China News Service, Zhengzhou, July 8th (Kan Li) The reporter learned from the Yellow River Water Conservancy Commission's Defense Bureau on the 8th that the 20-day Yellow River pre-flood water diversion and sediment adjustment reservoir operation was completed, and a total of 63.74 million tons of sediment was discharged.
The Yellow River is the river with the most sediment content in the world, with an average annual runoff of 53.5 billion cubic meters and an average annual sediment transport volume of up to 1.6 billion tons.
Less water and more sand lead to siltation of the downstream river bed, and the river bed is raised to form an overhang river.
The relevant person in charge of the Yellow River Water Conservancy Commission introduced that water and sediment regulation is to use main and tributary reservoirs to control the water and sediment process that enters the downstream, to shape a relatively coordinated water and sediment relationship, to reduce reservoir channel siltation, and to restore and maintain the middle water channel.
Statistics show that during the pre-flood water and sediment adjustment period in 2021, the maximum flow of the lower Yellow River is 4480 cubic meters per second, and the maximum sediment discharge of Xiaolangdi Reservoir is 378 kg per cubic meter. The cumulative amount of sediment discharged is 63.74 million tons and the amount of sand discharged into the sea is 36.23 million. Tons, ecological water replenishment at the end of the Yellow River is 137 million cubic meters.
It can be seen from the data that for many years of water and sand regulation, the ecological conditions of the lower Yellow River and the estuary delta have improved, the function of ecological corridors has been maintained, the area of wetlands has further increased, the number of organisms has grown steadily, and the biosphere has been thriving.
Currently, the Yellow River has entered the main flood season.
The Yellow River Water Conservancy Commission stated that it will strengthen the four measures of "forecasting, early warning, rehearsal, and pre-plan", based on the most unfavorable situation, and make the most adequate preparations to ensure the safety of flood control and the safety of people's lives and property.
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