Oxygen Transfer at Hydraulic Structures

The shortcomings of existing equations for the prediction of oxygen transfer at hydraulic structures are illustrated, particularly with reference to free overfall weirs. The effect of all important hydraulic variables is reviewed together with water quality effects, in particular the effect of dissolved salts. Modeling according to the Froude law of similarity, the oxygen transfer expressed as a deficit ratio, is shown to vary as a simplified function of the scale. Equations are submitted describing the oxygen transfer in an hydraulic jump and at a free overfall weir. The latter equation is shown to correlate successfully both model studies and measurements at a number of prototype structures and, further, its application to a variety of situations such as spillway jets, multiple jet weirs and cascade of pools is described. An equation to estimate the optimum pool conditions for oxygen transfer is presented.