DO Model for Discharges from Deep Impoundments

A simple model is presented for the annual dissolved oxygen (DO) cycle of releases from the hypolimnion of deep impoundments. The model includes mathematical formulations and rate constants for the processes of BOD decay, atmospheric reaeration, and thermal stratification. It was used to characterize the DO cycle of releases from 17 Tennessee Valley Authority reservoirs, using three years of weekly DO and temperature data. Rate constants were estimated using the quasilinearizatin technique for estimating unknown parameters in a system of ordinary differential equations. The results indicate that the model can reasonably simulate annual DO variations of turbine discharges from hypolimnetic waters. Since the model is a simple formulation of complex reservoir processes, it is best suited for preliminary analyses.