Site survey

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In site survey design, wind, wave height and current velocity is calculated. In addition, conditions like icing, mapping of seabed and tidal levels are documented. We have also developed methods for processing measured current data, which can provide a more accurate current description and reduce mooring equipment costs.

Site survey report

The findings from a site survey are summarized and presented in a site survey report. The report forms the basis for mooring analysis, which in turn determines the design of the fish farm. The site survey report is hence the foundation of a proper designed fish farm. Aquastructures performs numerical calculations of both wind-generated waves and ocean swells. We also perform a thorough control to reveal possible incorrect readings of the current measurements.

Calculation of ocean swell

Assessment of the influence of ocean swell has to be conducted for each site, according to NS 9415. In such cases, the impact of ocean swell must be determined based on numerical calculations, wave measurements or other methods. Using our in-house developed software AquaSwan, we perform detailed calculation of wind waves and swell combinations.

Aquastructures is accredited to perform wave and current calculations.

Wave Calculations are performed for both wind-generated waves and ocean swell. Wind-generated waves are calculated based on distance to shore and wind speed. For calculation of ocean swell used computational model SWAN.

AquaStructures performes site surveys, according to the NYTEK regulation.

NYTEK regulations require that it should be carried out a site survey before a fishfarm can be deployed at a site. Site survey will be carried out by an accredited inspection body and fulfill the requirements stipulated in EN 9415:2009.

Environmental parameters that will be described are:

  • Wind speed – Determination of wind speed at the site is used to calculate wind-generated waves with 10 and 50 year return period.
  • Wind-generated waves – NS9415: 2009 sets requirements for the determination of wind-generated waves and ocean swell by 10 and 50 year return period.
  • Ocean swell – if site is subjected to ocean swell, this should be calculated and combined sea conditions, with wind waves is determined.
  • Current speed – will be determined the design flow rate of 8 different directions with return period 10 and 50. Measurements should be made at depths of 5 and 15 meters.
  • Icing – Risk of icing must be documented on the basis of air temperature, wind exposure, wave exposure and sea temperature

 

 

In addition, water depth, bottom type and topography are described so that the system can be adapted to the site in the best possible way.

A good Site survey is necessary to calculate and dimension the mooring correctly, as well as choosing the right selection of key components.