Modeling of coastal morphological processes

Abstract

Morphology is the study of forms, whether of animals, plants or words; coastal morphology is the study of coastal forms. Some of these forms are hard (like rock) and do not move much. Others, such as beaches, dunes, channels, sandbars, shoals, are made of mud, sand, or even gravel and move all the time. Understanding and predicting these motions are what coastal morphologists try to do. The approach we take depends on the scale of the problem or process we are interested in. This scale ranges from small-scale ripples to entire tidal inlets or coast lines. The larger the length scale, the larger the timescale; the upper beach profile can adapt to a storm in hours; the coastline around a port can take decades to adapt, and the effects of closing a tidal inlet can be felt for many centuries. In coastal engineering, morphology is a core discipline. It is needed to assess damage to beaches, dunes, and barrier islands during extreme events; it is needed to understand and mitigate coastal erosion; it is important in the design of ports, to assess impact on the coast and estimate dredging requirements for the navigation channel and basins; it is needed in the design and impact studies of land reclamations and finally, it provides scenarios to use in coastal zone management. In this chapter, we will first discuss different types of coastal morphology models. We will then zoom in and focus on process-based modeling in more detail. First, the fundamentals of processbased modeling are described, which is followed by short descriptions of the commonly used types of process-based models. Subsequently, a number of modeling approaches considering different scales, from storm-event modeling to long-term modeling of estuaries are presented. We conclude by discussing some future directions.