ESTIMATED DISCHARGE VERSUS MEASURED DISCHARGE OF SELECTED STREAMS IN THE ACKERMAN UNIT OF THE TOMBIGBEE NATIONAL FOREST, MISSISSIPPI

The Tombigbee National Forest in Mississippi (Forest) is comprised of two units, the Ackerman Unit and the Trace Unit. The Ackerman Unit is located in east central Mississippi and contains numerous streams. There has been an ongoing program of monitoring streams within the Forest. During this monitoring effort stream discharge has been estimated. This project compared estimated discharge to discharge measured by using a current meter and by following standard procedures. This was done in order to establish the reliability of the estimated measurements. Discharge from three streams within the Forest was both estimated and measured at varied flow regimes. The Discharge was estimated from: approximated width, depth averaged from a few random locations, and a velocity estimated from movement of floating debris (e.g. leaves and twigs) using a stopwatch, and an engineers folding rule. Discharge was then measured with a Price-type AA current meter using standard procedures of intervals across the streambed, and of the depth of velocity measurements. The data obtained from the three streams show that, in half of the cases the estimated discharge was higher than the measured discharge, and in the other half of the cases, the measured discharge was higher than the estimated discharge. Thus, the actual measured discharges were similar to the estimated discharges. The results indicate that the estimated discharges obtained from the streams being monitored in the Forest are reasonable.