Answer geographical questions

Adjusting river sediment concentration is helpful to the regulation of downstream rivers.

Regulating surface runoff and improving flood control capacity in downstream areas

It is helpful to ensure the stability of industrial and agricultural water use in the middle and lower reaches (or to agricultural irrigation in the middle and lower reaches)

Water storage and power generation will contribute to the energy shortage in northern China.

You can say that if you are curious.

Sanmenxia Dam was jointly built by the Soviet Union. The Soviet Union sent engineers to build it according to the Soviet water conservancy model. Premier Zhou Enlai also visited the factory. However, the sediment problem of the Yellow River was not taken into account in the construction process, resulting in sediment deposition at the gate, river bed elevation and almost abandonment. Encourage maintenance after rectification. During the construction period, due to the breakdown of Sino-Soviet relations, the Soviet Union withdrew the dam construction engineer, which led to the dam being put into use before it was completed. The original design power generation is far from the actual power generation and power generation cost. The downstream effect is almost negligible. ..