The present paper proposes a methodology to optimise the design of a beach protection intervention at Saadiyat Island, of the Abu Dhabi city in the United Arab Emirates. In particular, a nourishment performance index (NPI) has been introduced to select among different design alternatives of a coastal engineering intervention related to the ongoing development of the island. The NPI is based on general factors such as the initial volume of sand necessary for the nourishment, the beach surface loss after the intervention and the closure depth. The proposed index, properly integrated with a numerical simulation of the beach morphodynamics, is shown to be promising in the evaluation of the feasibility for the planned coastal defence interventions. The adoption of different design scenarios has showed that the NPI value depends mainly on the built nourishment shoreline.

High-resolution, reliable global atmospheric and oceanic numerical models can represent a key factor in designing a coastal intervention. At the present, two main centers have the capabilities to produce them: the National Oceanic and Atmospheric Administration (NOAA) in the U.S.A. and the European Centre for Medium-Range Weather Forecasts (ECMWF). The NOAA and ECMWF wave models are developed, in particular, for different water regions: deep, intermediate, and shallow water regions using different types of spatial and temporal grids. Recently, in the Arabian Gulf (also named Persian Gulf), the Abu Dhabi Municipality (ADM) installed an ADCP (Acoustic Doppler Current Profiler) to observe the atmospheric and oceanographic conditions (water level, significant wave height, peak wave period, water temperature, and wind speed and direction) at 6 m water depth, in the vicinity of the shoreline of the Saadiyat beach. Courtesy of Abu Dhabi Municipality, this observations dataset is available; the recorded data span the period from June 2015 to January 2018 (included), with a time resolution of 10 min and 30 min for the atmospheric and oceanographic variables, respectively. At the ADCP deployment location (ADMins), the wave climate has been determined using wave propagation of the NOAA offshore wave dataset by means of the Simulating WAves Nearshore (SWAN) numerical model, the NOAA and ECMWF wave datasets at the closest grid point in shallow water conditions, and the SPM ’84 hindcasting method with the NOAA wind dataset used as input. It is shown that the best agreement with the observed wave climate is obtained using the SPM ’84 hindcasting method for the shallow water conditions.

The present paper proposes a new method to increase the number of sources of meteo marine information for the analysis of professionals and researchers in coastal and offshore engineering. The new method is mainly based on the actual geographical distance between a real and a virtual buoy and the dependence of the sea states on the characteristics of the wave development conditions; in fact, it mainly depends on the effective positions of the two locations, their geometric distance apart, and on the difference between the exposure of the point where the virtual buoy has to be located (S) with respect to the point of direct observation (O). It offers advantages compared to the traditional methods currently used; in fact, among the others, it is suitable for any sea condition: duration/fetch limited or fully arisen sea. The proposed method has been verified using data from buoys of the Mediterranean Sea (Italian and Spanish) and of the Atlantic Sea (Spanish) under different sea conditions. In particular, the time-series with a variable duration from a minimum of 2 up to a maximum of 7 years have been adopted. Use of the model is presently limited to deep water conditions. The verification, conducted without the need for any calibration, resulted positive.