Coastlineover

Coastlineover is a term used in coastal geography and environmental policy to describe a framework for understanding and quantifying changes to the boundary between land and sea over time. It can refer to both a descriptive phenomenon—the net movement of shorelines—and a comparative index that summarizes such movement within a defined region or period.

Origin and scope: The term emerged in academic discussions of coastal change in the early 2010s and has since appeared in diverse contexts, including geomorphology, risk assessment, and adaptation planning. Its use is not standardized, and practitioners may apply the concept differently depending on data availability, regional characteristics, and policy goals. Coastlineover is often invoked to discuss the cumulative effect of natural drivers such as sea-level rise, storms, and sediment supply changes, along with human influences like coastal engineering, nourishment projects, and land use changes.

Measurement and interpretation: In its formal sense, coastlineover denotes the net inland or seaward migration of the shoreline over a chosen time window, expressed as a rate or as an integrated distance. A positive coastlineover value typically indicates landward shoreline movement (erosion or relative sea-level rise), while a negative value indicates shoreline advancement toward the sea (progradation). The metric is sensitive to how the shoreline is defined (for example, the high-water line versus mean sea level), the data resolution, and the temporal scale used for analysis.

Applications and limitations: Coastlineover is used in risk assessments, adaptation planning, and communication with stakeholders about coastal change. However, the concept faces criticisms for lacking universal standards, potential misinterpretation, and dependence on data quality and methodological choices. See also shoreline change, coastal erosion, and living shorelines.