by the storm. The model results were tested again using real field observations, including offshore buoy data. Their research results were identified by the NSF as notable accomplishments and featured on the foundation’s Web site.

“We then used the coupled models to run various scenarios,” said Chen. “In the end, our modeling capabilities allowed us to understand and explain the collapse of coastal infrastructure during recent hurricanes, and provided a methodology for the assessment of coastal bridge vulnerability in hurricane-prone areas.”

Chen and his research team looked at storm surge and wind waves generated by last year’s Hurricane Gustav to analyze the interaction between these two factors and the coastal landscape. After receiving the NSF Career Grant more than three years ago, Chen has gone on to raise more than $1.5 million in federal research grants supporting his modeling work.