Reservoir flood season water level dynamic control method and reservoir flood season water level dynamic control device

Abstract

The application provides a reservoir flood season water level dynamic control method and a reservoir flood season water level dynamic control device, relates to the reservoir flood season management technical field, and provides the reservoir flood season water level dynamic control method, which comprises the following steps: obtaining typhoon data, weather forecasts and rainfall runoff forecasts of a reservoir for several years; determining a typhoon available forecast prediction period according to the typhoon data; determining a weather forecast available prediction period and a forecast rainfall grade according to the weather forecasts; determining a rainfall runoff forecast available prediction period according to the rainfall runoff forecasts; coupling analysis of the typhoon available forecast prediction period, the weather forecast available prediction period, the forecast rainfall grade and the rainfall runoff forecast available prediction period; and dynamically regulating and controlling the reservoir flood season water level according to the coupling analysis result. The reservoir flood season water level dynamic control method and the device make full use of meteorological elements in coastal areas, improve the reservoir flood prediction period in the coastal areas, and can increase the comprehensive utilization benefit of the reservoir.

Description

Technical Field

[0001] This invention relates to the field of reservoir flood season management technology, and in particular to a method and equipment for dynamic control of reservoir water level during the flood season. Background Technology

[0002] To improve the utilization rate of flood resources and the full storage rate of reservoirs, and to effectively leverage the comprehensive benefits of existing reservoir projects, the Ministry of Water Resources has proposed optimizing the scheduling and operation of water conservancy projects, steadily implementing dynamic control of reservoir flood control levels, improving and optimizing flood forecasting, increasing forecast accuracy, extending the lead time, and rationally utilizing rainwater and flood resources. Currently, the methods for dynamic control of reservoir water levels during the flood season are mostly based on reservoir rainfall-runoff forecasts. However, for coastal areas, due to unique topography leading to short and rapid river sources, and with rainfall often originating from typhoons, the lead time for rainfall-runoff forecasts is short, making it difficult to meet the requirements for dynamic control of reservoir water levels during the flood season. This is mainly reflected in the following aspects: (1) Coastal rivers that flow directly into the sea are short, have rapid currents, small drainage areas, and large riverbed gradients. Forecasting operations begin when measured rainfall occurs, and the forecast period for rainfall and runoff is mostly 4-8 hours. Considering the time required for issuing dispatch instructions, notifying upstream and downstream areas, and opening and closing reservoir gates, short-term rainfall and runoff forecasts are difficult to meet the requirements for dynamic water level control during the flood season.

[0003] (2) Weather forecasts can be extended appropriately, and operational forecasts can be made from the start of the weather system that produces rainfall. Considering the accuracy requirements, 24-hour weather forecasts are mostly used. Due to the rapid rise and fall of floods caused by the rainstorms formed by typhoon weather systems, the upper limit of the reservoir dynamic control during the flood season is limited. Moreover, the forecast information available by using only a single weather forecast is not comprehensive, and the comprehensive utilization benefits of the reservoir are not significant.

[0004] (3) Coastal areas are greatly affected by typhoons. Due to the lack of existing technology to use typhoon information for dynamic control of reservoir water levels during the flood season, the water levels of reservoirs in coastal areas that are responsible for flood control are low during the flood season, resulting in a decrease in the comprehensive utilization rate of reservoirs. Summary of the Invention

[0005] The purpose of this invention is to provide a method and equipment for dynamic control of reservoir water level during the flood season, so as to alleviate the technical problem that reservoirs in coastal areas cannot fully realize their comprehensive utilization benefits during the flood season in the prior art.

[0006] In a first aspect, the method for dynamic control of reservoir water level during the flood season provided by the present invention includes the following steps: Obtain typhoon data, weather forecasts, and rainfall-runoff forecasts for the reservoir location over a period of several years; Determine the forecast period for typhoon availability based on typhoon data over a certain number of years; Based on the weather forecast, determine the available forecast period and the forecast rainfall level; Determine the available lead time for rainfall and runoff forecasts based on rainfall and runoff forecasts; A coupled analysis was performed on the available forecast period for typhoons, the available forecast period for weather, the forecast rainfall level, and the available forecast period for rainfall and runoff. Dynamic regulation of reservoir water levels during the flood season is carried out based on the results of coupling analysis.

