WACoast a new information resource for WA coastal managers

1
WACoast a new information resource for WA
coastal managers

• Bob Gozzard
• Geological Survey of Western Australia

2
Outline of talk

• Extent of the study area
• What do we need to understand?
• Approach used to capture data
• WACoast outputs
• Use of WACoast data

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WACoast extent

• 2008 - 2009
• Lancelin to Cape Naturaliste
• 400 km
• 2009 2010
• Lancelin to Kalbarri
• 400 km

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What do we need to understand?

• Coastal landforms
• Geological control of beaches
• Beach morphology
• Coastal processes at a range of spatial and
  temporal scales
• Wind and wave climates
• Offshore sediment movement longshore littoral
  drift
• Sea-level change and its influence on the
  shoreline
• Anthropogenic influences on the shoreline
  groynes, breakwaters, marinas

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Coastal morphology
Rocky coasts ? calcarenite Cliffs and bluffs,
often undercut Rock pavements, platforms, reefs,
beachrock

• Rocky coasts ? gneiss
• Smooth slopes with boulders at base

Mixed sand and rock coasts Cuspate forelands,
tombolos, perched beaches
Sandy coasts Barrier systems, enclosed lagoons,
and beaches
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Approach used tocapture data

• Identify and capture the 198 individual beaches
  and intervening rocky coastline
• For each beach characterise the tidally-defined
  zones in the field
• nearshore, proximal foreshore, distal foreshore,
  proximal backshore, distal backshore, coastal
  exposure, and geological substrate
• four context photographs

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Approach used tocapture data

• Oblique aerial photographs
• Create fully attributed Smartline GIS layer
• Map landforms within 3 kmof the coast

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Outputs - GIS

• ArcGIS project
• Beaches and intervening rocky coastline
• SuperSmartline
• Beach characterisation
• Coastal geomorphology

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Outputs - atlas

• Oblique aerial photographs
• Georeferenced
• Interactive map-based
• Overview
• Detailed
• Zoom in and out
• Activate animatedsequence

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Use of WACoast data

• Regional scale coastal management
• Based on the concept of coastal compartments
• These units have responses and behaviours that
  must be understood and taken into account
• Local scale coastal management
• Based on littoral sediment cells
• Interaction of component geomorphological units
  produce a particular response

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Conclusion

• WACoast provides a better understanding of
• The importance of geology and geomorphology in
  coastal management
• Shoreline stability
• Effects of the interruption of offshore sediment
  source
• Coastal responses to sea-level change
• Coastal vulnerability

Blackwood River, Augusta
Albany
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• Listen! you hear the grating roar
• Of pebbles which the waves drawback, and fling,
• At their return, up the high strand,
• Begin, and cease, and then again begin
• Matthew Arnold
• Dover Beach
• New Poems (1867)