An ecological regulation method for inhibiting water bloom in tributaries of reservoirs

Abstract

An ecological regulation method for inhibiting water bloom of reservoir tributaries, through collecting water bloom monitoring historical data, analyzing the relationship between water level amplitude and algal biomass, determining the water level amplitude threshold for inhibiting water bloom, on the basis of combining reservoir regulation rules and reservoir inflow and outflow data, calculating and determining the regulation period meeting the requirement of inhibiting water bloom, in the regulation period, through regulating and controlling reservoir water level to the predetermined range and rising and falling according to the preset amplitude and frequency, water temperature stratification is destroyed, so that the water bloom of the tributaries is effectively inhibited, the method is implemented under the premise of meeting the requirements of flood control, power generation and navigation, realizes the multi-target collaborative management, is convenient to operate, has practical application value, and has important significance for improving the water ecological environment of the reservoir area and protecting the safety of water resources. Meanwhile, the present application can also dynamically adjust the regulation strategy according to real-time monitoring data to adapt to the water bloom prevention and treatment requirements under different seasons and different weather conditions, and can further improve the water bloom prevention and treatment effect in combination with other ecological engineering technologies.

Description

Technical Field

[0001] The invention relates to the technical field of water conservancy project dispatching, and in particular to an ecological dispatching method for suppressing algal blooms in reservoir tributaries. Background Art

[0002] The Three Gorges Project, a critical backbone project on my country's Yangtze River, has delivered significant benefits for flood control, power generation, shipping, and water resource utilization. However, algal blooms frequently occur in some tributaries of the Three Gorges Reservoir. These blooms can cause oxygen depletion and significant changes in water color. Some blooms even produce algal toxins and odors, impacting the reservoir's aquatic ecosystem and the lives of surrounding residents. While existing scheduling methods propose seasonal water level thresholds and scheduling methods, they are often incompatible with existing scheduling regulations for flood control, power generation, and shipping.

[0003] For example, CN109319853A discloses an ecological scheduling method for controlling algal blooms by regulating the flow rate of upstream tributaries. The method is as follows: adjusting the flow rate of upstream tributaries according to the changes in reservoir water level, the temperature of tributary bays and upstream tributary flows, forming a middle-layer backflow or non-stratified flow state in the area where algal blooms frequently occur, or reducing the intensity of surface backflow to suppress the outbreak of algal blooms; based on in-depth research on the outbreak mechanism of algal blooms in tributaries of river-type reservoirs and the law of flow state changes in areas where algal blooms frequently occur, the present invention proposes an ecological scheduling method for controlling algal blooms by regulating the flow rate of upstream tributaries according to changes in reservoir water level, forming a flow state that is not conducive to the outbreak of algal blooms in areas where algal blooms frequently occur, and thus controlling algal blooms; this method is a method of controlling algal blooms by changing the flow rate of upstream tributaries; there is still a situation where constraints such as flood control, power generation, and shipping do not match.

[0004] Therefore, how to optimize the ecological scheduling strategy, strengthen multi-objective collaborative management, and improve the convenience of actual operations are the technical problems to be solved by the present invention. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an ecological scheduling method for suppressing algal blooms in reservoir tributaries, thereby solving the problem of mismatching constraints in flood control, power generation and shipping in the existing ecological scheduling method.

[0006] To solve the above technical problems, the present invention adopts a technical solution: an ecological scheduling method for suppressing algal blooms in reservoir tributaries, comprising the following steps:

[0007] Step 1: Collect historical data on algal bloom monitoring, including the annual distribution of algal bloom frequency, algal biomass in reservoir tributaries during the bloom monitoring period, reservoir water level, and inflow and outflow data;

[0008] Step 2: Determine the water level fluctuation threshold for inhibiting algal blooms by statistically analyzing the relationship between water level fluctuation and algal biomass;

[0009] Step 3: Based on reservoir operation regulations and inflow and outflow data at different times, calculate whether the water level fluctuation meets the requirements for suppressing algal blooms and determine the time period for implementing bloom suppression operations. During this time period, the reservoir water level is regulated to a predetermined range, causing the water level to rise and fall according to a preset amplitude and frequency, thereby disrupting water temperature stratification and suppressing algal blooms in tributaries.

[0010] Step 4: Analyze the dispatching conditions and implement dispatching on the premise of meeting the requirements of flood control, power generation and shipping.

[0011] In a preferred solution, in Step 3, the reservoir water level is regulated to a predetermined water level range, and the water level rises at a daily average rate of not less than the set level for at least three consecutive days.

[0012] In a preferred solution, in Step 4, the analysis of scheduling conditions includes:

[0013] Step 4.1: For flood control, according to the reservoir's dispatching regulations, when the inflow is less than a preset threshold and the inflow for the next three days does not exceed another preset threshold, dispatch is carried out;

[0014] Step 4.2: Regarding shipping, the water level at the downstream Gezhouba Dam should be ensured not to fall below the preset value during the dispatch process to ensure shipping safety.

