Numerical Modelling of Arvandrud River Plume and the impact of wind and River Discharge on the plume structure By Three Dimensional and Hydro dynamical Model (FVCOM)

Arvandrud River Plume which is the main source of fresh water in the Persian Gulf and in addition its catchment area is settlement for about 54 million people is one of the most important phenomena in costal zones. . The river is the boundary line between Iran and Iraq and its plume extended in Iran, Iraq and Kuwait territory in Persian Gulf. Oceanographic studies are infeasible in the river and in its mouth due to geographic, politics, and security problems in the region. Despite the lack of in-situ data, this study is a serious step to the investigation to river plume. In this study salinity, temperature and water circulation of Persian Gulf were simulated by using oceanographic hydrodynamic model, FVCOM. Then, effects of wind and river discharge on structure of Plumes were investigated. For this purpose, 14 wind and 8 river discharge conditions have been used. The results show the river has a surface-advected plume that is highly affected by wind. The river plume area decreased with increasing wind speed. Three types of plumes were formed by different wind conditions, at the mouth of the river. Plume type 1 diverted toward the northwest coast of Persian Gulf and plume type 3 diverted toward the Kuwait coast. Plume type 2 was almost straight and was not diverted to the sides. The T-S diagram of surface water mass was very similar to all three modes, as a result, the plume shape and displacement is affected by wind.