TOPSIS-based ecological flow calculation method adaptability evaluation system

Abstract

The invention discloses an ecological flow calculation method adaptability evaluation system based on TOPSIS, and the system comprises the steps: calculating the ecological flow of a river channel according to an ecological flow calculation method, calculating an ecological flow magnitude index and a hydrological rhythm matching degree index according to the process of the ecological flow of the river channel, and taking the process of the ecological flow of the river channel as a reservoir discharge constraint. The method comprises the following steps: constructing a reservoir generating capacity maximum optimization scheduling model coupled with ecological constraints, taking long-series historical reservoir inflow runoff of a reservoir as model input, calculating a generating capacity index and an ecological flow guarantee rate index through model solution, and planning an ecological flow magnitude index, a hydrological rhythm matching degree index, the generating capacity index and the ecological flow guarantee rate index as a whole, so as to obtain a reservoir generating capacity maximum optimization scheduling model; and a TOPSIS-based scheme optimization model is constructed, the relative proximity of index values of different ecological flow calculation methods is calculated, and the ecological flow calculation method oriented to hydropower dispatching is optimized. Technical support is provided for selecting an ecological flow calculation method and reasonably determining ecological discharge constraint in hydropower optimization scheduling.

Description

Technical Field

[0001] The invention belongs to the technical field of reservoir regulation, and in particular relates to an adaptability evaluation system for an ecological flow calculation method based on TOPSIS. Background Art

[0002] In recent years, in order to make full use of water resources, a large number of cascade reservoirs and hydropower stations have been planned and built on the main and tributary rivers in the basin. While the construction of a large number of water conservancy projects has played a beneficial role, it has also blocked the natural hydraulic connection of the river, thus causing a series of water ecology and water environment problems.

[0003] The "Yangtze River Protection Law of the People's Republic of China" (2020) clearly stipulates ecological protection and ecological restoration in the form of legal provisions, reflecting my country's high requirements for ecological regulation in the new era and its determination to implement the concept of green development.

[0004] Ecological flow is a necessary condition for ensuring the safety of river water ecosystems. As early as the 1940s, the United States first proposed the concept of minimum ecological flow to improve and maintain river water ecology and water environment, forming the prototype of ecological flow. Since the 1950s, calculation methods for ecological flow have begun to appear. Up to now, according to statistics, there are more than 240 ecological flow calculation methods at home and abroad.

[0005] Since there are many methods for calculating ecological flow at present, and the calculation results of different methods are different, for cascade reservoirs mainly used for power generation, how to evaluate the adaptability of different ecological flow calculation methods in the optimal scheduling of power generation of cascade hydropower station reservoirs, and select ecological flow calculation methods that are beneficial to river ecological protection and can maximize the power generation benefits of cascade hydropower station reservoirs, is an important issue facing the current optimal scheduling of reservoir power generation. Summary of the invention

[0006] In order to solve the deficiencies in the above-mentioned prior art, the present invention provides an adaptability evaluation system for an ecological flow calculation method based on TOPSIS. On the basis of fully analyzing the ecological flow characteristics and their impact on hydropower optimization scheduling, the present invention coordinates the ecological flow magnitude index, hydrological rhythm matching index, power generation index and ecological flow guarantee rate index, constructs a TOPSIS scheme optimization model, calculates the relative proximity of the indicator values ​​of different ecological flow calculation methods, and optimizes the ecological flow calculation method for hydropower scheduling based on this, so as to achieve the maximum possible power generation benefit of cascade hydropower station reservoirs while ensuring river ecological protection, and provide technical support for selecting ecological flow calculation methods and determining ecological discharge constraints in hydropower optimization scheduling.

[0007] The object of the present invention is achieved in that:

[0008] A TOPSIS-based adaptability evaluation system for ecological flow calculation methods.

