A long-term (decadal scale) evolution model for microtidal barrier systems

Abstract A model is presented to simulate the long-term (decadal) evolution of microtidal spit-barrier systems. The model has been derived from the analysis of coastal processes taking place along the Trabucador-La Banya complex in the Ebro delta (Spanish Mediterranean coast). It is composed of two submodels to simulate the evolution of the seaside and bayside barrier shorelines. The outer coast submodel is of the one-line type, but formulated in curvilinear coordinates to reproduce the evolution of strongly curved coasts, which is a common configuration for spits. The model makes use of a long-term parameterization of the longshore sediment transport rate, which is formulated in terms of a morphological wave and a local transport constant. The inner coast submodel is based on a morphological equilibrium approach. It considers the overwash transport to be the dominant driving term contributing to the sediment budget of the inner coast. It makes use of the concept of critical barrier width to estimate the conditions under which overwash is able to contribute to bayside shoreline accretion. The model has been verified/calibrated for the Trabucador-La Banya system and it has been used to simulate its evolution under different climatic scenarios.

[1]  R. A. Jones,et al.  Simulation of large-scale coastal change using a morphological behaviour model , 1995 .

[2]  P. Leblond,et al.  ON THE FORMATION OF SPIRAL BEACHES , 1972 .

[3]  Nicholas C. Kraus,et al.  ANALYTICAL MODEL OF SPIT EVOLUTION AT INLETS , 1999 .

[4]  J. Quintana.  Evolución costera en el delta del Ebro. Un proceso a diferentes escalas de tiempo y espacio , 1997 .

[5]  Jr. Asbury H. Sallenger.  Storm Impact Scale for Barrier Islands , 2000 .

[6]  J. Jiménez,et al.  A MORPHOLOGICAL "MIXED-TYPE" MODEL FOR THE EBRO DELTA COAST , 1997 .

[7]  Paul D. Komar,et al.  Beach Processes and Sedimentation , 1976 .

[8]  Mark R. Byrnes,et al.  Geomorphic response-type model for barrier coastlines: a regional perspective , 1995 .

[9]  Jonathan Raper,et al.  Developing Process-Response Models for Spits , 1999 .

[10]  J. Jiménez,et al.  Medium-term coastal response at the Ebro delta, Spain , 1993 .

[11]  David R. Basco,et al.  A One-Dimensional Numerical Model for Storm-Breaching of Barrier Islands , 1999 .

[12]  B. Latteux,et al.  Approaches to long-term modelling of coastal morphology : A review , 1993 .

[13]  Agustín Sánchez-Arcilla,et al.  Modelling of Barrier-Spit System Evolution at Decadal Scale , 1999 .

[14]  J. Rees,et al.  Architectural stacking patterns of the Ebro delta controlled by Holocene high-frequency eustatic fluctuations, delta-lobe switching and subsidence processes , 1998 .

[15]  Peter Howd,et al.  Beach Processes and Sedimentation, Second Edition , 1998 .

[16]  Stephen P. Leatherman,et al.  Migration of Assateague Island, Maryland, by inlet and overwash processes , 1979 .

[17]  C. King,et al.  A Simulation Model of a Complex Recurved Spit , 1971, The Journal of Geology.

[18]  G. Stone,et al.  Louisiana barrier islands and their importance in wetland protection : Forecasting shoreline change and subsequent response of wave climate , 1998 .

[19]  J. Jiménez,et al.  Processes reshaping the Ebro delta , 1997 .

[20]  R. Morton.  Factors Controlling Storm Impacts on Coastal Barriers and Beaches-A Preliminary Basis for Near Real-Time Forecasting , 2002 .

[21]  K. Suh,et al.  Calculation of Tombolo in Shoreline Numerical Model , 1995 .

[22]  Stephen P. Leatherman,et al.  Overwash Hydraulics and Sediment Transport , 1977 .

[23]  Agustín Sánchez-Arcilla,et al.  Breaching in a wave-dominated barrier spit: The trabucador bar (north-eastern spanish coast) , 1994 .