24 September 2021

Climate change + flood: demonstration of the FloodRating™ scoring tool

Will climate change increase probability and severity of flood for your business or assets? With FloodRating, Callendar offers you an effective, comprehensive and detailed assessment solution. This score, a member of the ClimateRating™ physical climate risk rating system, is designed to identify your most exposed facilities, or systematically assess the vulnerability of a portfolio. This demonstration explains how it works and allows you to test the results interface.

Callendar ClimateRating system : demonstration of the visualisation of the impact of climate change on flood risk

FloodRating: Evolution of the risk of flooding with climate change on various sites in France


ClimateRating : How it works

The ClimateRating system currently includes the assessment of 4 risk (FloodRating, HeatRating, DroughtRating and FireRating) and GlobalRating, a comprehensive index of the physical impacts of climate change. Each of these assessment provides a synthetic view of local climate risks based on the aggregation of climate projections and geographical data. The objective is to provide a clear and rigorous answer to the question: “Can the current and future climate lead to extreme weather events that are damaging to my business or my assets?

Each index works on the same principle:

  1. It analyses a list of locations chosen by the user, which can range from a single building to several hundred thousand sites,
  2. The risks are evaluated location by location using recognized and transparent data and methodologies,
  3. These evaluations are aggregated in a risk score per decade,
  4. The results are available in the form of a database and a dynamic cartography.


How does FloodRating assess flood risk in the context of climate change?

1. Sites to study

The list of points to study is provided by the user. It can be, for example, geographical coordinates (latitude, longitude) of sites operated by an industrial company, locations of critical infrastructures on a territory, addresses from a real estate portfolio, etc.

We can assist you in defining this list of points: geocoding of addresses, conversion of reference coordinate systems, datamaning…

2. Risk assessment

Each risk score is calculated from the evaluation of specific sub-risks. In the case of flood risk, the sub-risks assessed are :

  • Fluvial or riverine flood created by an overflowing water body,
  • Pluvial flood caused by intense precipitations,
  • Permanent coastal submersion due to sea level rise,
  • Temporary coastal submersion taking into account storm surges and tides.

The severity of each type of flood and its evolution under the effect of climate change is evaluated by decade from reference projections and models validated by the scientific community. As an example, the metric used for the risk of permanent coastal flooding is the mean water height, obtained by subtracting a median projection of local sea level rise from Kopp & al., 2017 from the altitude extracted from the European Union’s Earth Observation Programme’s EU-DEM v1.1 digital elevation model.

These assessments are repeated for each of the study points. As a site is indirectly exposed to weather hazards that affect its environment (unavailability of access roads, degradation of infrastructure…), the score attributed for each sub-category also takes into account the evolution of risks in the immediate vicinity.

Details of the data and methodologies used in these calculations are available to users.

3. Calculation and aggregation of scores

A score is assigned to each site for each sub-risk. By default, the result is a normalized score from 0 to 100: a score of 0, for example, indicates that the site is part of the 1% most exposed points. The scores for each sub-risk are then aggregated to form a synthetic index.

The formulas used can be modified to reflect the specific vulnerability of an activity, for example by overweighting a risk category, or to fit an existing methodology.

4. Making results available

In order to allow for verification or customized analyses, a complete database is provided to users. It includes all the scores and intermediate results. In addition, a user guide details the data and methodologies used.

Users also have access to an interactive map designed to facilitate navigation through the results and identification of vulnerable sites. You can test it for yourself on this example:

Visualization of flood risks and their evolution under climate change with FloodRating


Do you want to know more?

Book a free 20-minutes online demonstration now, including:

  • the assessment of flood risks on up to 3 locations of your choosing in mainland France,
  • a question and answer session with one of our experts.

Book your free demo    Email us for more infos