[0009] The following steps are involved:

[0010] (1) Calculate the river ecological flow using different ecological flow calculation methods based on a long series of historical natural inflow runoff sequences;

[0011] (2) according to the river ecological flow process calculated by different ecological flow calculation methods in step (1), calculate the ecological flow magnitude index and hydrological rhythm matching index corresponding to different ecological flow calculation methods;

[0012] (3) Using the river ecological flow process calculated by different ecological flow calculation methods in step (1) as the reservoir discharge constraint, a reservoir power generation maximum optimization scheduling model coupled with ecological constraints is constructed;

[0013] (4) Using a long series of historical natural inflow runoff sequences as model input, the maximum optimal dispatch model of reservoir power generation coupled with ecological constraints is solved to calculate the power generation index and ecological flow guarantee rate index corresponding to different ecological flow calculation methods;

[0014] (5) Coordinate the ecological flow magnitude index, hydrological rhythm matching index, power generation index and ecological flow guarantee rate index, build a TOPSIS scheme optimization model, calculate the relative proximity of the index values ​​of different ecological flow calculation methods, and optimize the ecological flow calculation method for hydropower scheduling based on this.

[0015] Furthermore, the calculation method of the ecological flow magnitude index in step (2) is as follows:

[0016]

[0017] In the formula, a m,1 is the ecological flow magnitude index calculated by the mth ecological flow calculation method, m = 1, 2, ..., M; is the ecological flow of the tth month of the yth year calculated by the mth ecological flow calculation method of the ith reservoir in the cascade reservoirs, m 3 / s;T i is the length of the historical runoff sequence of the i-th reservoir, years; N is the number of cascade reservoirs, and when N=1, it means a single reservoir.

[0018] From this, we can see that the larger the ecological flow magnitude index calculated by the mth ecological flow calculation method, the better the matching degree of the mth ecological flow calculation method.

[0019] Furthermore, the hydrological rhythm matching index in step (2) includes an annual hydrological rhythm matching index and an inter-annual hydrological rhythm matching index. The calculation formula for the annual hydrological rhythm matching index is as follows:

[0020]

[0021] in,

[0022]

[0023] In the formula, a m,2 is the annual hydrological rhythm matching index of the calculation result of the mth ecological flow calculation method, m = 1, 2, ..., M; is the comprehensive average slope distance between the ecological flow process calculated by the mth ecological flow calculation method and the natural inflow runoff process of the cascade reservoirs in a year; is the natural inflow of the i-th level reservoir in the t-th month of the y-th year in the history of natural inflow, m 3 / s.

[0024] It can be seen from this that the smaller the annual hydrological rhythm matching index calculated by the mth ecological flow calculation method, the better the matching degree of the mth ecological flow calculation method.

[0025] The calculation method of the inter-annual hydrological rhythm matching index is as follows:

[0026]

[0027] in,

[0028]

[0029] In the formula, a m,3 is the inter-annual hydrological rhythm matching index of the calculation results of the mth ecological flow calculation method, m = 1, 2, ..., M; is the slope distance of two sets of equal time series constructed by the annual ecological water volume calculated by the mth ecological flow calculation method and the annual water inflow of cascade reservoirs over the years; Δt is the length of time per month, s.

[0030] It can be seen from this that the smaller the inter-annual hydrological rhythm matching index calculated by the mth ecological flow calculation method, the better the matching degree of the mth ecological flow calculation method.

[0031] Furthermore, the power generation index calculation formula in step (4) is as follows:

[0032]

[0033] In the formula, a m,4is the power generation index value of the cascade reservoirs under the constraints of the calculation results of the mth ecological flow calculation method, m = 1, 2, ..., M; is the multi-year average power generation of the cascade reservoirs under the constraints of the calculation results of the mth ecological flow calculation method, kWh.

[0034] It can be seen that the larger the power generation index calculated by the mth ecological flow calculation method, the better the matching degree of the mth ecological flow calculation method.

[0035] Furthermore, the calculation method for the multi-year average power generation of cascade reservoirs is as follows:

[0036] A long series of natural (interval) inflow runoff sequences are used as the input of the cascade reservoir optimization operation model. The results of different ecological flow calculation methods are used as the maximum model of medium- and long-term power generation of cascade reservoirs with discharge constraints, and the optimization operation simulation is carried out year by year.

