vízrajz

Vízrajz is the Hungarian term for hydrography, the science and practice of surveying bodies of water and producing maps and charts that describe their features. It covers measurement and description of rivers, lakes, harbors, and coastal zones, including depths (bathymetry), shorelines, water levels, currents, salinity, temperature, and sedimentation. The primary products are hydrographic charts and bathymetric maps used for safe navigation, inland waterway operation, and coastal engineering. Hydrographic data underpin flood risk management, water resource planning, environmental monitoring, and maritime infrastructure projects. Methods include hydrographic surveying, echo sounding and multibeam sonar for depth measurements, LiDAR bathymetry for shallow areas, aerial and satellite imagery, and GIS to integrate datasets.

Historically, hydrography developed from navigational surveying to a modern scientific discipline, evolving with technology from lead lines and sounding poles to sonar, satellite altimetry, and automated data collection. In Hungary and Central Europe, water surveying has supported major rivers such as the Danube, with national agencies and research institutes maintaining datasets and charts to assist navigation, hydrology, and planning.

See also hydrography, bathymetry, nautical chart, cartography, GIS, remote sensing.