Strait of Hormuz. Other significant islands in the Persian Gulf include Greater Tunb, Lesser Tunb and Kish administered by Iran, Bubiyan administered by Kuwait, Tarout administered by Saudi Arabia, and Dalma administered by UAE. In recent years, there has also been the addition of artificial islands for tourist attractions, such as The World Islands in Dubai and The Pearl-Qatar in Doha. Persian Gulf islands are often also historically significant, having been used in the past by colonial powers such as the Portuguese and the British in their trade or as acquisitions for their empires. Oceanography The Persian Gulf is connected to the Indian Ocean through the Strait of Hormuz. Writing the water balance budget for the Persian Gulf, the inputs are river discharges from Iran and Iraq (estimated to be per second), as well as precipitation over the sea which is around /year in Qeshm Island. The evaporation of the sea is high, so that after considering river discharge and rain contributions, there is still a deficit of per year. This difference is supplied by currents at the Strait of Hormuz. The water from the Persian Gulf has a higher salinity, and therefore exits from the bottom of the Strait, while ocean water with less salinity flows in through the top. Another study revealed the following numbers for water exchanges for the Persian Gulf: evaporation = –/year, precipitation = /year, inflow from the Strait = /year, outflow from the Strait = -/year, and the balance is 0 m (0 ft)/year. Data from different 3D computational fluid mechanics models, typically with spatial resolution of and depth each element equal to are predominantly used in computer models. Name Before being given its present name, the Persian Gulf was called many different names. In Babylonian texts, it was known as "the sea above Akkad." The Assyrians called it the "Bitter Sea". In 550 BC, the Achaemenid Empire established the first ancient empire in Persis (Pars, or modern Fars), in the southwestern region of the Iranian plateau. Consequently, in the Greek sources, the body of water that bordered this province came to be known as the "Persian Gulf". In the book of Nearchus known as Indikê (300 BC), the word "Persikon kolpos" is mentioned for multiple times meaning "Persian gulf". During the years 550 to 330 BC, coinciding with the sovereignty of the Achaemenid Persian Empire over the Middle East area, especially the whole