[0037] Affected by the discharge constraint, for the i-th level reservoir and time period where the natural (interval) inflow cannot meet the ecological flow discharge constraint (i.e., the reservoir outflow is less than the discharge constraint), according to the reservoir dispatching regulations, in order to ensure that the reservoir water level is not lower than the dead water level, the inflow and outflow balance mode is used for dispatching during this period, that is,

[0038]

[0039] In the formula, The calculation results of the mth ecological flow calculation method are as follows: under the discharge constraint condition, for the natural (interval) inflow process in the yth year, the average outflow and inflow of the i-th reservoir in the tth period, m 3 / s; is the calculation result of the mth ecological flow calculation method. As the discharge constraint condition, for the natural (interval) inflow process in the yth year, the average output of the i-th reservoir in the tth period, kW; k i is the comprehensive output coefficient of the i-th reservoir; Q genmax,i is the maximum flow capacity of the i-th reservoir unit, m 3 / s; The calculation result of the mth ecological flow calculation method is used as the discharge constraint condition, for the natural (interval) inflow process in the yth year, the power generation head of the i-th reservoir in the t period, m; is the calculation result of the mth ecological flow calculation method as the discharge constraint condition, for the natural (interval) inflow process in the yth year, the power generation of the i-th reservoir in the t period, kWh; N max,i is the installed capacity of the i-th reservoir unit, kW; Δt′ is the number of hours in time period t, h.

[0040] The multi-year average power generation of cascade reservoirs is calculated based on the annual optimal dispatch simulation results based on a long series of natural (interval) inflow runoff sequences. The calculation formula is as follows:

[0041]

[0042] in,

[0043] {T c}={T1}∩···∩{T i}∩···∩{T N} (11)

[0044] Where, T c is the length of the natural (interval) inflow runoff sequence of each level of the cascade reservoirs; {Ti} is the natural (interval) inflow runoff sequence of the i-th level reservoir; {T c} is the natural (interval) inflow runoff sequence of each level of the cascade reservoirs.

[0045] Furthermore, the calculation formula of the ecological flow guarantee rate index in step (4) is as follows:

[0046] a m,5 =p m (12)

[0047] In the formula, a m,5 is the guarantee rate index of the calculation result of the mth ecological flow calculation method, m=1,2,…,M, a m,5 ∈(0,1]; p m is the ecological flow guarantee rate under the constraints of the calculation results of the mth ecological flow calculation method, %.

[0048] From this, we can see that the larger the ecological flow guarantee rate index calculated by the mth ecological flow calculation method, the better the matching degree of the mth ecological flow calculation method.

[0049] Furthermore, the calculation method of the ecological flow guarantee rate is as follows:

[0050] In the process of cascade reservoir power generation maximum model simulation optimization scheduling using long series of historical runoff data, the ratio of years in which reservoir discharge meets ecological flow constraints to the total scheduling simulation years is calculated as follows:

[0051]

[0052] Where Y m It is the number of years in which the reservoir discharge meets the ecological flow discharge constraint during the long series simulation optimization scheduling of the cascade reservoir maximum power generation model under the constraint of the calculation results of the mth ecological flow calculation method.

[0053] Furthermore, the index convergence calculation of the TOPSIS scheme optimization method in step (5) is as follows:

[0054] According to the different indicator values ​​calculated by different ecological flow calculation methods, the matrix A is constructed, and the attributes of each indicator in the matrix A are converged, that is, the different categories of indicators involved in the matrix A are unified into "the larger the indicator value, the better" or "the smaller the indicator value, the better" by taking the inverse and other methods. For n indicators and m ecological flow calculation methods, there is

[0055]

[0056] In the formula, a m,n Represents the nth indicator value of the mth ecological flow calculation method.

[0057] Assuming that the attributes of the first n-1 indicators are that the larger the better, and the attribute of the nth indicator is that the smaller the better, if the values ​​of all nth indicators are greater than 0, the attributes in the matrix A can be converged by the following formula.

[0058] b mn =1 / a mn (15)

[0059] The matrix A' after the indicator attributes are converged is constructed according to the following formula, see the following formula.

[0060]

[0061] Furthermore, the indicator value is normalized and the calculation method is as follows:

[0062]

[0063] In the formula, A′ mn is the value of the mth row and nth column in A', z mn A′ mn The corresponding vector normalized value.

[0064] By z mn Construct the evidence Z, which is the matrix after the indicators are normalized, as shown in the following formula.

[0065]

[0066] Furthermore, the positive ideal solution and the negative ideal solution of the normalized index are calculated, and the positive ideal solution and the negative ideal solution of the matrix Z are calculated using the following formula.

[0067]

[0068] Where max(·) is the maximum value function; Z + is the positive ideal solution matrix; Z- is the negative ideal solution matrix; min(·) is the minimum value function.

