Coastal Flooding Risk assesses how sea level rise (SLR) increases frequency and severity of flooding caused by extreme weather events, such as storm surges.
This risk is calculated only for sites within 30 km of sea and with altitude within 20 meters above sea level.
This risk doesn't just measure permanent water rise, but quantifies how this rise erodes safety margin protecting coasts from historical disasters. To do so, it combines two key variables:
These two variables are combined into indicator called Flood Hazard Index (FHI):
An FHI of 1, for example, means new mean sea level has reached same height as what was once a catastrophic centennial flood.
The methodology for Coastal Flooding Risk assessment is state-of-the-art approach. It captures most critical and immediate danger of sea level rise: not permanent flooding, but dramatic amplification of extreme flood frequency and severity.
The idea of measuring erosion of historical 'safety margin' is most correct way to quantify this risk.
The central premise of our method — that main SLR impact is increasing extreme event frequency — is one of most important and alarming conclusions of latest IPCC reports.
Special Report on the Ocean and Cryosphere in a Changing Climate
Climate Change 2021: The Physical Science Basis These reports state with very high confidence that mean sea level rise (SLR) will cause dramatic increase in extreme sea level event frequency. Key conclusion is that 'extreme sea level events that historically occurred once per century (centennial events) will occur annually at many locations by end of this century'. Our Flood Hazard Index (FHI) allows precisely quantifying this process.
Modelling sea level rise impacts on storm surges along US coasts This study quantified how given SLR 'translates' into shortening return period of flood of certain height. It confirms that with 50 cm SLR (FHI approaching 1 at many locations), historical centennial flood can become event occurring every few years.
In conclusion, our methodology is state of the art. It captures fundamental scientific concept validated by IPCC (extreme event amplification), is based on standardized and scientifically validated input data (SLR projections and ESL dataset), and uses synthetic indicator (FHI) whose interpretation in terms of event frequency is fully supported by reference scientific literature.
The methodology for Coastal Flooding Risk assessment is state-of-the-art approach. It captures most critical and immediate danger of sea level rise: not permanent flooding, but dramatic amplification of extreme flood frequency and severity.
The idea of measuring erosion of historical 'safety margin' is most correct way to quantify this risk.
The central premise of our method — that main SLR impact is increasing extreme event frequency — is one of most important and alarming conclusions of latest IPCC reports. • Special Report on the Ocean and Cryosphere in a Changing Climate • Climate Change 2021: The Physical Science Basis These reports state with very high confidence that mean sea level rise (SLR) will cause dramatic increase in extreme sea level event frequency. Key conclusion is that 'extreme sea level events that historically occurred once per century (centennial events) will occur annually at many locations by end of this century'. Our Flood Hazard Index (FHI) allows precisely quantifying this process.
• Modelling sea level rise impacts on storm surges along US coasts This study quantified how given SLR 'translates' into shortening return period of flood of certain height. It confirms that with 50 cm SLR (FHI approaching 1 at many locations), historical centennial flood can become event occurring every few years.
In conclusion, our methodology is state of the art. It captures fundamental scientific concept validated by IPCC (extreme event amplification), is based on standardized and scientifically validated input data (SLR projections and ESL dataset), and uses synthetic indicator (FHI) whose interpretation in terms of event frequency is fully supported by reference scientific literature.