الفهرس 
REVIEW of LITERATUREOnly 14 pages are availabe for public view
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Abstract
There are five coastal inland lakes along Egypt’s Mediterranean coast that play an important role in improving the drainage water quality that eventually reach the Mediterranean Sea. These lakes participate significantly (up to 40%) in the national fish production, supporting the national economy and securing a source of provision and economic support and jobs (directly and indirectly) for many of the local communities. Lake Maryout is the most westerly of the four northern Delta lakes in Egypt, where large amounts of drainage waters that carry agricultural, domestic and industrial wastes are dumped into it every year. These wastewaters carry fertilizers, pesticides, organic matter and heavy metals, and pose a significant threat on Lake Maryout environment and affect the biological and microbiological life that are very important in the fish life cycle and fish production. As a result of the high nutrient loading, Lake Maryout has classified as intensively anthropogenic polluted and eutrophic. Eutrophication of a lake is a natural process that can be accelerated by man’s activities that introduce an excess of nutrients together with other pollutants. A eutrophic lake experiences an excessive growth of algae and larger aquatic plants; such growth consumes dissolved oxygen, vital for the fish and other animal life. This growth and proliferation of vegetation currently occurs significantly in Lake Maryout due to the high nutrient loadings that have been entering the lakes for a number of years.
In this study, eutrophication in Lake Maryout is assessed through numerical modeling. Two numerical models are developed, calibrated, and applied. The two models represent lumbed and detailed hydrodynamic and ecological modeling. The first model is an efficient eutrophication numerical model for Lake Maryout which performs water and nutrient balance calculations in a steady-state, spatially segmented hydraulic network. It accounts for advective transport, diffusive transport, and nutrient sedimentation. The application of the model to study load reduction scenarios enables an overall assessment and inferences on the eutrophication control in the light of the local and international regulations.
The research also presents one of first attempts to incorporate ecological modeling into hydrodynamic modeling. A coupled hydrodynamic/ecological model is developed and calibrated to simulate the spatiotemporally variable eutrophic response of Lake Maryout. Two-dimensional spatial and temporal distributions of seven interdependent water-quality state variables were simulated. The modeled water-quality state variables include dissolved oxygen, BOD, chlorophyll-a, and nutrients. The water-quality model was calibrated using monthly measured water-quality state variables data in one year. The model results sufficiently showed good agreement with the field measurements. This study shows that the developed coupled hydrodynamic and water quality model realistically simulates the spatial and temporal hydrodynamics and the water quality of Lake Maryout and can be used as a reasonable tool for the planning and management of the lake ecosystem.