Comparison of tracer methods and predictive equations for determination of stream-reaeration coefficients on three small streams in Wisconsin
Four modified nonradioactive-tracer methods and 20 predictive equations for determination of stream-reaeration coefficients in three small Wisconsin streams were compared with the radioactive-tracer method developed by Tsivoglou. Of the four modified-tracer techniques, the propane-area technique, which measures the total weight of propane gas passing stream-sampling stations, yielded the least mean absolute difference of 11.0 percent compared with the radioactive-tracer method. The propane peak concentration, ethylene peak concentration, and ethylene total weight methods gave mean absolute differences of 18, 21, and 26 percent, respectively. The top five ranking predictive equations were as follows: Tsivoglou-Neal with 18 percent mean error, Negulescu-Rojanski with 21 percent, Padden-Gloyna with 23 percent, Thackston-Krenkel with 29 percent, and Bansal with 32 percent. (USGS).