[0007] In conjunction with the first aspect, the present invention provides a first possible implementation of the first aspect, wherein the method for dynamic control of reservoir water level during the flood season further includes: performing phased processing of the flood season; The steps for dynamically regulating the reservoir's flood season water level based on the coupling analysis results include: Set separate upper and lower limits for water levels for each phase and period of the flood season; Based on the results of the coupling analysis, the water level was dynamically adjusted for each flood season period.

[0008] In conjunction with the first possible implementation of the first aspect, the present invention provides a second possible implementation of the first aspect, wherein the step of dividing the flood season into periods includes: dividing the flood season into time periods according to differences in meteorological causes; and / or using the moment of abrupt change in the meteorological conditions of the flood season as the time period division point.

[0009] In conjunction with the first aspect, the present invention provides a third possible implementation of the first aspect, wherein the step of determining the typhoon availability forecast period based on typhoon data over a certain number of years includes: Calculate the minimum time interval between the formation of a typhoon and the peak of the floodwaters at the reservoir; The typhoon forecast period closest to the minimum time interval was obtained through comparison; The maximum value between the typhoon forecast period and the minimum time interval is selected and used as the first available forecast period for the typhoon.

[0010] In conjunction with the third possible implementation of the first aspect, the present invention provides a fourth possible implementation of the first aspect, wherein the step of determining the available forecast period of a typhoon based on typhoon data further includes: taking the sum of the time from the formation of the typhoon to the forecast landfall time, the time for determining the rainfall level in the typhoon forecast, and the forecast period for rainfall and runoff as a second alternative available forecast period of a typhoon. Based on the typhoon forecast, real-time corrections are made to the time from the formation of the typhoon to the predicted landfall, the time for determining the rainfall level in the typhoon forecast, the forecast lead time for rainfall and runoff, and the available lead time for the second alternative typhoon is updated.

[0011] In conjunction with the fourth possible implementation of the first aspect, the present invention provides a fifth possible implementation of the first aspect, wherein the step of determining the available forecast period of a typhoon based on typhoon data further includes: comparing and selecting the minimum value between the first candidate available forecast period of a typhoon and the second candidate available forecast period of a typhoon, and using it as the corrected available forecast period of a typhoon.

[0012] In conjunction with the first aspect, the present invention provides a sixth possible implementation of the first aspect, wherein the step of determining the available forecast period and the forecast rainfall level based on the weather forecast includes: comparing the relationship between the weather forecast and the actual rainfall at different times during the typhoon; selecting the maximum value among the time periods with a forecast accuracy greater than a preset accuracy as the available forecast period, and determining the corresponding forecast rainfall level.

[0013] In conjunction with the first aspect, the present invention provides a seventh possible implementation of the first aspect, wherein the step of determining the available forecast period of rainfall-runoff forecast based on rainfall-runoff forecast includes: calculating the average runoff forecast period of rainfall-runoff forecast based on rainfall-runoff forecasts over a number of years.

[0014] In conjunction with the seventh possible implementation of the first aspect, the present invention provides an eighth possible implementation of the first aspect, wherein the step of performing coupled analysis on the typhoon availability forecast lead time, the weather forecast availability lead time, the forecast rainfall level, and the rainfall-runoff forecast availability lead time includes: calculating the total lag time for flood control information transmission and gate operation; if the difference between the average runoff lead time and the total lag time is less than or equal to a preset grace period, then the rainfall-runoff forecast availability lead time is ignored during the flood season water level control process.

[0015] Secondly, the reservoir flood season water level dynamic control device provided by the present invention is used to execute the above-mentioned reservoir flood season water level dynamic control method, or the reservoir flood season water level dynamic control device is used to store a computer program for executing the reservoir flood season water level dynamic control method.

