The subdivision hierarchy that is used is to first subdivide the shoreline into alongshore units, subdivide the shore units into across-shore components and categorize each of the components into zones. The subdivision hierarchy is illustrated in Figure 1. Each across-shore component can be systematically described in terms of physical characteristics such as morphology, texture and dominant processes. The descriptive nature of the system allows non- technical users of the information to grasp a basic picture of the shoreline. Component - a geomorphic feature, with unique form and texture, that is uniform alongshore the shore.
Components are polygons, with length usually exceeding length by several times.
Zones - a vertical reference frame to categorize components in the supratidal, intertidal or subtidal elevation levels. The zones provide an indirect indication of the dominant process affecting the component. This approach allows for the systematic description of the shoreline. By subdividing into smaller pieces, the major characteristics of the shore-zone can be recorded in tabular or database formats that facilitate recording of large amount of information. The concept of a shore unit is fundamental to understanding and using the mapping system.