[0069] Furthermore, the Euclidean distance calculation is performed, and the positive Euclidean distance and negative Euclidean distance of each solution are calculated using the following formula.

[0070]

[0071] Where D + , D - are the positive and negative Euclidean distances of the mth ecological flow calculation method, respectively; are the values ​​of the nth column in the positive ideal solution and negative ideal solution matrices respectively.

[0072] According to D + and D - Construct the positive Euclidean distance matrix and the negative Euclidean distance matrix respectively, as shown in the following formulas.

[0073]

[0074] In the formula, [] T Represents the transposed matrix of Matrix[].

[0075] Furthermore, the relative proximity of the positive and negative ideal matrix values ​​is calculated as shown in the following formula.

[0076]

[0077] Where, L m is the relative closeness of the mth ecological flow calculation method.

[0078] Furthermore, the TOPSIS scheme optimization method in step (5) is to optimize the ecological flow calculation method according to the relative approximation of different ecological flow calculation methods, and the calculation formula is as follows:

[0079] max{L1,L2,…,L m}(25)

[0080] Where max{·} is the maximum value of the relative closeness of different ecological flow calculation methods.

[0081] Positive and beneficial effects: 1. The adaptability evaluation system of the ecological flow calculation method for hydropower scheduling proposed in the present invention comprehensively considers the indicators of the ecological flow calculation method itself and the indicators that affect the optimal scheduling of hydropower. For cascade reservoirs mainly used for power generation, it provides scientific and technological support for selecting the ecological flow calculation method adapted to the optimal scheduling of hydropower and determining the ecological discharge constraints in the process of constructing the optimal scheduling model of cascade reservoir power generation; 2. The adaptability evaluation method of the ecological flow calculation method for hydropower scheduling proposed in the present invention requires simple and easy-to-obtain data, is convenient to calculate, and has reliable results. It has important practical significance and application value for cascade reservoirs mainly used for power generation to give full play to their power generation benefits and river ecological protection benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0082] Figure 1 is a flow chart of the present invention;

[0083] Figure 2 This is the geographical topological location map of the 11-level cascade reservoirs in the Wujiang River Basin;

[0084] Figure 3 The calculation results of different ecological flow calculation methods for Hongjiadu Reservoir;

[0085] Figure 4 This is a diagram of the multi-year average power generation and ecological flow guarantee rate of the Wujiang cascade reservoirs under different ecological flow constraints. DETAILED DESCRIPTION

[0086] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0087] A TOPSIS-based ecological flow calculation method adaptability evaluation system specifically includes the following steps:

[0088] (1) Calculate the river ecological flow using different ecological flow calculation methods based on a long series of historical natural inflow runoff sequences;

[0089] (2) according to the river ecological flow process calculated by different ecological flow calculation methods in step (1), calculate the ecological flow magnitude index and hydrological rhythm matching index corresponding to different ecological flow calculation methods;

[0090] (3) Using the river ecological flow process calculated by different ecological flow calculation methods in step (1) as the reservoir discharge constraint, a reservoir power generation maximum optimization scheduling model coupled with ecological constraints is constructed;

[0091] (4) Using a long series of historical natural inflow runoff sequences as model input, the maximum optimal dispatch model of reservoir power generation coupled with ecological constraints is solved to calculate the power generation index and ecological flow guarantee rate index corresponding to different ecological flow calculation methods;

[0092] (5) Coordinate the ecological flow magnitude index, hydrological rhythm matching index, power generation index and ecological flow guarantee rate index, build a TOPSIS scheme optimization model, calculate the relative proximity of the index values ​​of different ecological flow calculation methods, and optimize the ecological flow calculation method for hydropower scheduling based on this.

[0093] Example 1

[0094] Take the 11-level reservoirs in the Wujiang River Basin, including Hongjiadu, Puding, Yinzidu, Dongfeng, Suofengying, Wujiangdu, Dahuashui, Geliqiao, Goupitan, Silin and Shatuo, as an example (see Figure 2 ), respectively using the ecological flow determination method for natural runoff time distribution (including FPE method and DPE method), Tennant method, minimum monthly mean runoff method (MMR), Q p The ecological flow calculation hydrological method is used to calculate the ecological flow process of the Wujiang cascade reservoirs based on the historical long series of monthly average natural runoff data at the dam sites of the Wujiang cascade reservoirs in the Wujiang River Basin from 1952 to 2019. Figure 3 The annual average ecological flow of different ecological flow calculation methods is shown in Table 1 (to reduce space, only Hongjiadu Reservoir is used as an example for presentation).