[0015] Step 4.3: In terms of power generation, dispatching is carried out under the premise of meeting the peak-shaving needs of the power grid.

[0016] In the preferred solution, in Step 4, in June and July-August when algal blooms occur frequently, when the reservoir inflow is greater than the minimum scheduling threshold set for this month and the inflow for the next three days is not greater than the maximum scheduling threshold set for this month, scheduling is implemented; the minimum scheduling threshold and the maximum scheduling threshold set for June are different from those set for July-August.

[0017] In the preferred plan, in July and August, when the inflow is greater than the maximum set threshold, the focus will be on small and medium-sized flood scheduling, while also taking into account scheduling to suppress algal blooms, to ensure that the reservoir water level rises by no less than the set water level value for at least three consecutive days.

[0018] In a preferred solution, in Step 4, during the scheduling process, the water level is lowered according to the forecast flow after scheduling to avoid water abandonment.

[0019] In the preferred solution, in Step 4, during the scheduling process, a multi-objective optimization algorithm is adopted to comprehensively consider multiple factors such as water quality improvement, water resource utilization, and ecological protection to achieve the optimal decision for ecological scheduling; at the same time, a dynamic feedback mechanism is introduced to adjust the scheduling plan in real time to adapt to changing hydrological conditions and ecological environmental needs.

[0020] In the preferred solution, in Step 4, during the scheduling process, an intelligent prediction model is introduced to predict the occurrence trend of algal blooms in reservoir tributaries, providing a scientific basis for scheduling; at the same time, combined with water environment automatic monitoring technology, the water quality and algal bloom situation of reservoir tributaries are monitored in real time to provide data support for the adjustment of the scheduling plan.

[0021] In the preferred solution, in Step 4, during the scheduling process, a risk assessment system for algal blooms in reservoir tributaries is established, and the priority and urgency of the scheduling plan are determined based on the assessment results to ensure that effective response measures can be taken quickly when algal bloom risks occur, thereby reducing the impact of algal blooms on the ecological environment.

[0022] In the preferred solution, in Step 4, a dynamic update mechanism for risk assessment is introduced during the scheduling process. The risk assessment results are continuously revised and adjusted based on real-time data and hydrological conditions to ensure the pertinence and effectiveness of the scheduling plan. At the same time, an emergency response plan is established to clarify the response measures and disposal processes for algal bloom risks at all levels, thereby improving the ability to respond quickly to algal bloom risks.

[0023] The present invention provides an ecological scheduling method for suppressing algal blooms in reservoir tributaries, which has the following beneficial effects:

[0024] 1. The present invention solves the problem of mismatching constraints in flood control, power generation and shipping in the existing ecological scheduling method.

[0025] 2. The present invention effectively suppresses the occurrence of algal blooms in tributaries and improves the water ecological environment of the reservoir area by precisely regulating the reservoir water level.

[0026] 3. The present invention performs scheduling on the premise of meeting the requirements of flood control, power generation, shipping, etc., and realizes multi-objective collaborative management.

[0027] 4. The scheduling method of the present invention is easy to operate and has high practical application value.

[0028] 5. The implementation cases of the present invention show that compared with traditional methods, this method can significantly improve the ecological and economic benefits of the reservoir area; in addition, the method can be flexibly adjusted according to actual conditions to adapt to the ecological environment and economic development needs of different regions.

[0029] 6. By integrating advanced monitoring technologies and data analysis methods, the present invention realizes real-time monitoring and prediction of algal blooms in reservoir tributaries, provides a scientific basis for ecological scheduling, and further enhances its effectiveness and application scope.

[0030] 7. The scheduling scheme of the present invention also has significant advantages in reducing water resource waste and improving water resource utilization efficiency. Through refined management and optimized scheduling, it achieves sustainable utilization of water resources and provides new ideas and methods for reservoir management.

[0031] 8. The present invention reduces the water level according to the forecast flow after scheduling to avoid water abandonment; at the same time, the scheduling scheme of the present invention also fully considers the needs of the ecological environment, protects the living environment of aquatic organisms through reasonable flow control, and promotes the healthy development of the water ecosystem.

[0032] 9. The present invention adopts a multi-objective optimization algorithm in the scheduling process, and realizes global optimization of task allocation and scheduling by comprehensively evaluating multiple key indicators such as system resource utilization, task execution time and energy consumption; this algorithm can effectively improve the overall performance and efficiency of the system, reduce operating costs, and has good scalability and adaptability.

