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Presentation

This theme focuses on an interdisciplinary approach to evaluate the uncertainties of flood modeling, the resulting risks and the perception of different social groups (scientists, decision-makers, population). Such information will allow to improve methods, tools and representations for maps and risk maps and indicators, for instance.

Context

Floods often led to loss of human lives and important material damage. Numerical simulation is a classical tool for mapping flood hazard. Many models (commercial or research ones) exist to identify areas prone to flooding, to assist decision-makers in the design of operational management plans and in quick emergency decisions.

However, software based on numerical modeling and geographic information systems are not perfect, especially in the case of a local and sudden change in flow (log jam on a watercourse, mudslide , landslide...) or in the case of an extreme weather event.

These modeling imperfections can be studied and taken into account by calculating uncertainties in order to test the robustness of the flood hazard and risk simulation methods, and to deduce important information about the risk associated with the modelling errors.

Activities

Conceptual models

This theme notably focuses on the numerical modeling of watersheds (hydrology, hydraulics) and the modeling of socio-ecosystems (social sciences) of these watersheds in the framework of the project Idex-Emergence 2017-2019 PRIM'Eau, as an acronym for "Perception of the risk and uncertainties of modeling-Water".

The main case study is concerned with the catchment area of ​​Mutterbach (Moselle-Est) for the wealth of its hydraulic facilities and their uses over the last 100 years.

Numerical methods

In this theme, existing methods and software will be first evaluated by considering a diffusive wave model and a conceptual model used on the same watershed. Later higher-level methods will be proposed.

Best practices

Les méthodes numériques développées sont utilisables dans d'autres contextes. En voici un premier exemple.

Sensibilités

Cette étude concerne la modélisation d'écoulements souterrains sous une plate-forme industrielle afin d'évaluer les dispositifs d'atténuation des risques mis en place. Ce sont deux drains modélisés comme des rivières, en rose sur la figure (a) et d'une barrière quasi-imperméable représentée en noir. Les hauteurs piézométriques calculées sans perturbation sont tracées dans la figure (c). Par un calcul de sensibilité locale, la zone concernée par la barrière imperméable et les variations de hauteurs piézométriques sont très précisément évaluées, figures (c) et (d). Les lignes de flux sont tracées en rose dans la figure (c). A notre connaissance, la sensibilité des lignes de flux n'avait jamais été étudiée. Ces résultats sont publiés dans [2-MCWM17]. Mesures d'atténuation des risques et calcul de sensibilité