slide1
Download
Skip this Video
Download Presentation
COASTAL COMPARTMENTS, SEDIMENT CELLS AND VULNERABILITY ASSESSMENT: A Progress Report

Loading in 2 Seconds...

play fullscreen
1 / 27

COASTAL COMPARTMENTS, SEDIMENT CELLS AND VULNERABILITY ASSESSMENT: A Progress Report - PowerPoint PPT Presentation


  • 182 Views
  • Uploaded on

COASTAL COMPARTMENTS, SEDIMENT CELLS AND VULNERABILITY ASSESSMENT: A Progress Report. Presentation to WALIS MARINE GROUP MATT ELIOT AND IAN ELIOT Damara Pty Ltd, Innaloo , WA 19 July 2011. BASIC CONCEPTS

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'COASTAL COMPARTMENTS, SEDIMENT CELLS AND VULNERABILITY ASSESSMENT: A Progress Report' - zan


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1
COASTAL COMPARTMENTS, SEDIMENT CELLS AND VULNERABILITY ASSESSMENT:

A Progress Report

Presentation to

WALIS MARINE GROUP

MATT ELIOT AND IAN ELIOT

Damara Pty Ltd, Innaloo , WA

19 July 2011

slide2
BASIC CONCEPTS
  • The project develops a hierarchy of planning units, based on the geologic framework of the coast.
  • At the broadest planning levels the planning units comprise a set of discrete coastal compartments determined by geologic boundaries, structures, landforms and coastal aspect together with the landforms they contain.
  • At the most detailed planning levels the planning units are identified as sediment cells in which sediments sources, transport pathways and sinks can be clearly defined.
  • Together, coastal compartments and sediment cells provide a framework for a variety of applications including:
  • (a) planning and management of natural resources within the nearshore marine and coastal environment; and
  • (b) assessment of vulnerability to coastal hazards, climate change and rise in sea level.
slide3
Regions: Areas with recurring patterns of landform and geology suitable for regional mapping at scales of approximately 1:250,000

Zones: Broad sectors of the Australian continent based on climate

Divisions: Provides an overview of the whole state suitable for maps at scales of about 1:5,000,000

Provinces: Areas defined on geomorphologic or geological criteria suitable for regional perspectives at scales of about 1:1,000,000

Land Systems: Areas of characteristic landform patterns suitable for mapping at regional scales of 1:50,000 to 1:100,000

Landforms: A local unit based on one or more landforms suitable for mapping at scales of about 1:5,000 to 1:15,000

Compartments: A local unit based on one or more definite landforms suitable for mapping at scales of about 1:25,000 to 1:50,000

Sediment Cells: A local unit based on several linked landforms suitable for mapping at scales of about 1:5,000 to 1:25,000

slide5
POTENTIAL APPLICATIONS

COMPARTMENTS

Landforms (Framework) & Processes (Drivers)

PLANNING PURPOSES

Marine & coastal risk assessment

Marine & coastal planning

Habitat description

Marine conservation

EBFM

slide6
Major Landform Assemblages
  • (After: Searle & Semeniuk 1985)
  • Nearshore Morphology
  • Islands
  • Linear reefs and submarine ridges
  • Pavements
  • Sand banks
  • Sand flats and seagrass meadows
  • Landforms of the Shore
  • Shoreline shapes (straight, irregular, arcuate and zeta-form)
  • Rocky coasts (cliffs, ramps and platforms)
  • Beaches (sheltered and exposed forms)
  • Onshore Landforms
  • Limestone plateaux and outcrops
  • Foredunes
  • Frontal dunes (blowouts and parabolic dunes)
  • Barriers
  • Estuaries
  • Deltas
  • Coastal lagoons and wetlands
slide7
An extreme event or events may change the type or location of a land system.

eg. Avulsion (channel switching) and delta shift

STABILITY

SUSCEPTIBILITY

VULNERABILITY

Likelihood of erosional change to landforms related to current land surface condition

Likelihood of structural breakdown leading to a change in the land system

Likelihood of landform and/or land system change

=

+

Gradual landform change associated with land surface instability ultimately results in structural change.

eg. Barrier evolution

slide8
SUSCEPTIBILITY

Long-term Structural Change

STABILITY

Short-term Landform Change

Spit

Mouth

Ashburton River Delta 1963

Open river mouth

Active spit

Climbing dunes

Perched barrier and climbing dunes

Mouth

Ashburton River Delta 2009

Open river mouth

Active chenier

Cliff & talus slope

No barrier. Perched beach and old dunes

slide9
Rank 1: High cliff (>10m) plunging to subtidal level

Rank 2: Moderate to high cliff (>10m) with an intertidal platform

Rank 3: Cliff (5 - 10m high) and wide intertidal platform

The susceptibility of rocky coast refers to the intrinsic propensity of a coastal land system or landform structure to alter in response to projected change in metocean conditions over a long period, commonly extending to millennia.

Variation in structure may occur spatially, due to differences in rock type; or temporally as a result in the differences in the strength of the same rock type and exposure to disparate processes.

