Hydro-environmental modelling of the Arabian Gulf and Kuwait Bay

摘要

Studying and understanding the hydro-environmental characteristics of the Arabian Gulf has received growing interest over the past few decades. This is mainly attributed to the strategic importance of the area, since it has been utilised to transport most of the oil production from the Gulf states. Over the last five decades, rapid industrial coastal development also has taken place around the Gulf. Development has brought desalination, power and petroleum refining plants. Coastal developments and industrial and domestic sewage discharges have contributed to the total nutrient levels in the Gulf, which have enhanced unwanted algal growth in various coastal areas. More recently, climate change has brought flooding to the Gulf states and frequent dust storms, which have increased various environmental issues, such as sediment transport and nutrient sorption processes, also in the shallow regions of the Gulf. In the current study the geographic dispersion of numerical tracers and flushing characteristics, in terms of residence time, of the Gulf have been investigated. The study has revealed that dispersion of numerical tracers is chiefly controlled by tides in the Gulf, while winds had limited effects. The residence time in the Gulf was predicted to be almost 3 years using ELCOM. Kuwait Bay was also investigated in terms of the governing hydrodynamics using ELCOM. Similar to the Gulf, the study revealed that the Bay was chiefly driven by tides and to a lesser extent by winds. Detailed studies of temperature, using the same model, showed that temperatures varied seasonally in the Bay. In terms of salinity, investigations have shown that the Shatt Al Arab has an apparent effect on the Bay's salinity, particularly in the northern areas. The maximum residence time of the Bay was calculated to be 57 days near al Jahra using ELCOM. The main model refinements were conducted on including the phosphorus source terms in TRIVAST, based on experimental investigations in a hydraulics flume channel. The refinements included the addition of new source terms accounting for the adsorption of phosphorus to suspended sediments and bed sediments. Model investigations have shown that the model refinements improved the model predictions of phosphorus levels, with phosphorus being the limiting nutrient during high suspended sediment events in Kuwait Bay. In general, good water quality predictions in Kuwait Bay were achieved using both ELCOM-CAEDYM and TRIVAST. Predictions have shown that the Shatt Al-Arab waterway has significant effects of the water quality of the Bay. Better hydrodynamic predictions were achieved using ELCOM than TRIVAST for the Gulf and the Bay. This was due to the additional mathematical terms included in ELCOM, including, in particular, the terms representing tidal forces that were calculated from the gravitational potential.