A University of Texas at Arlington civil engineering researcher is filling in an information gap for the state by determining how much sediment is lost by Texas rivers to the ocean.
Yu Zhang, associate professor in the Department of Civil Engineering, received a $150,000 Texas Water Development Board grant to assess the amount of sediment transported from Texas rivers to the Gulf of Mexico. The project is titled “Best Practices in Modeling Sediment Transport and Budget Along Texas Coast.” He and his team will also work with the General Land Office to develop a Sediment Management Plan for the state.
Zhang said the Brazos River is the largest contributor to sediment in the Gulf among all the river systems in Texas. The Brazos River Delta has been growing since the diversion of its inlet in 1929. Part of his project will be to determine how this delta growth accelerates via abnormal sediment yield during major flooding events.
“We want to contrast physically the sediment transport during normal times and during flooding events for the Brazos River and the Colorado River,” Zhang said. “We’ll help reconstruct accurate sediment discharge into the Gulf. Texas needs more accurate data to determine the shoreline changes.”
His team will study how the waves carry the sediments once the sediment reaches the ocean.
“Excessive sediments are detrimental to navigation,” Zhang said. “They clog up the flow and a lot of dredging has to be done to counteract the sedimentation in coastal waterways and streams. In the meantime, however, a lack of sediment will alter the balance between sedimentation and erosion that may speed up shoreline retreat.”
He noted that Texas’ flat terrain can also cause sediment to accumulate further up shore.
“Sometimes, sediment collects so much that water from nearby rivers cannot flow out to the Gulf,” Zhang said.
Melanie Sattler, interim chair of the Department of Civil Engineering, said Zhang’s work will protect and enhance what is a natural asset for the state.
“Beaches, basins and estuaries are all valuable to citizens of the state of Texas,” she said. “Zhang’s work is helping get Texas’ shoreline stabilized. That’s valuable work.”