Migrants in Xiaolangdi reservoir area

Panorama of flood discharge of Sanmenxia dam

At 9: 00 a.m. on July 4th, Sanmenxia Water Control Project 202 1 took over the baton of the Yellow River for water and sediment regulation, and accurately opened the gate to provide follow-up power for water and sediment regulation in Xiaolangdi. In an instant, huge hoses gushed out, and the waves were rough and the canyon was shocked by sound (as shown on the right).

Since 2002, under the premise of fully considering the sediment transport capacity in the lower reaches of the Yellow River, the Yellow River Defense General has used the regulation capacity of Wanjiazhai, Sanmenxia and Xiaolangdi reservoirs to organize water and sediment regulation, effectively control and regulate the process of water and sediment, so as to make the unsuitable water and sediment relationship as harmonious as possible, which is beneficial to sediment transport, thus reducing downstream siltation and achieving the goal of not raising the downstream riverbed. The water and sediment regulation of the Yellow River before the flood season this year is the 20th application of water and sediment regulation of the Yellow River. It will particularly highlight the "bull nose" that regulates the relationship between water and sediment. In accordance with the principle of safety control and overall consideration, combined with the requirements of the middle reaches of the reservoir to meet the flood season, the current water and sediment regulation project in the middle and lower reaches of the Yellow River is the main body, supported by the combined water and sediment regulation technology of the middle and lower reaches of the reservoir group, and under the premise of ensuring flood control safety, the middle reaches of the reservoir will be scientifically regulated to realize sediment discharge and siltation reduction, and maintain the flow capacity of the downstream middle channel.

Ji Li, director of the Reservoir Dispatching Department of Sanmenxia Water Control Project Administration, told the reporter that Sanmenxia Water Control Project participated in the Yellow River water and sediment regulation for the 20th time according to the dispatching instruction of the Yellow River Committee. "From 9: 00 on July 4, according to the flow rate of 2000 cubic meters per second, it reached 4000 cubic meters per second after 4 hours, and then reached 4500 cubic meters per second until it was discharged. After the completion of water and sediment regulation, it was turned into normal use in flood season according to the dispatching instructions of the Yellow River Committee."

"It is estimated that the displacement will be 500 million cubic meters and the sediment discharge will be 30 million tons." Ji Li said that it is of great significance to extend the service life of Xiaolangdi Reservoir and increase the capacity of siltation reduction and flood discharge in the lower reaches of the Yellow River.

Sanmenxia water control project, as an important part of the Yellow River water and sediment regulation system, is in a superior special geographical position in the middle reaches of the Yellow River and has strong sediment regulation ability in flood season. Therefore, Sanmenxia reservoir plays a very important role in the joint operation of water and sediment regulation with Wanjiazhai and Xiaolangdi reservoirs. In the process of water and sediment regulation, Sanmenxia Water Control Project will gradually increase the flow until it discharges, and use about 500 million cubic meters of water above the flood limit level of Sanmenxia Reservoir to scour the sediment at the tail of Xiaolangdi Reservoir, which will provide powerful power for Xiaolangdi Reservoir to artificially shape the density flow and sediment discharge, directly control the process of water and sediment coming from Xiaolangdi Reservoir, enhance the power of subsequent water and sediment regulation, effectively improve the sedimentation distribution of Xiaolangdi Reservoir, increase the sediment discharge, maintain the effective storage capacity of Xiaolangdi Reservoir for a long time, and prolong its service life.

It is reported that in combination with the application of water and sediment regulation, the flood control drill of Sanmenxia Water Control Project will be carried out simultaneously to actually test the operation of the flood control work system, the actual combat level and emergency response capability of the flood control team, comprehensively improve the emergency response capability of flood control command and dispatch, and ensure the safety of the project.

The relevant person in charge of Sanmenxia Water Control Project Administration said that the reservoir has a large discharge and the water level changes dramatically. In order to ensure the safety of wading operations and personnel in the reservoir area during the period of water and sediment regulation, the bridges, pontoons and other facilities within the influence range of large flow are inspected. It is hoped that the flood control headquarters in the relevant downstream areas and relevant units will do a good job in safety prevention. (Fang Linyan, Liu Wei, Qi Jiawen/map)