Emergency storage capacity reserving and regulating method for dealing with drought-resisting scheduling of extra-low water year

Abstract

The invention discloses an emergency storage capacity reservation and regulation and control method for dealing with drought-resistant scheduling of an extra-low water year. The method comprises the following steps: acquiring basic data related to a drought-resistant scheduling control section; determining an emergency water scheduling flow demand of the control section; obtaining the water shortage time of a control section in an extra-low water year and the size of a water volume gap; acquiring the water supply capacity of each controlled reservoir in the cascade reservoir group at the upstream of the control section, and selecting an emergency reservoir which is included in the emergency dispatching range of the water volume of the control section in the extra-low water year based on the water supply capacity; and determining the emergency reservoir capacity of the control section upstream cascade reservoir group for dealing with drought-resisting scheduling of the extra-low water year, the reserved time of the emergency reservoir capacity and the distribution rule of the emergency reservoir capacity in each emergency reservoir. Through a scientific and reasonable emergency storage capacity reservation and scheduling strategy, optimal configuration of water resources can be realized, and the utilization efficiency of the water resources is improved. The method is simple and easy to implement, high in operability and suitable for various types of reservoirs and water resource management systems.

Description

Technical Field

[0001] The present invention relates to the technical field of drought emergency dispatching for cascade reservoirs, and particularly refers to a method for reserving and regulating emergency storage capacity for drought resistance dispatching in extremely dry years. Background Art

[0002] In recent years, global extreme climate events have occurred frequently, and drought disasters in river basins or regions have occurred from time to time. In addition, due to the uneven spatio-temporal distribution of water resources in some river basins and the insufficient regulation capacity of existing projects, there is a lack of water resources in the upstream regions, water quality problems in the middle and lower reaches, and the contradiction between water supply and demand is relatively prominent in some local areas and during some periods, so the demand for drought resistance water supply and water volume emergency dispatching is urgent.

[0003] Generally, in extremely dry years, when extremely severe drought occurs in the river basin or there are difficulties in water use in the middle and lower reaches of the river basin, and the dispatching and management measures in the affected areas still cannot guarantee water use, the upstream cascade reservoir group can redistribute the water volume of the whole river basin through emergency water volume dispatching and conduct compensatory regulation to cope with the drought resistance problem in extremely dry years.

[0004] At present, the joint dispatching of the upstream controlling reservoir group in the river basin mainly focuses on flood control, power generation, etc., and there is less research on water supply dispatching, especially on reservoir drought resistance dispatching in extremely dry years. Most reservoirs in the upstream of some river basins do not have the task of drought resistance water supply for the downstream in the preliminary design stage, and the relevant regulations on the dispatching method of drought resistance water supply are almost blank in the reservoir dispatching rules or plans. When serious drought occurs in the river basin, the emergency water volume dispatching method of the controlling reservoir group is relatively random, and the water resources benefit of the reservoir group cannot be fully exerted.

[0005] Therefore, it is necessary to study a method for reserving and regulating emergency storage capacity for drought resistance dispatching in extremely dry years, reserve a certain amount of water in advance, and scientifically and reasonably implement the emergency water volume dispatching of the reservoir group to give full play to the drought resistance water supply benefit of the reservoir group. Summary of the Invention

[0006] In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide a method for reserving and regulating emergency storage capacity for drought resistance dispatching in extremely dry years to ensure that there is sufficient water resource reserve in extremely dry years to meet the basic production, living and ecological needs.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0008] A method for reserving emergency storage capacity for drought resistance dispatching in extremely dry years, which is characterized in that it includes the following steps:

[0009] 1) Obtain relevant basic data of the drought resistance dispatching control section; a cascade reservoir group is arranged upstream of the control section;

[0010] 2) Based on the above basic data, determine the emergency water volume scheduling flow demand of the control section;

[0011] 3) Based on the above basic data and the emergency water volume scheduling flow demand, obtain the water shortage time and the magnitude of the water volume gap of the control section;

[0012] 4) Obtain the water supply capacity of each controlled reservoir in the cascade reservoir group upstream of the control section, and select the emergency reservoirs included in the scope of the emergency water volume scheduling of the control section based on the water supply capacity;

[0013] 5) Determine the emergency storage capacity of the cascade reservoir group upstream of the control section for drought resistance scheduling in extremely dry years, the reserved time of the emergency storage capacity, and the allocation rules of the emergency storage capacity among the emergency reservoirs.

[0014] As a preferred solution, in step 1), the above basic data includes the ecological flow of the drought resistance scheduling control section and the water demand in the downstream interval, long-term series water levels, the lowest navigable water level, the water level - flow relationship curve, the long-term series runoff data and conventional scheduling rules of the cascade reservoir group upstream of the control section, the water level - storage capacity curve, the dead water level and normal storage water level of each reservoir.

