General presentation

Discover the main uses


The territorial actors of Nouvelle-Aquitaine have united to improve knowledge related to the largest estuary in Europe in order to sustainably develop economic, recreational and tourist activities, with the aim of preserving biodiversity and environmental wealth, all in a context of climate change.

Indeed, the urgency imposed by the challenges of climate change implies an even stronger mobilization around the Garonne and the Gironde Estuary. While the first impacts of climate change are already visible, the rise of digital technology offers solutions for studying and anticipating future changes.

The co-construction of the River’s Digital Twins with territorial actors now offers new possibilities to facilitate work and collaboration within a community, as well as new perspectives to explore, to accelerate territorial resilience in the face of climate change.

The future of digital twins remains to be built with the community of users and contributors, guided by a governance to be created.

Questions arise about the use of these new tools; how to use and value them? What concrete benefits for the territory? What quality and accuracy of the forecasts made? How can we better prepare for the impacts of climate change? …

These are all questions that will find their answers collectively with the help of everyone; decision makers, sponsors, scientists, students and citizens.

The choice of open source technology and the sharing of source codes on the NAOS regional cluster are a guarantee of open-mindedness and a desire for transparency among the players in the project, initiated by the Atlantic Port of Bordeaux.

The animation of the River’s Digital Twins Community will make it possible to discover these tools, to pool efforts and share results, and to move forward together, in particular with the academic world to further increase knowledge and find answers to the climate challenges of tomorrow.

Everyone’s support is important, starting with the promotion of regional open source digital models during environmental studies and the transfer of improvements.

This guide will allow you to quickly understand the extent of the functionalities of the tools and to target the activities that correspond to your expectations. It describes version I of the digital twins developed in record time (one year between the ideation hackathon and the launch of the service). Many other themes that were identified during the hackathon are integrated into the roadmap to be carried out in the next versions to come.

The transition towards 2050

Achieving carbon neutrality as quickly as possible is a challenge launched on a planetary scale to limit the evolution of climate change; it begins at the regional level with cooperation, more frugal uses and the development of new technologies to achieve significant transformations.

The largest estuary in Europe holds opportunities to be identified, to be traded as a natural carbon sink or as a source of freshness for urban heat islands. And it must also be protected because biodiversity is beginning to be affected by the first impacts of climate change; conflicts of use of water resources and precariousness of aquatic life.

As environmental policies for adapting to climate change are gradually being developed and implemented, decision-makers and citizens must make the right choices for the coming years.

The River’s Digital Twins are prospective tools for predicting the impacts of environmental policies of change and adaptation around the river, and thus opportunities to better inform these decisions, through exchanges between the actors gathered within the community.

Who is this guide for?


Raising awareness of the impacts of climate change

Decision makers

Use of intuitive tools, without computer or modeling skills, with the help of a community of users


Exploitation of powerful simulation tools associated with the community repository of source codes with the help of a community of users and contributors.

The River’s Digital Twins consist of several distinct and interconnected platforms, the main ones being :

Digital simulation platform (LISOS)

LISOS is the high performance computing platform, on demand and able to parallelize simulations almost without limit while maintaining the same performance.

It provides the power needed to carry out the simulations of the numerical models, whether it is forecasts for the next few days, or specific studies that simulate any change, natural or not, on the river.

It has a work environment for the activities of design offices, scientists and students, and integrates a service that automatically launches simulations automatically triggered by other systems, even external to the digital twins, to provide them with results.

Free open source community digital forge (NAOS)

The NAOS community forge hosts the source codes of the project, and in particular the current digital models, and those to come, the forcing data (forecasts of daily flows, weather, etc.).

LISOS has direct access to each of the digital models. Thus the modifications made to the code can automatically trigger a digital simulation on the LISOS platform and update the data visible in the GIROS monitoring platform.

River monitoring tools (GIROS)

The GIROS platform responds more to a business approach with several different modules mainly targeting decision-makers. The platform allows intuitive visualization of forecasts and history of physico-chemical measurements.

Dredging and navigability modules

The dredging and navigability modules are reserved for the Bordeaux port area.

Simplified study module

This module is intended for all decision-makers who wish to carry out simulations that are limited to changes in forcing conditions (flow, weather, etc.) over short periods (a few days to weeks).

Garonne 2050 module

This module is aimed at citizens with the aim of raising awareness of the impacts of climate change on the territory of the Gironde estuary.

Upcoming modules

The platform remains open to the integration of new applications from the scientific world.


The evolution of the project now relies on the Community, the first members of which were brought together at the end of 2022 to initiate its animation.
Indeed, the River’s Digital Twins are a collaborative platform for sharing studies and open source codes, to improve tools and develop new models of the Gironde, or other rivers, even more detailed or integrating new tracers of observation of physico-chemical phenomena.

Workshops are planned for 2023 to collectively organize and structure training and working groups with users and contributors. The expertise of scientists is also expected to qualify the results of the modeling and prioritize with the water stakeholders the next expectations to be met.
It will then be a question of creating, within the regional forge NAOS, a new digital model, son of the current Gironde XL 3D model, which will bring new additional knowledge.

The regional forge and the Community will thus allow the coexistence within digital twins of operational models, validated for uses targeted by scientific partners, and exploratory models, shared between scientists.
The exploratory models are of course intended to mature until they become operational models.