The second priority of the Sendai Framework for Disaster Risk Reduction 2015–2030 stresses that, to efficiently manage risk posed by natural hazards, disaster risk governance should be strengthened for all phases of the disaster cycle. Disaster management should be based on adequate strategies and plans, guidance, and inter-sector coordination and communication, as well as the participation and inclusion of all relevant stakeholders—including the general public. Natural hazards that occur with limited-notice or no-notice (LNN) challenge these efforts.
Different types of natural hazards present different challenges to societies in the Global North and the Global South in terms of detection, monitoring, and early warning (and then response and recovery). For example, some natural hazards occur suddenly with little or no warning (e.g., earthquakes, landslides, tsunamis, snow avalanches, flash floods, etc.) whereas others are slow onset (e.g., drought and desertification). Natural hazards such as hurricanes, volcanic eruptions, and floods may unfold at a pace that affords decision-makers and emergency managers enough time to affect warnings and to undertake preparedness and mitigative activities. Others do not. Detection and monitoring technologies (e.g., seismometers, stream gauges, meteorological forecasting equipment) and early warning systems (e.g., The Australian Tsunami Warning System) have been developed for a number of natural hazard types. However, their reliability and effectiveness vary with the phenomenon and its location. For example, tsunamis generated by submarine landslides occur without notice, generally rendering tsunami-warning systems inadequate.
Where warnings are unreliable or mis-timed, there are serious implications for risk governance processes and practices. To assist in the management of LNN events, we suggest emphasis should be given to the preparedness and mitigation phases of the disaster cycle, and in particular, to efforts to engage and educate the public. Risk and vulnerability assessment is also of paramount importance. The identification of especially vulnerable groups, appropriate land use planning, and the introduction and enforcement of building codes and reinforcement regulations, can all help to reduce casualties and damage to the built environment caused by unexpected events. Moreover, emergency plans have to adapt accordingly as they may differ from the evacuation plans for events with a longer lead-time. Risk transfer mechanisms, such as insurance, and public-private partnerships should be strengthened, and redevelopment should consider relocation and reinforcement of new buildings. Finally, participation by relevant stakeholders is a key concept for the management of LNN events as it is also a central component for efficient risk governance. All relevant stakeholders should be identified and included in decisions and their implementation, supported by good communication before, during, and after natural hazard events.
The implications for risk governance of a number of natural hazards are presented and illustrated with examples from different countries from the Global North and the Global South.
Quantifying the effectiveness of early warning systems for natural hazards