[0033] 10. This invention introduces a dynamic feedback mechanism into the scheduling process to adjust the scheduling plan in real time to adapt to changing hydrological conditions and ecological and environmental needs. It also introduces advanced monitoring technology to collect and analyze hydrological data in real time to quickly respond to changes in water levels, flow rates, etc. At the same time, we work closely with ecological experts to ensure that the scheduling plan minimizes the negative impact on the ecological environment while ensuring the safe and stable operation of water conservancy facilities.

[0034] 11. The present invention introduces an intelligent prediction model into the scheduling process, which collects and analyzes system data in real time to predict future load changes and resource requirements. This intelligent prediction model can identify potential resource bottlenecks in advance, thereby automatically adjusting resource allocation strategies to ensure efficient operation of the system and maximum utilization of resources.

[0035] 12. The present invention combines water environment automatic monitoring technology in the scheduling process to monitor the water quality and algal bloom of reservoir tributaries in real time, providing data support for the adjustment of scheduling plans; at the same time, the present invention also introduces big data analysis technology to mine and analyze historical data, predict future water quality change trends, and provide a scientific basis for long-term scheduling planning; through this series of technical applications, the present invention can ensure the scientificity and efficiency of reservoir scheduling.

[0036] 13. During the scheduling process, the present invention establishes a risk assessment system for algal blooms in reservoir tributaries. By real-time monitoring of water quality data, combining historical data and meteorological information, and using machine learning and data mining technology, the risk of algal blooms in reservoir tributaries is predicted and assessed. At the same time, combined with the scheduling plan, water resource allocation is optimized, the risk of algal blooms is reduced, and the sustainable use of water resources is ensured.

[0037] 14. The present invention introduces a dynamic update mechanism for risk assessment in the scheduling process. Before each task scheduling, risk assessment is performed and the risk assessment model is updated based on the current state of the system and the specific requirements of the task. By real-time monitoring of various key indicators during task execution, the security and stability of task scheduling are ensured.

[0038] 15. The present invention establishes an emergency response plan, clarifies the response measures and disposal processes for algal bloom risks at all levels, and improves the ability to respond quickly to algal bloom risks; through real-time monitoring of water status, advanced data analysis technology is used to predict the trend of algal bloom occurrence and timely release early warning information; at the same time, it strengthens collaboration with relevant departments to form a joint force to jointly respond to algal bloom risks and ensure the stability and sustainable development of the water ecological environment.

[0039] 16. The present invention integrates multiple technologies such as intelligent scheduling, risk assessment, dynamic update and emergency response to form a comprehensive, efficient and intelligent reservoir scheduling and management system, providing strong technical support for the safe operation of reservoirs and the sustainable use of water resources.

[0040] 17. The present invention also uses big data analysis technology to monitor the entire reservoir scheduling process, collect and analyze scheduling data in real time, discover potential problems and adjust scheduling strategies in a timely manner to ensure the accuracy and reliability of reservoir scheduling; in addition, the present invention also supports remote monitoring and mobile office, which improves the convenience and flexibility of reservoir scheduling management.

[0041] 18. The present invention also introduces a machine learning algorithm to continuously optimize the scheduling strategy to adapt to the reservoir scheduling needs in different seasons and climatic conditions. At the same time, the present invention also takes into account the impact of reservoir scheduling on the surrounding environment and adopts a series of measures to reduce interference with the surrounding ecological environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0043] Figure 1 This is a flow chart of the method for calculating ecological dispatching parameters for suppressing algal blooms in reservoir tributaries according to the present invention;

[0044] Figure 2 This is the annual distribution map of the cumulative frequency of algal blooms in previous years as calculated by the present invention;

[0045] Figure 3 This is a scatter plot of the statistical relationship between the Xiaojiang River water level fluctuation and algae biomass in 2016, 2018, and 2019;

[0046] Figure 4 This is the Xiaojiang algal bloom monitoring point in the embodiment of the present invention;

[0047] Figure 5 The inflow and outflow of the reservoir and the water level in front of the dam during the ecological dispatching period in the embodiment of the present invention;

[0048] Figure 6 is the spawning amount of drifting egg-laying fish in the Yidu section before and after ecological regulation in the embodiment of the present invention;

[0049] Figure 7 This is a relationship diagram between the mean chlorophyll-a value representing the algae biomass and the water level in the river sections (XJ01-XJ03) with severe algal bloom during the scheduling period of the present invention. DETAILED DESCRIPTION

[0050] The technical solutions of the present invention are further described below with reference to the accompanying drawings and embodiments:

[0051] Example 1:

[0052] like Figure 1 As shown, an ecological scheduling method for suppressing algal blooms in reservoir tributaries includes the following steps:

[0053] Step 1: Collect historical data on algal bloom monitoring, including the annual distribution of algal bloom frequency, algal biomass in reservoir tributaries during the bloom monitoring period, reservoir water level, and inflow and outflow data;

[0054] Step 2: Determine the water level fluctuation threshold for inhibiting algal blooms by statistically analyzing the relationship between water level fluctuation and algal biomass;

[0055] Step 3: Based on reservoir operation regulations and inflow and outflow data at different times, calculate whether the water level fluctuation meets the requirements for suppressing algal blooms and determine the time period for implementing bloom suppression operations. During this time period, the reservoir water level is regulated to a predetermined range, causing the water level to rise and fall according to a preset amplitude and frequency, thereby disrupting water temperature stratification and suppressing algal blooms in tributaries.

