bathymetria

Bathymetry, sometimes referred to as bathymetria in some languages, is the science of measuring the depth of water bodies and mapping the shape of the underwater terrain. It describes how deep the water is at each location and how the seafloor or lake floor varies in elevation. Bathymetric data are essential for nautical charting, coastal engineering, marine science, and environmental management. Depth values are typically referenced to a standard vertical datum such as mean sea level.

Most bathymetric data are acquired with acoustic sounding systems deployed from ships, vehicles, or aircraft. Single-beam echo sounders measure depth along a narrow line beneath a platform, while multibeam echo sounders (MBES) emit multiple beams to cover wide swaths and produce detailed 3D maps of the seafloor. Side-scan sonar emphasizes seafloor texture but does not directly provide depth unless combined with other data. Light detection and ranging (lidar) bathymetry uses laser light to map shallow, clear-water bottoms. Satellite altimetry can infer large-scale seafloor features indirectly by analyzing sea-surface height patterns, albeit at coarser resolution. Data may be collected from ships, autonomous underwater vehicles, remotely operated vehicles, or airborne platforms.

Processing converts raw measurements into accurate depth values, applying corrections for the water column sound speed, tides, refraction, and vessel motion. Coordinates are tied to a geodetic reference frame and vertical datums, and the results are stored as bathymetric grids or models (for example, bathymetric digital elevation models) for analysis and visualization.

Applications include charting and navigation, coastal and harbor design, dredging planning, flood risk assessment, habitat mapping, sediment transport studies, and climate-related ocean research. Limitations include coverage gaps in turbid or deep-water regions, data gaps along coastlines, and the need for standardized processing and formats to enable sharing and interoperability.