by Elise Bernard
When a hurricane is headed toward the Louisiana coast, officials evaluate a variety of factors when determining the need for evacuation. One of the most pressing concerns is an area’s susceptibility to storm surge. LSU coastal engineering professor Q. Jim Chen, assisted by his graduate students, Kyle Parker, Ranjit Jadhav, Ke Liu and Ling Zhu, and postdoctoral researchers, Arash Karimpour and Kelin Hu, measures and models waves and storm surges of hurricanes to help emergency managers and Louisiana residents in preparing and responding to hurricanes making landfall on the Louisiana coast.
On Aug. 27, just one day before Hurricane Isaac made landfall, Chen, Parker, Jadhav and Karimpour installed an array of 12 wave and surge sensors along the east bank of Mississippi River and the perimeter of the Breton Sound Estuary in southeast Louisiana.
Their experiment was designed to measure the waves and storm surge on wetlands and nearby coastal infrastructure, such as levees and roadways. The rapidly-installed mobile wave and surge monitoring system consisted of seven wave gages and five surge gages.
“We have utilized high-performance computing technology available at LSU to obtain a timely forecast of coastal flooding and used the model forecast to guide our field measurements,” Chen said.
In collaboration with T. Baker Smith LLC, a Louisiana engineering firm, Chen’s group conducted a topographic survey near the sensors using the GPS network developed by the LSU Center for Geoinformatics, or C4G.
Funded by a completed federal grant, Chen’s group has developed the capability of rapidly installing wave and surge sensors on marshlands. Hurricane Isaac was the third distribution of wave and surge gauges prior to an incoming storm by Chen’s group, who had previously studied Tropical Storm Ida in 2009 and Tropical Storm Lee in 2011.
Although researchers have recognized the value of wetlands in reducing the impact of hurricanes, no systematic field observations of waves, surges and vegetation exists to determine the extent of flood risk reduction. Datasets, such as those collected by Chen, aid coastal engineers and scientists in developing and testing accurate computer models for predicting storm surge and wind waves over coastal wetlands.
In addition to field observations of waves and storm surge, Chen’s group also participated in forecasting storm surges and hurricane waves using the Advanced Surge Guidance System, or ASGS. Supported by the National Science Foundation and Louisiana Board of Regents, ASGS is a multi-state coastal modeling research and development effort providing advisory services related to approaching hurricane events.
The ASGS group successfully forecasted and displayed storm surge information for Hurricane Isaac for eight days, and a variety of users from federal, state and local agencies accessed the website and obtained information to make key decisions prior to the storm.
Responding to Louisiana’s demand for highly educated and skilled engineers like Chen to work on coastal and wetland problems, the LSU Department of Civil & Environmental Engineering launched a new Master of Science degree program in coastal and ecological engineering. The program was developed in response to the continuous threat of coastal flooding, erosion of Louisiana’s barrier islands and loss of coastal wetlands along Louisiana’s unique estuaries and shorelines resulting from hurricanes like those Chen studies.
“Future research is needed to integrate the storm surge forecast system with various disaster management tools to save lives and protect properties from future hurricane impacts,” Chen said.
For more information on the Department of Civil and Environmental Engineering, visit http://www.cee.lsu.edu.