[0056] Step 4: Analyze the dispatching conditions and implement dispatching on the premise of meeting the requirements of flood control, power generation and shipping.

[0057] In this embodiment, in Step 3, the reservoir water level is regulated to a predetermined range of 145-148 m, and the water level rises at an average daily rate of at least 0.7 m / d for at least three consecutive days.

[0058] Furthermore, in Step 4, the analysis of scheduling conditions includes:

[0059] Step 4.1: For flood control, according to the reservoir's dispatching regulations, when the inflow is less than a preset threshold and the inflow for the next three days does not exceed another preset threshold, dispatch is carried out;

[0060] Step 4.2: Regarding shipping, the water level at the downstream Gezhouba Dam should be ensured not to fall below the preset value during the dispatch process to ensure shipping safety.

[0061] Step 4.3: In terms of power generation, dispatching is carried out under the premise of meeting the peak-shaving needs of the power grid.

[0062] Furthermore, in Step 4, in June, when the reservoir inflow is greater than 18,000 m³ / s and the inflow in the next three days is not greater than 28,000 m³ / s, scheduling is implemented; in July and August, when the inflow is greater than 21,800 m³ / s and the inflow in the next three days is not greater than 28,000 m³ / s, scheduling is implemented.

[0063] Furthermore, in July and August, when the inflow exceeds 35,000 m³ / s, the regulation will focus on small and medium-sized floods, while also taking into account the regulation to suppress algal blooms, to ensure that the reservoir water level rises by at least 2m for at least three consecutive days.

[0064] Furthermore, in Step 4, during the scheduling process, the water level is lowered according to the forecast flow after scheduling to avoid water abandonment.

[0065] Furthermore, in Step 4, during the scheduling process, a multi-objective optimization algorithm is adopted to comprehensively consider multiple factors such as water quality improvement, water resource utilization, and ecological protection to achieve the optimal decision for ecological scheduling; at the same time, a dynamic feedback mechanism is introduced to adjust the scheduling plan in real time to adapt to changing hydrological conditions and ecological environmental needs.

[0066] Furthermore, in Step 4, during the scheduling process, an intelligent prediction model is introduced to predict the occurrence trend of algal blooms in reservoir tributaries, providing a scientific basis for scheduling; at the same time, combined with water environment automatic monitoring technology, the water quality and algal bloom situation of reservoir tributaries are monitored in real time, providing data support for the adjustment of the scheduling plan.

[0067] Furthermore, in Step 4, during the scheduling process, a risk assessment system for algal blooms in reservoir tributaries is established, and the priority and urgency of the scheduling plan are determined based on the assessment results to ensure that effective response measures can be taken quickly when algal bloom risks occur, thereby reducing the impact of algal blooms on the ecological environment.

[0068] Furthermore, in Step 4, a dynamic update mechanism for risk assessment is introduced during the scheduling process. Based on real-time data and hydrological conditions, the risk assessment results are continuously revised and adjusted to ensure the pertinence and effectiveness of the scheduling plan. At the same time, an emergency response plan is established to clarify the response measures and disposal processes for algal bloom risks at all levels, thereby improving the ability to respond quickly to algal bloom risks.

[0069] Example 2:

[0070] In another preferred embodiment, based on the above embodiment 1, Figures 2 to 7 As shown, an ecological scheduling method for suppressing algal blooms in reservoir tributaries, taking the Three Gorges Reservoir as an example, includes the following steps:

[0071] Step 1: Collect historical data on algal bloom monitoring, including the annual distribution of algal bloom frequency. Figure 2 As shown, the algal biomass (chlorophyll a value), water level of the Three Gorges Reservoir, and inflow and outflow data during the algal bloom monitoring period in the Three Gorges Reservoir tributaries;

[0072] Step 2: Count the main periods of algal bloom prevention and control, and analyze the relationship between water level fluctuation and algal biomass through scatter plots, such as Figure 3 As shown in the figure, the water level fluctuation threshold for inhibiting algal blooms is determined; when the daily water level fluctuation is between -1 and 1 m / d, chlorophyll a peaks.

