Real-time flood forecasting system for complicated river channels: A case study from Wangjiaba to Xiaoliuxiang section in the Huaihe River basin

随着社会经济的快速发展,洪水灾害造成的损失日益严重.洪水预报作为一项重要的防洪非工程措施,对防洪、抗洪工作起着至关重要的作用.淮河洪水危害的严重性和洪水演进过程的复杂性使得淮河洪水预报系统的研究长期以来受到高度重视.本文以王家坝至小柳巷区间流域为例,以河道洪水演算为主线,采用新安江三水源模型进行子流域降雨径流预报,概化具有行蓄洪区的干流河道,进行支流与干流、行蓄洪区与干流的洪水汇流耦合计算,采用实时更新的基于多元回归的方法确定水位流量关系,并以上游站点降雨径流预报模型提供的流量作为上边界条件、以下游站点的水位流量关系作为下边界条件,结合行蓄洪调度模型,建立具有行蓄洪区的河道洪水预报系统,再与基于K-最近邻(KNN)的非参数实时校正模型耦合,建立淮河中游河道洪水预报系统.采用多年资料模拟取得了较好的预报效果,并以2003和2007年大洪水为例进行检验,模拟结果精度较高,也证明了所建预报系统的合理性和适用性.;The losses caused by flood disasters are becoming increasingly serious with the rapid development of social economy.As an important non-engineering flood protection measure,real-time flood forecasting plays an important role in flood control.Due to the severity of flood disasters and the complexity of flood routing process in the Huaihe River basin,the research on flood forecasting system has been a focus for a long period.A case study from Wangjiaba to Xiaoliuxiang section is discussed and a research on flood forecasting system is presented in this paper.On the basis of the hydrologic characteristics in the study area,this paper takes flood flow routing as mainline,uses the Xin'anjiang model for runoff yield prediction,generalizes flood diversion and retarding regions, applies hydrologic and hydraulic methods to simulate flow routing in the main channels,and fits stage-discharge relationships by multiple regression method.A general system is established by integrating the above parts and then by coupling K-Nearest Neighbor method to attach real-time correction to forecasting results for the real-time forecasting system.Inspected in 2003 and 2007,the system achieved high prediction accuracy,which proves that the system is sound and can be applied to this basin.