samedi 27 mars 2010

Key Findings of Workshop on Rebuilding for Resilience: How Science and Engineering Can Inform Haiti's Reconstruction

Source: US Department of State/ Bureau of International Organization Affairs/Fact sheets

March 22-23, 2010
University of Miami, Coral Gables, Florida

The devastation caused by Haiti’s January 12 earthquake underscores the need to operationalize the principle of disaster risk reduction and to incorporate disaster mitigation into all aspects of reconstruction. Rebuilding efforts must not only focus on providing shelter and services but also on strengthening the resilience of the Haitian people and their communities to future earthquakes and other natural hazards.

What follows are key findings that will inform decisions of the March 31 International Donors’ Conference towards a New Future for Haiti. These messages emerged from two days of interdisciplinary dialogue at a workshop that brought together over 100 scientists, engineers, planners and policy makers drawn from government and non-governmental organizations, development agencies, the business, engineering and science communities, and academia. The deliberations benefited greatly from the active participation of a delegation comprised of Haitian government officials and academia.

The workshop identified key issues in four areas that are fundamental to the process of responsible reconstruction of Haiti: a) rebuilding requirements related to hazard assessment, b) adequate engineering of buildings and critical infrastructure, c) long-term data needs, and d) capacity building.

Convened by the U.S. National Science and Technology Council’s Subcommittee on Disaster Reduction, the workshop was co-sponsored by the U.S. Department of State, the U.S. Agency for International Development and the United Nations International Strategy for Disaster Reduction, and by the IRIS Consortium with support from NASA, the National Science Foundation, and the U.S. Geological Survey. Additional information on the workshop is available at


Hazard Assessment for Earthquakes, Inland Flooding, and Landslides
Earthquakes, inland flooding and landslides are the three greatest hazard concerns associated with resettlement, recovery, and initial reconstruction in Haiti. (Additional hazards are discussed elsewhere in this document.)

  • Hazards, Vulnerability, Risk, Planning – Hazard assessment is the first step in improving lives through vulnerability and risk assessments, all of which need to incorporate locally-identified societal needs. Hazard maps are the point of departure for vulnerability assessments leading to risk assessments, which are to be used in land-use planning for development and reconstruction. Varying values of financial and social risk will result in planning for different levels of protection (hospitals require different standards than marketplaces).
  • Maps of primary hazards exist and should be used – Preliminary maps for these three hazards have been developed, including probabilistic seismic hazard maps, and should be used to guide local standards of building and infrastructure. Haiti is also subject to hurricane and tropical-storm force winds, coastal subsidence and lateral spreading, tsunami, and drought, and preliminary maps for many of these hazards exist, or can be prepared.
  • These maps will be refined, in partnership among Haitians and others – Long-term investment and development require the expansion and refinement of natural-hazard analysis in Haiti (and the region) as we move forward. For example, we need to improve the seismic hazard maps to incorporate amplification due to soil conditions and liquefaction potential. Refined versions of the current hazard maps will be created over the coming year, based on studies that should be done in partnership by foreign and Haitian experts, leading to long-term capacity for continuing improvement.
  • Flooding and debris flows hazards are on the rise – Given the severity of human impacts to the Haitian landscape related to deforestation and soil degradation and erosion, the risks associated with flooding and mass movements (such as landslide and debris flow) are greater than would be expected from historical experience and are likely to increase more as a consequence of climate change. Temporary settlement and reconstruction along rapidly aggrading rivers and on unstable slopes should be avoided.
  • Critical sites require additional studies – For the most critical sites, individual studies will be needed to locally refine these preliminary maps.