[0073] Step 3: Combined with the Three Gorges Reservoir's operational procedures and inflow and outflow data from different periods, calculate whether water level fluctuations meet the requirements for algal bloom control. Accurately determine the time period for implementing operations to control algal blooms. June through August are ideal for operations to control algal blooms, with July and August focusing on operations for small and medium-sized floods while also taking algal bloom control into account.

[0074] To ensure that algal bloom scheduling is implemented, the initial and final water levels correspond to reservoir capacities V1 and V2, respectively. The inflow over three consecutive days is Q1, Q2, and Q3, respectively, and the duration of these three days is 3 days. To ensure consistent output curves within the scheduling period, the three-day average power generation flow, Q, is equal. Q = (Q1 + Q2 + Q3) / 3 - (V2 - V1) / 3 days. After the water level reaches its highest point, it then recedes to the initial water level within the scheduling regulations, subject to the flow and water level drawdown constraints.

[0075] According to historical monitoring data, the greater the water level rise and the longer it lasts, the lower the algal biomass. When the daily water level rise exceeds 1m / day, the algal biomass remains at a low level; when the daily water level rise approaches 0, the probability of algal biomass peaking is high. According to analysis, there is 3m of scheduling space between 145 and 148m, of which approximately 1m is used for power station peak regulation, and the remaining approximately 2m is used for scheduling. The scheduling period is at least 3 days, so the average daily water level rise is at least 0.7m / day. If conditions permit, the amplitude can be increased and the scheduling time can be extended, as shown in Table 1 below:

[0076] Table 1 Effect of lifting duration on algal biomass

[0077]

[0078] Step 4: Analysis of dispatching conditions: After the water level drops to 145m in June, ecological dispatching will be carried out at an appropriate time during the reservoir storage phase, taking into account the impact on flood control, power generation, and shipping.

[0079] In terms of flood control, according to the latest dispatching regulations of the Three Gorges Dam, the inflow during the flood season is less than 28,000 m³ / s, and the inflow in the next three days will not exceed 30,000 m³ / s. The water levels in Shashi and Chenglingji are lower than 41m and 30.5m respectively. There will be no moderate or above rainfall in the next three days, and the water level can fluctuate between 145m and 148m. In terms of shipping, the minimum discharge flow of Gezhouba Dam should meet the requirement that the water level of Miaozui downstream of Gezhouba Dam is not lower than 39.0m, that is, the discharge flow should be greater than 6,000 m³ / s. In August, the average daily outflow of the Three Gorges Reservoir should be no less than 18,000 m³ / s as much as possible. When the inflow is less than or equal to 18,000 m³ / s, the discharge will be based on the inflow. In terms of power generation, the main consideration is the peak-shaving effect of the Three Gorges Power Station on the power grid. The daily peak-shaving volume from 2019 to June 2021 is counted. In recent years, the peak-shaving volume of the power grid has increased year by year. The average peak-shaving volume in June 2021 was 4.43 million KW, and the maximum peak-shaving volume was 7.2 million KW.

[0080] Under the premise of meeting flood control and power generation requirements, when the Three Gorges reservoir inflow is less than 28,000 m³ / s and does not exceed 30,000 m³ / s over the next three days, the water level in June is generally between 145 and 148 m. Every 1-meter rise in the water level corresponds to an increase in reservoir capacity of approximately 500 million m³. Statistics show that the minimum power generation flow during the mid-to-late June period from 2019 to 2021 was 7,932 m³ / s. To meet extreme peak-shaving requirements and meet the minimum power generation flow, a 2-meter rise in the reservoir water level over three days requires a three-day average inflow of at least 17,977 m³ / s. This flow is the minimum flow required for operation. When the initial water level is above 146 m, the operation process may briefly exceed 148 m. Furthermore, to ensure that water is not abandoned during the later stages of operation, the water level should be reduced according to the forecasted flow after operation, with the prevention of water abandonment as a condition for implementing algal bloom operation.

[0081] From July to August, when the inflow is less than 28,000 m³ / s, according to the scheduling method of June, on the basis of satisfying the water level rising by 2m within three days, the discharge flow should also be at least greater than 18,000 m³ / s. Therefore, the three-day average inflow is at least 21,858 m³ / s. When the inflow reaches 28,000 m³ / s and the inflow does not exceed 35,000 m³ / s in the next three days, according to the scheduling regulations, the maximum water level shall not exceed 146.5m. If scheduling is carried out, the water level limit will be exceeded. When the inflow is greater than 35,000 m³ / s in the next three days, it will be scheduled according to small and medium-sized floods. When intercepting and storing floods, the water level can rise by 2m within three days.

[0082] Step 5: Summarize the phased (flow) and hierarchical scheduling schemes, as shown in Table 2:

[0083] In mid-to-late June, the algae biomass reached 30μg / L, and the affected area reached 2km or more. When the inflow into the Three Gorges Reservoir was greater than 18,000m³ / s and the inflow in the next three days was no more than 28,000m³ / s, the reservoir water level would rise by at least 2m in three days and then drop to the flood limit water level.

