摘要: To study the effects of urbanization on water quality, relations several stream processes to concentrations dissolved oxygen and other constituents were evaluated during low-flow periods for a 30.1-mi reach Richland Creek in southwestern Illinois. The used both measured data computer simulations. Reaeration rates traveltimes at various flow using steady-state, gas-tracer technique. Sediment-oxygen demands locations throughout reach. Stream discharge, stage, temperature, chemical-constituent two 24-hr July August 1984. then describe quality calibrate verify QUAL-II one-dimensional, model. 36 refs., 29 figs., 11 tabs.