[0015] As a preferred solution, in step 2), the method for determining the emergency water volume scheduling flow demand of the control section includes:

[0016] 2.1) According to the ecological flow of the control section and the water demand in the downstream interval, determine the emergency water volume scheduling flow Q1, and the calculation formula is as follows:

[0017] Q1 = Q e +Q dwdemand ;

[0018] In the formula, Q e is the ecological flow of the control section, and Q dwdemand is the water demand in the downstream interval of the control section;

[0019] 2.2) Obtain the emergency water volume scheduling flow Q2 according to the long-term series water level data of the control section and the lowest navigable water level;

[0020] 2.3) Obtain the emergency water volume scheduling flow demand of the control section based on Q1 and Q2.

[0021] Furthermore, step 2.2) includes:

[0022] (1) Conduct a frequency analysis on the long-term series water level data of the control section to obtain the water level corresponding to the set frequency P0;

[0023] (2) Based on the water level corresponding to the set frequency P0 and the lowest navigable water level, obtain the lowest water level of the control section, and the calculation formula is as follows:

[0024]

[0025] In the formula, L min is the lowest water level of the control section, is the water level at the set frequency P0 of the control section, L min，navi is the lowest navigable water level of the control section; L a is the safety margin of the lowest water level control index of the control section;

[0026] (3) Based on the water level - discharge relationship curve of the control section, calculate the lowest water level L min of the corresponding discharge Q2.

[0027] Furthermore, the set frequency P0≥95%, L a is 0 - 0.5m.

[0028] Further, step 2.3) includes: Selecting the larger value between Q1 and Q2 as the emergency water volume scheduling flow demand value of the control section.

[0029] As an optimized solution, in step 3), the method for obtaining the water shortage time and water volume gap includes:

[0030] 3.1) Based on the conventional scheduling rules of the cascade reservoirs upstream of the control section, using the long - series runoff data of the upstream cascade reservoirs, carry out runoff regulation calculation to obtain the long - series runoff processes of the upstream cascade reservoirs and the control section;

[0031] 3.2) Based on the long - series runoff process, obtain the start water shortage time and the last water shortage time of the control section year by year; Select the earliest start water shortage time and the latest last water shortage time as the water shortage time of the control section;

[0032] 3.3) Based on the long - series runoff process, obtain the water shortage discharge of the control section year by year and by time period. The calculation method is as follows:

[0033]

[0034] In the formula, Q t is the discharge of the control section at time t; Q′ t is the water shortage discharge of the control section at time t; Q min is the emergency water volume scheduling flow demand of the control section; t = 1, 2,......, m, where m is the total number of calculation time periods in a year;

[0035] 3.4) Obtain the annual total water shortage of the control section year by year. The calculation method is as follows:

[0036]

[0037] Wherein, W i is the total annual water shortage occurring at the control section in the i-th year during the long-term runoff process, where i = 1, 2,..., n, and n is the total duration of the long-term runoff data in years; T is the time period length of the long-term runoff data;

[0038] 3.5) Obtain the maximum value among the total annual water shortages of the control section over the years as the water volume gap of the control section in the extremely dry year. The calculation formula is as follows:

[0039] W max = max(W1, W2,..., W i ,..., W n ), where i = 1, 2,..., n

[0040] Wherein, W max is the maximum value among the total annual water shortages, that is, the said water volume gap.

[0041] As an optimal solution, in step 4), the calculation formula for the water supply capacity of each controlled reservoir in the upstream cascade reservoir group is as follows:

[0042] W wsc = V l - V dwl ;

[0043] Wherein, V dwl is the reservoir capacity corresponding to the dead water level of the reservoir; W wsc is the water supply capacity of a single reservoir; V l is the minimum value of the reservoir capacity corresponding to the reservoir water level at a specific time node over the years in the long-term runoff data; the said specific time node is the initial moment of the water shortage time of the control section.

[0044] As an optimal solution, in step 4), the selection method of the emergency reservoir includes:

[0045] 4.1) Starting from the reservoir adjacent to the control section and having weekly regulation or above capacity, calculate the water supply capacity coefficient of the reservoirs in the upstream cascade reservoir group of the control section that have weekly regulation or above capacity in turn. If the water supply capacity coefficient K wsc ≤ 0.5, then exclude this reservoir. If the water supply capacity coefficient K wsc > 0.5, then include it in the candidate reservoirs; the calculation formula for the water supply capacity coefficient is as follows:

[0046]

[0047] Wherein, K wsc is the water supply capacity coefficient of the reservoir; V rs is the regulation storage capacity of the reservoir;

[0048] 4.2) Starting from the control section adjacent to it, select one or more candidate reservoirs in sequence upstream as emergency reservoirs for the emergency water volume dispatch of the control section in extremely dry years.

[0049] As an optimal solution, in step 5), the reserved time for the emergency storage capacity is the water shortage time of the control section in step 3); the emergency storage capacity is the water volume gap of the control section; the distribution method of the emergency storage capacity among each emergency reservoir is as follows:

[0050]

[0051] In the formula, is the reserved emergency storage capacity of the j-th emergency reservoir, is the water supply capacity of the j-th emergency reservoir, j = 1, 2,..., J, J is the total number of emergency reservoirs, and W max is the water volume gap.

