[Explanation] On August 20th, according to the Yellow River Conservancy Commission of the Ministry of Water Resources of China (hereinafter referred to as the Yellow Committee), the hydrological department forecasted that the Yellow River No. 5 flood, which is continuously evolving, will be at the Tongguan Hydrological Station around 10 o'clock on August 21 It reached 6,600 cubic meters per second, the largest flood at the station since 1996.
Based on the rain and flood conditions of the upper, middle and lower reaches, the Yellow Committee will implement the joint water and sediment dispatching of the middle and lower reaches of the Yellow River from 12:00 on August 20. The Sanmenxia Reservoir will continue to run open, and the Xiaolangdi Reservoir will open 3 sand drainage holes and 1 orifice hole. In addition, the unit generates power to control the discharge, and simultaneously initiates the fourth-level emergency response for flood and drought disaster prevention in the middle and lower reaches of the Yellow River.
[Concurrent] Zhang Suping, Director of the Program Technology Division, Yellow River Conservancy Commission Defense Bureau, Ministry of Water Resources of China
In order to fully respond to the continuous development of the No. 5 flood, the Yellow River Commission decided to implement combined water and sediment regulation in the middle and lower reaches of the river in combination with the comprehensive needs of flood interception and peak reduction, reservoir sand discharge and river sediment reduction. From 12:00 on August 20, the discharge flow of Xiaolangdi Reservoir was increased to 4000 cubic meters per second, and the discharge lasted no less than 6 days.
[Explanation] It is understood that due to the recent continuous heavy rainfall in the middle reaches of the Yellow River, considering the inflow of water from the Weihe River and the north main stream of the Yellow River and the water addition between the sections, the hydrological department predicts that the Tongguan hydrological station on the main stream of the Yellow River will appear at 6600 cubic meters per hour around 10:00 on August 21 The peak flow of about 2 seconds, the flood volume in the next 7 days is about 3.2 billion cubic meters, which is the largest flood at Tongguan Hydrological Station since 1996, and the flood volume in 7 days is even larger than that in 1996.
[Concurrent] Zhang Suping, Director of the Program Technology Division, Yellow River Conservancy Commission Defense Bureau, Ministry of Water Resources of China
In this year's flood season, the upper reaches of the Yellow River has significantly more water. The Longyangxia and Liujiaxia Reservoirs have been operating at high water levels. In addition, various aspects predict that the Yellow River is likely to have autumn rains in West China this year. Therefore, to pre-plan the overall flood control needs of the river basin in the next step, the discharge volume of Dalangdi Reservoir must be increased in a timely manner. In this way, the water level in the reservoir area can be prevented from rising too fast during the subsequent flood interception operation, and it can also make full use of this midstream flood process to further wash the silt deposited in the Sanmenxia and Xiaolangdi reservoir areas, and promote the interannual regulation of the reservoir river sediment, while taking into account The shaping and adjustment of middle-water channels in downstream rivers and the safety of water resources will maximize the utilization of flood resources.
[Explanation] In response to this flood, the Yellow Committee has simultaneously activated the fourth-level emergency response for flood and drought disaster prevention in the middle and lower reaches of the Yellow River at 12 o'clock on the 20th, and issued a notice to relevant river affairs departments and local anti-fighting responsibilities, requesting compaction of flood prevention responsibilities. Overcome fluke psychology, strengthen dike inspections and engineering defenses, and do a good job in low beach areas and floating bridges and other water safety management, and at the same time send a working group to the downstream flood control line to ensure flood control safety.
Li Chaoqing, Li Yaqiang and Peng Qingqing report from Henan
Editor in charge: [Fang Jialiang]