Abstract:In order to calibrate the relationship curve between water level and discharge of the tailrace of BaishiReservoir, cross section size of the tailrace of Baishi Reservoir is calculated by use of measured data. According toactual situation of the channel, theoretical discharge calculation formula and coefficient (such as gradient, roughness,etc.) are selected, after calculation, theoretical curve of water level-discharge relationship is obtained. By selectingdischarge measurement methods under low, medium and high water levels in the reservoir channel, float method isselected to be used at low water level and high water level situation, current meter method is selected to be used atmiddle water level situation. By comparing the measured results with the theoretical values for many times, it is foundthat difference between them is within the error range, and the coincidence degree is very high, which verifies thattheoretical formula and parameters used in drawing water level-discharge curve of tailrace of Baishi Reservoir areaccurate and reasonable, and curve precision meets reservoir actual demand, which can provide reliable technologysupport for reservoir discharge measurement, provide valuable experience for the letdown discharge calculation oftailrace of similar reservoirs, and be used for future flood discharge calculation.