[0016] The embodiments of the present invention bring the following beneficial effects: by acquiring typhoon data, weather forecasts, and rainfall-runoff forecasts for a certain number of years in the reservoir location, the available forecast period for typhoons is determined based on the typhoon data for a certain number of years, the available forecast period for weather forecasts and the forecast rainfall level are determined based on the weather forecasts, and the available forecast period for rainfall-runoff forecasts is determined based on the rainfall-runoff forecasts. The available forecast period for typhoons, the available forecast period for weather forecasts, the forecast rainfall level, and the available forecast period for rainfall-runoff forecasts are coupled and analyzed. Based on the results of the coupling analysis, the reservoir's water level during the flood season is dynamically regulated. This fully utilizes the meteorological elements of the coastal area, improves the flood forecast period of reservoirs in the coastal area, and increases the comprehensive utilization benefits of the reservoir.

[0017] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 A flowchart illustrating the dynamic water level control method for reservoirs during the flood season provided in this embodiment of the invention; Figure 2 This is a flowchart illustrating the process of determining the forecast period for typhoon availability based on typhoon data over several years in the dynamic water level control method for reservoirs during the flood season, as provided in this embodiment of the invention. Detailed Implementation

[0020] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Physical quantities in formulas, unless otherwise specified, should be understood as basic quantities in the International System of Units (SI), or derived quantities derived from basic quantities through mathematical operations such as multiplication, division, differentiation, or integration.

[0022] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0023] like Figure 1 As shown in the figure, the reservoir flood season water level dynamic control method provided by the present invention includes the following steps: acquiring typhoon data, weather forecasts, and rainfall-runoff forecasts for a certain number of years in the reservoir location; determining the available forecast period for typhoons based on the typhoon data for a certain number of years; determining the available forecast period for weather forecasts and the forecast rainfall level based on the weather forecasts; determining the available forecast period for rainfall-runoff forecasts based on the rainfall-runoff forecasts; performing a coupling analysis on the available forecast period for typhoons, the available forecast period for weather forecasts, the forecast rainfall level, and the available forecast period for rainfall-runoff forecasts; and dynamically regulating the reservoir flood season water level based on the coupling analysis results.

[0024] During the flood season water level dynamic control of a large reservoir in Hainan, 45 years of measured typhoon, hydrological station (rain gauge) rainfall, and flood data from the reservoir's basin can be collected to create historical typhoon path maps. Floods with a return period of 2 years or more are considered major floods. Based on long-term typhoon, rainfall, and flood data, the location of typhoon formation centers can be statistically analyzed, along with characteristic indicators such as the time interval between typhoon formation and reservoir flood peak generation.

[0025] In the formula: This refers to the time when the flood peak occurs at the reservoir. The time of typhoon formation that caused the flood event; n is the total number of flood events; , , These represent the average, maximum, and minimum time intervals from the formation of the typhoon to the peak floodwaters generated by the reservoir.

[0026] Using the reservoir flood season water level dynamic control method provided by the implementing party, the patterns of typhoons, rainstorms, and floods were studied and analyzed. From the perspective of engineering safety, a preliminary typhoon forecast lead time was selected, and the selected lead time was verified by using typhoon forecast results from recent years. A coupled forecasting method combining typhoon, weather, and rainfall-runoff was proposed to fully utilize various forecasting methods, thereby improving the flood lead time for reservoirs in coastal areas.

[0027] In this embodiment of the invention, the method for dynamic control of reservoir water level during the flood season further includes: dividing the flood season into stages; and dynamically regulating the reservoir water level during the flood season based on the coupling analysis results, including: setting upper and lower limits for water levels for each flood season period; and dynamically adjusting the water level for each flood season period based on the coupling analysis results.

[0028] Specifically, the steps for dividing the flood season into periods include: dividing the flood season into time periods based on differences in meteorological causes; and / or using the moment of abrupt change in the quantitative meteorological conditions during the flood season as the time period division point.

[0029] Flood seasons in reservoirs can be divided into one phase (flood season), two phases (main flood season, pre-flood season, or post-flood season), or three phases (pre-flood season, main flood season, and post-flood season). To facilitate reservoir operation, the flood season should not be divided into more than three phases. Based on the variation patterns of flood peak and flood volume in the basin where the reservoir is located, the flood season phases are determined through a comprehensive analysis using methods such as meteorological factors and mathematical statistics, combined with the impact of reservoir operation.

