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Effect of the Aswan High Dam on the Nile flood and on the estuarine and coastal circulation pattern along the Mediterranean Egyptian coast
Author(s) -
Sharaf El Din S. H.
Publication year - 1977
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1977.22.2.0194
Subject(s) - oceanography , hydrography , submarine pipeline , geology , estuary , flood myth , mediterranean climate , hydrology (agriculture) , river mouth , sediment , continental shelf , estuarine water circulation , mediterranean sea , period (music) , geography , geomorphology , physics , geotechnical engineering , archaeology , acoustics
From 60–180 million tons of sediments and 18 ✕ 10 9 to 55 ✕ 10 9 m 3 of water were transported to the Mediterranean Sea by the Nile annually before the Aswan High Dam was erected in 1964. Before completion of the dam, during the flood period the estuarine circulation pattern was a two‐layer flow at the mouth of the two estuaries. In winter the circulation pattern was a one‐layer flow of seawater; this pattern has persisted during most of the year since 1964. The velocity of the currents at the mouth of the Nile branches reached more than 4 knots at the surface but was less than 0.5 knot at the bottom during the flood period before 1964; after 1964 this velocity dropped considerably. General oceanographic conditions in the offshore region beyond the continental shelf did not change noticeably, but hydrographic conditions over the continental shelf in front of the delta showed considerable change after 1964. Also, since 1964 almost no sediment has been discharged from the Nile. This has produced an imbalance in the near‐coast sediment budget, increasing erosion at the two mouths of the river and shifting the sediments along the coast.