白石水库尾水渠水位-流量关系曲线率定与分析

Calibration and analysis of water level-discharge curve of tailrace of Baishi Reservoir

为率定白石水库尾水渠水位-流量关系曲线,以白石水库尾水渠为研究对象,利用实测数据计算出渠道的断面尺寸,根据渠道的实际情况选定理论流量计算公式和比降、糙率等系数,经过计算得出水位-流量关系理论曲线,再通过对水库渠道内低、中、高水位下测流方法的选择,确定在低水位和高水位下采用浮标法,在中水位下采用流速仪法,并将多次实测结果与理论值进行比较,发现两者差值均在误差范围内,吻合度非常高,最终验证所绘制的白石水库尾水渠水位-流量理论关系曲线采用的理论公式和参数准确、合理,曲线精确度符合水库的实际需求,以此为水库流量测验提供可靠的技术支持,同时也为同类型水库的尾水渠计算下泄流量提供宝贵经验,可用于今后的泄洪流量测算。

In order to calibrate the relationship curve between water level and discharge of the tailrace of Baishi Reservoir,cross section size of the tailrace of Baishi Reservoir is calculated by use of measured data.According to actual 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 selecting discharge measurement methods under low,medium and high water levels in the reservoir channel,float method is selected to be used at low water level and high water level situation,current meter method is selected to be used at middle water level situation.By comparing the measured results with the theoretical values for many times,it is found that difference between them is within the error range,and the coincidence degree is very high,which verifies that theoretical formula and parameters used in drawing water level-discharge curve of tailrace of Baishi Reservoir are accurate and reasonable,and curve precision meets reservoir actual demand,which can provide reliable technology support for reservoir discharge measurement,provide valuable experience for the letdown discharge calculation of tailrace of similar reservoirs,and be used for future flood discharge calculation.