Evaluation of Cross-Shore Profile Behavior in Medium-Term Timescales Using XBeach: A Case Study of Zarabad Fishery Harbor, Iran

Among the numerous problems that decrease the capability of a harbor in the country, seasonal sedimentation is identified as a major problem for many fishery harbors. In 2007, Zarabad Fishery Harbor conditions were also identified as critical due to the large volume of sand accumulation and consequent closure of its entrance.  Numerical modeling of coastal bed level change was implemented to provide insight into the typical response of the Zarabad beach to regular wave attacks, and to obtain an operational and validated model for the site. Advanced numerical models employed to predict coastal evolution at a variety of time and spatial scales usually include many free parameters that require calibration to the available field data. The XBeach numerical model was selected for its capacity to accurately model hydrodynamic and morphological processes over a two-dimensional domain.  It comprises about 250 model settings that approximately 150 of these settings relate to physical and numerical Behavior and the other 100 are case-specific parameters. In this research, 11 parameters are adopted to optimize the model prediction efficiency for Zarabad Fishery Harbor area. For calibration and validation stages, two cross-shore profiles and two medium-term time periods are selected. The model showed great promise in predicting the evolution of cross-shore profiles under water, but as expected, the dry part results showed major errors. XBeach proved to be an operational tool to predict cross-shore profiles in the area, in such timescales. Although, more tests are needed to utilize the model in longer time periods with regard to the duration of simulations.

Keywords:

XBeach model , Cross-shore profiles , Sand accretion and erosion , Beach sedimentation , Bed level change