Country – France
Objective of the climate change vulnerability analysis for real estate assets in France and Australia
Climate change is having a significant impact on hydrological regimes, with direct effects on areas vulnerable to extreme climatic events such as flooding and low water.
Objective of assessing climatic extremes
The aim of this assessment of climate extremes in the Fresquel watershed is to provide decision-makers with quantitative and strategic data to support informed adaptation choices in the face of future water resource challenges. Through a detailed analysis in several phases, this study aims to identify the most vulnerable areas of the watershed and provide hydrological indicators up to 2050, consistent with climate change scenarios.
This methodology is based on three successive phases, combining climate indicators, a hydrological impact model and hydrological indicators.
Phase 1: Production of localized indicators of climate change to 2050
The first step is to produce territorialized climate indicators, representative of expected climate variations up to 2050 for the Fresquel watershed. Based on two climate change scenarios (namely, a moderate and a more severe scenario), this phase aims to understand how temperatures, precipitation patterns and extreme weather events could evolve in the region.
Territorialized indicators enable us to map precisely the areas most exposed to these variations, providing an overview of potentially at-risk and vulnerable areas.
What’s more, these climate indicators provide a solid basis for assessing the effects of climate change on water resources. These help anticipate periods of extreme heat, drought or intense precipitation, all of which can have a direct impact on water resources. For example, indicators such as average temperature, annual precipitation distribution or evapotranspiration will prove useful in assessing possible impacts on water resources and identifying the most appropriate adaptation strategies.
Phase 2: Setting up a hydrological impact model
The second phase of this evaluation involves the implementation of a hydrological impact model, designed to simulate the reactions of the Fresquel basin to future climatic conditions and more particularly related to extreme weather events. This model will take into account data such as relief, soil composition and vegetation, as well as the climatic indicators produced in Phase 1. Its aim is to provide realistic projections of the evolution of river flows, groundwater levels and other key elements of water management in the watershed.
Le modèle hydrologique permet de saisir la réaction des diverses parties du petit cycle de l’eau face aux changements des extrêmes climatiques. Among other things, prolonged periods of drought could lower groundwater levels, while higher rainfall could increase the risk of flash floods.
By simulating these effects under future conditions, this model provides a crucial database for assessing the particular vulnerabilities of the Fresquel watershed and identifying measures that could reduce these hazards.
Figure 1 – Types of hydrological models according to the watershed representation.
Phase 3: Production of extreme hydrological indicators for 2050
The final phase consists of producing extreme hydrological indicators, particularly for floods and low-water periods, for the 2050 horizon. Using climate data and projections from the hydrological impact model, indicators such as the frequency, duration and intensity of floods and low-water periods are generated for the two climate scenarios considered. These extreme hydrological indicators are essential for decision-making, as they provide a quantitative estimate of the most severe climatic impacts that could affect the basin.
Floods and low water levels are among the most worrying climatic events for water resource management, as they put existing infrastructures to the test and directly affect ecosystems and populations. By providing projections of water resources up to 2050, this phase makes it possible to anticipate the development and adaptation measures needed to protect vulnerable areas.
For example, measures such as dike reinforcement, flow management or additional reservoirs could be recommended to reduce the impact of flooding. At the same time, strategies to save water and recharge groundwater may be needed to cope with longer, more intense low-water periods.
Towards informed decision-making for climate change adaptation
Ultimately, this assessment of climate extremes and more specifically hydrological extremes in the Fresquel watershed provides decision-makers with a set of indicators and data essential for developing adaptation and resilience strategies. By identifying the most vulnerable areas and producing specific projections to 2050, this study helps local stakeholders understand the potential impacts of climate change on water and act accordingly.
By using a data-driven approach, this assessment of climate extremes enables informed choices to be made about the investments needed to secure and protect infrastructure against the risks of climate extremes.
The solutions that emerge from this analysis may include measures such as strengthening hydraulic infrastructures, optimizing water resource management, or protecting wetlands and natural ecosystems that play a key role in the watershed’s hydrological resilience.
Conclusion
As part of our climate change and water resources data services, this assessment of climate and hydrological extremes provides a clear roadmap for climate change adaptation in the Fresquel watershed, combining climate projections, a hydrological model and hydrological risk indicators. This analysis of the evolution of climate extremes therefore offers a structured framework to support water management decisions, contributing to a sustainable and resilient approach to future climate challenges.
Read the report on this risq’o study.