Recently, Cantonese people have to accept the "baptism" of rainfall almost every day, and the water level of many rivers in Guangdong has also risen significantly. According to the latest news from the Pearl River Water Resources Commission of the Ministry of water resources, the No. 3 flood in 2022 and the No. 1 flood in 2022 occurred successively in Xijiang and Hanjiang rivers. According to the prediction of Qingyuan Hydrological Bureau, the first numbered flood of this year may occur at Shijiao station of Beijiang control station around June 15. (Hanjiang Gaopo water control project) However, this year's "dragon boat water" has also "quenched the thirst" of Dongjiang. According to the data provided by the Dongjiang River Basin Authority, the rainfall in May was nearly 37% higher than that in the same period of the year, and the drought situation in the Dongjiang River Basin since 2020 has been effectively alleviated. Compared with last winter and this spring, the water level of Xinfengjiang reservoir (Wanlv Lake) has increased significantly. As of 8:00 on June 13, the water level of Xinfengjiang reservoir has risen to 101.68m, which is the first time that it has exceeded 101m after 520 days of operation since 2021, and has laid a solid foundation for water regulation in the dry season this winter and next spring. (in the afternoon of May 16, the reporter saw that the water level of the reservoir was rising near Wanlv lake.) "How can there be a drought in the rain rich south?" For ordinary citizens, unless they are affected by the reduction of water pressure and salt tide when using domestic water, they do not feel the drought strongly most of the time. Especially when the summer flood season comes, "dragon boat water" and typhoons are often accompanied by a lot of rainfall, so that many friends will ask "soul torture": "how can drought occur in the rain rich south?" "In fact, the uneven spatial and temporal distribution of water resources has always been a difficult problem for the development of Guangdong." Zhengyafeng, deputy section chief of the water resources management section (basin monitoring center) of Dongjiang Bureau, said that last year, the rainfall in Dongjiang basin was not only less than that in normal years, but also almost all the rainfall was in the southern coastal areas, and the upstream catchment area did not store much water. There are many typhoons and precipitation in Guangdong during the flood season, which is easy to cause floods. However, once the flood season is over, the precipitation in Guangdong will become less. This requires Guangdong to do a good job in reservoir storage management while flood control in the flood season, so as to make full preparations for water regulation in the dry season. (on April 8, 2021, a Jie's family in Tongyu Town, Chaoyang District, Shantou City newly purchased a super large capacity water storage tank.) In addition to natural conditions, the growing demand for water is another important factor. As the main water source in the Pearl River Delta, Dongjiang currently supports 28% of the population and 48% of the GDP with 18% of the total water resources in the province. The development and utilization rate of water resources has approached the internationally recognized warning line of 40%. Taking Shenzhen as an example, public data show that in the 20 years from 2000 to 2020, the permanent resident population of Shenzhen has increased from 7.01 million to 17.56 million. The rapid growth of population and economic scale has further intensified the demand for water. Since there are no big rivers flowing through, more than 85% of Shenzhen's water needs to be diverted from Dongjiang. As the "lifeline project" of Shenzhen, Dongjiang water source project has delivered more than 10billion m of water supply to Shenzhen in the past 20 years?. In the winter of last year, due to the continuous reduction of upstream water volume, the staff of the project "watched the water level of the upstream Xinfengjiang reservoir every day". (Taiyuan pump station of Dongshen water supply project) "Water regulation is like playing chess with God" In addition to the "blessing" of rainfall, the "thirst quenching" of Dongjiang River also contributed to the refined regulation of water volume in Guangdong basin. Dongjiang Bureau of Guangdong Province has strengthened the consultation, research and judgment of water and rain conditions in the basin, implemented fine regulation on a daily basis, and paid equal attention to flood control and water storage. Since May this year, it has coordinated the three major reservoirs to store more than 2.35 billion m of water?, Among them, the return storage capacity of Xinfengjiang reservoir exceeds 1.5 billion M?. Xinfengjiang reservoir is the most critical link for water regulation in Dongjiang River Basin. Since 2020, Xinfengjiang reservoir has faced a "dilemma" due to the impact of drought. On the one hand, the reservoir is difficult to store water due to the small amount of water from the upstream; On the other hand, the output of Xinfengjiang reservoir determines whether the downstream water can suppress the salt tide, which directly affects the water use experience in Dongguan. Although the newly developed salt tide rolling prediction system can take advantage of the time error peak of filtration and storage after pumping, the effect is limited after all. For the "salty