Matthew Hiatt
Associate Professor Louisiana State University
- Baton Rouge LA
Dr. Hiatt’s research investigates hydrology and hydrodynamics in coastal systems using numerical modeling and field measurements.
Media
Biography
Areas of Expertise
Research Focus
Coastal Hydrology & Hydrodynamics
Dr. Hiatt’s research focuses on coastal hydrology and hydrodynamics, revealing how water, sediment, and nutrients circulate through river deltas, estuaries, and wetlands. He pairs field measurements with remote sensing and numerical modeling to map transport pathways and guide restoration design and flood-resilience planning along the Gulf Coast.
Accomplishments
LSU Rainmaker Emerging Scholar in Science, Technology, Engineering & Mathematics
2025
Worley Professor of Excellence
2024
LSU Alumni Association Rising Faculty Research Award
2022
LSU C-I Teaching Fellow
2023- 2024
NSF CAREER Award
2022
Joseph Lipsey, Jr. and Richard A. Lipsey Excellence in Teaching Award
2021
Education
University of Texas at Austin
Ph.D.
Civil Engineering
2016
University of Texas at Austin
M.S.E.
Civil Engineering
2013
University of Kansas
B.S.C.E.
Civil Engineering
2011
Affiliations
- American Geophysical Union
- European Geophysical Union
- American Society of Civil Engineers
- Tau Beta Pi
- International Association for Hydro-Environment Engineering and Research
Media Appearances
LSU Celebrates Six Rainmakers
Louisiana State University online
2025-03-10
Associate Professor Matthew Hiatt studies the hydrology and geomorphology of river deltas and estuaries with a focus on coastal ecosystem design solutions. His research focuses on the flow of water, sediment, and nutrients between rivers and their surrounding wetlands with an emphasis on how these flows change over time. His work informs the ongoing efforts to protect and restore Louisiana’s coast and helps forecast flood risk in the Mississippi River Delta.
[...]
“The complexity of coastal ecosystems is a fascinating puzzle that I’m ceaselessly motivated to piece together,” Hiatt said. “I am honored to work alongside bright and passionate students and faculty to better understand the fundamental processes shaping coastlines, and develop solutions that protect both people and the environment.”
Dr. Matthew Hiatt Receives Worley Professor of Excellence Award
LSU Sports online
2024-10-08
“I can think of no better place in the world to conduct my research and connect with students than the College of the Coast & Environment at LSU,” said Dr. Hiatt. “The passion and motivation that LSU students have for addressing coastal issues, both in our state and around the world, is unparalleled. I am honored to work alongside them to understand the processes shaping our coastline and to develop solutions, especially when they directly impact Louisiana.”
4 LSU professors awarded National Science Foundation's most prestigious early-career grant
The Advocate online
2022-07-24
Matthew Hiatt
Hiatt will receive $480,917 over five years to research complex coastal hydrological processes essential to predicting future effects of coastal restoration strategies.
Primarily focused in Louisiana, Hiatt said he'll use fieldwork and numerical modeling to combine five years of field measurements in the Wax Lake Delta with computer simulations of long-term and short-term changes to the delta to understand dynamic patterns of water movement changes through time.
"We're trying to understand how things like sea level rise and things like changes in sediment distribution affect the growth of the delta and subsequently influence how the hydrology or water movement changes as the system grows," he said.
Articles
Water exposure time distributions controlled by freshwater releases in a semi‐enclosed estuary
Water Resources Research2025
Freshwater diversions manage water shortages, salinity, and control floodwater by redirecting river flows; however, their full ecological and hydrological impact remains unknown. This study examines the Lake Pontchartrain Estuary in Louisiana using a hydrodynamic model and Lagrangian particle tracking to assess how diversion operations (open, closed) and tributary discharge levels (low, median, high) influence water exposure time—the cumulative duration water remains in a domain, including re‐entry. Exposure time was analyzed based on the time required for 50%, 75%, and 90% of released particles (E50 ${E}_{50}$, E75 ${E}_{75}$, and E90 ${E}_{90}$) to leave a defined region of interest (ROI).
