基于马斯京根法的嫩江江桥-大赉段洪水演算

Analysis on flood in Jiangqiao-Dalai reach of Nenjiang River based on Segmented Muskingum method

针对嫩江江桥-大赉河段洪水演进不平衡问题,首先分析了1998年前后江桥和大赉两个水文站的径流变化规律;然后引入河道洪水演进损失系数,建立了基于分段马斯京根方法的江桥-大赉河段的洪水演算模型;最后利用1998年后洪水资料,采用粒子群优化算法率定了河道洪水演进参数和洪水演进损失系数,并分析了参数和损失系数的合理性。结果表明,由于受1998年大洪水的冲刷以及河道两岸冲毁的影响,嫩江江桥-大赉段河道洪水传播速度加快,同时在演进过程中洪水向河道外满溢,导致上下游水量不平衡。

In the light of the imbalance flood routing problem of Jiangqiao-Dalai reach of Nenjiang River,firstly,we analyzed the runoff variation characteristic of Jiangqiao and Dalai hydrological station before and after 1998,a big flood year; secondly,we introduced the channel flood routing loss coefficient and established the flood routing model of Jiangqiao-Dalai reach based on the segmented Muskingum method. Lastly,based on the flood data after 1998 we calibrated channel flood routing parameters and flood loss coefficient by using particle swarm optimization algorithm and analyzed the rationality of parameters and loss coefficient. The results show that due to the souring and destroying of the flood in 1998,the flood spreads quicker in Jiangqiao-Dalai reach,at the same time,the flood overflows the river in the evolution process,causing water imbalance. The results indicate that the flood loss coefficient is feasible and can improve the flood simulation accuracy.