确定河流水质参数的抛物方程近似拟和法

提出了一种新的分析瞬时投放示踪剂条件下的一维河流水团示踪试验数据,进而确定河流水质参数的方法.该方法利用抛物方程拟和t1/2c t曲线的峰部区域,推导出利用曲线上3点坐标值计算该抛物方程的极大值和对应时间的公式,利用该时间公式建立计算河流断面平均流速的公式.在此基础上,对浓度时间数据进行转换,推导出计算河流纵向弥散系数和综合排放参数的计算公式.理论推导和算例表明,抛物方程近似拟和法具有对试验数据组数的要求不高、计算过程比较简单和同时能够计算3个水质参数等优点.

Approximate fitting method of parabolic equation for determination of water quality parameters for rivers

A new method was presented to analyze 1-D water-mass tracer test data and further to determine the water quality parameters of rivers under the condition of instantaneous injection of tracers. By fitting of the top part of t ~(1/2) c-t curve with the parabolic equation, formulas for calculation of the maximum value and corresponding time of the parabolic equation with the coordinates of three points on the curve were derived, and then, with the formulas derived, a formula for calculation of the average flow velocity of different river sections was constructed. Based on the above work, the formulas for calculation of the longitudinal dispersion coefficient and discharge parameter were also derived by concentration-time data transformation. Theoretical derivation and examples of calculation show that the approximate fitting method of the parabolic equation is of such advantages as low requirement for the number of test data, simple process of calculation, and simultaneous calculation of three water quality parameters.