Climate oscillation factors controlling hydrodynamic variability in urban lagoons under extreme environmental conditions in the southern Arabian Gulf, United Arab Emirates

Coastal lagoons are one of the most important natural assets in the Arabian Gulf region. The lagoons of Al Khalid, Al Khan and Al Mamzar play an essential role in the regional socio-economic environment. Studies assessing the marine environmental conditions have indicated that a combination of anthropogenic stressors with elevated residency time results in a noticeable degradation of the water quality and modification of natural hydrodynamic of the lagoons. Due to their shallow nature and restricted exchange with the sea, they are vulnerable and respond rapidly to any natural or anthropogenic perturbation. The relative sea level rise in the Arabian Gulf was estimated to be about +2.2 mm/yr with predictions to continue rising during the 21st century, intensifying coastal hazards in UAE lagoons. The purpose of this paper is to discuss the present circulation and flushing patterns in the coastal lagoons and investigate the impact of sea level rise on the internal mixing processes and water quality in the context of climate change. Here, the lagoon’s hydrodynamics will be investigated with a high-resolution two-dimensional model coupled with a transport module to calculate the resulting transport of materials within the system and interconnected lagoons, taking into consideration the present and the projected sea level rise.