EVALUATION OF EUTROPHICATION CONTROL STRATEGIES FOR THE KEBAN DAM-RESERVOIR

The reservoir of the Keban Dam in eastern Anatolia is a very deep and large water body subject to significant seasonal water level fluctuati ons within a given hydrological year. At the present time, different s ections of the reservoir have different trophic status and the upper p ortion of the reservoir, in particular, is eutrophic. In this regard, there is a need for the assessment of alternative strategies to be imp lemented for phosphorus and thus eutrophication control in this segmen t of the reservoir. In this study, mathematical modeling techniques ar e used to compare various alternatives in terms of their relative effe ctiveness for phosphorus control. With this intention, a two dimension al depth-averaged hydrodynamic model and a three-dimensional compartme ntal water quality model are coupled to represent the complex water bo dy dynamics prevailing in the reservoir, After calibration and verific ation, the coupled model was used to simulate dissolved oxygen and eup hotic chlorophyll-a concentrations under different scenario conditions corresponding to various strategies proposed for phosphorus control. The modelling effort has yielded valuable information that can be used by decision makers for the evaluation of different management alterna tives including reduction of the phosphorus load coming from point as well as diffuse sources within the catchment area, use of baffles and construction of pre-dam structures. (C) 1997 Elsevier Science B.V.