[0052] The present invention also provides an emergency storage capacity reservation system for drought resistance dispatch in extremely dry years, which is used to implement the above-mentioned emergency storage capacity reservation method for drought resistance dispatch in extremely dry years. The special feature lies in: including:

[0053] A data storage module for storing the relevant basic information of the drought resistance dispatch control section;

[0054] An emergency storage capacity reservation module for obtaining the emergency storage capacity, the reserved time of the emergency storage capacity, and the distribution rule of the emergency storage capacity among each emergency reservoir of the cascade reservoir group upstream of the control section for drought resistance dispatch of the control section in extremely dry years based on the basic information stored in the data storage module.

[0055] The present invention also provides an emergency storage capacity regulation method for drought resistance dispatch in extremely dry years. The special feature lies in: including: obtaining the emergency storage capacity, the reserved time of the emergency storage capacity, and the distribution rule of the emergency storage capacity among each emergency reservoir of the cascade reservoir group upstream of the control section for drought resistance dispatch of the control section in extremely dry years through the above-mentioned emergency storage capacity reservation method for drought resistance dispatch in extremely dry years; before the start of the reserved time of the emergency storage capacity, ensure that each emergency reservoir reserves the corresponding emergency storage capacity; during the reserved time, when extremely dry water occurs and drought conditions appear at the control section, and it is necessary to start the emergency water volume dispatch of the cascade reservoir group upstream, conduct regulation according to the following rules:

[0056] a. Maintain the original dispatching rules of the cascade reservoir group, give priority to taking water use restriction measures, and stop the water storage of the cascade reservoir group upstream;

[0057] b. If the emergency situation still does not ease, increase the lower limit of the minimum discharge flow of the emergency reservoir and activate the emergency storage capacity: When there are multiple emergency reservoirs at the control section, if the multiple emergency reservoirs are parallel reservoirs, take the minimum discharge flow of the reservoir as the basis, and allocate the water supply volume to the downstream according to the proportion of the stored water volume in the reservoirs, and keep the reservoirs falling synchronously; if the multiple emergency reservoirs are series reservoirs, preferentially activate the emergency storage capacity of the emergency reservoir immediately upstream of the control section, and increase the discharge flow of other emergency reservoirs to keep the reservoirs falling synchronously;

[0058] c. When all emergency reservoirs have fallen to the dead water level, keep the reservoir capacity at the dead water level and add a new emergency reservoir; the new emergency reservoir is a reservoir that is adjacent to the original emergency reservoir, has the ability of weekly regulation or above, and the water supply capacity coefficient K wsc > 0.5;

[0059] d. Repeat step c until no new emergency reservoir can be added, and activate the storage capacity below the dead water level;

[0060] Steps a to d are executed in sequence. If the emergency situation eases when executing one of the steps, stop executing the subsequent operations.

[0061] The present invention also provides a computer-readable storage medium, which is characterized in that: the computer-readable storage medium stores computer instructions, and the computer instructions are used to make a computer execute the above-mentioned emergency storage capacity reservation method or emergency storage capacity regulation method for drought resistance dispatching in a particularly dry year.

[0062] The present invention also provides an electronic device, which is characterized in that: it includes: a memory and a processor, the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to execute the above-mentioned emergency storage capacity reservation method or emergency storage capacity regulation method for drought resistance dispatching in a particularly dry year.

[0063] Compared with the prior art, the beneficial effects of the present invention are:

[0064] According to the time and space distribution of the dry water events occurring at the control section, the present invention statistically analyzes the flow requirements of the emergency water volume dispatching at the control section, and combines the joint water supply capacity of the important controlled reservoir groups, and proposes a method for reserving and regulating the emergency storage capacity of the reservoir group for drought resistance dispatching in a particularly dry year. Combining the operating characteristics of the reservoir, and taking the principle of avoiding major interference with the existing dispatching operation mode, the present invention clarifies the reservation time and size of the emergency storage capacity of the reservoir group, which can ensure the timely and effective emergency water volume dispatching and provide decision-making support for the drought resistance dispatching of the reservoir group.

[0065] The present invention can effectively cope with the drought situation in extremely dry years. By reserving an emergency storage capacity for downstream water replenishment, it improves the guarantee ability of water resources and reduces the losses caused by drought. Through scientific and reasonable emergency storage capacity reservation and scheduling strategies, it can achieve the optimal allocation of water resources and improve the utilization efficiency of water resources. The method of the present invention is simple and easy to implement, highly operable, and applicable to various types of reservoirs and water resource management systems. Description of the Drawings

[0066] Figure 1 It is a schematic flow chart of a method for reserving and regulating the emergency storage capacity for drought resistance dispatching of a kind of the present invention for cascaded reservoir groups;

[0067] Figure 2 It is a schematic diagram of the positions of each controlled reservoir and the X control section in the embodiment. Detailed Embodiment

[0068] In order to better explain the present invention, the main content of the present invention is further clarified below in conjunction with the drawings and specific embodiments, but the content of the present invention is not limited to the following embodiments only.