[0030] Meteorological causal analysis method: By analyzing the meteorological factors that affect the dynamic conditions and water vapor supply conditions of the basin at different stages of the flood season, and based on the changing patterns of the flood season in the basin, different meteorological causal factors are used as the dividing points for the flood season.

[0031] Mathematical statistics method: Using long-term series of rainfall and flood measurement data, calculate statistical indicators such as the probability of the annual maximum flood and the proportion of rainfall in each month of the flood season to the whole year, and plot the flood peak scatter map. The flood season is divided by statistical indicators and abrupt change points in the scatter map.

[0032] For example, when analyzing the flood season of a large reservoir in Hainan Province, the meteorological causal analysis method was used as follows: The reservoir's flood season is from June to October. Analysis of typhoon, rainfall, and flood data from 1972 to 2016 (45 years) revealed that all floods during the reservoir's flood season were caused by typhoons. From June to September, there were slightly more typhoons in the South China Sea. Summer typhoons occur in high-energy environmental fields, and the seasonal northward shift of the Intertropical Convergence Zone (ITCZ) and the activity of tropical weather systems such as the southwest monsoon contribute to the combined effects of summer typhoon systems and other tropical weather systems. Combined with the influence of mountainous terrain, this results in strong, widespread, and prolonged heavy rainfall in the reservoir's basin. October is dominated by typhoons in the Northwest Pacific, while late autumn typhoons and rainstorms occur in low-energy environmental fields. If combined with weak cold air from the north, the intensity of the heavy rainfall can increase, but the rainfall intensity and the affected area are relatively smaller. Therefore, there are meteorological causal flood phases in June-September and October.

[0033] The process of dividing the reservoir into periods using mathematical statistics is as follows: Based on statistical analysis of 45 years of long-term data, the probability of the annual maximum flood occurring in June, July, August, September, and October is 6.7%, 22.2%, 22.2%, 22.2%, and 17.8%, respectively. The proportion of rainfall in each month to the annual total is 13.8%, 16.3%, 18.8%, 18.9%, and 12.9%, respectively. Simultaneously, the annual and monthly maximum flood peak flow distribution maps of the reservoir were plotted. It can be seen that the rainfall and flood magnitude are significantly larger from July to September, while June and October are roughly equivalent. Based on mathematical statistics, July to September is the main flood season, and June and October can be divided into the pre-flood season and the post-flood season.

[0034] Furthermore, a combination of mathematical statistics and meteorological causal analysis can be used. Taking the aforementioned reservoir phasing as an example, considering the convenience of reservoir scheduling, more phasing makes scheduling more complex and increases risks. June, as the pre-flood season, has little impact on the reservoir's end-of-flood storage, while October, as the post-flood season, is conducive to end-of-flood storage, affecting the reservoir's comprehensive utilization benefits. Based on mathematical statistics and causal analysis, the main influence is from typhoons in the South China Sea from June to September, while October is mainly influenced by typhoons in the Northwest Pacific. Therefore, through causal analysis, mathematical statistics analysis, and comprehensive analysis of the impact on reservoir scheduling, the flood season of Dalong Reservoir is determined to be divided into two phases: the main flood season from June to September and the post-flood season in October.

[0035] like Figure 1 and Figure 2 As shown, the steps for determining the usable forecast period for typhoons based on typhoon data over several years include: calculating the minimum time interval from typhoon formation to reservoir flood peak; comparing and obtaining the typhoon forecast period closest to the minimum time interval; and selecting the maximum value between the typhoon forecast period and the minimum time interval, using it as the first alternative usable forecast period for typhoons. It should be noted that, to ensure dispatch safety and data representativeness, the typhoon and flood analysis data used for typhoon usability forecast grading should be at least 30 years.

