As of April 28, the rainfall in the Pearl River basin was higher than that of the same period in normal years. The flood came early and fiercely. Under the unified command of the Ministry of Water Resources, water conservancy departments at all levels in the Pearl River Basin have thoroughly implemented the spirit of General Secretary Xi Jinping's important instructions on disaster prevention, mitigation and relief of "two insistences and three changes", strengthened the "four precautions" measures, penetrated the "four feelings" defense, scientifically dispatched, stopped floods and cut peaks, effectively defended the Beijiang, Hanjiang and Dongjiang rivers against multiple floods, and built an "iron wall" for flood prevention and flood control.
Strengthen the inspection and defense of embankments and culverts
Bac Giang Embankment
At about 4 o'clock in the afternoon of April 25, the showers in Sanshui District, Foshan City, Guangdong Province first stopped. In the Huangtang section of the Beijiang embankment, the river outside the embankment is mighty and flooding, and the embankment is calm and life is normal.
The Beijiang embankment is located on the left bank of the lower reaches of the Beijiang River, starting from Qibeiling, Shijiao Town, Qingcheng District, Qingyuan City, Guangdong Province, passing through Sanshui District of Foshan City to Nanhai District, defending Guangzhou, Foshan, Qingyuan, Baiyun Airport, Beijing-Guangzhou Railway, etc., and is known as "the first embankment in southern Guangdong".
"The name 'Sanshui' originates from the confluence of the three rivers of Beijiang, Xijiang and Suijiang. The water system here flows into the main stream like an umbrella, and the volume is large and rapid, which has always been the focus of flood control work. Zeng Jinhong, director of the flood control and engineering construction management department of the Beijiang Basin Administration of Guangdong Province, said that in the process of facing the current round of Beijiang No. 2 flood, more than 2,700 people went to the embankment to inspect the embankment at the peak of a single day to ensure that the Beijiang embankment was safe and sound.
"The Huangtang section of the Beijiang embankment is a strong permeable foundation embankment section, and the inspection of the embankment can not be sloppy at all. Li Weikang, wearing a blue vest, is an "old water conservancy" of the Beijiang Embankment Management Department of the Beijiang River Basin Administration of Guangdong Province, and has repeatedly jumped into the water during flood control and rescue to deal with dangerous situations such as embankment pipe surges. During this period, he and his colleagues worked rain or shine, encrypting the frequency of inspections, focusing on possible water seepage, pipe surges, loopholes, cracks, collapses and other embankment dangers, staring wide eyes and carefully investigating, and not letting go of any subtle hidden dangers.
"The Bac Giang embankment is a key area of the Bac Giang flood control engineering system. We have continuously consolidated the embankment by means of sand filling and pressure seepage, heightening and thickening, filling ponds and consolidating the foundation, etc., and at the same time have reserved sufficient flood control materials. Zeng Jinhong said.
Guangxi Beihai City, Hepu County total river sluice project
Dike and culvert gates are known as the "top brand" of flood control and flood control. The Baiquwei seawall in Hepu County, Beihai City, Guangxi Province is located between the Nandong Waterway and the Zhoujiang River at the mouth of the Nanliu River, and faces Beibu Gulf and Beihai City across the river in the south. "Since the implementation of the Baiquwei seawall renovation project in Hepu County in 2014, nearly 26 kilometers of seawalls have been strengthened and renovated, and 41 drainage and tidal culvert gates have been rebuilt. Huang Feixiang, director of the defense center of the Hepu County Water Conservancy Bureau in Guangxi, introduced that since April, there have been many heavy rainfalls in the local area, and they organized personnel to inspect the embankment along the Baiquwei seawall on foot, focusing on inspecting the embankment dam, bank slope collapse, termite hazards, road cracks, etc., and also formulated the 2024 annual flood control and rescue emergency plan for the Baiquwei seawall in advance, and made every effort to prepare for flood control.
