FIELDWORK AT TEIGNMOUTH, UK

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FIELDWORK AT TEIGNMOUTH, UK

• Overview of the characteristics of the May 2003
  Campaign
• (Phase II 12/05/03 30/05/03)

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CONTENTS

• Site characteristics
• Objectives of the field campaign
• Coastal State Indicators field data needs
• Comparison of data collected (Phase I vs Phase
  II) (how, where, main variables, main results)
• Morphology measurements
• Shoreline surveying
• ADCP measurements (currents and waves).
• SLOT data (waves, currents, and sediment
  transport)
• Summary

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SITE CHARACTERISTICS

• Complex system of multiple bars
• Long-term cycle (5-8 years)

• Sandbar movement cause
• Navigational problems
• Recreational hazards
• Governs sediment budget on the beach (affecting
  the structural stability of seawall)

slot
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OBJECTIVES

• Provide ground truth for validation and
  development of video-derived CSIs
• Provide in-depth understanding of the
  morphological cycle (video) and the associated
  (short term) sediment transport processes (SLOT).
  
• Show data availability and methods of collection
  to partners

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CSI FIELD DATA MATRIX
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MORPHOLOGICAL SURVEYS

• Rational
• Ground truth for Video - CSIs
• Breaking wave patterns (2D)
• Intertidal mapping (3D)
• Subtidal mapping (3D)
• Location of dredging
• System Classification

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MORPHOLOGICAL SURVEYS

• How?
• Kinematic DGPS mounted on quad-bike or boat (
  echosounder) land-based station.

• 13 -23 May (2003)

26 Nov 10 Dec 2002
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MORPHOLOGICAL SURVEYS

• Where and how many

• Nov- Dec 2002 (Phase I)
• 6 Quad-bike surveys
• 3 Boat surveys

• May 2003 (Phase II)
• 4 Quad-bike surveys
• 3 Boat surveys

tracks
tracks
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SHORELINE SURVEYING

• Rational
• Ground truth for Videoderived Intertidal
  mapping
• Assess shoreline variability in time and space
  (swash)
• Related with wave energy level (In which way?)
• Estimate errors in video-derived shoreline
  detection

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SHORELINE SURVEYING

• November 2002
• Hand-held DGPS following shoreline compare with
  rapid sampling

• May 2003
• Trinocular video system on the beach
• Resolves elevations (z) and variability in time.
• 12.5 hr footage sampled at 1 Hz.

• Problems
• Difficult to operate
• Cannot resolve shoreline variability (space and
  time)

BACK
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SHORELINE SURVEYING (Trinocular video)
3 video cameras
Looking at a delimited area on the beach
Data cabled to a car-based PC
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3D CURRENTS IN CHANNEL (ADCP)

• Rational
• Surface currents in channel
• Can we identify the channel through current
  structure
• Intensity of currents at channel
• Surface currents elsewhere
• Can rip currents be identified

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3D CURRENTS IN CHANNEL (ADCP)

• November 2002
• Not performed

• May 2003
• Collaboration with University of Cantabria (ADCP)
• Problems
• Need to remain stationary (no bottom
  tracking)
• Current measurements in the channel in June with
  bottom tracking ADCP.

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WAVE DIRECTIONAL SPECTRUM (ADCP)

• Rational
• Directional wave climate offshore (CSI)

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WAVE DIRECTIONAL SPECTRUM (ADCP)

• Where and How
• ADCP mounted in a steel frame
• Deployed by boat at 4-5 m depth offshore from
  the
• Ness Headland

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WAVE DIRECTIONAL SPECTRUM (ADCP)

• November 2002
• 22 days of data (every 30 min)

• May 2003
• 18 days of data (every 30 min)

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SHORT-TERM PROCESSES (SLOT)

• Rationale
• Understanding the sediment transport mechanisms
  important for the long term morphological changes
  (Robinsons cycle)

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SHORT-TERM PROCESSES (SLOT)

• Onshore migration of sandbanks in the vicinity of
  coastal inlets is a very common phenomena.

• Kennebeck River, Maine, USA

• Wadden Sea Inlets, NL

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SHORT-TERM PROCESSES (SLOT)

• Which variables, where and when
• OBS (suspended sediments), EMCM (horizontal
  currents), PT (surface elevation), installed at
  the low water mark.

SLOT

• November 2002
• 3 SLOT systems in 5 different positions.
• Shore attached bar and adjacent beach
• 65 tides of data at 2 Hz

S
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V
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SLOT 3 ON CREST OF SHORE-ATTACHED BAR
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STORM PEAK ON 10 DECEMBER
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SUMMARY
Field data needs Nov Dec 2002 May 2003 Future
Bathymetric surveys ? ? ?
Beach morphology ? ? ?
Shoreline surveying ? ? ?
ADCP (currents) ? ? ?
ADCP (directional waves) ? ? ?
SLOT data ? ? ?

• All this data is now available on the server

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SHORT-TERM PROCESSES (SLOT)
BACK
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SHORT-TERM PROCESSES (SLOT)

• System state on May 2003 (from seawall)

• System state on May 2003 (from pier)

BACK
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Phase I Morphological SurveysNov Dec 2002
Quad-bike surveys
Boat surveys
BACK
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Phase II Morphological SurveysMay 2003
Quad-bike surveys
Boat surveys
BACK