[0036] In practical applications, the sum of the time from the formation of the typhoon to the predicted landfall time, the time for the typhoon forecast to determine the rainfall level, and the forecast period for rainfall and runoff is used as the second available forecast period for the typhoon. At the same time, the time from the formation of the typhoon to the predicted landfall time, the time for the typhoon forecast to determine the rainfall level, and the forecast period for rainfall and runoff are adjusted in real time based on the typhoon forecast, and the second available forecast period for the typhoon is updated.

[0037] The minimum value between the first and second candidate typhoon availability forecast periods is selected and used as the revised availability forecast period for typhoons.

[0038] Specifically, through analysis and research on actual typhoon, rainfall, and flood patterns, and considering reservoir operation safety, the typhoon forecast lead time is determined by the shortest historically measured time interval—the interval between typhoon formation and the minimum flood peak at the reservoir. Taking into account operational forecasting time intervals, the selected typhoon forecast lead time is comprehensively considered. The following methods can generally be used to preliminarily determine this: The primary goal is to find the minimum time interval between the formation of a typhoon and the peak of a flood in a reservoir. The time period closest to the typhoon forecast: The minimum value in the formula corresponds to i Value i d , T tp The lead time can be used for typhoon forecasting; △t This refers to the time interval for typhoon operation forecasts. tmax This refers to the forecast period. For example, if the typhoon forecast information is currently released for 24 hours, 48 ​​hours, 72 hours, 96 hours, and 120 hours, then... △t =24h, tmax =5. This is then integrated with the typhoon operation forecast period to determine the typhoon's exploitable forecast period. For example, the reservoir in Hainan. T dmin =45h, i d =2, then T tp =48h.

[0039] In addition to determining the reservoir's scheduling forecast period, it is also necessary to determine the activation conditions for scheduling. This implementation method fully utilizes typhoon forecast information, using the forecast rainfall level during the typhoon as the scheduling criterion. Because the accuracy of typhoon forecasts has improved year by year, and recent data is more representative, it is recommended to select typhoon forecast and actual typhoon data from the past 10-20 years, analyze and select the rainfall level during the typhoon forecast period (no rain or scattered light rain, light rain, moderate rain, heavy rain, torrential rain, extremely heavy rain, and exceptionally heavy rain). Generally, rainfall levels with an accuracy rate of over 80% are considered to meet the accuracy requirements. The typhoon forecast rainfall level can be comprehensively selected from the perspectives of engineering safety margin, reservoir dynamic control safety, and reliability. In Hainan, the rainfall level of the torrential rain during the typhoon during this reservoir meets the accuracy requirements. From a safety perspective, the level is lowered by one, i.e., the level of torrential rain or above during the typhoon is used as the activation condition for reservoir dynamic control.

[0040] Typhoon forecasts, typically selected from long-term data, can utilize the lead time. It is relatively representative, but the possibility of extreme values ​​in the future cannot be ruled out. In order to ensure the safety of reservoir operation, the forecast period for typhoon utilization is determined after being revised according to the real-time typhoon forecast.

[0041]

[0042]

[0043] in, For the real-time forecast lead time of typhoons, In preparation for the period from the formation of a typhoon to its predicted landfall time, The timing for determining rainfall levels is part of the typhoon forecast. For the forecast period of rainfall and runoff, The forecast lead time can be used to make real-time corrections to typhoons.

[0044] For example, analysis of actual typhoon and rainfall data from the past 10 years shows that the shortest time from typhoon formation to significant flooding in reservoirs was Typhoon Dianmu in 2016. This typhoon was used to test the effectiveness of selecting usable forecast periods for typhoons. At that time, the forecast time from typhoon formation to landfall was 49 hours, the forecast time for heavy rainfall was 24 hours, and the forecast time for rainfall and runoff was 6 hours. T tps =79h, far less than the available forecast time for the first alternative typhoon. T tp =48h, indicating that the results of the long-series data analysis are highly representative, thus determining =48h.

[0045] Furthermore, the steps for determining the available lead time and forecast rainfall level based on weather forecasts include: comparing the relationship between weather forecasts and actual rainfall at different times during the typhoon period; selecting the maximum value among the time periods with forecast accuracy greater than the preset accuracy as the available lead time for weather forecasts, and determining the corresponding forecast rainfall level.

