CN115860421A

CN115860421A - Ecological flow dynamic calculation method and system adaptive to target guarantee rate

Info

Publication number: CN115860421A
Application number: CN202211678897.4A
Authority: CN
Inventors: 张明波; 邴建平; 邓鹏鑫; 徐长江; 贾建伟; 邹振华; 邵骏; 王栋; 徐伟峰
Original assignee: Bureau of Hydrology Changjiang Water Resources Commission
Current assignee: Bureau of Hydrology Changjiang Water Resources Commission
Priority date: 2022-12-26
Filing date: 2022-12-26
Publication date: 2023-03-28
Anticipated expiration: 2042-12-26
Also published as: CN115860421B

Abstract

The invention provides an ecological flow dynamic calculation method and system adaptive to a target guarantee rate, wherein the method comprises the following steps: determining a distribution difference coefficient of runoff in a year according to a target guarantee rate based on target section runoff historical data; wherein the annual distribution difference coefficient of the runoff is the ratio of daily average runoff to monthly average runoff corresponding to the target section at the target guarantee rate; determining the annual runoff withering difference coefficient according to the target section flow edge distribution; wherein the runoff annual withering difference coefficient represents the difference of runoff annual withering change; and determining an ecological flow target value based on the runoff annual distribution difference coefficient and the runoff annual withering difference coefficient. The hydrologic evolution characteristics and management and assessment targets can be scientifically and reasonably combined, the reasonability and accuracy of ecological flow calculation are effectively improved, and powerful technical support is provided for basin ecological flow monitoring, early warning and management protection.

Description

Ecological flow dynamic calculation method and system adaptive to target guarantee rate

Technical Field

The invention relates to the technical field of hydrology and water resources, in particular to an ecological flow dynamic calculation method and system adaptive to a target guarantee rate.

Background

The guarantee of the ecological flow of rivers and lakes is an important measure for maintaining the health of rivers and lakes, and the great deal of ecological civilization construction and water conservancy reform development is concerned. The method aims at maintaining the functions of the river and lake ecological system, scientifically determines the ecological flow, strictly manages the ecological flow, strengthens the monitoring and early warning of the ecological flow, and quickens the establishment of a river and lake ecological flow determination and guarantee system which has reasonable target, clear responsibility, powerful guarantee and effective supervision.

The ecological traffic can be divided into basic ecological traffic and target ecological traffic. The basic ecological flow is the minimum flow in the river channel which maintains the basic form and the basic ecological function of the river, prevents the river channel from cutting off, and avoids the situation that the aquatic organism community of the river is damaged by the restoration; the target ecological flow refers to the amount of water which needs to be reserved in the river course and maintains the normal performance of the ecological environment function corresponding to the ecological environment protection target given by rivers, lakes and marshes. Obviously, whether the basic ecological flow or the target ecological flow needs to meet a certain protection target, so the determination of the ecological flow needs to be coordinated with the river protection and management target.

At the present stage, the river and lake ecological flow control is mostly examined by taking basic ecological flow as a target, and the standard reaching rate of the basic ecological flow of the key river and lake is generally required to be not lower than 90%. However, the target ecological flow is often low in standard reaching rate in actual assessment and cannot meet the management requirement. For rivers with large annual variation difference in runoff years, the river is controlled by adopting basic ecological flow with a single numerical value, cannot adapt to the natural hydrological situation change characteristics of a drainage basin, and is difficult to meet the requirements of ecological base flow standard reaching rate in flat and dry water years.

Therefore, how to provide a method and a system for dynamically calculating ecological traffic adaptive to a target guarantee rate to improve the rationality and accuracy of ecological traffic calculation becomes an urgent problem to be solved.

Disclosure of Invention

Aiming at the defects in the prior art, the embodiment of the invention provides an ecological flow dynamic calculation method and system adaptive to a target guarantee rate.

The invention provides an ecological flow dynamic calculation method adaptive to a target guarantee rate, which comprises the following steps:

determining a distribution difference coefficient of runoff in a year according to a target guarantee rate based on the historical data of the runoff of the target section; wherein the annual distribution difference coefficient of the runoff is the ratio of daily average runoff to monthly average runoff corresponding to the target section at the target guarantee rate;

determining a runoff annual withering difference coefficient according to the target section flow edge distribution; wherein the runoff annual withering difference coefficient represents the difference of runoff annual withering change;

and determining the ecological flow target value based on the runoff annual distribution difference coefficient and the runoff annual withering difference coefficient.

