Discharge, particularly in high flows, is among the most important information necessary for water resources planning and management. Measurement of discharge by conventional methods requires a great amount of time. Therefore, discharges in unsteady flows can not be effectively measured by using conventional methods. To properly measure discharge in unsteady high flows, an efficient method is required.; An efficient method of discharge measurement requires that the amount of measurement time must be short, and that the method must be simple. An efficient method presented herein is based on the regularity in open channel flows that nature maintains a constant ratio of mean to maximum velocities at a channel section by adjusting the velocity distribution, and, if the channel is erodible, the channel geometry. The method is founded on Chiu's velocity distribution equation, and takes advantage of the constant ratio of the mean velocity and maximum velocities. The maximum velocity can be easily determined on a single vertical.; Three models were developed to help estimate the cross-sectional area. The cross sectional area can be determined from the gage height, the water depth at the y axis, and the product of the channel width at the water surface and the water depth at the y axis.; An efficient method of discharge measurement is verified and tested by using both the laboratory and stream flow data. It is applicable to both the steady and unsteady flows. It can spare a hydrographer from exposure to hazardous environments and can sharply reduce the measurement time and cost. It can also be used to automate the discharge measurement and makes the real-time forecasting of discharge possible during unsteady flows.
展开▼
