Return period contraction of coastal storm surge height extremes (declared percentile threshold regime)
| Object type | Damage Signal |
|---|---|
| SIGNAL Earth ID | DS-00362 |
| Observable type | Coral reef live cover fraction |
| Unit | % (%) |
| Temporal structure | Annual |
| Monitoring backbone | — |
Return period contraction of coastal storm surge height extremes (declared percentile threshold regime) The return period contraction of coastal storm surge height extremes represents a quantifiable change in the frequency and intensity of extreme storm surge events impacting coastal regions globally. This phenomenon is closely linked to climate-system forcing factors that influence oceanographic and atmospheric conditions. It is particularly relevant to the health and sustainability of coral reef ecosystems, which are sensitive to changes in sea level and storm surge dynamics.
Coral reefs serve as critical environmental receptors within the ocean-biogeochemical domain, and their live cover fraction is an important observable metric for assessing reef condition. Variations in storm surge extremes can lead to physical damage and ecological stress on coral reefs, affecting their live cover and overall resilience.
Understanding the contraction of return periods for these extreme events aids in characterizing the evolving risk landscape for coastal ecosystems and human communities. This assessment is part of a broader effort to monitor and interpret environmental changes driven by climate factors at a global scale.
Geographic / System Context
[edit]This signal pertains to coastal regions worldwide where coral reefs are present and susceptible to storm surge impacts. Coral reefs are distributed across tropical and subtropical oceans, often in shallow, nearshore environments that are directly influenced by coastal storm surge phenomena. The geographic scope encompasses diverse reef systems, including those in the Caribbean Sea, Indo-Pacific region, Red Sea, and other global coral habitats. These ecosystems exist within complex oceanographic and climatic systems, where sea level variability and storm intensity can vary regionally.
Monitoring and Measurement
[edit]Monitoring of coral reef live cover fraction involves a combination of remote sensing technologies, in situ surveys, and ecological assessments conducted by marine research institutions and environmental agencies. Measurement of coastal storm surge height extremes typically relies on tide gauge data, satellite altimetry, and hydrodynamic modeling. However, the integration of these datasets to assess return period contraction requires advanced statistical analysis of temporal trends in extreme surge events. Currently, the monitoring backbone for this signal is under development, with anticipated contributions from global oceanographic and climate monitoring networks.
Within the SIGNAL system, this phenomenon is treated as a defined environmental signal whose boundaries and measurement conventions are described below.
Signal Definition
[edit]This Damage Signal is derived from the observable type 'Coral reef live cover fraction' and represents the contraction in the return period of extreme coastal storm surge heights exceeding a declared percentile threshold. It quantifies the change in frequency at which extreme surge events occur, reflecting a shift toward more frequent or intense storm surges that impact coral reef conditions. The signal is expressed as an annual percentage change in live coral cover attributable to these surge extremes.
Boundary Conditions
[edit]Boundary inclusions encompass all coastal coral reef areas globally where storm surge events surpass the defined percentile threshold for extreme surge height. This includes reefs subject to direct physical impact from storm surges and associated hydrodynamic forces. Boundary exclusions involve coral reef regions not exposed to storm surge extremes above the threshold, as well as areas where other stressors dominate coral cover changes without measurable influence from surge events. The signal does not include non-coastal or deep-water reef systems beyond the reach of storm surges.
Aggregation Semantics
[edit]Geographic aggregation is performed at global and regional scales to capture spatial variability in storm surge impacts on coral reefs. Temporal aggregation is annual, reflecting year-to-year changes in return period contraction. Cross-signal aggregation involves integration with related environmental signals such as coastal flood inundation extent, coastal storm surge height, and global mean sea level to provide a comprehensive understanding of coastal hazard dynamics. Aggregation methods account for spatial heterogeneity and temporal trends to support robust interpretation of environmental impacts.
Observational Status
[edit]Currently, the monitoring framework for this signal is being established, with ongoing efforts to refine data integration and analysis methods. Data on coral reef live cover and storm surge extremes are available from various sources, but harmonized global datasets specific to this signal are limited. Future SIGNAL releases aim to enhance temporal resolution, improve geographic coverage, and incorporate additional observational inputs to better characterize the dynamics of return period contraction and its ecological consequences.
Related Signals
[edit]- Coastal flood inundation extent
- Coastal storm surge height
- Global mean sea level
Key Associated People
[edit]- Silpa Kaza — Contributor (World Bank) [Domain expert]