Compound Coastal, Fluvial, and Pluvial Flooding During Historical Hurricane Events in the Sabine–Neches Estuary, Texas

Abstract

When storm surge, river discharge, and rainfall occur simultaneously or in succession, they may cause compound flooding and exacerbate impacts in coastal communities. In traditional modeling approaches, these driving processes are simulated separately, leading to discrepancies between simulated and observed data and highlighting the need for coupled modeling frameworks. Here, we develop a coupled coastal–fluvial–pluvial model for the Sabine–Neches Estuary in southeastern Texas using Delft3D to simulate flood extent and depth during Hurricanes Rita, Ike, and Harvey. For each hurricane, four scenarios (i.e., coastal, fluvial, pluvial, and compound) are modeled to determine the relative contribution of each driving force to water levels across the domain. Our results reveal that tropical cyclones such as Harvey that are accompanied by extended periods of rainfall produce the largest extent and longest duration of compound flooding. Such storms also produce highly dynamic and evolving patterns of compound flooding over their duration, with multiple flood peaks that can inhibit response and recovery efforts. When simulating these storms, a coupled model can provide substantial improvements over coastal‐, fluvial‐, and pluvial‐only models, decreasing root mean square error by 69%, 69%, and 79%, respectively. In contrast, storms with short‐duration rainfall and moderate to severe storm surge produce less extensive compound flooding, which is typically dominated by coastal–pluvial interactions. Our results further highlight the potential for compound flooding at the locations of critical water infrastructure assets, suggesting the need for flood adaptation approaches that are robust to multiple types of flooding.

The State of Texas Wetlands: A Review of Current and Future Challenges

“…The Environmental Defense Fund (2023) estimated the wetlands in the Galveston Bay region of Texas provide storm protection benefits worth over $2 billion annually. Another study valued the storm protection benefits of the wetlands in the Sabine-Neches Lake estuary at up to $1.2 billion annually (Maymandi et al, 2022). The same study argues these wetlands can reduce the damage caused by storms by up to 70%.…”

“…This helps to reduce the risk of downstream flooding and damage to property (Antolini et al, 2020). Coastal wetlands act as a buffer to storm surges, slowing the water flow and providing habitat for soil-stabilizing plants, preventing erosion (Feagin et al, 2009;Maymandi et al, 2022). The…”

Probabilistic Storm Surge and Flood-Inundation Modeling for the Texas Gulf Coast Using Super-Fast INundation of CoastS (SFINCS)

“…Several studies have investigated the simulation of hydrodynamics and waves (Chen & Curcic, 2016;Hope et al, 2013;Maymandi et al, 2022;Veeramony et al, 2012;Xu et al, 2023), as well as methodologies for addressing storm surge and wave heights (Kennedy et al, 2011;Lee et al, 2017). Mitigating these risks requires a comprehensive understanding of TC-induced hazards and effective decision-making tools.…”

Hindcasting compound pluvial, fluvial and coastal flooding during Hurricane Harvey (2017) using Delft3D-FM

“…Delft3D has been used to investigate flooding during Harvey, but only to a limited extent. For example, Maymandi et al (2022) investigated hurricane-induced flood hazards in the Sabine-Neches Estuary in Southeast, Texas, and demonstrated the flood extent and spatial and temporal influence of flooding in a single estuary, using Delft3D model. Muñoz et al (2022) combined Delft3D with the Ensemble Kalman Filter (EnKF) technique to improve the accuracy of compound flood maps around Galveston Bay.…”