waveexposure

Wave exposure is a measure used in coastal and marine science to describe how much wave energy reaches a location on the coast or in the nearshore environment. It reflects the combined effect of wind-generated waves, their direction, and the physical barriers and terrain that may amplify or reduce energy reaching the shore.

Factors that influence wave exposure include fetch length, wind speed and duration, storm activity, water depth and bathymetry, and the orientation of the coastline relative to prevailing waves. Topographic features such as headlands, reefs, offshore bars, islands, and nearshore topography can shield or focus wave energy, producing spatial variation in exposure over short distances. Seasonal patterns and long-term climate variability also affect exposure regimes.

Exposure is estimated from observations and models. In situ sensors such as wave buoys and pressure gauges provide measurements of significant wave height and period, while radar and remote sensing offer broader coverage. Numerical models (for example SWAN and WaveWatch III) simulate wave fields near shore to derive exposure metrics. In ecology and coastal engineering, exposure is often summarized with an index or used in conjunction with wave power calculations, which scale with Hs^2 and wave group velocity.

Applications include guiding coastal erosion risk assessments, sediment transport studies, habitat suitability for marine organisms, and the design of maritime structures. Understanding wave exposure helps anticipate which areas are more vulnerable to storm surge, overwash, and shoreline retreat, as well as how energy disperses along complex coastlines.

Limitations include the spatial and temporal variability of waves, the influence of tides, currents, and breaking waves, and uncertainties in models and input data. Because exposure is context-dependent, its interpretation often requires coupling with other environmental factors such as bathymetry, sediment characteristics, and ecological tolerance. See also: coastal exposure, wave climate, wave power, coastal engineering.