LAKE DYNAMICS AND THE EFFECTS OF FLOODING ON TOTAL PHOSPHORUS

The concentration of total phosphorus in Lake Washington before and after the sewage diversion project was simulated using first-order linear dynamics. The dynamics of total phosphorus was adequately represented by two independent time scales based on water renewal and sedimentation. The water renewal time scale was modelled as a time dependent process. Sedimentation of total phosphorus appeared constant over the 16-year data period. A marked increase of total phosphorus in the lake occurred during two flood periods when high concentrations of total phosphorus corresponded to small values of the water renewal time scale (i.e., high flows). At other times, peak concentrations of total phosphorus in the inflow coincided with large values of the water renewal time scale and the lake was dynamically unable to respond to these peaks. -from Author