situation" faced by Dongguan, the most important thing is to increase the water volume in the upstream in real time and accurately to suppress the salty tide. (Dongguan water plant monitors the water quality around the clock to ensure the safety of the factory water.) When and how much water to release can not only suppress the salty tide, but also save the water storage of the reservoir to the greatest extent. This time, water regulation has become the key to solve this problem. How to dispatch water volume? To put it simply, it is necessary to regulate the outlet water of the reservoir in real time according to the downstream weather. When there is rain in the downstream and certain standards are met, it is necessary to immediately reduce the outflow of the reservoir and save the reservoir water as much as possible. In normal years, Xinfengjiang reservoir only needs to adjust the "water release" plan once a month on the basis of the annual dispatching plan of Dongjiang River Basin. However, from January 2020, the water regulation in Dongjiang River Basin has been changed from "monthly consultation" to "ten day consultation". Three months later, the "ten day consultation" has been changed to "daily consultation". After the implementation day meeting, zhengyafeng needs to update the water situation in real time. Even in the middle of the night, as long as the downstream reaches the dispatching conditions, she will negotiate urgently to coordinate with the upstream reservoir to temporarily stop power generation and water release in advance. "Just like playing chess with God, we need to size up the situation and judge quickly so that the reservoir can save more 'water resources'." Zhengyafeng said. Due to the impact of recent heavy rainfall, the Dongjiang River Basin has a large amount of water. Since May this year, Xinfengjiang reservoir has been in the state of shutdown and water storage in other periods except for the power generation flow required by unit operation and management. (the picture shows Dongjiang water resources quantity and quality monitoring center) "Water conservancy should prepare for a rainy day at any time" From monthly scheduling to ten day scheduling and then to daily scheduling, the frequency of water transfer has changed from monthly to accurate to hours and minutes. The refined scheduling of the entire Dongjiang River Basin is like a complex chess game, and the break continues. Water conservancy experts pointed out that in the most critical and difficult period of drought resistance, the water used for basin regulation is basically the water stored and accumulated by these large reservoirs, especially the Xinfengjiang reservoir. "Without these water conservancy project systems to effectively regulate and store water, it would be impossible to cope with this round of drought and ensure the water supply safety of nearly 50million people in the Dongjiang River receiving area, and the consequences would be unimaginable." Experts' opinions not only point out the importance of water conservancy projects, but also reflect a problem from the side - it is not enough to rely on the Dongjiang River alone to ensure the safety of water supply, and inter basin water transfer is inevitable. At present, the water resources allocation project in the Pearl River Delta is accelerating and is expected to be completed in advance by the end of 2023. At that time, the abundant Xijiang water will become a supplementary water source for Guangzhou, Shenzhen, Dongguan and other cities in the Pearl River Delta, effectively "unbundling" Dongjiang water resources. Not only the Pearl River Delta, Guangdong's "big" water resources allocation has already been rolled out in the whole province. According to the "851" water conservancy high-quality development blueprint of Guangdong, accelerating the construction of the "five vertical and five horizontal" backbone network of water resources allocation will become a "key move" to solve the problem of water resources supply in Guangdong. Specifically, the main stream of Dongjiang River, Xijiang River, Beijiang River, Hanjiang River and Jianjiang River is taken as the "vertical" and the allocation of water resources in the Pearl River Delta, the allocation of water resources in Guangdong around the Beibu Gulf, the optimal allocation of water resources in eastern Guangdong, the Pearl River water supply integration project and the Dongshen water supply project are taken as the "horizontal", covering 16 prefectures in the province to be listed, with a beneficiary population of more than 76million. "Since ancient times, water conservancy has been a major event for people's livelihood. We should prepare for a rainy day at any time." Water conservancy experts said that the plight of water resources in Guangdong has not been completely solved. They called on the whole people to save water, strengthen the overall planning and fine regulation of river basins, speed up the construction of water conservancy infrastructure, and optimize the allocation pattern of water resources. Water conservancy in Guangdong is still on the way. Good weather is just an "accidental" gift from nature. In fact, the water regime has been changing from abundance to dryness. For water conservancy, it is an unchanging task to deeply understand the current situation of water resources and take the initiative to prepare for a rainy day. (Xinhua News Agency)