The coastal tract (Part 1): A conceptual approach to aggregated modelling of low-order coastal change

Evolution of coastal morphology over centuries to millennia (low-order coastal change) is relevant to in coastal management (e.g., systematic shoreline erosion). This type of coastal change involves parts normally ignored in predictions required for management of coastal morphology: i.e., shoreline evolution behavior of the continental shelf and coastal plain. We therefore introduce a meta-morphology, the defined as the morphological composite comprising the lower shoreface, upper shoreface and backbarrier sent). It is the first order-system within a cascade hierarchy that provides a framework for aggregation in modeling low-order coastal change. We use this framework in defining boundary conditions and internal to separate low-order from higher-order coastal behavior for site-specific cases. This procedure involves of a data-model by templating site data into a structure that complies with scale-specific properties predictive model. Each level of the coastal-tract cascade is distinguished as a system that shares sediments internally. sharing constrains morphological responses of the system on a given scale. The internal dynamics of involve morphological coupling of the upper shoreface to the backbarrier and to the lower shoreface. mechanisms govern systematic lateral displacements of the shoreface, and therefore determine trends advance and retreat. These changes manifest as the most fundamental modes of coastal evolution upon order (shorter-term) changes are superimposed. We illustrate the principles in a companion paper (The Part 2).