[0046] For example, we collect long-term weather forecast data (24h, 48h, and 72h) issued by meteorological departments, compare and analyze them with actual rainfall, and evaluate the accuracy of weather forecasts. We focus on analyzing the differences between weather forecasts and actual rainfall at different times during typhoons, using forecasts with higher accuracy (over 80%) as a basis to select the available forecast lead time and forecast rainfall level, thus determining a 24-hour available forecast lead time for reservoir weather.

[0047] Furthermore, the steps for determining the available lead time of rainfall-runoff forecasts based on rainfall-runoff forecasts include: calculating the average lead time of rainfall-runoff forecasts based on runoff forecasts over several years.

[0048] In this embodiment, the rainfall-runoff forecast uses the Xin'anjiang model with three water sources or other verified hydrological forecasting models that meet the accuracy requirements. The timing of the measured rainfall peak and the timing of the inflow flood peak in the basin above the reservoir dam site are analyzed to select the available lead time for rainfall-runoff forecasting.

[0049] Furthermore, the steps for coupled analysis of the typhoon forecast availability, weather forecast availability, forecast rainfall level, and rainfall-runoff forecast availability include: calculating the total lag time for flood control information transmission and gate operation; if the difference between the average runoff forecast period and the total lag time is less than or equal to the preset grace period, then the rainfall-runoff forecast availability is ignored during the flood season water level control process.

[0050] When analyzing the reservoir in this example implementation using coupled forecasting of typhoons, weather, and rainfall runoff, the small catchment area, short river course, and steep riverbed slope result in a short time for flood formation from rainfall, with an average forecast period of only 6 hours. Analysis using the Xin'anjiang hydrological forecasting model reveals that the approximately 6-hour timeframe for issuing dispatch instructions, gate opening and closing, and upstream and downstream notifications poses a significant risk to flood control decisions. From a safety-first perspective, the rainfall-flood forecasting and dispatching scheme is temporarily disregarded to allow for a safety margin in dispatching. Given a typhoon forecast period of 48 hours and the occurrence of a rainstorm or heavier rainfall system, to further ensure reservoir dispatching safety, it is determined that if a typhoon or rainstorm or heavier rainfall occurs within 48 hours, the reservoir will enter a pre-discharge operation to lower the water level. If the 24-hour weather forecast indicates a rainstorm or heavier rainfall system, the reservoir should continue pre-discharge to the lower limit of the design flood season level, and then be dispatched according to the original design flood control dispatching operation mode.

[0051] The specific methods for dynamically regulating reservoir water levels during the flood season are as follows: A comprehensive analysis of the reservoir's basic engineering characteristics, dam safety status, flood discharge facility operation, reservoir management, automatic hydrological monitoring, and external conditions for dynamic water level control during the flood season, including upstream reservoir areas and downstream flood protection targets, determines that the flood control criteria for a large reservoir in Hainan are: during the pre-discharge phase, the safe flow rate at the downstream flood control section is 1550 m³ / h, corresponding to the warning water level. 3 Based on different typical floods, and through comparison of water level control schemes in two stages (typhoon and weather forecasts, as rainfall and runoff forecasts are too short to meet control requirements), the recommended upper limit for flood season water levels is: 61.90m during the main flood season and 69.50m during the post-flood season; the lower limit is the original flood season limit for the reservoir: 58.45m during the main flood season and 66.95m during the post-flood season. According to the aforementioned flood stages and forecast periods, and based on flood control regulation calculations, the principles for dynamic control and scheduling of flood season water levels are determined as follows: (1) Dynamic control and scheduling scheme for the water level of Dalong Reservoir during the main flood season: If the reservoir area is forecasted to have no rainfall exceeding the level of heavy rain or no typhoon impact within 48 hours, the reservoir water level can be maintained at 61.90m; if the typhoon impact is forecast 48 hours later, the reservoir should consider a flow rate of 1550m³ corresponding to the downstream warning water level. 3 / s, control the rate of change of the outflow, pre-release according to the reservoir's discharge capacity, and lower the water level to 58.9m after 24 hours. At this time, according to the latest rainfall forecast, if there is still heavy rain or above in 24 hours, the flow rate corresponding to the downstream warning water level will continue to be considered in the next 24 hours, the rate of change of the outflow will be controlled, and pre-release will be carried out according to the reservoir's discharge capacity to lower the water level to the lower limit of the main flood season water level of 58.45m.

