Persian Gulf as "The Northwestern limit of Gulf of Oman". This limit is defined as "A line joining Ràs Limah (25°57'N) on the coast of Arabia and Ràs al Kuh (25°48'N) on the coast of Iran (Persia)". The gulf is connected to Indian Ocean through Strait of Hormuz. Writing the water balance budget for the Persian Gulf, the inputs are river discharges from Iran and Iraq (estimated to be 2000 cubic meters per second), as well as precipitation over the sea which is around 180mm/year in Qeshm Island. The evaporation of the sea is high, so that after considering river discharge and
Persian Gulf BC, the southern part of the Persian Gulf was dominated by the Dilmun civilization. For a long time the most important settlement on the southern coast of the Persian Gulf was Gerrha. In the 2nd century the Lakhum tribe, who lived in what is now Yemen, migrated north and founded the Lakhmid Kingdom along the southern coast. Occasional ancient battles took place along the Persian Gulf coastlines, between the Sassanid Persian empire and the Lakhmid Kingdom, the most prominent of which was the invasion led by Shapur II against the Lakhmids, leading to Lakhmids' defeat, and advancement into Arabia, along