[0069] As Figure 1 shown, a method for reserving the emergency storage capacity for drought resistance dispatching of a kind of the present invention for cascaded reservoir groups specifically includes the following steps:

[0070] 1) Obtain basic data, including collecting data such as the ecological flow of the drought resistance dispatching control section and the water use demand in the downstream interval, long-term series water levels, the lowest navigation water level, the water level-discharge relationship curve, etc., obtain the long-term series runoff data, conventional dispatching rules, water level-storage capacity curve, dead water level, normal storage water level, etc. of the upstream cascaded reservoir groups of the control section. The long-term series runoff data is for a total of n years, and the calculation time scale is monthly average, ten-day average or weekly average, with a total of m calculation periods per year.

[0071] 2) Determine the emergency water volume dispatching flow demand of the control section. The steps for determining the emergency water volume dispatching flow demand of the control section mainly include:

[0072] 2.1) Determine the emergency water volume dispatching flow Q1 according to the ecological flow of the control section and the water use demand in the downstream interval:

[0073] Q1 = Q e + Q dwdemand ;

[0074] In the formula, Q e is the ecological flow of the control section, and Q dwdemand is the water use demand in the downstream interval of the control section.

[0075] 2.2) Arrange the long-term water level data of the control section in descending order, conduct frequency analysis, and calculate the water level value corresponding to the frequency P = 95%.

[0076] Based on the P = 95% frequency water level of the control section and the upper limit of the lowest navigable water level, take the envelope value and appropriately increase it by 0.5 m as the safety margin of the lowest water level control index of the control section.

[0077] L min = max(L P = 95%, L min navi ) + 0.5;

[0078] In the formula, L min is the lowest water level index of the control section, L P＝95％ is the water level at the P = 95% frequency of the control section, and L min，navi is the lowest navigable water level of the control section. The frequency P represents the hydrological frequency. If the ten-day average water level is statistically analyzed, that is, the long-term ten-day average water levels are sorted from large to small, and the frequency P = α / (β + 1), where α is the sorting of the corresponding data and β is the total number of long-term data.

[0079] Based on the water level-discharge relationship curve of the control section, calculate the discharge Q2 corresponding to the lowest water level L min of the control section.

[0080] 2.3) Determine the flow demand for emergency water volume regulation of the control section: Q min = max(Q1, Q2).

[0081] 3) Based on the long-term runoff data of the cascade reservoir group upstream of the control section for drought resistance regulation and the flow demand for emergency water volume regulation, calculate the time when water shortage occurs at the control section in a particularly dry year and the magnitude of the water volume gap. The specific steps are as follows:

[0082] Based on the conventional regulation rules of the cascade reservoir group upstream of the control section, use the long-term runoff data to carry out runoff regulation calculations to obtain the long-term runoff processes of the upstream cascade reservoir group and the control section.

[0083] Obtain the start time of water shortage and the end time of water shortage of the control section year by year; select the earliest start time of water shortage and the latest end time of water shortage among them as the water shortage time of the control section.

[0084] According to the minimum flow index of the control section - the flow demand Q min for emergency water volume regulation, combined with the long-term runoff process of the control section, statistically calculate the magnitude of the water volume gap of the control section over the years, and select the maximum value of the annual water shortage total as the water volume gap of the control section in a particularly dry year.

[0085]

[0086] W max = max(W1, W2, ..., W i ,…,W n ), i = 1, 2, ……, n

[0087] In the formula, Q t is the flow rate at the control section during time period t; Q' t is the water shortage flow rate at the control section during time period t; W i is the total annual water shortage that occurs at the control section in the i-th year during the long-term runoff process; W max is the maximum total annual water shortage over the years at the control section during the long-term runoff process, that is, the water volume gap; t = 1, 2, ..., m, where m is the total number of calculation time periods within each year; T is the length of the time period of the long-term runoff data.

[0088] 4) First, calculate the water supply capacity of each controlling reservoir above the control section. The specific calculation steps for the water supply capacity include:

[0089] Based on the runoff regulation calculation results in step 3), annually count the water storage volume at the initial moment of the water shortage time at the control section for a single reservoir and obtain the minimum value of the water storage volume at the initial moment of the water shortage time for each year of the corresponding reservoir. Analyze the water supply capacity of the reservoir based on the reservoir water level, that is, the existing water storage volume. The water supply capacity refers to the available reservoir capacity between the reservoir water level and the dead water level. The water supply capacity W wsc of a single reservoir is:

[0090] W wsc = V l - V dwl ;

[0091] In the formula: V l is the minimum value of the water storage volume at the initial moment of the water shortage time at the reservoir over the years in the long-term runoff data (the reservoir capacity corresponding to the minimum reservoir water level at the initial moment over the years), and V dwl is the reservoir capacity corresponding to the dead water level of the reservoir.

[0092] Secondly, select the reservoir group included in the scope of the emergency water volume dispatch at the control section. The specific calculation steps include:

[0093] Comprehensively consider the regulation reservoir capacity, water supply capacity, and distance from the control section of the reservoir group. Prioritize selecting the reservoirs adjacent to the control section and having a weekly regulation capacity or above, and calculate the water supply capacity coefficient K wsc , and select one or more candidate reservoirs as the emergency reservoirs included in the scope of the emergency water volume dispatch at the control section.

