Olivier Therond, an agronomist with a passion for modelling, is the development coordinator for the MAELIA platform. He answers our questions about the future scientific challenges facing MAELIA-Delta, the prospects for implementing the model in other regions, and the importance of engaging with local actors in order to design a decision-support tool that is as closely aligned as possible with the realities of the Camargue.
1/ What are the next scientific challenges for making MAELIA-Delta correspond even more closely to the reality in the field?
MAELIA aims to integrate academic and local knowledge on the structure and dynamics of ecological and socio-economic systems and their interactions. In its current version, MAELIA-Delta models the interactions between agriculture and daily water flows in plots influenced by the climate. To achieve our objective of modelling the Camargue, we still need to incorporate the representation of water flows in irrigation and drainage canals, their relationships with lagoons and marshes, and the dynamics of the bird and fish species on which conservation priorities are focused. We already have most of the building blocks needed for these modelling extensions; the challenge now is to link them together in a coherent way. We will then need to enable MAELIA-Delta to quantify management indicators that are meaningful to stakeholders in the Camargue.
2/ Do you think this approach could be applied to other areas facing similar challenges?
We have designed the developments to be as generic as possible, meaning they can be applied to any region whose general characteristics are similar to those of the Camargue: natural and man-made water flows, hydro-salinity dynamics arising from the interactions between hydrology and irrigated agriculture. MAELIA-Delta is therefore intended to be used in other deltas to support local stakeholders in defining their parameters for balanced water management. But one thing at a time: we first plan to further develop the model before rolling it out in other areas.
3/ How have discussions with managers and local stakeholders influenced the development of the model?
As with any modelling process aimed at supporting decision-making, the issues raised by stakeholders involved in managing a territory determine and frame the development work. In Rose Rodier’s PhD thesis,[1] we implemented a conceptual modelling approach based on gathering and formalising the knowledge of local experts on these issues. This conceptual model enabled us to define the modelling objectives in detail, that is the entities and processes to be represented, the scenarios to be simulated, and the indicators to be assessed. The modelling process was therefore organised to meet these needs; this ensures the tool is relevant for addressing the questions raised by stakeholders in the Camargue.
[1] Rodier Rose, Olivier Boutron and Olivier Therond. 2026. ‘Integrated modelling of activity networks, ecosystem services and biodiversity on the Camargue Island. Assessment of the impacts of climate change and agroecological transition on a delta.’