Relation of channel slope to reaeration of Michigan streams

Reaeration coefficients (k₂), which are rate constants for the process of oxygen absorption from the atmosphere, have been computed for Michigan's streams using an equation developed by Bennett and Rathbun (1972). Mean velocity and mean depth data, which are necessary for the computation, have been extracted from discharge measurements made at gaging stations throughout the State. The computed k₂ values have been related to channel slopes obtained from topographic maps. Regression equations have been derived that express the relation of k₂ to slope for streams at mean flow, median flow, 7-day 2-year low flow, and 7-day 10-year low flow. The equations indicate that an increase in channel slope or a decrease in streamflow increases k₂.