[0094]

[0095] In the formula, V rsis the regulating storage capacity of the reservoir, if K wsc >0.5, indicating that the reservoir has a certain regulation capacity, and the reservoir is included in the selection range as a candidate reservoir.

[0096] 5) Determine the emergency storage capacity that needs to be reserved in the control section, the reservation principle and reservation time of emergency storage capacity between different reservoirs. The specific calculation steps include:

[0097] Emergency storage capacity V required for control section es is the maximum water shortage of the control section over the years W max , the emergency storage capacity can be allocated to each emergency reservoir according to the proportion of the reservoir’s water supply capacity.

[0098]

[0099] In the formula, is the reserved emergency storage capacity of the jth emergency reservoir, is the water supply capacity of the jth emergency reservoir, j = 1, 2, ..., J, and J is the total number of emergency reservoirs.

[0100] The time reserved for emergency storage capacity is the time when the water shortage in the control section occurs.

[0101] The present invention also provides an emergency storage capacity reservation system for drought relief scheduling in extremely dry years, which is used to implement the above-mentioned emergency storage capacity reservation method for drought relief scheduling in extremely dry years, and its special features are: including:

[0102] Data storage module, used to store basic data related to drought relief dispatch control section;

[0103] The emergency storage capacity reservation module is used to obtain the emergency storage capacity, the reservation time of the emergency storage capacity, and the allocation rules of the emergency storage capacity in each emergency reservoir for the upstream cascade reservoir group of the control section to cope with the drought relief scheduling of the control section in an extremely dry year based on the basic data stored in the data storage module.

[0104] The present invention also provides an emergency storage capacity control method for drought relief scheduling in extremely dry years, comprising: obtaining the emergency storage capacity, the reserved time of the emergency storage capacity, and the allocation rule of the emergency storage capacity in each emergency reservoir of the upstream cascade reservoir group of the control section for drought relief scheduling in the extremely dry year through the above-mentioned emergency storage capacity reservation method for drought relief scheduling in the extremely dry year; before the start of the emergency storage capacity reservation time, ensuring that each emergency reservoir reserves the corresponding emergency storage capacity; within the reserved time, when an extremely dry season occurs and drought occurs in the control section, and the upstream cascade reservoir group needs to start emergency water volume scheduling, control is performed according to the following rules:

[0105] a. Maintain the original dispatching procedures unchanged and give priority to water restriction measures, including stopping water storage in relevant cascade reservoirs;

[0106] b. If the emergency situation still cannot improve, increase the lower limit of the minimum discharge of the emergency reservoir and activate the emergency storage capacity to replenish water to the downstream until the drought situation is alleviated and it resumes normal operation; when there are multiple emergency reservoirs at the control section, if the multiple emergency reservoirs are parallel reservoirs, the minimum discharge can be used as the basis, and the water replenishment volume to the downstream can be allocated according to the proportion of the water storage in the reservoirs, and it is appropriate for the reservoirs to draw down synchronously; if the multiple emergency reservoirs are series reservoirs, the emergency storage capacity of the emergency reservoir immediately upstream of the control section should be activated first, and the discharge of the upstream reservoirs participating in the emergency operation should be adjusted in a timely manner to ensure that the adjacent reservoir maintains a certain emergency storage capacity and the reservoirs draw down synchronously;

[0107] c. When all the emergency reservoirs are completely or basically drawn down to the dead water level, add a new emergency reservoir and transfer the emergency operation task to the new emergency reservoir. The regulation method of the new emergency reservoir adopts the method in step 3);

[0108] d. Repeat step c until no new emergency reservoir can be added, that is, when all relevant reservoirs are drawn down to the dead water level and the emergency situation still cannot be alleviated, the storage capacity below the dead water level can be activated to replenish water to the downstream;

[0109] Among them, steps a to d are executed in sequence. If the emergency situation is alleviated when executing one of the steps, stop executing the subsequent operations.

[0110] Embodiment

[0111] Taking the X control section of the main stream of the Yangtze River as an example, the average annual flow of the X control section is 7460 m 3 / s, and the controlled reservoirs built above the section include R1 - R12, a total of 12 controlled reservoirs.

[0112] 1) Obtain basic data, including collecting data such as the ecological flow of the X control section, water use demands in the downstream reach, long - series water levels, the lowest navigable water level, water level - discharge relationship curves, etc., and obtain long - series runoff data, conventional operation rules, water level - storage curves, dead water levels, normal storage levels, etc. of the cascade reservoir group upstream of the control section. The long - series runoff data is 55 years in total, the calculation time scale is ten - day average, and there are 36 calculation periods per year.

[0113] 2) Considering the ecological base flow of the river channel and water use demands such as domestic, industrial, irrigation, and shipping in the downstream, determine that the minimum flow control index Q1 of the X control section is 2110 m 3 / s. Conduct a frequency analysis on the long - series runoff data of the X control section. The ten - day average water level L P＝95％ at the 95% guarantee rate is 258.91 m. Considering the safety margin L aThe 0.5 m redundancy. Based on the X control section having no requirement for the lowest navigable water level, the lowest water level control index L of the X control section min is 259.41 m. Based on the water level-discharge relationship curve of the X control section, the discharge Q2 corresponding to the lowest water level control index of 259.41 m is 2000 m 3 / s. Taking the larger value of Q1 and Q2 to determine the minimum discharge control index of the X control section, that is, the flow demand Q for emergency water volume scheduling min is 2110 m 3 / s.

