中文摘要：

提出了一种在河流突然排污情况下，分析河段下游两个时刻的c-x数据，确定河流水质参数与排放参数的方法．将描述一维河流水质的解析解进行适当变化，根据相关极值法的原理，推导出了计算相应两个浓度观测时刻的中间参数的公式．在此基础上，推导出了河流断面平均流速的计算公式．将c—x数据转化为y～x中间计算数据，分别建立了相应两个观测时刻的y—x直线方程，应用线性回归法或直线图解法，能够分别确定两个直线方程的直线常数．利用直线常数和中间计算参数值，可以分别计算出污染物的排放时间、排放位置坐标、河流纵向离散系数、断面平均流速和排放参数等参数值．最后，利用算例说明了方法的具体运算步骤．

英文摘要：

In order to determine pollution parameters as the longitudinal dispersion coefficient D, average velocity V of fiver stream and the coordinate and the time of pollutant injection in the case of instantaneous injection, a new method is proposed. In this method, the expression describing one-dimensional water mass tracer test in river stream in the case of instantaneous injection is transformed and two linear regression equations are deduced at two different moments of pollutant concentration observation. With application of correlation coefficient and extreme principle to these two linear equations, the formula to estimate the average velocity V of stream is derived. Then the observed data at two observation moments can be transformed to the two groups of computation intermediate data. With these two groups of computation intermediate data, all the linear constants of these two linear equations can be determined with linear regression method. The formulas to determine the coordinate and the time of pollutant injection, longitudinal dispersion coefficient D, average velocity V of stream and injection parameter W/A may be derived from the expressions of linear constants and intermediate computation parameters. Finally, the procedure for application of this method is shown in detail by examples.