Sediment as Story: DOCS' Liu receives almost $500k to use sediment to study compound floods

BATON ROUGE - After Hurricane Katrina, researchers looking to understand the storm’s impact on the coasts of Mississippi and Louisiana focused on storm surge.

As climate change makes hurricanes bigger, wetter and slower moving, however, such a singular focus may no longer be sufficient.

Storms like Hurricane Harvey linger longer and drop more precipitation. This can lead to inland flooding and, subsequently, a compound flood -  a complex flood event that occurs on a coastline when waters from a storm surge combine with freshwater flooding.

“This is an issue at the cutting edge of natural disaster research,” said Kam-biu Liu, the George Barineau III Professor in the Department of Oceanography & Coastal Sciences, or DOCS.

Liu and his collaborators at the University of North Texas have recently begun an almost $500,000 grant from the National Science Foundation to study the impacts a compound flood can have on a coastline.

They will be examining soil samples from around the Texas coast as they attempt to determine which sediment deposits were pushed into the coastline during a storm surge and which washed down during an inland flood.

The scientists’ goal is to create a method to reliably determine the origin of the sediment, which will provide valuable information for both coastal researchers and managers.

Liu, who is considered the father of paleotempestology – the study of ancient hurricanes – said being able to differentiate between sediment deposits originating on land versus those from the ocean will provide better information about ancient storms.

More knowledge about ancient storms provides a better baseline for comparison to modern storms, and therefore more information about how the climate is changing.  

Coastal managers and wetland scientists will also benefit from being able to distinguish between the two types of sediment. Coasts and coastal wetlands around the world are under threat from rising sea levels, and understanding how much sediment can be predicted to wash into an area during a compound flooding event may prove useful in terms of understanding how wetlands can be built.

Liu, a highly decorated researcher who most recently received the AGU Gilbert F White Award, noted that he has been funded by NSF over 30 times throughout the course of his career. “My feeling is that I owe NSF a great gratitude over the 30 some years, I have been funded almost continuously by NSF,” Liu said. “NSF is a great research and scientific funding institution, and I am greatly grateful to NSF for funding my research over my career.”