Beyond bathymetry – coastal marine mapping
Travis Mason
The Southeast and Southwest Strategic Regional Coastal Monitoring
Programmes in the UK have started to fill the “white ribbon” – the
nearshore region with typically very little data – with swath
bathymetry from about 1km offshore to the inter-tidal beach, through
collaboration with the Maritime & Coastguard Agency’s Civil
Hydrography Programme. This sharing of resources has proved a very
cost-effective solution, using the MCA/UKHO’s IHO Order 1a
specification and over-sight of the survey to ensure the suitability
of the data for navigation safety, whilst fulfilling the need for
maritime Local Authorities to obtain hitherto unobtainable data useful
for a range of coastal engineering applications.
The advent of high-quality backscatter data, collected simultaneously
with the full-density swath bathymetry has opened up a range of
applications beyond traditional navigation and charting. The Channel
Coastal Observatory has recently used the backscatter and bathymetry
for marine mapping of sediments and habitats to EUNIS level. Figure 1
shows an example of the bathymetry and resulting EUNIS Level III
marine habitat mapping near Folkestone, Kent. Such detailed results
are of crucial importance for designation of potential Marine
Conservation Zones and other environmentally-designated areas yet, at
present, few of the potential conservation areas have been mapped to
this level of detail from swath bathymetry and backscatter.
Identification of areas of sediment, sand waves (indication a mobile
seabed) and pipelines etc. are of particular interest for coastal
engineering.
All the bathymetry data collected by the Programmes is made freely
available and free, via a website where interested parties can
download directly the data they want, together with full FGDC-standard
metadata. Information about the surveys will soon be added to the
MEDIN website with INSPIRE-compliant metadata.
The Programmes have deployed an extensive coastal wave and tide
network; the real-time wave and tide parameters are increasingly used
for thresholds for coastal operations and surveys. The tide gauges
are of GLOSS standard and deployed to sit inside the UK National Tide
Gauge Network, notably at sites where there has been little tidal
information historically. Again, all data are freely available, and
the quality-controlled data are sent to the UKHO.