Modelling the Effects of Vegetation Distribution and Density on Hydrological Connectivity and Water Age in a River Delta
Ecohydrology2025
Water transport timescales (WTTs) quantify how long it takes for water to travel through or remain in a system and are often cast as indicators of ecosystem function and health. Such timescales are known to be affected by vegetation in various environments. We quantify the impact of floodplain vegetation on WTTs within the Wax Lake Delta (WLD), a river delta system in Louisiana, USA, using a high‐resolution Delft3D Flexible Mesh (DFM) model incorporating vegetation‐induced flow resistance. We show that increased vegetation density leads to extended WTTs within vegetated sections of WLD while fostering flow localization and accelerating transport within distributary channels. We find that the presence or absence of floodplain vegetation significantly influences the volumetric flow directed towards the floodplain, with spatial distribution exerting more control than vegetation density.
Hydrometeorological drivers of the 2023 Louisiana water crisis
Geophysical Research Letters2024
During summer and fall 2023, Louisiana experienced a historic local drought while dry conditions elsewhere in the central US withheld vital runoff from the Mississippi River, leading to below‐normal discharge into the Gulf of Mexico. Thus, by late October 2023, Louisiana was gripped by two super‐imposed water crises: a severe local drought and saltwater contamination in the Mississippi River channel. This study frames the development of the water emergency through the lens of flash drought using the Evaporative Demand Drought Index (EDDI). The EDDI shows south Louisiana experience a flash drought during June 2023, while the Mississippi River basin was subsequently characterized by large expanses of high‐percentile EDDI in August‐September 2023 shortly before the saltwater intrusion episode along the lower Mississippi River.
Response of river delta hydrological connectivity to changes in river discharge and atmospheric frontal passage
Frontiers in Marine Science2024
Atmospheric frontal passage is a common meteorological event that can significantly affect hydrodynamics in coastal environments, including the hydrological connectivity between channels and floodplains that regulates material transport in river deltas. This study is focused on the influence of atmospheric cold fronts on the hydrological connectivity between channels and floodplains within the Wax Lake Delta using the Delft3D FM model. The results demonstrate a substantial effect of passing cold fronts on the exchange of water and transport fraction between the primary channels and floodplains. This impact is intricately connected to the morphodynamical characteristics of the floodplains, the intensity of cold fronts, river discharge, Coriolis force, and tidal currents. The passing cold fronts can enhance or reverse the direction of water exchange between channels and floodplains.
Impacts of tropical cyclones on wave and current regime in a shallow, microtidal bay
Continental Shelf Research2024
In shallow, microtidal coastal regions storms play a significant role in influencing wave climate and circulation patterns. In the northern Gulf of Mexico, understanding the effects of tropical cyclones on hydrodynamic processes is crucial for making predictions in the face of rapid wetland loss and increasing human interventions via restoration and protection strategies, such as river diversions. In this study, two bottom-mounted upward-facing Acoustic Current Doppler Profilers and separate wave recorders were installed in Barataria Bay (Louisiana, USA) to measure waves and current velocities responding to the passage of multiple tropical cyclones in fall 2020 and summer 2021. Analyses of depth-averaged current velocities suggest diurnal astronomic constituents drive currents over a 6-8 day period during and after storms, despite the microtidal nature of the bay.
Event Appearances
Human exposure forecasts to future cyanobacteria toxicity in Louisiana: The need to predict species shifts, potency, and modality along the freshwater-to-marine continuum in a changing climate
2024 | American Geophysical Union (AGU) Ocean Sciences Meeting New Orleans, LA
Evaluating the Effect of River Discharge on Cold Front Induced Water Transport in the Wax Lake Delta, Louisiana
2024 | American Geophysical Union (AGU) Ocean Sciences Meeting New Orleans, LA
Beyond a friction coefficient: The role of vegetation in channel-floodplain Matthew Hiatt- C
2023 | American Geophysical Union (AGU) Fall Meeting San Francisco, CA
Research Grants
Collaborative Research: RAPID: Determining the Impacts of a Combined Historical Watershed and Regional Drought on Coastal Louisiana Wetland Ecohydrology,
National Science Foundation
2023-2024
Mississippi River Delta Transition Initiative
National Academy of Sciences Gulf Research Program
2023-2028
Relationships between vegetation and discharge on distributary channels in the Birds Foot Delta: bifurcations and sediment flux
LSU AgCenter
2023-2025
CAREER: Dynamic water transport timescales: Quantifying hydrodynamic responses to perturbations across time and space in a river delta
National Science Foundation
2022-2027
