Houston Daily

A new numerical computer model has been developed by Hanadi Rifai, a professor of Civil and Environmental Engineering and director of the Hurricane Resilience Research Institute at the University of Houston. This model aims to provide insights into the movement of water in estuaries, where fresh and saltwater intersect. Professor Rifai has two decades of experience in studying Galveston Bay, focusing on its tidal patterns, and pollution diffusion, and understanding how ecosystems maintain balance.

Rifai’s model, which is highlighted in the journal Environmental Science and Pollution Research, is designed to help evaluate the effects of climate variability and sea level changes on coastal communities. “Models such as this one will be critical for evaluating climate variability and sea level fluctuation impacts on these lifeline systems for coastal communities,” she explains. The model will guide strategies to protect water quality, wildlife, and mitigate flooding and pollution.

Professor Rifai has a significant history of conducting sediment sampling, even during hurricanes Ike and Harvey. She stresses the importance of continuous sampling over time and the integration of rainfall and stream flow data in predictive modeling. "An important lesson learned has been that the estuary while thriving and vibrant, is a complex system with many ‘moving parts’, and is sensitive to external influences," Rifai notes. These influences include extreme weather events and industrial activities.

The research reveals that rainfall accelerates water movement, particularly in deeper waters. The convergence of rivers and estuaries presents unpredictable water flows. Furthermore, storms contribute to reducing salinity but increase suspended sediments, resulting in the redistribution of pollutants within the estuary. “The interactions between the water column and the underlying sediment and how to model those was a key focus,” states Rifai.

Adithya Govindarajan from Gradient Corp. and Martin Nguyen, a graduate student in Rifai’s lab, collaborated on this project, underscoring the multidisciplinary efforts in advancing estuarine research.