Hydrographic surveys also known as bathymetric surveys focuses on measuring and mapping the depths and contours of underwater terrain, such as the seafloor, lakebed, riverbed, or any submerged areas of interest. Bathymetric Surveys are essential for various purposes, including navigation, charting, resource management, environmental assessment and scientific research. Here’s an overview of how bathymetric surveys are carried out and the equipment used.
Bathymetric Survey Methods:
Multibeam Sonar Surveys
Multibeam sonar is one of the most common methods for conducting bathymetric surveys. This technology involves the use of a sonar system that emits multiple sonar beams simultaneously in a fan-shaped pattern. The beams bounce off the seafloor or other underwater features and are then collected by the sensor. By measuring the time, it takes for the sound waves to return, the system calculates water depth and creates detailed bathymetric maps.
Single-Beam Sonar Surveys
Single-beam sonar is another method used in bathymetry, primarily in shallower water bodies. It works similarly to multibeam sonar but emits a single sonar beam. This method is suitable for smaller-scale surveys and areas with less complex underwater terrain.
Side-Scan Sonar Surveys
Side-scan sonar is used to create detailed images of the seafloor or lakebed. It operates by emitting sonar signals horizontally to the side of the survey vessel. These signals bounce off the seabed and return to the sensor, creating a visual representation of the seafloor’s texture and features.
Some bathymetric surveys use laser-based systems that measure the distance between the survey vessel and the seafloor. These systems can provide high-resolution depth data in clear water conditions.
Hydrographic surveys are a crucial component of geomatics, as they provide valuable geospatial data for marine and coastal applications. he data collected in hydrographic surveys are used in combination with other geomatics datasets to create comprehensive geospatial databases that support various industries, including maritime transportation, offshore resource exploration, environmental conservation, and coastal zone management
In summary, hydrographic surveys are vital for ensuring safe navigation, managing water resources, protecting the environment, and supporting infrastructure development in the geomatics industry. They provide essential geospatial information for a wide range of applications both at sea and in coastal regions.