[0095] Table 1 Annual average ecological flow of Hongjiadu Reservoir using different ecological flow calculation methods

[0096]

[0097] Based on the annual average ecological flow of each cascade reservoir calculated using different ecological flow calculation methods, the ecological flow magnitude indicators of the 11-level cascade reservoirs of the Wujiang River are calculated (see Table 2).

[0098] Based on a series of natural monthly historical average runoff data from the dam sites of each reservoir in the Wujiang River Basin from 1952 to 2019 and the calculation results of different ecological flow calculation methods, the annual slope distance between the calculation results of different ecological flow of each reservoir in the cascade and the natural water inflow process within the year, and the comprehensive slope distance between the calculation results of different ecological flow calculation methods of each reservoir in the cascade and the natural water inflow process within the year, the annual hydrological rhythm matching index of different ecological flow calculation methods of the Wujiang River cascade was calculated, see Table 2.

[0099] According to the calculation method of the inter-annual hydrological rhythm matching index, the inter-annual hydrological rhythm matching index values ​​of the cascade reservoirs in the Wujiang River Basin were calculated, see Table 2.

[0100] The results of different ecological flow calculation methods are used as ecological discharge constraints to construct a model for the maximum optimal dispatching of power generation of the Wujiang cascade reservoirs coupled with ecological constraints. The water levels at the beginning and end of the dispatching period of each reservoir are the multi-year average reservoir water levels at the beginning and end of the corresponding reservoir. The historical monthly average runoff data of the dam sites of each reservoir in the Wujiang River Basin from 1952 to 2019 are used as the model input. Through year-by-year optimization simulation, the multi-year average power generation and ecological flow guarantee rate of the cascade reservoirs under the constraints of the calculation results of different ecological flow calculation methods are calculated. Figure 4 .

[0101] According to the calculation results of the multi-year average power generation and ecological flow destruction rate of the Wujiang cascade reservoirs under different ecological flow constraints, the power generation index and ecological flow guarantee rate index of the Wujiang cascade reservoirs under different ecological flow constraints are calculated, see Table 2.

[0102] Table 2 Evaluation indexes of adaptability of ecological flow calculation method for Wujiang cascade reservoirs

[0103]

[0104] According to the above-calculated ecological flow magnitude index, annual hydrological rhythm matching index, inter-annual hydrological rhythm matching index, power generation index and ecological flow guarantee rate index of the Wujiang cascade reservoirs, the TOPSIS scheme optimization model was used to calculate the relative proximity of the index values ​​of different ecological flow calculation methods in the optimal scheduling of power generation of the Wujiang cascade reservoirs, and the maximum value of the relative proximity was determined, which is the optimal ecological flow calculation method, see Table 3.

[0105] Table 3 Relative closeness of index values ​​of different ecological flow calculation methods

[0106] Method Name FPE DPE Tmin TGeneral T Good TGood Relative closeness 0.695 0.829 0.510 0.558 0.481 0.440 The method name T is fine MMR <![CDATA[Q 90 -year]]> <![CDATA[Q 95 -year]]> <![CDATA[Q 90 -Month]]> <![CDATA[Q 95 -Month]]> Relative closeness 0.484 0.623 0.567 0.557 0.768 0.804

[0107] As shown in Table 3, according to the relative closeness calculation results of the index values ​​of different ecological flow calculation methods in the optimal dispatch of Wujiang cascade reservoir power generation, the adaptability of different ecological flow calculation methods in hydropower optimal dispatch is as follows: DPE method, Q 95 (calculated on a monthly basis), Q 90 (Calculated on a monthly basis) It has good adaptability, and its comprehensive evaluation indicators are all above 0.7, among which the DPE method is the most adaptable, and its relative proximity is 0.829; the adaptability of the three flow states of "good", "good" and "very good" by the Tennant method is poor, and its comprehensive evaluation indicators are all below 0.5, among which the adaptability of the "good" flow state of the Tennant method is the worst, and its relative proximity is 0.440.

