Transcript Data, Information and Tools for Effective Coastal Erosion

Concepts and Science for
Coastal Erosion Management
Data, Information and Tools for
Effective Coastal Erosion
Management
James Sutherland
HR Wallingford
Concepts and Science for
Coastal Erosion Management
Data, Information and Tools for Effective
Coastal Erosion Management
• We live in a data-rich age
– If you can afford it
• There are many ways of collecting lots
of data
– From megabytes to terabytes
• Increased volumes of data do not
necessarily help coastal management
– Drowning in numbers
Concepts and Science for
Coastal Erosion Management
Data, Information and Tools for Effective
Coastal Erosion Management
Purpose of this presentation:
• Review beach monitoring methods
• Review numerical modelling tools
– Not necessarily useful for management
• Review data handling/display tools
• Explain role of coastal state indicators
• Provide monitoring guidance
Concepts and Science for
Coastal Erosion Management
Monitoring methods
• Point measurements
– Tell-tail scour monitor
Recovery
Lowering
3
Recovery
Lowering
Tide, beach levels (mCD) Hs (m)
3.5
2.5
2
1.5
1
0.5
Tide Height
0
24/05/2005 00:00
Scour monitor
24/05/2005 12:00
Hs
25/05/2005 00:00
Date and Time GMT
25/05/2005 12:00
Concepts and Science for
Coastal Erosion Management
Monitoring methods
• Cross-shore profiles
– Theodolite,Total station,
– DGPS,
– CRAB, WESP,
– laser scanner,
– Argus or other camera system,
– X-band radar.
Concepts and Science for
Coastal Erosion Management
Monitoring methods
• Map tidelines,
• Ortho-rectified aerial
or satellite photos,
• Topographic lidar
• Bathymetric lidar
• Synthetic aperture
radar
– (side-looking airborne
radar)
Concepts and Science for
Coastal Erosion Management
Data management and display
• Modern systems capable of handling huge
volumes of data through the data life-cycle
• Increasing importance of meta-data and
international standards
• Measure once, use often
• Central data stores
• Use of GIS
Concepts and Science for
Coastal Erosion Management
Numerical Models for Erosion
Management
Concepts and Science for
Coastal Erosion Management
Tools for Erosion Management
• Historical trend analysis
– Often least-squares linear trend;
– More sophisticated methods require more
data of better quality
– Prediction relies on continuation of
historic trend
Concepts and Science for
Coastal Erosion Management
Numerical Models for Erosion
Management
• One-line models
– Simple but robust
– Used to model decades of shoreline
positions
• Coastal profile models
– Cross-shore erosion under storms
– Poor at modelling beach recovery after
storms
– Used to model days to weeks
Concepts and Science for
Coastal Erosion Management
Numerical Models for Erosion
Management
• Coastal area models
– Flows + waves + sediment transport +
morphology
– Model areas are 102 to 104 km2
– Model simulates days to weeks
– Extension to longer timescales through
simplification
Concepts and Science for
Coastal Erosion Management
Numerical Models for Erosion
Management
• System models of morphology
– SCAPE and ASMITA
– Model simplified interactions between
elements;
– Simulations of 10 to 103 years
– Limited spatial resolution
• Systems models of flooding
– RASP and PAMS in UK, VNK in NL
Concepts and Science for
Coastal Erosion Management
COAST3D question
• How can we use models and data to
assist coastal management?
• Most detailed process models do not
answer questions at the time and space
scales that are of interest to coastal
managers
• One approach is to use Coastal State
Indicators
Concepts and Science for
Coastal Erosion Management
Coastal State Indicators
• “Coastal State Indicators for Coastal
Erosion”
– Tuesday, Session 18 ‘Coastal Erosion
Indicators’, 16:30 – 16:45, Europa
Auditorium
Concepts and Science for
Coastal Erosion Management
Coastal State Indicators
• Coastal State Indicators are a “reduced
set of parameters that can simply,
adequately and quantitatively describe
the dynamic-state and evolutionary
trends of a coastal system.”
– Jiménez and van Koningsveld, 2002
• Indicators used in implementing a
policy
Concepts and Science for
Coastal Erosion Management
Frame of Reference
Concepts and Science for
Coastal Erosion Management
Frame of Reference
Concepts and Science for
Coastal Erosion Management
Coastal State Indicators
• Derived from analysis of system
– Understanding state of system
– Given a policy to implement
– Chosen a means to implement the policy
– Require thresholds
– Adaptive management
Concepts and Science for
Coastal Erosion Management
Coastal State Indicators
Concepts and Science for
Coastal Erosion Management
Coastal State Indicators
• Dune strength, Barrier width, Backshore
width, dune zone width, dune zone height
• Total barrier volume
• Momentary coastline, Beach width, Barrier
crest position, Shoreline position,
• Coastal foundation, Shoreface volume,
coastal slope
Concepts and Science for
Coastal Erosion Management
Coastal State Indicators
• Are being regularly used at three pilot
sites;
• Are appropriate for the users;
• Not just data
– Require a policy
– Require a threshold
Concepts and Science for
Coastal Erosion Management
Monitoring guidance
• Monitor for a purpose:
– Understand system
– Derive coastal state indicators
– Measure coastal state indicators
• Different stages may require different data
• Establish ground controls and datum
• Set standards