The invention also provides an ecological flow dynamic calculation system adapting to the target guarantee rate, which comprises the following steps: the system comprises a distribution difference calculating unit, a withering difference calculating unit and an ecological flow calculating unit;

the distribution difference calculating unit is used for determining a distribution difference coefficient within a runoff year according to a target guarantee rate based on the historical data of the runoff of the target section; wherein the annual distribution difference coefficient of the runoff is the ratio of daily average runoff to monthly average runoff corresponding to the target section at the target guarantee rate;

the rich-lean difference calculating unit is used for determining a runoff annual rich-lean difference coefficient according to the target section flow edge distribution; wherein the runoff annual withering difference coefficient represents the difference of runoff annual withering change;

and the ecological flow calculation unit is used for determining an ecological flow target value based on the runoff annual distribution difference coefficient and the runoff annual peak-to-peak difference coefficient.

The invention also provides an electronic device, which comprises a memory, a processor and a computer program which is stored on the memory and can run on the processor, wherein when the processor executes the program, the steps of any one of the above ecological flow dynamic calculation methods for adapting the target guarantee rate are realized.

The present invention also provides a non-transitory computer readable storage medium, on which a computer program is stored, which when executed by a processor, implements the steps of any of the above methods for dynamically calculating ecological flow rate adapted to a target guaranteed rate.

According to the ecological flow dynamic calculation method and system adaptive to the target guarantee rate, provided by the invention, through the research on the historical data of the runoff of the target section, the natural hydrological situation change characteristics of a drainage basin are considered, the annual distribution difference coefficient and annual runoff peak-to-peak difference coefficient of the runoff are defined, the ecological flow dynamic control target in different time periods in the year is scientifically determined, and the rationality and the accuracy of ecological flow calculation are effectively improved.

Drawings

In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings needed for the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.

FIG. 1 is a flow chart of a dynamic calculation method of ecological flow adaptive to a target guarantee rate according to the present invention;

FIG. 2 is a fitting graph of the edge distribution of runoff in 6 months on the A section provided by the invention;

FIG. 3 is an edge distribution fitting graph of the annual assessment target flow of the section A provided by the invention;

FIG. 4 is a combined distribution fitting graph of runoff at a section of 6 months and annual assessment target flow provided by the invention;

FIG. 5 is an ecological flow dynamic control target with section A satisfying target cooperative adaptation provided by the present invention;

FIG. 6 is a box chart of the annual warranty rate of the dynamic control target of ecological flow with different cross sections according to the invention;

FIG. 7 is a schematic structural diagram of an ecological flow dynamic calculation system adapted to a target guarantee rate according to the present invention;

fig. 8 is a schematic physical structure diagram of an electronic device provided in the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

At the present stage, the river and lake ecological flow control is mostly examined by taking basic ecological flow as a target, and the standard reaching rate of the basic ecological flow of the key river and lake is generally required to be not lower than 90%. Although the target ecological flow is widely researched in the academic world, an effective method is still lacked, the standard reaching rate is low in the practical assessment of the ecological flow, and the management requirement cannot be met.

The basic ecological flow is mostly determined in a single value, the method of hydrology, hydraulics and the like is adopted for calculation, and for rivers with small annual change difference in runoff year, the calculated ecological flow basically can meet the requirement of an assessment control target.

However, for rivers with large annual variation difference in runoff years, the river is controlled by adopting basic ecological flow with a single numerical value, the natural hydrological situation change characteristics of the drainage basin cannot be adapted, and the goal that the standard reaching rate of ecological basic flow in flat and dry water years is not lower than 90% is difficult to meet. Even if the water amount of part of full water years is excessively concentrated in the flood season, the condition that the annual assessment is seriously not up to the standard still occurs. In addition, due to the influence of climate change and human activities, the measured runoff sequence often has non-stationary change, and the uncertainty of the inflow water further aggravates the difficulty of single-value assessment of ecological flow.

Therefore, in order to effectively promote the scientificity and rationality of ecological flow formulation, a dynamic management and control mechanism of an ecological flow target is needed to be established, the natural hydrological situation change characteristics of a basin can be met, the ecological flow management can be strict, and the river and lake ecological flow determination and guarantee system construction can be effectively promoted.

