基于断波的溃坝洪水演进分析模型研究

Study on Dam Break Flood Routing Model Based on the Discontinuous Wave

精准分析预测溃坝洪水演进至下游断面的流量过程,对科学应对堰塞湖、溃坝等洪水灾害极其重要.针对溃坝洪水非恒定急变流特性,采用断波动坐标法将溃坝洪水演进非恒定流问题转化为恒定流问题,联合连续性方程和动量方程推导断波波速和流量计算公式,应用微元法实现溃口和下游演进断面的溃坝洪水流量计算,提出基于断波的溃坝洪水演进分析模型,并通过“10·11”白格堰塞湖溃决洪水演进进行验证.结果表明,叶巴滩电站实测的白格堰塞湖溃决洪水,演进至苏洼龙电站的洪峰流量误差为1.44%,时间提前了10min,演进至奔子栏、石鼓、梨园电站的洪峰流量误差在10%左右,验证了模型的可行性和合理性.基于断波的溃坝洪水演进分析模型计算高效稳定,可有效支撑应急处置决策.

Forecast of the discharge process of dam break flood routing to the downsrteam section is extremely important for scientifically response to flood disasters such as barrier lake or dam break.In view of the dam break flood characteristics of Unsteady Rapidly Varied Flow,the dynamic coordinate method of discontinuous wave is used to transform the unstready flow issure of dam break flood routing into stready flow issue.The calculation of dam break flood and routing to downstream section applied the microelement method to put foward a dam-break flood routing analysis model based on dicontinuous wave,which is verified by the“10·11”Baige barrier lake breach flood routing.The results show that the measured peak discharge of Baige barrier lake breach flood in Yebatan Hydropower Station,which routed to Suwalong Hydropower Station just has an error of 1.44%with the time is 10 min ahead,the peak discharge error of the flood routing to Benzilan,Shigu and Liyuan hydropower stations are around 10%.The feasibility and rationality of the model are verified.This work also demonstrated the efficiency and stability of the discontinuous wave flood routing model,it can effectively support emergency disposal decisions.