Aswan Dam have been flooded by Lake Nasser. Before the construction of the High Dam, the Nile deposited sediments of various particle size – consisting of fine sand, silt and clay – on fields in Upper Egypt through its annual flood, contributing to soil fertility. However, the nutrient value of the sediment has often been overestimated. 88 percent of the sediment was carried to the sea before the construction of the High Dam. The nutrient value added to the land by the sediment was only 6,000 tons of potash, 7,000 tons of phosphorus pentoxide and 17,000 tons of nitrogen. These amounts are
Aswan 330, the legion stationed here received a bishop from Alexandria; this later became the Coptic Diocese of Syene. The city is mentioned by numerous ancient writers, including Herodotus, Strabo, Stephanus of Byzantium, Ptolemy, Pliny the Elder, Vitruvius, and it appears on the Antonine Itinerary. It also is mentioned in the Book of Ezekiel and the Book of Isaiah. The latitude of the city that would become Aswan – located at 24° 5′ 23″ – was an object of great interest to the ancient geographers. They believed that it was seated immediately under the tropic, and that on the day of