[0052] During the flood receding phase, if the forecast indicates no typhoon impact and no rainfall exceeding the level of heavy rain in the next 48 hours, and the water level is above 61.90m at the current moment, the reservoir will continue to release water to 61.90m and maintain the water level at 61.90m; if the water level is below 61.90m at the current moment, the reservoir will begin to store water. If the forecast indicates a typhoon impact or rainfall exceeding the level of heavy rain in the next 48 hours, the pre-release scheduling plan will still be followed to control the water level down to the lower limit of the dynamic control zone for flood season water level, which is 58.45m.

[0053] (2) Dynamic control and scheduling scheme for the water level of Dalong Reservoir during the flood season after the flood season: If the reservoir area is forecasted to have no rainfall of level 3 or above, or no typhoon impact within 48 hours, the reservoir water level can be maintained at 69.50m. If a typhoon impact is forecasted after 48 hours, Dalong Reservoir can temporarily refrain from pre-discharge. After 24 hours, based on the latest rainfall forecast, if a typhoon impact or rainfall of level 3 or above is forecasted after 24 hours, the downstream warning water level and corresponding flow rate will be considered in the next 24 hours. The discharge flow rate will be controlled, and pre-discharge will be carried out according to the reservoir's discharge capacity, pre-discharging the water level to the post-flood season lower limit water level of 66.95m.

[0054] During the flood receding phase, if no typhoon is forecasted to form and no rainfall exceeding the level of torrential rain in the next 48 hours, and the water level is above 69.50m at the current moment, the reservoir will continue to release water to 69.50m and maintain the water level at 69.50m; if the water level is below 69.50m at the current moment, the reservoir will store water back in; if a typhoon is forecast to affect the reservoir or there is rainfall exceeding the level of torrential rain in the next 48 hours, the reservoir will be operated according to the pre-release scheduling method for the rising phase, controlling the water level to drop to the lower limit of the dynamic control zone for flood season water level, which is 66.95m.

[0055] By adopting the dynamic water level control method for reservoirs during the flood season provided in this embodiment, compared with the original fixed flood control water level scheduling scheme, the lead time for the target reservoir can reach up to 48 hours. The flood control water level during the main flood season is dynamically controlled between 58.45m and 61.90m, and during the post-flood season between 66.95m and 69.5m. The highest water level of the reservoir remains unchanged, and the maximum outflow is basically the same as the original scheme, without increasing the flood control risk of the reservoir area and downstream protected objects. Through dynamic water level control during the flood season, the post-flood water level increases compared with the original design scheme, thereby increasing the reservoir's water storage capacity after the flood season, which is beneficial for subsequent water supply and power generation, and increases the reservoir's beneficial effects. After implementing dynamic water level control during the flood season at a large reservoir in Hainan, the average annual domestic and industrial water supply increased by 23.85 million m³ (12.1%), irrigation water supply increased by 5.66 million m³ (4.4%), and power generation increased by 2.38 million kWh (8.1%), all under the same guarantee rate. For reservoirs in coastal areas affected by typhoons, this method can be used to implement a dynamic water level control scheme during the flood season. This scheme can be combined with real-time forecast corrections and a multi-period dynamic control method based on the coupled analysis of typhoon forecasts, weather forecasts, and rainfall-runoff forecasts to study the upper and lower limits of dynamic water level control during different stages of the flood season. This determines the dynamic water level control scheme for the flood season. Compared with single-period water level control, reservoir operation is more flexible and safer. It can effectively improve the flood forecast period for flood control operation of reservoirs in coastal areas and increase the comprehensive utilization benefits of reservoirs.