Engineering Issues for Buildings and Critical Infrastructure

The workshop identified four aspects of the rebuilding challenge from an engineering perspective:

Owner-built new construction

  • Owner-built construction represents 80 to 90% of the construction within Haiti, and thus building back better in Haiti requires improvements to the owner-built construction process.
  • Use better building materials – The construction materials and practices currently used in Haiti (i.e., reinforced concrete and concrete blocks) can be improved to build structures that are resistant to both earthquakes and hurricanes.
    Improve construction methods – Specific improvements to construction methods should be identified (e.g., tamping of concrete to remove voids), as well as appropriate features of the structural details (e.g., reinforcement locations).
  • Provide examples of home designs – Five to ten standard prescriptive designs should be developed, each of which includes engineering drawings and building instructions, so that owners do not need to develop specific building plans that incorporate appropriate detailing.
  • Provide training and demonstration projects – Improvements to construction practice will require hands-on training sessions and demonstration projects at vocational schools (e.g., masons school) and local communities, as well as follow up visits to ensure that the improvements are being implemented.
  • Provide incentives for proper implementation – Incentives for implementing the developed improvements must be identified.
  • Study improved designs for future development – In the long term, considerations should be given to alternative types of structures and more sustainable solutions, using partnerships of Haitian and foreign designers.

New engineered infrastructure

Infrastructure represents a wide range of facilities, including civic buildings (e.g. schools, hospitals, government buildings), bridges, ports, water distribution systems, power generation and distribution systems, drainage systems, waste-water collections systems, and solid waste management systems.

  • Use seismic engineering – Due to the importance of infrastructure facilities, they should be seismically engineered using appropriate design codes.
  • Adopt and/or modify existing design codes – This process requires adoption/modification of existing design codes for the unique setting in Haiti, and the adopted design code must use appropriate hazard estimates (e.g., ground-shaking design levels derived from seismic hazard maps) as the basis for design.
  • Work within regulatory framework with trained personnel – The design code needs to be implemented within an appropriate regulatory framework that includes certification, inspection, and enforcement. Enforcement of building codes will require capacity building of municipal engineers, and public works department engineers and construction industry workers such as masons, carpenters, and contractors.
  • Encourage sustainable practices – Sustainable practices should be used whenever possible.

Rehabilitation of existing buildings and infrastructure

Throughout the country (both within and beyond the earthquake affected area), buildings and infrastructure are at risk of collapsing in the next earthquake. Buildings that survived the Jan. 12 earthquake are not necessarily earthquake-resistant.

  • Assess buildings and infrastructure – An assessment of the seismic vulnerability of existing buildings and infrastructure must be undertaken, and structures found to be deficient must be rehabilitated. These assessments should initially target essential facilities (e.g., civic buildings, institutional infrastructure, historic buildings) that are important to the population as a whole.
  • Identify retrofitting methods applicable to Haiti – Cost-effective rehabilitation strategies should be identified that are appropriate for the structural conditions in Haiti.
  • Provide demonstrations of rehabilitation effectiveness – Demonstrations should be developed (e.g., videos of shaking table tests that compare the responses of non-rehabilitated and rehabilitated structures) that illustrate the effectiveness of rehabilitation.
  • Identify and implement incentives for compliance – Incentives for rehabilitating existing buildings should be identified and implemented, in order to encourage participation in resilient reconstruction.

Landslide and liquefaction mitigation

Landslides and liquefaction represent hazards in which the ground fails, generating significant damage. Landslides are a concern in steeper terrain and can be triggered by various mechanisms including rainfall and earthquakes. Liquefaction occurs in saturated, loose sand when earthquake shaking is large enough to temporarily transform the soil into a liquid-like state.

  • Identify susceptible areas – Areas prone to landslides and liquefaction should be identified through the integration of geologic data, soil data, and topographic data, and measures should be taken to minimize the risk posed by these hazards, either through enforced zoning or mitigation measures.
  • Improve soil in reclaimed land – Reclaimed land, such as the area around the port, is particularly prone to liquefaction, and measures should be taken to improve the soils in these areas.
  • Improve embankments and other structures – Soil fill materials used in road embankments and bridge approaches, as well as soft soils underlying roadbeds, may move considerably during an earthquake, resulting in roads that are impassible. These embankments and fill materials should be seismically engineered to perform better during earthquakes.