[0114] 3) For the X control section, according to the existing dispatching operation modes of each controlled reservoir, based on the dispatching strategy of "maintaining high water level operation as much as possible on the premise of meeting the minimum downstream discharge requirement and guaranteed output", carry out long-term series (1959 - 2013) runoff regulation calculations to obtain the ten-day average runoff process of the X control section from 1959 to 2013. According to the minimum discharge control index of 2110 m 3 / s, statistically analyze the water shortage situation of the X section under natural conditions. The time of water shortage at the X control section is from January to April, and the maximum water volume gap is about 820 million m 3 , that is, the maximum annual water shortage total amount W max is 820 million m 3 , which occurred from January to April in 1963.

[0115] 4) Represent the water supply capacity of each reservoir by the reservoir water level, that is, the stored water volume. There are a total of 12 controlled reservoirs (R1 - R12) built above the X control section, as Figure 2 shown. Among them, the regulation performances of reservoirs R7, R8, R9, and R12 are weekly regulation and above, and the regulation storage capacities are relatively large. The stored water volume at the end of each month of the four reservoirs is statistically analyzed in Table 1.

[0116] Among the controlled reservoirs above the X control section, reservoirs R7, R8, R9, and R12 all have relatively large regulation storage capacities and are suitable for undertaking the task of emergency water supply. At the end of December of each year, that is, at the initial moment of the water shortage time at the X control section, the minimum stored water volumes of reservoirs R7 and R8, that is, the water supply capacity W of a single reservoir wsc are 4.154 billion m 3 and 2.465 billion m 3 respectively, accounting for 84.6% and 73.1% of the regulation storage capacity, that is, K wsc are 84.6% and 73.1% respectively. The minimum stored water volume W of reservoir R9 at the end of December of each year wsc is 4.728 billion m 3 , accounting for 73.2% of the regulation storage capacity. The minimum stored water volume W of reservoir R12 at the end of December of each year wsc is 3.378 billion m 3, accounting for 86.7% of the regulated storage capacity. Since R9 and R12 are relatively close to the X control section, they should be given priority. Therefore, the emergency water volume scheduling at the X section is considered to be shared by the two reservoirs R9 and R12.

[0117] 5) The emergency water volume required at the X control section is 0.82 billion m 3 , R9 and R12 are parallel reservoirs, and the emergency storage capacity is allocated according to the proportion of the water supply capacity of the two reservoirs. The minimum water supply capacities of the two reservoirs R9 and R12 are 4.728 billion m 3 and 3.378 billion m 3 respectively. Allocated according to the water supply capacity, the emergency storage capacities set for the X section by the two reservoirs R9 and R12 are as follows:

[0118] R9:

[0119] R12:

[0120] The emergency storage capacities of the two reservoirs R9 and R12 account for 7.4% and 8.7% of the regulated storage capacity respectively. The reserved time for the emergency storage capacity is from January to April. Judging from the proportion of the emergency storage capacity in the regulated storage capacity, since the emergency storage capacity starts to be used at the end of December and can be lowered to the dead water level by the end of April, the impact on the existing operation mode is not significant. The storage capacity allocation is shown in Table 2.

[0121] Table 1: Statistical table of the water storage volume of important reservoirs at the end of each month. Storage capacity and water volume unit: billion m 3

[0122]

[0123] Table 2: Allocation table of the emergency storage capacity of the emergency reservoirs at the X control section

[0124]

[0125] (5) When a particularly dry water situation occurs and a drought situation appears at the X control section, and the upstream cascade reservoir group needs to start emergency water volume scheduling, the usage method of the emergency storage capacity is as follows:

[0126] ① First, still maintain the normal scheduling unchanged, and give priority to taking water use restriction measures, including that all relevant cascade reservoirs stop storing water;

[0127] ② If the situation still cannot improve, the cascade reservoirs undertaking the emergency scheduling task, namely reservoirs R9 and R12, can appropriately increase the lower limit of the minimum discharge flow until the drought situation is relieved and return to normal scheduling;

[0128] ③ When the main reservoirs undertaking the emergency task are completely or basically lowered to the dead water level, the emergency scheduling task is transferred to other reservoirs, namely R7 and R8;

[0129] ④ When the emergency situation has not been alleviated even after all relevant candidate reservoirs, namely Reservoirs R7, R8, R9, and R12, have been drawn down to the dead water level, the storage capacity below the dead water level can be utilized to replenish water to the downstream.

[0130] ⑤ When multiple reservoirs jointly conduct emergency dispatching for the same control section, for parallel reservoirs, the minimum discharge can be used as the basis, and the water replenishment volume to the downstream can be allocated according to the proportion of the water storage in the reservoirs, with the aim of synchronous drawdown of the reservoirs; for series reservoirs, the emergency storage capacity of the emergency reservoir immediately upstream of the control section should be given priority, and the discharge of the upstream reservoirs participating in the emergency dispatching should be adjusted in a timely manner to ensure that a certain emergency storage capacity is maintained in the adjacent reservoirs.

