Thermal Stratification in Lake Nasser, Egypt Using Field Measurements

This study describes and discusses the water temperature gradient of Lake Nasser. The Lake (23°N and 32°E) is the second largest man-made lake in the world. The results of the study showed that its water column mixes to bottom in February, with a weakly difference of only less than three degrees. Winds blowing across the lake's surface cause the water to pile up on the downwind layers. The lake becomes thermally stratified in July, when the inflow at the southern region of the Lake and air temperature reaches ultimate. The epilimnion extends to a depth of 12 m below the lake surface, with average temperature of 29.7°C. The thermocline thickness in the lake changes from region to another. Its thickness is 5 m at the southern region, with a difference of five degrees. The northern and the middle regions of the lake have the thickness of 13 m, with a nine degrees difference. The hypolimnion of the northern and middle regions of lake Nasser is below approximately 25 m, while in the southern region , it is below about 17 m depth. The average temperature of the hypolimnion in the lake is about 18.5°C. The thermal stratification is influenced by the weather condition and the water inflow to the lake.