[0084] From July to August, the algae biomass reaches 30μg / L, and the affected area reaches 2km or more. When the inflow into the Three Gorges Reservoir is greater than 21,800m³ / s and the inflow in the next three days is no more than 28,000m³ / s, the reservoir water level will rise by at least 2m in three days and then drop to the flood limit water level. If conditions permit, it will be implemented at least 3m in three days.

[0085] From July to August, the algae biomass reached 30μg / L, and the affected range reached 2km and above. The inflow was greater than 35,000m³ / s. The scheduling was mainly for small and medium-sized floods, while also taking into account the scheduling to suppress algal blooms. The reservoir water level rose by at least 2m every three days.

[0086] From July to August, the algae biomass reaches 30μg / L, and the impact range reaches 2km or more. When the inflow into the Three Gorges Reservoir is greater than 28,000m³ / s and the inflow in the next three days is no more than 35,000m³ / s, according to the scheduling regulations, the Three Gorges Reservoir will not exceed 146.5m. When there is a flood control demand downstream, ecological scheduling to suppress algal blooms can be implemented as appropriate.

[0087] Table 2 Scheduling plan

[0088]

[0089] Example 3:

[0090] In another preferred embodiment, based on the above embodiment 2, as Figure 3 、 4 As shown, the Three Gorges Reservoir has carried out ecological regulation that takes into account both promoting the natural reproduction of the four major carps and preventing and controlling algal blooms in the reservoir tributaries. Artificial monitoring is carried out in Xiaojiang, a tributary with serious algal blooms. The monitoring indicators include five conventional water parameters, nitrogen and phosphorus nutrients, and algal biomass. During the regulation period, the maximum inflow of the Three Gorges Reservoir was 37,000 m³ / s (20:00 on the 27th), the minimum inflow was 20,800 m³ / s (2:00 on the 23rd), and the average inflow was 28,000 m³ / s; the maximum outflow was 31,700 m³ / s (20:00 on the 28th), the minimum outflow was 19,200 m³ / s (2:00 on the 23rd), and the average outflow was 24,300 m³ / s.

[0091] During the dispatching process, it was monitored that blue algae bloom occurred in Xiaojiang Reservoir Bay, and the serious river section (XJ01-XJ03 from Xiaojiang River estuary to Huangshi Town) Figure 4 As shown in the figure, the average chlorophyll a concentration in the surface layer of the water reached 58.33 μg / L.

[0092] More than 14,000 fish eggs were collected from the Yichang to Yidu section of the river, with an estimated total egg runoff of 15.3 billion, of which about 8.8 billion were from the four major fish species. The peak spawning season was mainly on June 28, with an average daily total egg density of 7,000 eggs per 1,000 m 3 .

[0093] During the operation, the water level of the Three Gorges Reservoir ranged from 145.53 to 145.74 meters. During the ecological operation period for algal bloom prevention and control, the water level continued to rise, from 145.8 to 148.54 meters. The water level rose by 2.74 meters over three days, with an average daily increase of 0.91 meters. The water level rose by 0.67 meters, 0.92 meters, and 0.99 meters over the three days, respectively. The largest increase occurred on the third day, after which the water level stabilized.

[0094] As the water level rose, the average chlorophyll-a concentration in the severely affected river section showed a decreasing trend, dropping to around 10 μg / L on the first day after the operation ended. The severe algal bloom in the 6 km section from Shuangjiang Bridge at the Xiaojiang River estuary to Huangshi Town in Yunyang County basically subsided. The daily average chlorophyll-a value in the severely affected river section (XJ-HS section) was significantly negatively correlated with the water level, with a determination coefficient R ² The monitoring results show that reservoir regulation during the flood season has a good inhibitory effect on the algal bloom in Xiaojiang River.

[0095] This ecological dispatch is a coordinated dispatch that takes into account both promoting fish reproduction and preventing and controlling algal blooms in tributaries. It is calculated that the power generation increased by approximately 81 million kWh compared with conventional dispatch, fully realizing the ecological and economic benefits of the Three Gorges Reservoir.

[0096] In the preferred solution, in Step 3, the reservoir water level is regulated to a predetermined range, and the water level rises at a daily average rate of not less than the set value for at least three consecutive days. The above setting ensures the stability and reliability of water level changes and effectively avoids misjudgments due to accidental factors. At the same time, this setting also takes into account climate change and seasonal factors, making water level management more scientific and reasonable.

