Coastal altimetry - Litto3D®

Mis à jour le 09/07/2024

Flight over St Pierre and Miquelon

Litto3D®, continuous mapping of the coastal fringe ...

In 2002, the European Parliament and the Council of the European Union recommended that Member States establish national strategies for the management of coastal zones in order in particular to preserve the integrity and functioning of the coastal environment but also to take into account the climate changes that threaten it.

In this context, the interministerial committee for the sea of April 29, 2003 ordered a Coastal Geographic Reference (RGL) from Shom and the IGN, the objective of which is to provide integrated cartgrahy of the coastal zone.

The creation of this RGL is based on the acquisition, processing and dissemination of coastal data: this is the Litto3D® program, designed to meet multiple mapping needs for :

  • Coastal protection (coastline evolution due to erosion, protection of coastal areas, protection of flora and fauna)
  • Risk prevention (flooding, pollution, natural disasters)
  • Development (ports, tourism, industry)
  • Exploitation of living and mineralresources
  • Scientific research and studies
  • Military needs

... based on a cutting-edge acquisition technique: LiDAR

Within the Litto3D® program, the Shom is in charge of the maritime part - from the top of the foreshore to a depth of 30 meters. Data acquisition is carried out by LiDAR: airborne topographic and bathymetric lasers that scan the ground and seabed to map relief.

  • A “red” laser for topographic surveys, concerning exclusively the land areas at the time of the survey.
  • • Two “green” lasers for bathymetric surveys, for submerged land. These lasers have many advantages such as the ability to quickly map large areas, the possibility of probing dangerous or inaccessible areas by sea, and the ease of continuously probing the strip of coastal water and the intertidal zone.
Airborne LiDAR Laser

Litto3D product - Île-d'Houat

Easily accessible data to meet user expectations

The product is available in two forms: three-dimensional point seedings (ground, above ground) and meshed and qualified digital terrain models (1m and 5m resolution), all structured in 1km² slabs.

Use of Litto3D® data is open, free and unrestricted (Open License ). They can be downloaded from and viewed on data.shom. fr (Reference data section > Coastal altimetry).

Quelques exemples d'applications concrètes des données Litto3D®

Prévision des submersions marines

Litto3D - Vigilance Vague Submersion

Les données Litto3D® permettent d'améliorer les capacités de prévision du système national de la Vigilance Vague Submersion opéré par Météo France.










Programme d’Action pour la Prévention des Inondations

Modèle numérique de terrain de la baie de Saint-Malo

Logo Saint Malo

Dans le cadre du Programme d'Actions de Prévention des Inondations de Saint-Malo, les données Litto3D® Bretagne et Normandie ont été fusionnées avec les données des sondeurs acoustiques pour fournir un modèle bathymétrique haute résolution aux abords de Saint-Malo et pour tout le golfe normand-breton. Ce modèle alimentera les futures capacités de prévision des risques de submersion marine et d'inondation à terre.



Application au profit de la navigation

Litto3D route sécurisée pour le Rhodanus

Echouage du Rhodanus

Grâce aux données Litto3D®, une route sécurisée a pu être définie pour la sortie du Rhodanus suite à son échouage sur les côtes de Corse en octobre 2019.



Découvrez les projets régionaux Litto3D®