Changing tendency of river runoff at lower reaches of the Huanghe River and countermeasures for reducing its effects
黄河下游河川径流的变化趋势与对策

The annual runoff at the lower reaches of the Huanghe River appears a decline tendency year by year, which is related to annual drop of precipitation and rise of water consumption at the upper middle reaches of the river. The ratio of the measured annual runoff between the 1990s and the 1980s was 65 1% at Huayuankou Station. The annual maximum discharge in the river also shows an annual reducing tendency and the situation of higher water level accompanied with smaller discharge but bigger flood threat has occurred. The ratio of the average maximum discharge between the 1990s and the 1980s was 68 6% at Huayuankou Station. The small discharge or absence of flow in the river shows an annual increasing tendency, in which the ratio of the cumulative days with absence of flow in the 1990s to that in the 1980s was 8 2 to 1 at Lijin Station. The feasible countermeasures for reducing the effects of absence of flow in the river were analyzed in this paper.