Seasonal variation of High Dam Lake water

Abstract Seasonal vertical and horizontal variations in water level, temperature, conductivity, transparency, pH, dissolved oxygen, free carbon dioxide, calcium, magnesium, total hardness, sulphates, soluble silicates, inorganic ortho‐phosphates, chlorides, bicarbonates, nitrates and nitrites were determined during the period January to December 1983 (winter, spring, summer and autumn). The samples were taken from surface, at 25, 50, 65 and 80% depth between Abu Simbel and the High Dam wall (Abu Simbel, Tushki, Tomas, Korosko, El Madig, Allaqi, Wadi Abyad, Kalabsha and El Ramla). The results showed that the water depth in the Lake was in range 171.79 to 169.42 m a.m.s.l; temperature, 15.0 to 30.4 °C; conductivity, 18.7 to 30.0 mSm‐1; transparency, 50 to 450 cm; dissolved oxygen, 0.2 to 12.0 mg/L; free CO2, 0.88 to 5.88 mg/L; CO3 2‐, 4 to 24 mg/L; HCOJ ,78 to 108 mg/L; NO2 ‐, 0.256 mg/L; NO3 ‐, 0.05 to 3.76 mg/L; PO4 3‐, 0.002 to 0.156 mg/L; SiO2, 4.8 to 10.7 mg/L; Ca2+, 17.9 to 39.6 mg/L; Mg2+, 4.2 to 14....