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Survey Techniques

Land Survey

Technology has moved on substantially since the first surveys were carried out in 1991. In the early days the topographic beach profiles were set out using reference objects (landmarks) and bearings from a permanent physical marker. Nowadays GPS is used almost exclusively to survey the profile lines. This allows accurate positioning of the profile line, ensures repeatability and avoids nearly all human error. Data collection is now quicker and quality control much easier as all data are recorded and traceable.

Bi-annual shore-normal beach profiles are surveyed at 1km centres. In addition profiles are surveyed for selected scheme specific sites at closer spacing (down to 20m).

Bathymetric Survey

In Anglian we predominantly continue to opt for single-beam bathymetric profiles, but we have recently undertaken a swath bathymetry survey of Hamford Water, due to its shallow water depths and irregular shape.

There is a rolling programme of open-coast and estuaries, originally surveyed as extensions to beach profiles and now with additional bathymetric profiles at 250m spatial resolution.

Whereas in the past the bathymetric data had to be reconciled using tide gauges, today the vessel is positioned using RTK GPS from shore-based control stations, which avoids the need to install the tide gauges.

Aerial Photography

Digital aerial photography of the whole frontage is collected and delivered as ortho-rectified images

Wave monitoring

5 directional Waverider buoys were deployed in 2006 along the Anglian Region's coastal frontage at locations with water depths of approx. 20m below CD, along with 20 recorders (at locations with water depths of 4m to10m below CD). Suspended sediment data are collected in conjunction with the acoustic nearshore recorders.

From September 2009, the recorders will be removed but 4 of the 5 Waverider buoys will remain as part of WaveNet.