黄河内蒙河段水流数值模拟研究

针对黄河内蒙河段孔兑较多、洪水变幅较大、水文监测站点较少的实际情况,采用数值模拟方法,建立了内蒙河段水流数学模型,通过对模型的验证及孔兑入汇计算结果的分析,表明该模型可以真实反映内蒙河段孔兑入汇的流态及相关水力要素变化,可以作为该河段河道规划整治的研究手段之一。黄河内蒙河段孔兑的大流量入汇会对干流区的流态以及水位产生明显影响,使流向改变、水流上滩、水位壅高,因此区域防洪规划和河道整治中应予以高度重视。考虑到内蒙河段孔兑入汇干流带来的影响,不仅体现在水流形态上,而且泥沙淤积是河床演变的关键所在,加之短时段内又难以模拟水流的高含沙量过程,所以下一步工作将是在现有水流模拟基础上模拟计算含沙水流过程。

Flow numerical simulation for Inner Mongolia reach of the Yellow River

In the light of the real conditions of Inner Mongolia reach of the Yellow River, a mathematical model is established based on the case of the flood variation, tributaries, and insufficient hydrologic monitoring stations. The confluence analysis and calculation results show that the numerical model can truely reflect the flow regime in the Inner Mongolia river reach from the tributaries and the related changes in hydraulic elements, which can be used as one of the research methods for regalation of this river reach. The large inflow discharge from the tributaries in Inner Mongolia into the mainstream of the Yellow River can give considerable influence on the flow regime and water level in the mainstream zone, and result in changes in flow direction, water flow over the beach, rise of stage, so those problems concerned should be paid much attention to and be taken into account in the regional flood control planning and river regulation. Considering the tributary inflow into the mainstream of the Yellow River in the Inner Mongolia reach has impacts not only on the flow pattern, but also on river channel process, it is difficult to simulate the flow process of high sediment concentration within a short period, so the next step is to simulate the process of sediment-laden flow on the basis of the existing flow.