At IRDL, Ashraf Maskoni explored the stability of complex gravitational currents in coastal environments.
Ashraf Maskoni, chercheur·e au sein de IRDL (Institut National Polytechnique de Bretagne).
Thèse soutenue en 2023 à l'école doctorale École doctorale Sciences Pour l'Ingénieur (Lorient ; 2022-....).
Référencée dans le réseau ABES/STAR, cette thèse répond aux critères de rigueur de l'enseignement supérieur français.
Research on gravitational currents in coastal environments is undeniably relevant, especially in the current context of oil spills, which have become a concerning reality in many regions of the world. These often catastrophic events threaten not only marine ecosystems but also local economies that depend on the health of these fragile environments. The coasts of Benin, for example, are particularly vulnerable to these incidents, given their proximity to heavily trafficked shipping lanes. Ashraf Maskoni, through his thesis, highlights the complex dynamics that govern these currents, focusing on the interactions between immiscible liquids. This approach allows for anticipating the behaviors of these currents during spills, thus providing valuable tools for managing environmental crises.
Modeling the stability of interfaces between immiscible liquids is one of the key outcomes of this research. Indeed, understanding how these liquids interact and move under the influence of gravity is essential for predicting the impacts of a spill. Density and viscosity gradients play a crucial role in this dynamic. For example, a liquid denser than seawater, when spilled, tends to sink, complicating the management of the situation. This means that hydrocarbons, once spilled, can sink into the water layers, making their recovery even more difficult. This thesis proposes advanced mathematical models that simulate these interactions, thereby identifying the conditions that favor the stability or instability of gravitational currents.
The practical implications of these results are vast. The recommendations arising from this research are clear: it is imperative to develop oil spill management strategies based on solid scientific data. This involves not only a better understanding of physical phenomena but also close collaboration between researchers, decision-makers, and economic actors. In West Africa, and particularly in Benin, where the risks of spills are high, these strategies must be adapted to local specificities. For example, taking into account local marine currents, seasonal variations, and geographical characteristics is essential for developing effective intervention plans.
Research on the effects of temperature gradients and interfacial tension on the stability of gravitational currents is also an area to explore to strengthen response capabilities to maritime incidents. Indeed, water temperature can influence the viscosity of liquids, thereby altering their behavior during a spill. Moreover, the interfacial tension between hydrocarbons and water can determine how these substances mix or separate, directly impacting cleanup strategies. Therefore, a thorough study of these factors could provide valuable insights to improve response techniques.
In summary, this thesis is not limited to a theoretical analysis. It paves the way for concrete applications in coastal resource management and marine ecosystem protection. The results obtained by Maskoni are an invitation to rethink our approaches to current environmental challenges. The question that arises is: will we be able to leverage this knowledge to anticipate and effectively manage future environmental crises?
It is crucial that governments and non-governmental organizations recognize the importance of this research. By integrating this new knowledge into environmental policies, it is possible to reduce the risks associated with oil spills. Furthermore, raising awareness among coastal communities about these issues is equally essential. By involving local populations in prevention and response efforts, we can not only protect ecosystems but also preserve the livelihoods of thousands of people who depend on the sea. Thus, Maskoni's thesis is not limited to an academic framework but is part of a comprehensive approach to preserving our marine environment.
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Sources et accès
Ashraf Maskoni. Stability of complex gravity currents in coastal environment. Reactive fluid environment. Université de Bretagne occidentale - Brest, 2023. English. ⟨NNT : 2023BRES0026⟩. ⟨tel-04440646⟩