The coastal topo- bathymetric DEM for the coasts of the Gironde estuary - downstream with a resolution of 0.0002° (~ 20 m) was prepared as part of the TANDEM project. It covers an area around the Gironde estuary, its Atlantic mouth and extends to Bordeaux (Garonne river) and Libourne (Dordogne river). The DEM takes the form of two complementary grids: 1) Downstream estuary (from the Gironde river mouth to Pauillac); 2) Upstream estuary (from Pauillac to Bordeaux on the Garonne river, and to Libourne on the Dordogne river). The DEM is designed to be implemented in the hydrodynamic models of the TANDEM project in order to estimate the coastal effects of tsunamis for the Atlantic and English Channel, where French nuclear power plants have been installed for about 30 years. This product is available with the Lowest Astronomic Tide (LAT) or the Mean Sea Level (MSL) as a vertical datum.

The coastal topo- bathymetric DEM for the coasts of the Gironde estuary - upstream with a resolution of 0.0002° (~ 20 m) was prepared as part of the TANDEM project. It covers an area around the Gironde estuary, its Atlantic mouth and extends to Bordeaux (Garonne river) and Libourne (Dordogne river). The DEM takes the form of two complementary grids: 1) Downstream estuary (from the Gironde river mouth to Pauillac); 2) Upstream estuary (from Pauillac to Bordeaux on the Garonne river, and to Libourne on the Dordogne river). The DEM is designed to be implemented in the hydrodynamic models of the TANDEM project in order to estimate the coastal effects of tsunamis for the Atlantic and English Channel, where French nuclear power plants have been installed for about 30 years. This product is available with the Lowest Astronomic Tide (LAT) or the Mean Sea Level (MSL) as a vertical datum.

The coastal topo- bathymetric DEM for the coasts of the Saint-Jean-de-Luz bay with a resolution of 0.0002° (~ 20 m) was prepared as part of the TANDEM project. It covers Saint-Jean-de-Luz bay and the surrounding area. The DEM is designed to be implemented in the hydrodynamic models of the TANDEM project in order to estimate the coastal effects of tsunamis for the Atlantic and English Channel, where French nuclear power plants have been installed for about 30 years. This product is available with the Lowest Astronomic Tide (LAT) or the Mean Sea Level (MSL) as a vertical datum.

The present dataset is based on a nine site study of fine seabed topography in intertidal zones. Four coral sites (Maupiti A, B and C and Niau islands) and five rocky sites (Ars en Ré, Socoa, Parlementia A and B and Banneg island) have been explored. The data has been gathered using on-foot GNSS RTK for all sites (Trimble R8/R8S and Leica sytems) except Banneg island, where aerial Lidar data from Litto3D program has been used. The horizontal resolution varies between 3.8 and 12cm allowing to describe a wide range of spatial scales (generally over 3 spectral decades). The data has been processed to explore the statistical and spectral metrics which can be used to characterize the architectural complexity of seabeds. Owners: - Topographic survey on Ars-en-Ré : profile X, Z in meter along a transec was operated on 10-15 Jan 2021 with On-foot Trimble R8/R8S GNSS RTK by Shom, Gladys and Univ. de Montpellier - Topographic survey on Maupiti Hoe: profile X, Z in meter along a transec was operated on 5-10 July 2018 with on-foot Trimble R8/R8S GNSS RTK by GLADYS and Université de Montpellier - Topographic survey on Niau : profile X, Z in meter along a transec operated on 10 Nov. 2021 with On-foot Trimble R8/R8S GNSS RTK - by CEREGE and MIO (OSU Pytheas) - Topographic survey on Parlementia A, and B : profile X, Z in meter along a transec was operated on 22 Fev 2023 with on-foot Leica GNSS RTK by SIAME, UPPA - Topographic survey on Socoa : profile X, Z in meter along a transec was operated on 21 Fev 2023 with on-foot Leica GNSS RTK by SIAME, UPPA and Shom - Topographic survey in high resolution of Banneg island (X, Y, Z) is made by aerial lidar litto3D on spring 2012/2013 by Shom and IGN