中文摘要：

新安江模型河网汇流参数Cs主要取决于河网形态及地貌特征规律,针对PUB（Prediction in Ungauged Basin）问题,从物理机理分析的角度,构建描述河网汇流动态变化的微分方程并给出适当的定解条件,用解析法得出微分方程的解,从而探索出在无实测水文资料地区适用的Cs计算方法。选取中国湿润地区和半湿润地区25个流域,统计并分析了各流域次洪模型的Cs计算值和率定值。结果表明,从总体来看计算值和率定值基本上相等;不论流域是否分块,提出的Cs计算方法均适用;当其他参数保持不变,虽然Cs取计算值时所得到的次洪模拟结果略逊于取率定值的模拟结果,但误差在可接受的范围之内,也能取得良好的模拟效果;如果令Cs取计算值,再重新率定其余的各项参数,能够使模拟精度得到进一步提高。采用该法可推求无实测资料地区的汇流参数Cs值,使模型在无资料地区的应用成为一种可能。

英文摘要：

The river network flow concentration parameter Cs of the Xin＇anjiang model is mainly controlled by topological and geomorphological characteristics of the river network. In order to address the issues of Predictions in Ungauged Basins（ PUB）,we developed a physically based method to estimate the values of Cs in ungauged basins from the numerical solutions of the partial differential equations with proper definite solution conditions,which describe the dynamic changes of flow concentration processes of the river network. This method can be easily applied to the ungauged basins. To evaluate the robustness and effectiveness of this method,we applied it to derive the Cs values of the Xin＇ anjiang model and calibrated the Cs parameter directly in 25 humid and semi-humid basins in China. The results show that both derived and calibrated values were comparable to each other in general. Regardless of whether the catchment was divided into sub-catchments,the proposed estimation method was applicable. Although the model simulations using the estimated Cs values were slightly poorer than those using calibrated Cs values,these simulations were within the range of acceptable errors and satisfied the flood forecasting standard. Additionally,using the estimated Cs and recalibrating the other parameters further improved the accuracy of resultant simulations. By adopting this method,the Cs value can be obtained in the ungauged basins and makes it easier to apply the Xin＇anjiang model in the ungauged basins.