金沙江“10·10”白格堰塞湖溃坝洪水反演分析

准确预测堰塞湖溃坝洪水流量过程在堰塞湖应急抢险过程中极其重要。以白格堰塞湖下游水文站实测的洪水过程为依据,通过DB-IWHR溃坝洪水分析程序和GST洪水演进模型,分别采用不同冲刷侵蚀参数对"10·10"白格堰塞湖漫顶自然泄流过程进行了反演分析。结果发现:冲刷参数a=1.100 0、b=0.000 6时,叶巴滩、拉哇水文站模拟结果与实测流量结果最为接近。由此判断"10·10"白格堰塞湖溃决洪峰流量为10 882.78 m~3/s,溃决历时6.2 h到达洪峰流量,最终溃口水面宽度为99.66 m。运用DB-IWHR溃坝洪水分析程序结合基于GPU加速技术的GST洪水演进模型,计算效率得以大大提高,可以在应急抢险工作中实现快速、精准的预测。

Back analysis on dam-breach flood of "10.10" Baige barrier lake on Jinsha River

Forecast of dam-break flood discharge of barrier dams is extremely important in its emergency rescue process. Based on the measured flood discharge at the downstream hydrological gauge stations of the Baige barrier dam on the Jinsha River, we perform back analysis on the natural overtopping discharge process, using DB-IWHR dam flood analysis program and GST flood evolution model. The results show that when erosion parameters a, b was respectively 1.1000 and 0.0006, the inversion results best fit the measured discharges. It was concluded that the dam breach has a peak flow of 10882.78 m3/s occurring at 6.2 h after the breach, and the final breach width was calculated to be 99.66 m. This work also demonstrated the efficiency of DB-IWHR and GST in flood evolution calculation in emergency rescue works.