RESERVOIR HYDROLOGIC ROUTING FOR THE HYDRODYNAMIC OF AL-MANZALA LAKE, EGYPT

Abstract

Al-Manzala lake receives most of the agricultural drainage water of the east Nile Delta region in Egypt. As a consequence, hydrological status of the lake has been changed due to this process. Accordingly, knowing the interaction between Mediterranean Sea water and lake’s water was desired. Under these circumstances, reservoir hydrologic routing procedure was implemented to investigate the lake’s hydrodynamic. In this context, the lake hydrodynamic is represented by water level and flow direction. To implement the flood routing process, meteorological data and lake’s water resources were investigated, collected, and analyzed. The study developed an auxiliary diagram that relates storage change within the lake and outflow to the sea. Reservoir hydrologic routing results estimated lake’s water level, outflow, and storage change in the lake for the study period. In addition, an inflow-outflow hydrograph was developed. Furthermore, the water budget of the lake was investigated. Results analysis indicated that water level fluctuates between 17.5 and 56 cm with an average value of 37 cm above mean sea level. This fluctuation maintains a continuous flow from the lake to the sea. In addition, water budget results defined evaporation losses (27.8%), outflow (64.5%), and change in storage (7.7%). It is recommended to study the effect of climate change induced sea-level rise and the Mediterranean Sea tide on the hydrodynamic and hydrologic status of the lake.