[0108] The method of the present invention starts from the calculation results of the ecological flow calculation method and its impact on hydropower optimization scheduling, coordinates the ecological flow magnitude index, hydrological rhythm matching index, power generation index and ecological flow guarantee rate index, constructs a TOPSIS optimization scheme, calculates the relative proximity of the indicator values ​​of different ecological flow calculation methods, and optimizes the ecological flow calculation method for hydropower scheduling based on this, which provides scientific and technological support for the selection of ecological flow calculation methods and the reasonable determination of ecological discharge constraints in hydropower optimization scheduling.

Claims

1. A TOPSIS-based ecological flow calculation method adaptability evaluation system, characterized in that: The following steps are involved: (1) Calculate the river ecological flow using different ecological flow calculation methods based on a long series of historical natural inflow runoff sequences; (2) according to the river ecological flow process calculated by different ecological flow calculation methods in step (1), calculate the ecological flow magnitude index and hydrological rhythm matching index corresponding to different ecological flow calculation methods; (3) Using the river ecological flow process calculated by different ecological flow calculation methods in step (1) as the reservoir discharge constraint, a reservoir power generation maximum optimization scheduling model coupled with ecological constraints is constructed; (4) Using a long series of historical natural inflow runoff sequences as model input, the maximum optimal dispatch model of reservoir power generation coupled with ecological constraints is solved to calculate the power generation index and ecological flow guarantee rate index corresponding to different ecological flow calculation methods; (5) Coordinate the ecological flow magnitude index, hydrological rhythm matching index, power generation index and ecological flow guarantee rate index, build a TOPSIS scheme optimization model, calculate the relative proximity of the index values ​​of different ecological flow calculation methods, and optimize the ecological flow calculation method for hydropower scheduling based on this.

2. The adaptability evaluation system of the ecological flow calculation method based on TOPSIS according to claim 1 is characterized by: The calculation method of the ecological flow magnitude index in step (2) is as follows: In the formula, a m,1 is the ecological flow magnitude index of the calculation result of the mth ecological flow calculation method, m = 1, 2, ..., M; is the ecological flow of the tth month of the yth year calculated by the mth ecological flow calculation method of the ith reservoir in the cascade reservoirs, m 3 / s;T i is the length of the historical runoff sequence of the i-th reservoir, in years; N is the number of cascade reservoirs, and when N=1, it is a single reservoir; From this, we can see that the larger the ecological flow magnitude index calculated by the mth ecological flow calculation method, the better the matching degree of the mth ecological flow calculation method.

3. The adaptability evaluation system of the ecological flow calculation method based on TOPSIS according to claim 1 is characterized by: The hydrological rhythm matching index in step (2) includes an intra-annual hydrological rhythm matching index and an inter-annual hydrological rhythm matching index.

4. The adaptability evaluation system of the ecological flow calculation method based on TOPSIS according to claim 3 is characterized by: The calculation formula for the hydrological rhythm matching index within the year is as follows: in, In the formula, a m,2 is the annual hydrological rhythm matching index of the calculation result of the mth ecological flow calculation method, m = 1, 2, ..., M; is the comprehensive average slope distance between the ecological flow process calculated by the mth ecological flow calculation method and the natural inflow runoff process of the cascade reservoirs in a year; is the natural inflow of the i-th level reservoir in the historical natural inflow of the t-th month of the y-th year, m 3 / s; annual hydrological rhythm matching index; It can be seen from this that the smaller the annual hydrological rhythm matching index calculated by the mth ecological flow calculation method, the better the matching degree of the mth ecological flow calculation method.

5. The adaptability evaluation system of the ecological flow calculation method based on TOPSIS according to claim 3 is characterized by: The calculation method of the inter-annual hydrological rhythm matching index is as follows: in, In the formula, a m,3 is the inter-annual hydrological rhythm matching index of the calculation results of the mth ecological flow calculation method, m = 1, 2, ..., M; is the slope distance of two sets of equal time series constructed by the annual ecological water volume calculated by the mth ecological flow calculation method and the annual water inflow of the cascade reservoirs over the years; Δt is the length of time per month, s; It can be seen from this that the smaller the inter-annual hydrological rhythm matching index calculated by the mth ecological flow calculation method, the better the matching degree of the mth ecological flow calculation method.