[0131] The "year" mentioned in this application document refers to the "hydrological year". The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention. Other parts not described belong to the prior art.

Claims

1. An emergency storage capacity reservation method for drought resistance dispatching in extremely dry years, characterized in that: It includes the following steps: 1) Obtain the relevant basic data of the drought-resistant dispatch control section; a cascade reservoir group is arranged upstream of the control section; 2) Based on the above basic data, determine the emergency water volume dispatch flow demand of the control section; 3) Based on the above basic data and the emergency water volume dispatch flow demand, obtain the water shortage time and the size of the water volume gap of the control section; 4) Obtain the water supply capacity of each controlled reservoir in the upstream cascade reservoir group of the control section, and select the emergency reservoirs included in the scope of the emergency water volume dispatch of the control section in the extremely dry year based on the water supply capacity; 5) Determine the emergency storage capacity of the upstream cascade reservoir group of the control section for drought-resistant dispatch in the extremely dry year, the reserved time of the emergency storage capacity, and the allocation rules of the emergency storage capacity among the emergency reservoirs.

2. The emergency storage capacity reservation method according to claim 1, characterized in that: In step 1), the above basic data includes the ecological flow of the drought-resistant dispatch control section and the water demand of the downstream section, the long-term series of water levels, the lowest navigable water level, the water level-discharge relationship curve, the long-term series of runoff data and the conventional dispatch rules of the upstream cascade reservoir group of the control section, the water level-storage curve, the dead water level and the normal storage water level of each reservoir.

3. The emergency storage capacity reservation method according to claim 1, wherein: In step 2), the method for determining the emergency water volume dispatch flow demand of the control section includes: 2.1) According to the ecological flow of the control section and the water demand of the downstream section, determine the emergency water volume dispatch flow Q1, and the calculation formula is as follows: Q1 = Q e +Q dwdemand ; Where, Q e is the ecological flow of the control section, and Q dwdemand is the water demand in the downstream section of the control section; 2.2) Obtain the emergency water volume dispatch flow Q2 according to the long-term series of water level data of the control section and the lowest navigable water level; 2.3) Obtain the emergency water volume dispatch flow demand of the control section based on Q1 and Q2.

4. The emergency storage capacity reservation method according to claim 3, characterized in that: The above step 2.2) includes: (1) Conduct a frequency analysis on the long-term series of water level data of the control section to obtain the water level corresponding to the set frequency P0; (2) Based on the water level corresponding to the set frequency P0 and the lowest navigable water level, obtain the lowest water level of the control section, and the calculation formula is as follows: Where, L min is the lowest water level of the control section, is the water level at the set frequency P0 of the control section, and L min，navi is the lowest navigable water level of the control section; L a is the safety margin of the lowest water level control index of the control section; (3) Calculate the lowest water level L of the control section based on the water level-discharge relationship curve of the control section min The corresponding discharge Q2.

5. The emergency storage capacity reservation method according to claim 4, characterized in that: The set frequency P0≥95%, L a is 0 to 0.5 m.

6. The emergency storage capacity reservation method according to claim 4, characterized in that: Step 2.3) includes: Select the larger value of Q1 and Q2 as the emergency water volume dispatch flow demand value of the control section.

7. The emergency storage capacity reservation method according to claim 1, characterized in that: In step 3), the method for obtaining the water shortage time and the water volume gap includes: 3.1) Based on the conventional dispatch rules of the upstream cascade reservoir group of the control section, use the long-term series of runoff data of the upstream cascade reservoir group to carry out runoff regulation calculation to obtain the long-term series of runoff processes of the upstream cascade reservoir group and the control section; 3.2) Based on the above long-term series of runoff processes, obtain the start water shortage time and the last water shortage time of the control section year by year; select the earliest start water shortage time and the latest last water shortage time as the water shortage time of the control section; 3.3) Based on the above long-term series of runoff processes, obtain the water shortage flow of the control section year by year and by time period, and the calculation method is as follows: Where Q t is the flow rate at the control section during time period t; Q′ t is the water shortage flow rate at the control section during time period t; Q min is the flow rate demand for emergency water volume scheduling at the control section; t = 1, 2,......, m, where m is the total number of calculation time periods in a year; 3.4) Obtain the annual total water shortage of the control section year by year, and the calculation method is as follows: Where, W i is the total annual water shortage occurring at the control section in the i-th year during the long-term runoff process, where i = 1, 2,..., n, and n is the total duration of the long-term runoff data in years; T is the time length of the long-term runoff data period; 3.5) Obtain the maximum value of the annual total water shortage of the control section over the years as the water volume gap of the control section in the extremely dry year, and the calculation formula is as follows: W max = max(W1, W2,..., W i ,..., W n ), i = 1, 2, ……, n Where W max is the maximum value in the total annual water shortage, i.e., the water volume gap.

