The survey of physical features present underwater is known as hydraulic survey or bathymetric surveying. It is the study of determining all factors below the surface of the water that affect all maritime activities such as dredging, marine constructions, offshore drilling, and so on.
The majority of hydraulic surveying is done in response to government concerns. For shallow water, it’s mostly done with sensors, sounding, or electronic sensor systems. The data gathered during hydrographic surveying is used to create nautical charts, which entails the following:
– Available depths
– Aids in navigation harbour facilities
What are the Preliminary Steps in Hydraulic Surveying?
The technique starts with the location of certain control points along the beach. Using stationary boats, the sounding method is used to determine the depth at various sites. Sounding locations can be obtained by moving from the boat to the control points or by establishing a point in the boat and obtaining soundings from there.
Certain preparations must be made before to the procedure:
Reconnaissance is required for every project since it requires a start-up plan to be completed successfully and economically. A thorough reconnaissance of the entire survey region is conducted in order to determine the optimum method of conducting the survey.
This would make it easier to complete the survey to the satisfaction of the requirements and specifications that govern such activity. Aerial images might be beneficial to this research.
- Locating Horizontal Control
The horizontal control is required to locate all land and sea features in their correct relative positions. As a result, a sequence of lines with lengths and azimuths is calculated using triangulation or other methods.
In order to carry out rough works, a tachometric and plane table survey might be carried out. Because topography, vegetation, kind, and size of topography change the rules, no standards are retained for establishing horizontal control.
- Locating Vertical Control
Vertical control must be established prior to sounding. A number of milestones have been set up to serve as vertical controls. Benchmarks are used to set and check the levels of gauges.
- Prepare for the Survey
Before you begin, double-check that all of your tools are in working order. All of the batteries should be charged, and the boat should be filled with fuel. The computer should be loaded with all pre-survey data.
An outline of the water body, track lines for the vessel to follow, and validated quality control sites to check into are all included in this data. Make sure you’re aware of any potential hazards in the vicinity, such as bridges, docks, sand bars, and so on.
The area of dredging is one of the most important applications of the hydraulic survey. Dredging is the process of clearing the seabed of weeds, silt, and rocks. This could be done to enhance the shipping business by building inland waterways. Small ships can be utilized to complement domestic trade if rivers are deepened enough.
Dredging can also be used to alter drainage patterns that affect irrigation, erosion, and other factors. Underwater surveying gathers data that is frequently used to approve capital projects. The offshore industry benefits from surveying since it allows for remote maintenance checks on oil and gas structures.