NUMERICAL SIMULATION OF THE WATER INTRUSION AND FLOW REGIME IN ARVAND RIVER

Arvand is a narrow river-estuary in the south-west of Iran that forms a part of the border between Iran and Iraq (Figure 1). It is formed by merging the Tigris andEuphrates rivers in Iraq and Karun River in Iran. Three major cities, namely Abadan and Khoramshahr in Iran and Basra in Iraq, are located around it, with the river runningmostly towards the south to reach the Persian Gulf [1]. The total length of this river is about 204 km. Figure 1. Study area (Arvand River) Since the upstream fresh water of Arvand river is used for agricultural purposes, the salinity intrusion and flow regime of the Arvand River has a great importance for the neighboring countries. The water quality of the river has serious implications for water security of neighboring regions of the river, with visible signs of ecosystem deterioration, and lack of adequate and good quality water for human consumption [2]. The tidal range in the Arvand River varies from up to 3 m in the southern part, at the river mouth, to about 1 m in the middle part, at Khoramshahr portand eventually to about 0.4 m at the upstream of the river (where Tigris and Euphrates connect).