渭河是黄河的最大支流 ,华县水文站是渭河下游的主要控制站。洪水漫滩后 ,滩槽水流产生交换 ,使水流结构发生了变化 ,滩槽水流掺混区的流速分布反常。随着水位的升高 ,主槽流速、断面平均流速不但不增大 ,反而比漫滩前出现大幅度的削减 ,这是不同于他站的典型特性。漫滩洪水的Z～Q、Z～A、Z～V关系曲线也以平滩水位为拐点 ,曲线曲率发生变化 ,用曼宁公式制作高水预报曲线受到限制 Weihe River is the largest tributary of the Yellow River, Huaxian Hydrological Station is the main control station in the lower reaches of the Weihe River. Flood floodplain, beach trough water exchange, so that the water flow structure has changed, beach tidal flow mixing zone flow velocity anomaly. As the water level rises, the main channel flow rate and the average cross-section flow rate will not only increase, but will be drastically reduced compared with that before the floodplain. This is a typical characteristic different from that of other stations. The curves of Z ~ Q, Z ~ A and Z ~ V of floodplain flooding also take the flat beach water level as the inflection point, and the curve curvature changes. The curve of high water forecasting by Manning formula is limited