TY - JOUR

T1 - Role of spatial variability of soil resistance in alongshore variability of coastal barriers response to superstorm surges

AU - Elsayed, Saber M.

AU - Goseberg, Nils

N1 - Funding Information: The financial support of the German Research Foundation (Deutsche Forschungsgemeinschaft; DFG) for the first author (fund no. EL 1017-1/1) within the research project ReFresh (Response of Coastal Barriers and Freshwater Aquifers to Extreme Storm Surges and Flooding) is gratefully acknowledged.

PY - 2020/12/31

Y1 - 2020/12/31

N2 - Sand dunes and other natural coastal barriers (e.g. barrier islands) represent important components of the defense system against consequences of storm surges. However, in many coastal systems, major storm surges represent important drivers of coastal erosion. Increased extreme events potentially result in accelerated coastal erosion, coastal barrier breaching, and coastal flooding. The response of a barrier to a storm surge is often determined by mutual interaction among the driving hydrodynamics, the subsequent morphodynamics, and the local geology, including spatial variations of subaqueous bathymetry and subaerial topography. However, the effect of alongshore variability of soil properties on the alongshore varying response is not yet considered. Therefore, this study examines soil parameters that may affect coastal erosion during major storm surges. Moreover, it applies a novel extension of the numerical model XBeach that accounts for spatial variation of soil properties to an artificial dune system of spatially varying soil permeability. Results showed that variability of soil permeability alongshore the dune results in alongshore varying resistance to erosion so that breaches may occur at the locations of less resistance that are corresponding to locations of higher soil permeability. Outcomes of the numerical simulations proved also that reduced soil permeability represents a nature-based solution that increases the resilience of natural defense systems during major storm surges by mitigating rates of coastal erosion.

AB - Sand dunes and other natural coastal barriers (e.g. barrier islands) represent important components of the defense system against consequences of storm surges. However, in many coastal systems, major storm surges represent important drivers of coastal erosion. Increased extreme events potentially result in accelerated coastal erosion, coastal barrier breaching, and coastal flooding. The response of a barrier to a storm surge is often determined by mutual interaction among the driving hydrodynamics, the subsequent morphodynamics, and the local geology, including spatial variations of subaqueous bathymetry and subaerial topography. However, the effect of alongshore variability of soil properties on the alongshore varying response is not yet considered. Therefore, this study examines soil parameters that may affect coastal erosion during major storm surges. Moreover, it applies a novel extension of the numerical model XBeach that accounts for spatial variation of soil properties to an artificial dune system of spatially varying soil permeability. Results showed that variability of soil permeability alongshore the dune results in alongshore varying resistance to erosion so that breaches may occur at the locations of less resistance that are corresponding to locations of higher soil permeability. Outcomes of the numerical simulations proved also that reduced soil permeability represents a nature-based solution that increases the resilience of natural defense systems during major storm surges by mitigating rates of coastal erosion.

KW - Alongshore variability

KW - Barrier breaching

KW - Dune erosion

KW - Soil resistance

KW - Spatially varying permeability

UR - http://www.scopus.com/inward/record.url?scp=85112323951&partnerID=8YFLogxK

U2 - 10.9753/icce.v36v.papers.41

DO - 10.9753/icce.v36v.papers.41

M3 - Conference article

AN - SCOPUS:85112323951

VL - 36

JO - Proceedings of the Coastal Engineering Conference

JF - Proceedings of the Coastal Engineering Conference

SN - 0161-3782

T2 - 2020 Virtual International Conference on Coastal Engineering, vICCE 2020

Y2 - 6 October 2020 through 9 October 2020

ER -