Field and Laboratory Studies on Nile Phytoplankton in Egypt III. Some Physical and Chemical Characteristics of Aswan High Dam Lake (Lake Nasser)

Seasonal, local and monthly vertical variations in physical and chemical characteristics of Aswan High Dam Lake (AHDL) were followed during the period from March 1982 to February 1984. The results show that there were distinct seasonal thermal variations. Similarly, thermal stratification was evident from late spring through early autumn. Oxygen content appeared to vary with the changes in pH value. Water transparency in the southern part was greatly reduced by the incoming silt laden flood especially in summer months. Consequently, nitrate-nitrogen and total residue increased considerably in this part during summer. The recorded minimum N-concentration (2.35μg l−1) was certainly limiting the growth of phytoplankton. Suspended and organic matter exhibited somewhat irregular variations at least during the period of this study.