8. The emergency storage capacity reservation method according to claim 1, characterized in that: In step 4), the calculation formula for the water supply capacity of each controlled reservoir in the upstream reservoir group is as follows: W wsc = V l - V dwl ; Where V dwl is the storage capacity corresponding to the dead water level of the reservoir; W wsc is the water supply capacity of a single reservoir; V l It is the minimum value of the storage capacity corresponding to the reservoir water level at a specific time node in the long series of runoff data over the years; the specific time node is the initial moment of water shortage in the control section.

9. The emergency storage capacity reservation method according to claim 1, wherein: In step 4), the method for selecting the emergency reservoir includes: 4.1) Starting from the reservoir adjacent to the control section and having the ability of weekly regulation or above, calculate the water supply capacity coefficient of the reservoirs with the ability of weekly regulation or above in the cascade reservoir group upstream of the control section in turn. If the water supply capacity coefficient K wsc ≤ 0.5, then exclude this reservoir. If the water supply capacity coefficient K wsc > 0.5, then include it in the candidate reservoirs; The calculation formula of the water supply capacity coefficient is as follows: where K wsc is the water supply capacity coefficient of the reservoir; V rs is the regulating storage capacity of the reservoir. 4.2) Starting from the control section adjacent to it, select one or more candidate reservoirs upstream in sequence as emergency reservoirs for the emergency water volume dispatch of the control section in extremely dry years.

10. The emergency storage capacity reservation method according to any one of claims 1 to 9, characterized in that: In step 5), the reserved time for the emergency storage capacity is the water shortage time of the control section in step 3); the emergency storage capacity is the water volume gap of the control section; the distribution method of the emergency storage capacity among the emergency reservoirs is as follows: Wherein, is the reserved emergency storage capacity of the j-th emergency reservoir, is the water supply capacity of the j-th emergency reservoir, j = 1, 2,......, J, where J is the total number of emergency reservoirs, and W max is the water volume deficit.

11. An emergency storage capacity reservation system for drought resistance dispatching in extremely dry years is used to implement the emergency storage capacity reservation method for drought resistance dispatching described in any one of claims 1 to 10, and is characterized in that: Including: A data storage module for storing the relevant basic information of the drought resistance dispatch control section; An emergency storage capacity reservation module for obtaining, based on the basic information stored in the data storage module, the emergency storage capacity of the cascade reservoirs upstream of the control section for drought resistance dispatch of the control section in extremely dry years, the reserved time for the emergency storage capacity, and the distribution rules of the emergency storage capacity among the emergency reservoirs.

12. An emergency storage capacity regulation method for drought-resistant operation in extremely dry years, characterized in that: Including: Obtain the emergency storage capacity of the cascade reservoirs upstream of the control section for drought resistance dispatch of the control section in extremely dry years, the reserved time for the emergency storage capacity, and the distribution rules of the emergency storage capacity among the emergency reservoirs through the emergency storage capacity reservation method for drought resistance dispatch in extremely dry years described in any one of claims 1 to 10; before the start of the reserved time for the emergency storage capacity, ensure that each emergency reservoir reserves the corresponding emergency storage capacity; during the reserved time, when extremely dry water occurs and the control section is in a drought situation and the upstream cascade reservoirs need to start emergency water volume dispatch, regulate according to the following rules: a. Maintain the original dispatch regulations of the cascade reservoirs, give priority to taking water use restriction measures, and stop the water storage of the upstream cascade reservoirs; b. If the emergency situation has not been alleviated yet, increase the lower limit of the minimum discharge flow of the emergency reservoir and activate the emergency storage capacity: when there are multiple emergency reservoirs at the control section, if the multiple emergency reservoirs are parallel reservoirs, use the minimum discharge flow of the reservoir as the basis and allocate the water supply to the downstream according to the proportion of the water storage in the reservoirs to keep the reservoirs falling synchronously; if the multiple emergency reservoirs are series reservoirs, give priority to activating the emergency storage capacity of the emergency reservoir adjacent to the control section upstream and increase the discharge flow of other emergency reservoirs to keep the reservoirs falling synchronously; c. When all emergency reservoirs have been drawn down to the dead water level, maintain the emergency reservoir storage at the dead water level and add a new emergency reservoir; the new emergency reservoir is a reservoir adjacent to the original emergency reservoir, with weekly regulation capacity or above and a water supply capacity coefficient K wsc > 0.5; d. Repeat step c until no new emergency reservoir can be added and activate the storage capacity below the dead water level; Steps a to d are executed in sequence. If the emergency situation is alleviated when executing one of them, stop executing the subsequent operations.

13. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions for causing a computer to execute the emergency storage capacity reservation method for drought resistance dispatch in extremely dry years described in any one of claims 1 to 10 or the emergency storage capacity regulation method for drought resistance dispatch in extremely dry years described in claim 12.

14. An electronic device, characterized in that: Including: A memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to execute the emergency storage capacity reservation method for drought resistance dispatch in extremely dry years described in any one of claims 1 to 10 or the emergency storage capacity regulation method for drought resistance dispatch in extremely dry years described in claim 12.

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