[0097] In the preferred solution, in Step 4, in June and July to August when algal blooms frequently occur, when the reservoir inflow is greater than the minimum scheduling threshold set for this month and the inflow for the next three days is not greater than the maximum scheduling threshold set for this month, scheduling is implemented. The minimum scheduling threshold and the maximum scheduling threshold set for June are different from those for July to August. The above settings can ensure that the reservoir is reasonably scheduled during the high incidence period of algal blooms, thereby ensuring the reservoir water storage capacity and avoiding the outbreak of algal blooms due to excessive water volume.

[0098] In the preferred scheme, in July and August, when the inflow is greater than the highest set threshold, the scheduling will be mainly for small and medium-sized floods, while taking into account the scheduling to suppress algal blooms, to ensure that the reservoir water level rises by no less than the set water level value for at least three consecutive days; the above settings can, through reasonable scheduling when the water volume in the reservoir is large, reduce flood control pressure and effectively suppress the occurrence of algal blooms; in addition, when the inflow continues to be lower than the lowest set threshold, water-saving scheduling will be implemented to cope with possible droughts.

[0099] In the preferred solution, in Step 4, during the scheduling process, the water level is drawn down based on the predicted flow rate after scheduling to avoid water abandonment. This setup ensures the safe operation of the reservoir while fully utilizing water resources. Furthermore, a real-time monitoring module has been integrated into the system to promptly identify and resolve potential issues, ensuring the smooth progress of the entire scheduling process.

[0100] In the preferred solution, in Step 4, during the scheduling process, a multi-objective optimization algorithm is adopted to comprehensively consider multiple factors such as water quality improvement, water resource utilization, and ecological protection to achieve the optimal decision for ecological scheduling; at the same time, a dynamic feedback mechanism is introduced to adjust the scheduling plan in real time to adapt to changing hydrological conditions and ecological environmental needs; the above settings effectively improve the flexibility and adaptability of scheduling, and ensure the scientific nature and effectiveness of the scheduling plan; in addition, it also strengthens collaboration with other relevant departments to jointly promote the sustainable utilization of water resources and the protection of the ecological environment.

[0101] In the preferred solution, in Step 4, during the scheduling process, an intelligent prediction model is introduced to predict the occurrence trend of algal blooms in reservoir tributaries, providing a scientific basis for scheduling; at the same time, combined with water environment automatic monitoring technology, the water quality and algal bloom situation of reservoir tributaries are monitored in real time to provide data support for the adjustment of the scheduling plan; the above settings ensure the accuracy and timeliness of the scheduling process, effectively reduce the risk of algal blooms, and ensure the water ecological security of the reservoir and its surrounding areas; at the same time, this also provides reference experience and methods for similar reservoir management.

[0102] In the preferred solution, in Step 4, during the scheduling process, a reservoir tributary algal bloom risk assessment system is established, and the priority and urgency of the scheduling plan are determined based on the assessment results, ensuring that effective response measures can be taken quickly when algal bloom risks occur to reduce the impact of algal blooms on the ecological environment. The above settings achieve optimal allocation of water resources and protection of the ecological environment through refined management and timely response. At the same time, the solution also takes into account the coordinated development of reservoir scheduling and the surrounding environment, promoting a win-win situation for ecology and economy.

[0103] In the preferred solution, in Step 4, a dynamic update mechanism for risk assessment is introduced during the scheduling process. The risk assessment results are continuously revised and adjusted based on real-time data and hydrological conditions to ensure the pertinence and effectiveness of the scheduling plan. At the same time, an emergency response plan is established to clarify the response measures and disposal processes for algal bloom risks at all levels, thereby improving the ability to respond quickly to algal bloom risks. The above settings will greatly enhance the flexibility and reliability of the scheduling system, provide strong guarantees for responding to complex and changing hydrological environments, and reduce the impact of algal bloom risks on ecosystems and water resource security.

[0104] In summary, the present invention provides an ecological scheduling method for suppressing algal blooms in reservoir tributaries, which solves the problem of mismatch of constraints in flood control, power generation, and shipping in the existing ecological scheduling methods; by precisely controlling the reservoir water level, the occurrence of algal blooms in tributaries is effectively suppressed, and the water ecological environment of the reservoir area is improved; scheduling is performed under the premise of meeting the requirements of flood control, power generation, shipping, etc., and multi-objective collaborative management is achieved; and the ecological scheduling method is simple to operate and low in cost, and is suitable for the management of algal blooms in various reservoir tributaries; the present invention is of great significance for maintaining the ecological balance of reservoirs and promoting the sustainable use of water resources; in addition, the present invention can also serve as an important supplement to reservoir management strategies, provide a scientific basis for reservoir management, further promote the development of reservoir management in a scientific, refined and intelligent direction, and achieve a comprehensive improvement in the ecological, economic and social benefits of the reservoir; the implementation of the present invention not only enhances the ability of the reservoir to respond to algal bloom events, but also improves the overall operation efficiency and resource utilization efficiency of the reservoir through multi-objective collaborative management, laying a solid foundation for achieving sustainable development of the reservoir. At the same time, the application of this ecological scheduling method can also promote the research and development and innovation of related technologies, and provide strong support for technological progress in the field of reservoir management; in the future, with the continuous development and improvement of technology, it is believed that the ecological scheduling method of the present invention will play a more important role in reservoir management.

