Publications scientifiques

Long-term datasets documenting the evolution of coastal forms and processes, through the provision of recurring beach as well as shoreface morphological observations and accompanying time-series of environmental controls, remain difficult to collect and are rarely made available. However, they are increasingly needed to further our understanding of coastal change and to improve the models that will help planning what our future coast will be.

The proposed article deals with the assessment of coral reef impact on runup-induced coastal flooding over a two years and 10 months period at Anse Maurice, a reef-fringed pocket beach located at Guadeloupe Island, in the Caribbean region. The reef is mainly constituted by complex structures of Acropora Palmata dead colonies. Daily maximum marine inundation was assessed using a fixed video system. Daily Highest Runups (DHR) remains primarily correlated to individual storm event as extreme runups are observed in correlation with storm swells.

Tides are changing on human timescales, and an understanding of reasons for these changes is important for inundation risk assessments and coastal defence planning. Tides are often regarded as astronomically generated phenomena, however recently published literature has investigated changes in tidal characteristics driven by non-astronomical factors.

Mobile marine species display complex and nonstationary habitat use patterns that require understanding to design effective management measures. In this study, the spatio-temporal habitat use dynamics of the vulnerable dugong (Dugong dugon) were modelled from 16 satellite-tagged individuals in the coral reef lagoonal ecosystems of New Caledonia, South Pacific.

On 5 December 2018, a magnitude M_w  7.5 earthquake occurred southeast of Maré, an island of the Loyalty Islands archipelago, New Caledonia. This earthquake is located at the junction between the plunging Loyalty Ridge and the southern part of the Vanuatu Arc, in a tectonically complex and very active area regularly subjected to strong seismic crises and earthquakes higher than magnitude 7 and up to 8.

Dike breaches occurs regularly during storm events. This phenomenon contributes to amplify considerably the impact of floods on coastal areas. It represents an important cost for repairing existing infrastructures in the vicinity of the sea-dike. Then, they must be upgraded to prevent breaches. In the present study, ANEMOC and REFMAR dataset were analysed, off Camargue coasts, to quantify the storm hazards in terms of wave height and sea level wind setup. Repartition laws were adjusted on dataset to build a 2D-copula which is used to estimate events return periods.

In this chapter, we present a second example of statistical estimation of extreme quantiles: millennial quantiles for storm surges at Brest (France), based on hourly sea-level measurements. We run sensitivity tests on parameter values, on the choice of analytic models for distributions, and on the statistical estimation methods chosen. Uncertainty in estimates and associated confidence intervals are also calculated and compared.

Submersion risks assessment requires different tools and methods from regional to coastal scales. The Shom’s strategy relies on numerical modelling and observational systems applied in a challenging multi-scale context. At regional scales, storm surge and wave models Hycom and Wavewatch III, bathymetric digital terrain models (DTMs) and observational tide/buoy networks used within the operational national storm surge service (Homonim project with Météo-France) are presented, as well as their applications in climatological 40-year hindasts.

Significant developments have been made in the observation systems and techniques of estimating sea level towards meeting the standard accuracy requirement of Global Climate Observation Systems (GCOS). This study undertakes a systematic review of the current advances in estimating sea level change in the context of the 4^th industrial revolution. Trends in the use of main observation systems such as tide gauges, satellite altimetry, and ancillary systems such as GNSS and Autonomous Surface Vehicles were explored.