Also waiting for the end is Wu Yuning, deputy director of the Nanliujiang Comprehensive Management Center of the Hepu County Water Conservancy Bureau. The Nanliu River Comprehensive Management Center is responsible for the operation and management of the Zongjiang sluice in Hepu County, and the Nanliu River passes through the Zongjiang sluice, which has become one of the key projects for flood control and drainage in Beihai City due to the "short source and rapid flow" of the water system in the coastal area.
"We have set up a duty team for the main river sluice gates, and adhere to the 24-hour rotation and leadership system. Wu Yuning said that the Zongjiang sluice set up a flood prevention and rescue emergency leading group, and compiled the emergency plan for flood prevention and rescue of the Zongjiang sluice, the emergency plan for safety management, and the implementation plan for the control and use plan, etc., and implemented the flood prevention responsibility, materials, and plans in detail to ensure that "it is better to be prepared than to be prepared, not to be unprepared."
Scientific scheduling of water projects to stop floods and cut peaks
"Nanxiong fell into the water and sprinkled wet stones, went to Shaoguan and rose three feet, fell to Yingde and flooded half of the wall, and soaked to Qingyuan and walked without land. This is a popular saying in Qingyuan, Guangdong Province, to the effect that the rain only wets the stones in the upper reaches of the Beijiang River, and the water gradually increases and when it reaches the middle and lower reaches, it is enough to flood the town. The Beijiang River is the second largest water system of the Pearl River, and the flood confluence in the upper reaches of the mountains and hilly areas is fast, while the main stream of the middle and lower reaches flows through the area with a gentle slope and slow flow rate, resulting in heavy rainfall, the middle and lower reaches often fail to drain water in time and cause floods, so the middle and lower reaches have always been the top priority of flood control in the Beijiang River.
Beijiang Feilai Gorge Water Conservancy Hub
"From April 19 to April 22, we received a total of six dispatch orders. Huang Geng, deputy general manager of Guangdong Yuehai Feilaixia Hydropower Co., Ltd., said. Located about 40 kilometers northeast of Qingyuan City, Guangdong, the Feilaixia Water Conservancy Project is a key project for flood control of the Beijiang River, which plays an important role in ensuring the flood control safety of the middle and lower reaches of the Beijiang River and Qingyuan City.
In order to cope with the catastrophic flood in the Beijiang River, under the unified command of the Ministry of Water Resources, the Pearl River Water Conservancy Committee of the Ministry of Water Resources (hereinafter referred to as the "Pearl River Committee"), the Guangdong Provincial Department of Water Resources, and other relevant units and departments dispatched 350 million cubic meters of reservoir capacity in the upper and middle reaches of the Beijiang River in advance, and promptly activated the Feilaixia Reservoir to store 204 million cubic meters of floodwater, reducing the peak flood flow of Shijiao Station of the Beijiang Control Station by 1,300 cubic meters per second. Changhu and other reservoirs impound 210 million cubic meters of floodwater, reduce the inflow of Feilaixia Reservoir by 1,300 cubic meters per second, minimize the scope of the protection area of the Polo Pit, and further reduce the peak flood flow of Shijiao Station by 700 cubic meters per second.
Through the dispatch of the main and tributary reservoirs such as Feilai Gorge, the flood control effect is obvious, and the flood magnitude of the Beijiang River is successfully controlled within the safe discharge of the Beijiang embankment, and the peak flood volume does not exceed the safe discharge of the embankment, which effectively reduces the flood control pressure along the downstream line, ensures the flood control safety of key protection objects such as the Guangdong-Hong Kong-Macao Greater Bay Area, and achieves the dispatching goal of not using the flood storage and detention area of the Weijiang River.
Since the maximum inflow of the Feilai Gorge Water Conservancy Project at 3 o'clock on April 22, the flood water has continued to discharge. "According to the forecast, there may be a flood process in the Beijiang River in the next few days, and the current Feilai Gorge is still in an open state according to the operating procedures, and we will pay close attention to reducing the water level of the reservoir capacity to prepare for the next flood storage. Huang Geng said.
