中文摘要：

在用马斯京根法进行河道流量演算时,由于传统的试算法在精度和客观性上的欠缺,目前广泛使用最小二乘法来进行优化计算。在应用最小二乘法时,发现选择不同的目标函数会对最终的流量计算结果的精度产生影响。因此,本文应用了两种目标函数：河槽蓄量误差最小和出流量误差最小,推导了它们在最小二乘意义上的流量演进参数解析式,进而研究了对流量计算精度的影响。对3场洪水过程的模拟结果表明,以出流量误差最小为目标函数所获得的流量计算精度更高：与河槽蓄量误差最小相比,相对平均绝对误差分别降低了4%,25%和25%,说明使用出流量误差最小作为优化的目标函数更为有效。

英文摘要：

The Least Squares（LS） method is the most commonly used optimization method in applying the Muskingum method for flow routing in river channels,to remedy the negative influence of the traditional trial-and-error method,for being lack of accuracy and objectivity.When the LS method was used as the optimization method,it was discovered that application of different objective functions would influence the accuracy of the outflow routing results.Therefore,in order to investigate this affection,this study applied two objective functions： minimal storage calculation error and minimal outflow calculation error,in optimizing the river channel flow routing.The analytical solutions of the estimated parameters were deduced based on two objective functions,and their influence on the routing accuracies were investigated.The simulation results of three flood events show that,the routing accuracy by using the minimal outflow error is less than that using the minimal storage calculation error as the objective function： respectively being decreased at a rate of 4%,25% and 25% for the Relative Mean Absolute Error（RMAE） being used as the accuracy index,indicating that the minimal outflow calculation error is a more effective objective function in this occasion.