clifflines

Clifflines is a term used in geomorphology and coastal studies to denote a linear feature that traces the approximate alignment of cliff faces along a coastline, escarpment, or steep topographic boundary. In geographic information systems, clifflines are derived by identifying abrupt changes in elevation and slope to produce a continuous line that marks cliff edges. The concept supports consistent characterization of vertical relief across maps and datasets.

Origins and terminology. Although informal in many early references, clifflines gained broader use in 2000s and 2010s coastal risk assessments as researchers sought standardized cliff delineation for erosion modelling and hazard zoning. The term does not refer to a single official dataset but to a class of derived features that may be produced by various workflows.

Methodology. Data sources include airborne LiDAR, UAV photogrammetry, and high-resolution satellite digital elevation models. A typical workflow classifies terrain cells by slope or planimetric relief and identifies a contiguous line where cliff-grade conditions are met. Post-processing filters spurious lines, snaps to shoreline anchors, and optionally links to adjacent coastal segments.

Applications. Clifflines support coastal management, hazard assessment, land-use planning, and construction oversight. They facilitate rapid comparison of cliff retreat over time when paired with time-series elevation data.

Limitations and considerations. Clifflines are sensitive to data quality and seasonal conditions; they represent approximate boundaries rather than precise endpoints; updates are required after major events.

Related terms include cliffs, escarpments, coastal erosion, and GIS-based cliff mapping.