Impact of topography on groundwater salinization due to ocean surge inundation

verfasst von

Xuan Yu, Jie Yang, Thomas Graf, Mohammad Koneshloo, Michael A. O'Neal, Holly A. Michael

Abstract

Sea-level rise and increases in the frequency and intensity of ocean surges caused by climate change are likely to exacerbate adverse effects on low-lying coastal areas. The landward flow of water during ocean surges introduces salt to surficial coastal aquifers and threatens groundwater resources. Coastal topographic features (e.g., ponds, dunes, barrier islands, and channels) likely have a strong impact on overwash and salinization processes, but are generally highly simplified in modeling studies. To understand topographic impacts on groundwater salinization, we modeled a theoretical overwash event and variable-density groundwater flow and salt transport in 3-D using the fully coupled surface and subsurface numerical simulator, HydroGeoSphere. The model simulates the coastal aquifer as an integrated system considering overland flow, coupled surface and subsurface exchange, variably saturated flow, and variable-density groundwater flow. To represent various coastal landscape types, we simulated both synthetic fields and real-world coastal topography from Delaware, USA. The groundwater salinization assessment suggested that the topographic connectivity promoting overland flow controls the volume of aquifer that is salinized. In contrast, the amount of water that can be stored in surface depressions determines the amount of seawater that infiltrates the subsurface and the time for seawater to flush from the aquifer. Our study suggests that topography has a significant impact on groundwater salinization due to ocean surge overwash, with important implications for coastal land management and groundwater vulnerability assessment.

Organisationseinheit(en)

Institut für Strömungsmechanik und Umweltphysik im Bauwesen

Externe Organisation(en)

Helmholtz-Zentrum für Umweltforschung (UFZ)
University of Delaware

Typ

Artikel

Journal

Water resources research

Band

52

Seiten

5794-5812

Anzahl der Seiten

19

ISSN

0043-1397

Publikationsdatum

01.08.2016

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Gewässerkunde und -technologie

Ziele für nachhaltige Entwicklung

SDG 13 – Klimaschutzmaßnahmen

Elektronische Version(en)

https://doi.org/10.1002/2016WR018814 (Zugang: Geschlossen)