Tropical cyclone Hazard level: Very low ?

Tropical cyclones are intense rotating storm systems that form over warm tropical oceans, characterized by strong winds, heavy rainfall, and storm surges. These systems derive energy from warm ocean waters and can cause damage through multiple mechanisms: high-speed winds, torrential precipitation leading to flooding, and coastal inundation from storm surge. The severity depends on the cyclone's intensity, size, forward speed, track, and the vulnerability of affected areas.

In the area you have selected (The Gambia) cyclone (also known as hurricane or typhoon) hazard is classified as very low according to the information that is currently available. This means that there is less than 0.1% chance per year of potentially-damaging cyclone-strength winds in your project area (less than 1% chance in the next 10 years). Based on this information, the impact of cyclones does not need to be considered in different phases of the project. Although the hazard is considered to be very low in the project location based on the information available in ThinkHazard!, other sources may show some level of cyclone hazard. If local or additional information sources suggest that there are cyclones, seek expert guidance on additional recommended actions.

Recommendations

• INSURANCE: For cyclone wind risks that cannot be mitigated, consider insurance products specifically aimed at alleviating the financial costs associated with wind risk. More information
  ×

  • During the design and construction phases, consider a ‘builders risk’ insurance policy for your project, in particular if the policy can cover aggregate weather hazards including those directly related to cyclones (such as extreme rainfall, wind and storm surge).

  • After construction is complete, consider a long-term hazard policy to protect your investment, especially if it covers other more significant hazards in your project area.

  Close
• INTERACTING HAZARDS: Project planning, design, and construction practices should account for strong wind from potential cyclones in your project area. More information
  ×

  Context - Throughout the project from design to construction, you should understand the level of wind hazard in your project area. Keep in mind that in a changing climate, windstorms may be experienced in regions where they have been historically rare. Also be mindful that other short-term wind events (such as severe thunderstorms) may be highly localized and still cause significant wind damage.

  Mitigation - While the wind hazard level for your project location is VERY LOW, well-constructed buildings will reduce the risk of other hazards that may be present in your project area. For example, properly constructed roofs and building connections that do well in high winds also withstand strong ‘gravity loads’ from heavy snow and ice. Properly formed and sealed foundations may reduce impacts during flooding. Consider wind along with other related hazards in the overall mitigation strategy for your project.

  Close
• EMERGENCY RESPONSE PLANS: Identify the regional and national government’s emergency response policy and protocols to cyclones (including coastal and inland flooding and wind hazard) in your project area and incorporate as necessary. More information
  ×

  • During the design and construction phases, consider a review of the emergency response procedures laid out by the government in your project area. These procedures will take into account the hazards inherent to your region, including cyclone wind hazards, and should confirm that the risks are VERY LOW.

  • After construction is complete, be mindful of local emergency response procedures and if they change with regard to the hazards of strong winds, and consider increasing your resilience via improved building mitigation and/or insurance products.

  Close
• CRITICAL INFRASTRUCTURE: If the project involves the development of critical infrastructure (e.g., a hospital, fire station, or power transmission line), or will support critical infrastructure, you should consider how your project can be affected by wind that occurs outside of the specific project location. More information
  ×

  CONTEXT: - For projects that relate directly to critical infrastructure (such as a hospital project, utility expansion, or communications facility), there is a need for the assets to function post-event either to maintain essential services or to provide emergency response and recovery efforts.

  • Most projects (even unrelated to infrastructure) rely upon public services such as electricity, water, communications, etc. and provide services or products that are important to the local, regional or national economy and commerce. Thus, even when the project itself is not damaged by cyclone winds, it may not remain functional due to disruptions in critical infrastructure. The chain of supply of these critical services should be considered and contingency plans developed for each service (e.g. water, electricity, transportation networks). In particular, if the project is for infrastructure development (e.g., a new electrical sub-station), its connection to the wider service network should be planned carefully.

  • Damage and disruption to the local transportation network may not disrupt the functioning of a facility, but it can prohibit personnel from reaching critical infrastructure or an emergency facility.

  MITIGATION: - Consider all dependencies on your project that are vulnerable to wind. Consider redundant (backup) systems whenever possible, in conjunction with service providers. For example, in the event of a power outage does the budget support housing backup generators and, if not, what would be the most likely electrical service available? If power were lost for 1 day, 1 week, etc. what would be the financial impact? Are there insurance products that can protect the project from such an interruption (see insurance section)?

  • Play out disaster scenarios (scenario planning) to stress such conditions on your project and to plan how to respond.

  • Conduct cost/benefit analysis to determine if on-site backup power generation is an option within the budget. Independent wireless communication (e.g., VHF) radio may be a cost-efficient option for communications redundancy and prove vital in a time of crisis.

  • If roads and transportation access are important to the project, either for on-site staff or for post-event operations (e.g., ambulance service) consider alternative routing, or if the risks are high an alternative site for the project.

  • Dependencies to infrastructure are often difficult to manage. If the dependencies are high and the cost of mitigation and redundancy are over budget, consider an alternative site for the project.

  Close
• TECHNICAL EXPERTISE: Consult with an expert familiar with cyclone wind hazard and risk-related construction practices in your local area. Such consulting professionals include structural engineers, civil engineers, and atmospheric scientists. Incorporate local and subject matter expertise in the design, construction, and maintenance phases of your project. More information
  ×

  • During the design and construction plan review phases, wind engineers can review the latest available literature and data to ensure that your project is indeed not subject to significant risk from cyclone winds.

  • After construction is complete, experts can check for literature that has been published since construction began to ensure the wind risk remains VERY LOW and is not an emerging risk for the project.

  Close