Marine environment monitoring : The basic requirements to support Marine Renewable Energies

Transcription

1 Marine environment monitoring : The basic requirements to support Marine Renewable Energies

2 SHOM in brief SHOM is the French Government agency in charge of Hydrography and Oceanography SHOM s vocation is to make available the best qualified information on physical environment to meet both civilian and military requirements 2

3 SHOM in brief 518 staff 2011 : charts 75 books ~ 340 ENCs Real time support to Naval operations One of Europe s largest maritime spatial database Facilities 3 Brest (500 staff) Toulouse, Saint-Mandé, Toulon, Nouméa, Papeete ISO 9001 : 2008 Quality management standard

4 The hydro-oceanographic flotilla Coastal Survey vessels La Pérouse Borda Laplace t In-service date: Ocean Survey vessel Beautemps-Beaupré t Co-funded by Defence (95%) & Research (5%) In-service date: December 2003 Ocean Research vessel Pourquoi pas? t Co-funded by Research (55%) & Defence (45%) In-service date: September

5 Summary 5 Preliminary conditions to exploit marine renewable energies State of knowledge What should be done to acquire a better knowledge Resources needed to acquire the missing information

6 Exploitation of Marine Renewable Energies Exploitation of marine renewable energies such as those derived from the wind, waves, tidal currents requires first to confirm two essentials: As a consequence, it is indispensable to obtain: A close knowledge of the physical process involved in the production, e.g. tidal currents prediction along the whole water column in the case of tidal turbine farms, wind, swell And a high resolution access to the seafloor morphology and texture Data are available but: 6 Is the energy potential sufficient to be worth harnessing? Is the seafloor suitable for installation of equipment? the information is sometimes insufficient, data are sparse and sometimes missing, And most of the time, data are ancient and require to be updated

7 Summary 7 Preliminary conditions to exploit marine renewable energies State of knowledge What should be done to acquire a better knowledge Resources needed to acquire the missing information

8 State of knowledge : bathymetry Precise punctual data is available However, it is too sparse to assess the seafloor morphology and slope 1,200 m

9 State of knowledge: seafloor texture and tidal currents predictions The data used to assess the tidal Punctual data exists but is sparse and ancient (depths measured with lead lines) 9 stream energy are most of the time extracted from a SHOM atlas based on a 1998 modelling The forces of current on display are restricted to values averaged between the bottom and the sea surface

10 Summary 10 Preliminary conditions to exploit marine renewable energies State of knowledge What should be done to acquire a better knowledge (example of a tidal turbines farm) Resources needed to acquire the missing information

11 What should be done to acquire a better knowledge A high resolution DTM (MBES survey), possibly completed by a description of conspicuous, punctual topographic irregularities (wrecks, submerged rocks, obstructions). 11

12 What should be done to acquire a better knowledge High resolution chart of seafloor texture Chart of sediment thickness grey: rocks purple: pebbles orange: pebbles and gravels 12 yellow: sand green: sand and gravels red: rocks (no sediment) orange: sediment less than 1 metre thick yellow: sediment 1-3 metres thick blue: 3-5 metres thick grey: 5-10 metres thick green: sediment more than 10 metres thick

13 What should be done to acquire a better knowledge Sea/land seamless beach survey - Morpho-sedimentary characteristics of the energy cable landing points 13 A 3-D modelling of the tidal currents (15 m)

14 Summary 14 SHOM in brief Preliminary conditions to exploit marine renewable energies State of knowledge What should be done to acquire a better knowledge Resources needed to acquire the missing information

15 Acquisition of data : bathymetry, seafloor texture data and sediment thickness. Bathycelerimeter: Sound velocity measurements GNSS positioning Side scan sonar: Detection of obstructions Tide gauge: Observation of tide to reduce soundings to chart datum) MBES: Measurement of depth

16 Tidal current modelling Combined with precise bathymetric DTM and detailed tide records, the current time series generate accurate 3-D tidal current model The 3-D model can split up the water column in several «current slices». Generally, it is sufficient to consider near-bottom, near-surface and middepth currents. Time series extracted from a current profiler 16

17 Thank you for your attention