Hydrography is the science that measures and describes the physical features of bodies of water and the land areas adjacent to those bodies of water. Surveying with multibeam echo sounders is the primary method of obtaining hydrographic data. By mapping out water depth, the shape of the seafloor and coastline, the location of possible obstructions and physical features of water bodies, hydrography helps keep our maritime transportation system moving safely and efficiently. Multibeam echo sounder beams sweep the seafloor as the ship passes over the survey area. Multibeam echo sounder beams bounce off the seafloor and return to the ship where the depth is recorded.
Hydrography is the science that measures and describes the physical features of the navigable portion of the Earth’s surface and adjoining coastal areas. Hydrographic surveyors study these bodies of water to see what the “floor” looks like.
Hydrographic survey companies to measure the depth and bottom configuration of water bodies. That data is used to update nautical charts and develop hydrographic models. This information is vital to navigating the ocean and our nation’s waterways.
Hydrographic surveys are also used in NOAA’s Integrated Ocean and Coast Mapping program, providing information for several purposes, including seafloor structural construction, laying pipelines and cables, dredging, anchoring and understanding fish habitats.
Types of the Hydrographic Survey that the Hydrographic Survey Companies do:
Harbor Survey
This survey is intended for the safe navigation of vessels near ports and their surroundings.
Passage survey
This survey is intended for safe navigation in main sea lanes.
Coastal Survey
This survey is intended for safe navigation and gaining knowledge about the bottom topography, sea-bottom sediments, and more in offshore waters.
Survey for correction
The survey for correction (general hydrographic survey) is designed to measure water depths, coastlines, and geological features after dredging, artificial fish-reef installation, and such, and change waterway-related publications such as nautical charts accordingly.
The primary purpose of hydrographic surveying is in water depth estimation, which is achieved by bathymetric surveys. Some of the other most common uses of Hydrographic survey companies include waterway planning, dredging analysis, and wreck location.
Another application of surveying is in the construction and planning of docks, harbors, and dams. For example, it is important to ensure that the water depth in and around ports is sufficient to allow ships to enter and berth safely. Also, the portion of the seabed that supports floating structures must have a strong foundation. Dams also require adequate knowledge of the surrounding terrain to ensure structural strength.
The top 10 Hydrographic Survey Companies in Australia are:
- Acquamap Hydrographic Services
- iXblue Australia
- Total Hydrographic
- McMullen Nolan Group
- Tetra Tech
- Astute Surveying
- Precision Hydrographic Services
- Bruttour International
- Leica Geosystems
- MNG
Hydrographic Survey companies also help in ship navigation by providing possible paths that a vessel can take. Certain ocean routes may lie at low depths or may have rocks and coral deposits. This poses a major danger to ships and hence needs to be recorded properly. By charting safe routes that do not cross any dangerous terrain, surveying helps the shipping industry. Surveying also has agricultural uses by determining alluvial and silt deposits near water bodies. As deltas have incredibly fertile lands, such areas can be specifically allotted for farming activities. Also, by studying river discharge, erosion and its effects on arable land can be studied.
Lastly, hydrographic surveys are often conducted by private organizations. They are undertaken for geological reasons, determine appropriate locations for oil and gas structures, install underwater communication devices and military applications. These are usually undertaken by large Hydrographic Survey companies that already own docks and ships.