[0056] The reservoir flood season water level dynamic control device provided in this embodiment of the invention is used to execute the reservoir flood season water level dynamic control method, or, the reservoir flood season water level dynamic control device is used to store a computer program for executing the reservoir flood season water level dynamic control method. The reservoir flood season water level dynamic control device has the technical effects of the above-mentioned flood season water level dynamic control method, which will not be described in detail here.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for dynamic control of reservoir water level during the flood season, characterized in that, Includes the following steps: Obtain typhoon data, weather forecasts, and rainfall-runoff forecasts for the reservoir location over a period of several years; Determine the forecast period for typhoon availability based on typhoon data over a certain number of years; Based on the weather forecast, determine the available forecast period and the forecast rainfall level; Determine the available lead time for rainfall and runoff forecasts based on rainfall and runoff forecasts; A coupled analysis was performed on the available forecast period for typhoons, the available forecast period for weather, the forecast rainfall level, and the available forecast period for rainfall and runoff. Dynamic regulation of reservoir water levels during the flood season is carried out based on the results of coupling analysis; The steps for determining the forecast period for usable typhoons based on typhoon data over a certain number of years include: Calculate the minimum time interval from typhoon formation to reservoir flood peak; compare and obtain the typhoon forecast period closest to the minimum time interval; compare and select the maximum value between the typhoon forecast period and the minimum time interval, and use it as the first alternative typhoon available forecast period; The sum of the time from the formation of the typhoon to the predicted landfall time, the time for the typhoon forecast to determine the rainfall level, and the forecast period for rainfall and runoff is used as the second available forecast period for the alternative typhoon. The time from the formation of the typhoon to the predicted landfall time, the time for the typhoon forecast to determine the rainfall level, and the forecast period for rainfall and runoff are adjusted in real time based on the forecast of the typhoon, and the second available forecast period for the alternative typhoon is updated. The minimum value between the first and second candidate typhoon availability forecast periods is selected and used as the revised availability forecast period for typhoons.

2. The method for dynamic control of reservoir water level during the flood season according to claim 1, characterized in that, Also includes: The flood season should be handled in stages; The steps for dynamically regulating the reservoir's flood season water level based on the coupling analysis results include: Set separate upper and lower limits for water levels for each phase and period of the flood season; Based on the results of the coupling analysis, the water level was dynamically adjusted for each flood season period.

3. The method for dynamic control of reservoir water level during the flood season according to claim 2, characterized in that, The steps for phased processing of the flood season include: The flood season is divided into periods based on differences in meteorological causes; And / or, use the moment of sudden change in quantitative meteorological conditions during the flood season as the dividing point for the time period.

4. The method for dynamic control of reservoir water level during flood season according to claim 1, characterized in that, The steps for determining the available forecast period and forecast rainfall level based on weather forecasts include: Compare the relationship between weather forecasts and actual rainfall at different times during typhoons; The maximum value among the time periods with a forecast accuracy greater than the preset accuracy is selected as the available lead time for weather forecasting, and the corresponding forecast rainfall level is determined.

5. The method for dynamic control of reservoir water level during the flood season according to claim 1, characterized in that, The steps for determining the available lead time for rainfall-runoff forecasts based on rainfall-runoff forecasts include: The average runoff lead time for rainfall-runoff forecasts is calculated based on runoff forecasts over several years.

6. The method for dynamic control of reservoir water level during the flood season according to claim 5, characterized in that, The steps for performing coupled analysis on the typhoon availability forecast lead time, the weather forecast availability lead time, the forecast rainfall level, and the rainfall-runoff forecast availability lead time include: Calculate the total delay time for flood control information transmission and gate operation; If the difference between the average runoff forecast period and the total lag time is less than or equal to the preset grace period, then the available forecast period for rainfall and runoff will be ignored during the flood season water level regulation process.

7. A reservoir flood season water level dynamic control device, characterized in that, The reservoir flood season water level dynamic control device is used to execute the reservoir flood season water level dynamic control method according to any one of claims 1-6, or the reservoir flood season water level dynamic control device is used to store a computer program for executing the reservoir flood season water level dynamic control method according to any one of claims 1-6.

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