Rank 4: Rock pavement or intertidal platform and low bluff (<5m high)

Rank 5: Gently sloping rocky shore

ROCKY COAST SUSCEPTIBILITY

The sequence illustrated here loosely follows that described by Sunamara (1992).

slide10
Rank 1: Episodic Transgressive Barrier

Nested blowouts and parabolic dunes.

Rank 3: Stationary Barrier

Low or narrow ridge of blowout

Rank 2: Prograded Barrier

Low, foredune ridge plain

The susceptibility of a sandy barrier refers to the intrinsic propensity of the structure comprising the barrier system to alter in response to projected change in metocean conditions, particularly sea level rise over.

Barrier formation occurs over a long period, commonly millennia, although structural change from one type to another may occur within tens to hundreds of years.

Rank 4: Receded Barrier

Low narrow dune ridge & old shoreline

Rank 5: Mainland Beach

Narrow duns & beach abutting bedrock.

SANDY (BARRIER) COAST SUSCEPTIBILITY

The sequence illustrated here follows that described by Roy (1994).

slide11
Rank 3: Perched beach adjoining a low bluff

Rank 1: No beach OR a foredune is located on a high rock platform (>HAT)

Rank 2: Perched beach is located on a supratidal rock platform

Estimates of beach instability are based on the exposure of the beach to metocean processes.

The variability of sandy beaches in different settings has been described by Nordstrom (1992) and Short (2005).

The stability of sandy beaches perched on rocky substrates is not as well known, although such beaches are common features of the Australian coast. The sequence shows beaches subject to increasing exposure to wave and sea level variation.

Rank 4: Perched beach on an intertidal platform or beachrock ramp

Rank 5: Perched beach on shallow inshore pavement

STABILITY ON MIXED SANDY AND ROCKY COAST

The sequence illustrated here follows that described by da Silva (2010).

slide12
Rank 1: Undisturbed dune sequence OR

Fully vegetated (>75% cover on barrier).

Rank 2: 50 to 75% vegetation cover on barrier OR <25% active dunes or bare sand

Rank 3: 25-50% vegetation cover on barrier OR 25-50% mobile dune

Estimates of instability are based on the land surface condition and the proportion of area in a compartment or cell that is currently bare sand or subject to erosion.

Destabilisation of dunes occurs with destruction of a foredune, scarping of the frontal dunes or removal of the vegetation cover.

Changes to vegetation cover take place in a short period, commonly sub-decadally.

Rank 5: Mobile sand sheets OR <25% vegetation cover on barrier.

Rank 4: <50% vegetation cover on barrier OR 50-75% active dunes or bare sand

STABILITY ON SANDY COAST

The sequence illustrated here follows that described by Short (1988).

slide13
Land system and landform description and

Ranking for susceptibility and instability

slide17
INDICATIVE VULNERABILITY MATRIX

MIXED SANDY AND ROCKY COAST

slide20
VULNERABILITY ESTIMATES

COMPARTMENTS AND CELLS

slide21
INDICATIVE VULNERABILITY MATRIX

BASED ON LARGE LAND SYSTEMS

VULNERABILITY = SUSCEPTIBILITY + INSTABILITY

slide22
VULNERABILITY ESTIMATES

PRIMARY COMPARTMENTS

slide23
POTENTIAL APPLICATIONS

COMPARTMENTS

Landforms (Framework) & Processes (Drivers)

PLANNING PURPOSES

Marine & coastal risk assessment

Marine & coastal planning

Habitat description

Marine conservation

EBFM

slide24
START

DETERMINE THE SCOPE 0F PROJECTED CHANGE & RESPONSE URGENCY

Community Involvement through information gathering and workshops

Determine gaps in available information and assess further needs

Community Involvement through information exchange and workshops

Monitor and assess actions implemented under the strategy

Improve understanding of the biophysical environment

Implement strategy based on current available information

ISO 31000 Methodology applied to NCCOE (2004) vulnerability assessment

Acquisition of new information and data as the cycle is repeated

Determine a strategy for hazard management and risk avoidance

Agree on environmental, social and economic values for risk mitigation

(1) Initial strategy is based on available information.

(2) Review strategy at 5 year intervals

Identify areas requiring new work or replacement of infrastructure

Estimate current environmental, social and economic costs

Identify projected hazards and risks to people & property

Community Involvement through information exchange and workshops

PLANNING CYCLE FOR COASTAL RISK ASSESSMENT

Project in cycle

Community participation

Planning for hazard & risk mitigation

© Ian Eliot 2009

slide25
AS NZS (2009) ISO 31000

Risk Assessment Framework Adapted to Coastal Management

From: Rollason et al. (2010)

and Rollason & Haines (2011)

slide26
Commonwealth Climate Change Assessments

Cities Project

NCVA

LAPP

ANUGA

PNP

State Government Coastal Assessments

Coastal Process Studies

Coastal Hazard Assessments

Coastal Planning Studies

SPP2.6 Review

Pilbara Cities

Regional Strategies

Local Government Coastal Assessments

DIVERSE!!

ad