6. The adaptability evaluation system of the ecological flow calculation method based on TOPSIS according to claim 1 is characterized by: The power generation index calculation formula in step (4) is as follows: In the formula, a m,4 is the power generation index value of the cascade reservoirs under the constraints of the calculation results of the mth ecological flow calculation method, m = 1, 2, ..., M; is the multi-year average power generation of the cascade reservoirs under the constraints of the calculation results of the mth ecological flow calculation method, kWh; It can be seen that the larger the power generation index calculated by the mth ecological flow calculation method, the better the matching degree of the mth ecological flow calculation method.

7. The adaptability evaluation system of the ecological flow calculation method based on TOPSIS according to claim 6 is characterized by: The calculation method for the multi-year average power generation of cascade reservoirs is as follows: A long series of natural (interval) inflow runoff sequences are used as the input of the cascade reservoir optimization operation model. The results of different ecological flow calculation methods are used as the maximum model of medium- and long-term power generation of cascade reservoirs with discharge constraints, and the optimization operation simulation is carried out year by year. Affected by the discharge constraint, for the i-th level reservoir and time period where the natural (interval) inflow cannot meet the ecological flow discharge constraint (i.e., the reservoir outflow is less than the discharge constraint), according to the reservoir dispatching regulations, in order to ensure that the reservoir water level is not lower than the dead water level, the inflow and outflow balance mode is used for dispatching during this period, that is, In the formula, The calculation results of the mth ecological flow calculation method are as follows: under the discharge constraint condition, for the natural (interval) inflow process in the yth year, the average outflow and inflow of the i-th reservoir in the tth period, m 3 / s; is the calculation result of the mth ecological flow calculation method. As the discharge constraint condition, for the natural (interval) inflow process in the yth year, the average output of the i-th reservoir in the tth period, kW; k i is the comprehensive output coefficient of the i-th reservoir; Q genmax,i is the maximum flow capacity of the i-th reservoir unit, m 3 / s; The calculation result of the mth ecological flow calculation method is used as the discharge constraint condition, for the natural (interval) inflow process in the yth year, the power generation head of the i-th reservoir in the t period, m; is the calculation result of the mth ecological flow calculation method as the discharge constraint condition, for the natural (interval) inflow process in the yth year, the power generation of the i-th reservoir in the t period, kWh; N max,i is the installed capacity of the i-th reservoir unit, kW; Δt′ is the number of hours in period t, h; The multi-year average power generation of cascade reservoirs is calculated based on the annual optimal dispatch simulation results based on a long series of natural (interval) inflow runoff sequences. The calculation formula is as follows: in, {T c }={T1}∩···∩{T i }∩···∩{T N } Where, T c is the length of the natural (interval) inflow runoff sequence of each level of the cascade reservoirs; {Ti} is the natural (interval) inflow runoff sequence of the i-th level reservoir; {T c } is the natural (interval) inflow runoff sequence of each level of the cascade reservoirs.

8. The adaptability evaluation system of the ecological flow calculation method based on TOPSIS according to claim 1 is characterized in that: The calculation formula of the ecological flow guarantee rate index in step (4) is as follows: a m,5 =p m In the formula, a m,5 is the guarantee rate index of the calculation result of the mth ecological flow calculation method, m=1,2,…,M,am,5∈(0,1]; p m is the ecological flow guarantee rate under the constraints of the calculation results of the mth ecological flow calculation method, %; From this, we can see that the larger the ecological flow guarantee rate index calculated by the mth ecological flow calculation method, the better the matching degree of the mth ecological flow calculation method.

9. The adaptability evaluation system of the ecological flow calculation method based on TOPSIS according to claim 8 is characterized in that: The calculation method of ecological flow guarantee rate is as follows: In the process of cascade reservoir power generation maximum model simulation optimization scheduling using long series of historical runoff data, the ratio of years in which reservoir discharge meets ecological flow constraints to the total scheduling simulation years is calculated as follows: Where Y m It is the number of years in which the reservoir discharge meets the ecological flow discharge constraint during the long series simulation optimization scheduling of the cascade reservoir maximum power generation model under the constraint of the calculation results of the mth ecological flow calculation method.

10. The adaptability evaluation system of the ecological flow calculation method based on TOPSIS according to claim 1 is characterized by: According to step (5), a TOPSIS optimization scheme is constructed to calculate the relative proximity of the index values ​​of different ecological flow calculation methods, and based on this, the ecological flow calculation method for hydropower scheduling is optimized.

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