ECLAC Disaster Assessment Training Manual Section V ii Coastal Engineering: Reconstruction Managemen

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ECLAC Disaster Assessment Training Manual
Section V (ii) Coastal Engineering
Reconstruction Management and Mitigation
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Objectives

•     To familiarize the assessor with the process
  that should be followed in organizing any
  reconstruction efforts.
•     To emphasize the importance of accessing a
  proper data base during the reconstruction
  process, and of using appropriate design
  criteria.
•     To outline the necessity for post
  construction efforts, which should include proper
  monitoring and maintenance.

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Management Requirement 1Understanding the cause
of the disaster

• Knowledge of the National Hurricane Centre
  database of storms, which dates back to 1876
  (http//www.nhc.noaa.gov/) rainfall records
• Proper hindcasting of hurricane waves from a
  knowledge of the hurricane wind field
• Transformation of the hurricane wave climate from
  deep water to the nearshore zones
• Extremal analysis of the hindcast wave climate or
  rainfall records, so that design conditions can
  be extracted. What return period should be used
  for design? 50 year or 100 year

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Management Requirement 1Understanding the cause
of the disaster

• What part does climate change play, if any, in
  the development of a design criterion?

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Management Requirement 2What can be affected by
the disaster

• This requires proper mapping of the
  coastal/river infrastructure, which in turn calls
  for knowledge of the following
• Locations, physical extents and condition of
  coastal and river infrastructure
• Extent of coastal communities, population,
  location of critical infrastructure, degree of
  vulnerability
• Representation of this data on digital mapping is
  desirable, or at the very least, on 12500 scale
  mapping
• Definition of coastal infrastructure such as
  roads, etc.

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Grande Anse Bay, Grenada
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Dominica
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Management Requirement 3How damages are
effected

• Requires a sound knowledge of the processes that
  can result in damage to coastal/river
  infrastructure and shorelines. These include
• Beach characteristics, seabed bathymetry and
  sediment processes
• Benthic substrates in the relevant nearshore
  areas
• Nearshore wave climates for design and perhaps
  day-to-day conditions
• Tidal fluctuations, global sea level rise and
  storm surge estimates
• Effect of existing and proposed sea defences on
  shoreline processes and
• River hydrology/hydaulics

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Mitigation Strategy Data RequirementsImplement
ing protection against diasters

• Design and construction of coastal defence or
  river training works. Data requirements include
• Topographic bathymetric survey (admiralty
  charts)
• Preliminary engineering design of shore
  protection or river training works (concept
  development, site understanding, recommended
  options)
• Preliminary costing of works (examples from
  similar works)

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Mitigation Strategy Data RequirementsImplement
ing protection against diasters

• EIA for proposed works (develop terms of
  reference approved by regulatory agencies)
• Modification of Preliminary Design to accommodate
  EIA findings, and presentation of results
• Selection of the preferred option
• Final design of works (must be designed to
  withstand impacts).
• Preparation of the contract doicuments
• The tender process and
• Construction of the works.

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• Protection against disasters can also take the
  form of building setbacks, emergency relief
  planning, improvements to the building code, or
  preperation of a CZMP. This process requires
• A sound knowledge of the areas most at risk
  (socio-economic data)
• Knowledge of the population and infrastructure
  within the risk area (vulnerability assessment)
• Identification of safe shelters (emergency
  response planning requires that shelters be
  accessible during hurricane conditions)

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2-Tonne boulder in lobby of Trident Hotel a
good case for set-back limits?
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Protection further includes

• A proper evacuation plan (disaster management
  planning)
• Improvements to the building codes (required for
  CUBIC)
• Development of a CZMP, which can be used as a
  vulnerability reduction tool.

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Mitigation Strategies (contd)Ensuring
longevity of defence investment

• This requires proper maintenance of coastal/river
  defence works/. Issues to be considered here
  include
• Monitoring of shoreline movement or change on a
  regular basis (beach profile monitoring on a
  regular basis)
• Evaluation of effectiveness of sea defence or
  river training works
• Estimation of residual life left in structure or
  works and of the need to do repairs to works
• Evaluation of long-term impacts, if any, on the
  adjacent shoreline, and the need to modify works
  to minimise any identified impacts.

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Negril after Hurricane Mitch
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Self Assessment

• By this stage you should be able to evaluate the
  necessary steps required to evaluate, design,
  implement and monitor the reconstruction works
  that would be needed following a disaster.