Risk analysis simulation of Tuzla Kamil Abdüs Lagoon

Lagoons are lakes formed behind the shores separated by land from coast, and linked to sea through a waterway. The effects of wind, wave, current, sedimentation transportation, and bottom structures can be defined as lagoon dynamics. With the effects of lagoon dynamics, there occurs constant movement of water in and out between lagoons and seas. Sea pollution is an important factor that negatively affects the water quality of lagoon systems with high ecological values. The aim of the study is to present analyses which could establish the scientific evidences used in urgent action and risk planning regarding the water quality of lagoon systems affected by sea pollution. Kamil Abdüs Lagoon in Tuzla County of Istanbul was chosen as study area. Mathematical model used in the hydrodynamic calculations of lagoon were solved by different equilibriums with kinematic and dynamic approaches. The essence of kinematic and dynamic approaches is composed of pressure gradient and momentum equilibrium between bottom and surface stress. Current fields were calculated through a highly resolved mesh using 2D hydrodynamic modelling. Locations of different numbers of Lagrange particles, left in these stream fields and dispersed by random walks and shifts were determined under different wind and tidal conditions in times. Thus, simulation of particle exchanges between sea and lagoon was performed and the obtained results were analyzed. It is quite important for emergency actions required for lagoon systems to determine the statistically significant number of pieces that provides the fastest and the most efficient results in the necessary decision making processes for risk evaluation and emergency cases. According to the results of hydrodynamic modelling, simulation results demonstrated that self-clearing time of the lagoon showed highly significant differences depending on the number of particles in use. Conditions including different particle numbers (65.073, 299.771 and 1.200.850) were carried out using parallel computers with 13 and 23 processors, and the results were compared. Considering the fact that statistical reliability is increased with high particle numbers, it is observed that Kamil Abdüs Lagoon is cleaned from the pollution effect of sea origin with different particles between 9.1 and 12.6 days. As can be concluded, the total number of particles used in the particle monitoring methods has a highly significant effect on the results.