Relationship Between Cross-Shore Active Profile and One-Line Shoreline Evolution Models Performance

Abstract

Coelho, C., Lima, M. and Veloso-Gomes, F., 2013. Relationship Between Cross-Shore Active Profile and One-Line Shoreline Evolution Models PerformanceOne-line shoreline evolution models, such as GENESIS and LTC, are commonly used to predict coastal configuration changes, where the alongshore sediment transport is controlled by waves, water level, sediments' sources and sinks and sediments' properties. Nevertheless, these models' performance is also affected by considerations related to the definition of cross-shore active profile width, where both models present some differences. In GENESIS, the onshore limit of active profile is defined by the beach berm height, while in LTC, this limit is defined by the wave runup. In what regards the offshore boundary, depth of closure defines the limit in both models. However, GENESIS considers an average value, representing all the waves and all the extension of the modelled stretch whereas LTC allows considering a fixed value, similar to GENESIS, or a variable value depending on each wave height along the time. These considerations have impacts on the definition of the active width of the cross-shore profiles and, consequently, on the shoreline development along time. Thus, in this paper, cross-shore profiles tests are performed, ranging the depths of closure and onshore limits of cross-shore active profiles, in order to evaluate their influence in the shoreline evolution.