Claims

1. An ecological dispatching method for suppressing algal bloom in reservoir tributaries, characterized in that: The method comprises the following steps: Step 1: Collect historical data on algal bloom monitoring, including the annual distribution of algal bloom frequency, algal biomass in reservoir tributaries during the bloom monitoring period, reservoir water level, and inflow and outflow data; Step 2: Determine the water level fluctuation threshold for inhibiting algal blooms by statistically analyzing the relationship between water level fluctuation and algal biomass; Step 3: Based on reservoir operation regulations and inflow and outflow data at different times, calculate whether the water level fluctuation meets the requirements for suppressing algal blooms and determine the time period for implementing bloom suppression operations. During this time period, the reservoir water level is regulated to a predetermined range, causing the water level to rise and fall according to a preset amplitude and frequency, thereby disrupting water temperature stratification and suppressing algal blooms in tributaries. Step 4: Analyze dispatching conditions and implement dispatching while meeting flood control, power generation, and shipping requirements; During the scheduling process, a multi-objective optimization algorithm is used to comprehensively consider multiple factors, including water quality improvement, water resource utilization, and ecological protection, to achieve the optimal decision for ecological scheduling. At the same time, a dynamic feedback mechanism is introduced to adjust the scheduling plan in real time to adapt to changing hydrological conditions and ecological and environmental needs. During the dispatching process, an intelligent prediction model is introduced to predict the occurrence trend of algal blooms in reservoir tributaries, providing a scientific basis for dispatching. At the same time, combined with automatic water environment monitoring technology, the water quality and algal bloom situation of reservoir tributaries are monitored in real time, providing data support for the adjustment of dispatching plans. During the scheduling process, a risk assessment system for algal blooms in reservoir tributaries will be established, and the priority and urgency of the scheduling plan will be determined based on the assessment results to ensure that effective response measures can be taken quickly when algal bloom risks occur, thereby reducing the impact of algal blooms on the ecological environment.

2. The ecological scheduling method for suppressing algal bloom in reservoir tributaries according to claim 1, characterized in that: In Step 3, the reservoir water level is regulated to a predetermined range, and the water level rises at a daily average rate of not less than the set level for at least three consecutive days.

3. The ecological scheduling method for suppressing algal bloom in reservoir tributaries according to claim 1, characterized in that: In Step 4, the analysis of scheduling conditions includes: Step 4.1: For flood control, according to the reservoir's dispatching regulations, when the inflow is less than a preset threshold and the inflow for the next three days does not exceed another preset threshold, dispatch is carried out; Step 4.2: Regarding shipping, the water level at the downstream Gezhouba Dam should be ensured not to fall below the preset value during the dispatch process to ensure shipping safety. Step 4.3: In terms of power generation, dispatching is carried out under the premise of meeting the peak-shaving needs of the power grid.

4. The ecological dispatching method for suppressing algal bloom in reservoir tributaries according to claim 1, characterized in that: In Step 4, in June and July-August, when algal blooms frequently occur, when the reservoir inflow is greater than the minimum scheduling threshold set for the current month and the inflow for the next three days is no greater than the maximum scheduling threshold set for the current month, scheduling is implemented. The minimum scheduling threshold and the maximum scheduling threshold set for June are different from those for July-August.

5. The ecological dispatching method for suppressing algal bloom in reservoir tributaries according to claim 4, characterized in that: In July and August, when the inflow is greater than the maximum set threshold, the focus will be on small and medium-sized flood regulation, while also taking into account the regulation of suppressing algal blooms to ensure that the reservoir water level rises by no less than the set water level value for at least three consecutive days.

6. The ecological dispatching method for suppressing algal bloom in reservoir tributaries according to claim 1, characterized in that: In Step 4, during the scheduling process, the water level is lowered according to the forecast flow after scheduling to avoid water abandonment.

7. The ecological dispatching method for suppressing algal bloom in reservoir tributaries according to claim 1, characterized in that: In Step 4, a dynamic update mechanism for risk assessment is introduced during the scheduling process. Based on real-time data and hydrological conditions, the risk assessment results are continuously revised and adjusted to ensure the pertinence and effectiveness of the scheduling plan. At the same time, an emergency response plan is established to clarify the response measures and disposal processes for algal bloom risks at all levels, thereby improving the ability to respond quickly to algal bloom risks.

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