Work on the hydrodynamics study has begun with some of the field work already having been completed. The study consists of a number of sections of work to be undertaken in stages. Some of this work will be carried out by contractors with other sections being done by Joint Client Group member organisations.

Survey work

On-site survey work has been undertaken by staff from the Aberdeen Institute for Coastal Science and Management at Aberdeen University as the first stage in acquiring the present day Digital Elevation Model (DEM). This was carried out using a Trimble GX 3D (terrestrial LiDAR) advanced surveying and spatial imaging sensor that uses high speed laser and video to capture millions of coordinates and image data very quickly.To ensure the survey data was accurately located, ground control points were fixed using two Trimble 5800 GPS receivers. This equipment was also used to survey the more level areas of South Ford.To integrate all of the above described datasets, they need to be geographically referenced in the same coordinate system and this will be the standard British National Grid generally adopted for Scottish surveys.

Measuring changes (part 1, part 2)

The objective of constructing two Digital Elevation Models dating present day and from 1984 is to undertake a comparison and to measure the change which has taken place in the South Ford since the causeway was built. Powerful computer software, BAE Socetset, is to be used to produce the 1984 DEM from the aerial photos. Since both DEMs are in digital format, they can be compared in 2 and 3 dimensions to enable changes in the South Ford to be analysed. This will be done using Geographical Information System (GIS) software and will produce both comparisons of changes in the volume of sand in the South Ford, and changes in location of shoreline – erosion and accretion.

Sediment analysis & dating

Another important aspect of the study is to determine the rate over time and the composition of sediment or sand which forms the bed of the South Ford. Samples of sediment have been taken by coring into the seabed and the resulting cores are now being analysed in Dundee. This is being done to establish how quickly sand is building up and where this sand is coming from so that trends can be determined for future years.

Hydrodynamic modelling

Computer modelling work is due to begin and the object of this will be to run various scenarios which will simulate the effects of past and future storms in the South Ford. These models will be an important factor in determining what effect the presence of the causeway will have during storms and whether if Gualan Island, the barrier island to the west of the Ford, is allowed to continue to erode, what impact this will have on the extent of flooding on land and property around the coastline.

Flood risk assessment

The next stage in the study is to undertake assessments of past flooding and this will involve people living on the coasts of the South Ford and learning from their experience of past storms. Using computer visualisations from the scenario models and local knowledge, consideration will be given to future flood risk which will form the basis for how these risks can be managed.

During the next 9 months, people will be asked to answer a few questions and encouraged to give their opinion on storms and flooding and how this affects them. Towards the end of the study public meetings will be held both to gather information and then to present the findings of the study. The final report is due in autumn 2010.