The Datengxia Water Conservancy Project is precisely dispatched to ensure the safety of flood control
Reservoir storage is known as the "trump card" of flood control and flood control. In recent years, the Datengxia Water Conservancy Project has adhered to the unified and precise dispatch of the river basin, and has successfully resisted multiple numbered floods in the Xijiang River, especially in the process of preventing the No. 4 flood of the Xijiang River in 2022, with the limited flood control capacity during the construction period, 700 million cubic meters of flood water will be impounded, and the maximum flood peak will be reduced by 3,500 cubic meters per second, so as to avoid the flood peak of the Xijiang River and the Beijiang River.
Since the beginning of the flood this year, the Pearl River basin has occurred one after another, and the flood control situation is severe and complex, Datengxia Company has strengthened rainwater monitoring and forecasting and rolling consultation, research and judgment, accurately grasped the timing of scheduling, carefully carried out equipment inspection and maintenance, and waited for all aspects of flood prevention and preparedness, and went all out to ensure the safety of the project, reservoir area and downstream flood control, and effectively guaranteed the safety of people's lives and property in the basin.
Build a "four predictions" platform to achieve accurate forecasting
The "four precautions" platform for flood and drought disaster prevention in the Pearl River
On the Pearl River flood and drought disaster prevention "four predictions" (forecast, early warning, rehearsal, and plan) platform, real-time data such as rainfall and river water levels are scrolled on the electronic screen, and the overall rain and water conditions of the river basin are at a glance.
"Now we have incorporated all the major water conservancy projects in the basin into the system, improved the data support, optimized the computing algorithm, and made the prediction and forecast of the 'four predictions' platform more accurate, and entered the 2.0 version era. Xie Xuhe, deputy chief of the Flood and Drought Disaster Prevention Department of the Pearl River Commission, introduced.
Since April, the Pearl River Commission has made full use of the "four predictions" platform for flood and drought disaster prevention in the Pearl River, implemented flood forecasts in an encrypted, rolling and refined manner, and issued eight flood warnings and more than 20,000 early warning text messages, which has won valuable time for command and dispatch decision-making and active prevention and control. At the same time, according to the flood forecasting results, multiple schemes simulated and rehearsed the multi-numbered flood evolution process of the Beijiang, Hanjiang and Dongjiang rivers, compared and optimized the scheduling scheme of the reservoir group in the basin, and issued dispatching instructions to accurately guide flood defense.
Accurate monitoring and reporting is the "eyes and ears" of scientific decision-making on flood control and flood control. "If there is a flood discharge, then we will issue an early warning on the 'four pre-forecast' platform and issue it directly, which is very convenient. We use it every day at the moment. Huang Guangdan, head of the water regulation section of the hub management center of Datengxia Company, said.
It is reported that in accordance with the requirements of physical and digital "two-handed", Datengxia Company has continuously consolidated the foundation of calculations, optimized the algorithm model, improved the level of computing power, and continuously improved the "four pre-planning" systems of digital twin Datengxia flood control and water quantity scheduling, combining "forward" rehearsal and "reverse" deduction to provide support for reservoir scheduling decisions. At present, the water monitoring and reporting system of the Datengxia Water Conservancy Project covers 111 special rainfall stations and 90 hydrological (bit) stations, and also accelerates the construction of rain measurement radar, and the radar network controls the key area of 17,000 square kilometers of the reservoir area.
It is understood that the Ministry of Water Resources is speeding up the improvement of the rainwater monitoring and forecasting system, in accordance with the principle of "should be set up, should be measured, should be online", focusing on the actual needs of flood control and reservoir scheduling in the river basin, and accelerate the construction of meteorological satellites and rain measurement radars, rain gauge stations, hydrological stations composed of rainwater monitoring and forecasting "three lines of defense", to further extend the flood prediction period and improve the accuracy of flood forecasting.
Authors: Meng Hui, Ding Enyu, Wu Yirong