Effects of Creek Topology on Salinization of Coastal Marsh Due To Storm Surges

Abstract Creek topology varies widely across coastal marshes and strongly influences surface and subsurface flow patterns. These flow dynamics, in turn, affect salt transport within the marsh system. Both processes are critical in storm surge inundation and consequent subsurface salinization. In this study, we employed modeling tools to understand the role of creek networks in salt transport due to storm surges. We developed a stochastic morphodynamic model to represent three typical creek network groups: sparse, intermediate, and dense groups. We then utilized a variable‐density, coupled surface‐subsurface, flow and salt transport model to simulate a theoretical storm surge overwash event. We examined how the presence of creek affects the extent and location of salinization by evaluating differences in salinity of surface waters and the subsurface. The salinization assessment showed that dense creek networks attenuated storm surge inundation and limited the surface salinization extent. The highest occurrence of reverse creek and groundwater flow directions was found in the sparse group, which delayed the salt flushing. The recovery from salinization varies nonlinearly in creek water, marsh sediments, and aquifers. Our study suggests that creek topology significantly affects the resilience of coastal marshes to storm surge salinization, with important implications for coastal land management and ecosystem restoration.