A multidisciplinary approach to sustainable water resource management in island environments facing climate change and extreme weather events: The Chios Island as a pilot case

The impact of climate change and human activities on water resource trends is now a major societal challenge.

This is particularly true in Mediterranean island environments, where poor water resource management, combined with the effects of climate change, leads to water scarcity, ecosystem degradation, and conflicts over water use. This is notably the case for the island of Chios, in the Eastern Aegean, which:

• faces significant water stress ;
• experiences extreme weather events ;
• is characterized by a complex hydrogeological context.

A better understanding of hydrosystems will enable more accurate assessment of the resource and its sustainable and resilient management to address the consequences of climate change.

This thesis therefore aims to address two main scientific issues :

• Characterizing different hydrosystems in relation to geological heterogeneity:
  Are they isolated from one another ? Can we assess their recharge and discharge (including discharge into marine environments) ? How can we manage them in an integrated manner ?

• Understanding the dynamic response of these highly sensitive systems to extreme events:
  How do these events fit into a gradual trend of climate deterioration ? What are their impacts ?

The scientific strategy to be implemented will be based on a cross-cutting, multi-scale approach including:

1. a phase of geological, hydrogeological, and hydrochemical characterization ;
2. a numerical modeling phase : currently, enabling the validation of conceptual models through prediction and comparison with hydrogeological behavior; prospectively, enabling the anticipation of hydrosystem behavior under various climate impact scenarios, particularly the response to extreme events.