Capacity Building

The value of international investments in hazard-resistant structures will be greater if investments are also used to strengthen the country’s social and institutional capacity in order to endow broad cross-sections of Haitian society with the knowledge and resources to continually reduce the country’s vulnerability to natural hazards well into the future. Build communities, not just houses.

  • Provide direct financial support for education and training – Capacity building should be promoted with direct financial support for education, training and outreach, including programs for local masons, other vocational training, adult literacy, primary and secondary education, universities, and development of the Haitian science and engineering communities.
  • Preserve cultural heritage and social strengths – Haiti’s cultural heritage should be preserved throughout the rebuilding process, but the country’s recovery should also be transformative. Recognizing that widespread internal displacement has weakened many communities, perform assessments of social capital to determine needs at the local level.
  • Solicit community participation– Local communities should be engaged in a participatory planning process to promote buy-in for the reconstruction plan, a sense of ownership for rebuilding efforts, and build capacity through direct engagement with reconstruction issues.
  • Communicate facts of hazards – Assistance projects should budget for communication and outreach that works to dispel rumors about hazard risk and promotes risk-wise behavior. Communication of the hazards is essential, and education of the people and development agencies should accompany widespread distribution of hazard maps and promulgation of construction standards.
  • Use local markets – Leverage local markets for cost savings to avoid high international transaction costs, promote business continuity, and stimulate the local economy.
  • Budget for hazard mitigation, reducing impacts of future events – Allocate a portion of the rebuilding budget for sustained hazard mitigation, recognizing that much of the future vulnerability to hazards is represented by structures and communities not immediately impacted by the last event.

Long-Term Data Needs

In addition to identifying the existing hazard assessment tools that can be used to inform

investments in rebuilding, the workshop also identified a number of areas where additional data acquisition is needed to refine hazard zonation, recurrence frequency, and city master planning based on identifying areas of significant risk from various hazards. Major data needs for improved risk and vulnerability assessments include:

  • Improved topographic and bathymetric information – The currently available 90-meter resolution Shuttle Radar Topography Mission (SRTM) data are not sufficient. Higher-resolution SRTM data exist and should be released. There is an associated need for still higher-resolution light detection and ranging (LIDAR) acquisition in key hazard-prone areas.
  • Remote-sensing data and studies – Continued and enhanced remote sensing observations are required to monitor and update hazard assessments. Satellite-based optical and synthetic aperture radar observations are needed to support field observations and to monitor surface deformation associated with strain accumulation and mass movements.
  • Field surveys for geology and soil classifications – Soil type and texture information is essential for slope-stability studies, reforestation planning, determination of site-specific seismic shaking amplification, and flood modeling.
  • Monitoring networks for multiple hazards – Reconstruction plans need to invest in a long-term program for development of monitoring capabilities, which must include a strong Haitian local capacity and infrastructure for long-term viability. In-situ networks of rain and river gauges are required for analysis and model verification for use in flooding and landslide hazard evaluation, as well as for agricultural and hydro power optimization. Seismograph and GPS networks are required for improving the assessment of earthquake and related hazards. Social tracking data are needed to improve vulnerability assessments and evaluate adoption of risk-wise behavior.
  • Consideration of geophysical drivers of natural hazards – Scientific observations and analysis are inherently regional in scope; natural hazards know no borders. Targeted investment in a regional capability that incorporates and builds upon capacity developed in Haiti will improve the sustainability of monitoring activities. This is an important consideration for hazards that have long recurrence intervals in any one location but have devastating impacts when they strike. The regional approach should leverage existing networks, infrastructures, organizations and social capacity to the extent possible and should facilitate access to the information generated.

1 commentaire:

  1. Hello Friends, good blog with helpful insight into best practices on the world response to Haiti.