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.

On 18 March 2012, a female specimen of the sand tiger shark, Carcharias taurus, measuring 256 cm, was by-caught by a net fisherman targeting narrow-barred Spanish mackerel, Scomberomorus commerson, off Dalma Island in Abu Dhabi waters. This occurrence represents the first documented record of C. taurus in United Arab Emirates waters. The geographical distribution of this species in the Arabian/Persian Gulf is discussed and updated. The limited records of this species in this body of water may be due to the absence of rigorous species landing reports across countries bordering the Arabian/Persian Gulf.