Hydrographic Survey vs Bathymetric Survey
Bathymetric Survey
The survey of physical features present underwater is known as hydrographic surveying or bathymetric surveying. It is the science of determining all aspects that effect all marine activities such as dredging, marine constructions, and offshore drilling.
Bathymetry is a technique for accurately mapping the under-water bottom. It will aid in the correlation and understanding of data acquired from other technologies that produce sub-bottom data, as well as a quality check of the results. This accuracy is critical because the other methods measure thickness from the bottom.
The approach works by sending an acoustic signal and measuring the transit time to determine depth. This method of depth conversion begins with the measurement of sound velocity in the water at various depths. To ensure accuracy, this calibration is performed twice a day.
Water depth measurements should be precise to within ten centimetres.
Bathymetry equipment is a small piece of equipment that is put on a boat and used in conjunction with other geophysical technologies to undertake surveys.
A grid layout is used to perform the survey. The line spacing is determined by the needed resolution. A Differential Global Positioning System is used to accomplish precise positioning.
Multiple methods can be used for bathymetric surveys:
Surveying using several beams
A boat’s multibeam echo sounder puts out a wide variety of beams across a “swath” of the waterbody bottom. Data is captured and processed as the beams bounce back from the waterbody’s floor. On the boat during the survey, the processed data can be displayed in real time. In bigger bodies of water, multi-beam surveying is commonly used.
Surveying with one beam:
Single-beam bathymetry detects the water depth immediately beneath the boat instead of putting out a large number of beams. For smaller aquatic bodies, single-beam surveys are commonly utilised.
The ADCP (Acoustic Doppler Current Profiler) is a device that measures how fast sound travels through
Streamflow is measured with ADCPs throughout the USGS. Sound waves are transmitted by ADCPs and reflected off silt and other elements in the water to determine the velocity of the water. Bathymetric mapping can be done with the information collected by ADCPs.
Profilers for the sub-surface:
The most typical application of sub-bottom profilers is to examine the layers of sediment and rocks beneath the water’s surface. A sound wave is sent to the water’s surface via a transducer. This sound wave is strong enough to penetrate the water’s surface. Sound wave data can be mapped to reveal the strata beneath the water’s surface.
Underwater Autonomous Vehicle Ecomapper:
In regions where boats can’t go, the Ecomapper can capture comprehensive bathymetric data down to one-foot contours. Side-scan sonar and a Doppler velocity log are used in the Ecomapper.
Bathymetric surveys are used in a variety of studies, including:
- Inundation by floods
- Stream and reservoir contours
- Leakage
- Stabilization and scour
- Water-quality research
- removing the dam
- spill and biological
- Storage and pond and reservoir filling
Hydrographic Survey
Is the science of measuring and describing features that have an impact on maritime navigation, marine construction, dredging, oil exploration/drilling, pipeline damage assessment, and other disciplines. Water depth soundings, shorelines, tides, currents, seafloor, and submerged impediments that relate to the previously stated activities are all heavily emphasised. Hydrographic surveys convert raw data obtained during the survey process into information that can be used by the end-user.
Hydrographic surveying’s applications
Hydrographic surveying is used in the following ways:
- Engineering of Docks and Harbors
- Irrigation
- River Projects
- Reclamation of land
- Water Energy
- Flood Prevention
- sewage removal
Hydrographic Surveying’s Applications
The following are some of the applications of hydrographic surveying:
- The bed’s depth can be determined.
- It is possible to determine the shorelines.
- Preparing a Navigation Chart
- Measure direct currents to find the sewer fall.
- Scouring, silting, and abnormalities in the bed can all be detected while determining the mean sea level.
- measuring the tide
- Measurement of river and stream discharge
- Bridges, dams, and harbours are among the massive constructions proposed.
Hydrographic surveys are carried out for a variety of purposes, including geological causes, determining the best places for oil and gas buildings, installing underwater communication gear, and military applications. Falcon Survey Engineering Consultants is offered hydrographic surveys in UAE. They provide the post-survey analyses of the installation site and propose the best design and integration of the sensor and station as per requirement. For more information visit them now.