How to accurately, reasonably and efficiently determine the ecological flow target is one of the problems to be solved urgently in the fields of hydrological analysis and ecological environment protection, and is also a key point and a foundation for effectively promoting the construction of an ecological flow guarantee system.

Fig. 1 is a flowchart of an ecological traffic dynamic calculation method adapted to a target guaranteed rate, as shown in fig. 1, the present invention provides an ecological traffic dynamic calculation method adapted to a target guaranteed rate, including:

s1, determining annual distribution difference coefficients of runoff based on historical data of the runoff of a target section according to a target guarantee rate; wherein the annual distribution difference coefficient of the runoff is the ratio of daily average runoff to monthly average runoff corresponding to the target section at the target guarantee rate;

s2, determining a runoff annual peak-to-peak difference coefficient according to the flow edge distribution of the target cross section; wherein, the runoff annual withering difference coefficient represents the difference of runoff annual withering change;

and S3, determining an ecological flow target value based on the runoff intra-year distribution difference coefficient and the runoff annual withering difference coefficient.

Specifically, a section of a researched river reach is selected, and ecological flow management and assessment requirements and a guarantee rate limit value of the target section are determined. In the comprehensive current stage of ecological flow management assessment practice, assessment requirements are annual assessment, a guarantee rate is taken as an assessment index, and a guarantee rate not lower than 90% is taken as an assessment limit value. In the invention, the guarantee rate of the assessment target is recorded as P, and different values can be set according to the assessment requirement on the guarantee rate and the assessment time.

After the research section is determined, the runoff history of the target section is collected and sortedAnd data including natural monthly runoff and actually measured daily runoff series of the target section length series. Setting the series of natural monthly runoff of the section as Q (i, j), wherein i is a series of years, and j is a month; the section actual measurement daily runoff series is marked as Q _c (i, j, k), i being the series of years, j being the month, k being the number of days. Generally, the years of the historical data series are not less than 20 years, and the specific time length can be adjusted according to actual conditions.

After the historical data and the target guarantee rate of the runoff of the target section are determined, in step S1, based on the historical data of the runoff of the target section, a quantile method is adopted to calculate the ratio of the daily average runoff to the monthly average runoff corresponding to the target guarantee rate of the section in different periods, the annual distribution difference coefficient of the runoff is determined, and the annual distribution difference coefficient is defined as K ₁ 。

In step S2, a probability analysis theory is introduced, edge distribution of flow corresponding to the target guarantee rate in the year-month period is determined, a runoff annual peak-to-peak difference coefficient is determined according to the target cross-section flow edge distribution, and the annual peak-to-peak difference coefficient is defined to be K ₂ 。

It can be understood that the runoff annual abundance difference coefficient represents the difference of runoff annual abundance change, the specific expression form and the calculation formula can be designed according to the actual situation, and the invention is not limited to this.

In step S3, based on the distribution difference coefficient and the annual peak-to-background difference coefficient of the runoff, the annual and annual change difference coefficient of the runoff is coupled, the ecological flow dynamic control target meeting the target cooperative adaptation is corrected and calculated, and the ecological flow target value is determined.

It can be understood that the specific calculation formula for correcting the ecological flow according to the distribution difference coefficient in the runoff year and the runoff annual rich-wither difference coefficient is matched with the expression form of the distribution difference coefficient in the runoff year and the runoff annual rich-wither difference coefficient, the specific calculation formula can be designed according to actual requirements, and the invention is not limited to this.

According to the dynamic ecological flow calculation method adaptive to the target guarantee rate, provided by the invention, through the research on the historical data of the runoff of the target section, the natural hydrological situation change characteristics of a drainage basin are considered, the annual distribution difference coefficient and the annual peak-to-peak difference coefficient of the runoff are defined, the dynamic control target of the ecological flow in different time periods in the year is scientifically determined, and the rationality and the accuracy of the ecological flow calculation can be effectively improved. The problems that in the prior art, the annual difference of runoff is large in year and the annual water quantity is uncertain, so that the basic ecological flow with a single numerical value cannot adapt to the natural hydrological situation change characteristics of a watershed and the setting of basic ecological flow data is not scientific are effectively solved.

Optionally, the dynamic calculation method for ecological flow adaptive to the target securing rate, provided by the invention, determines the annual distribution difference coefficient of runoff according to the target securing rate based on the historical data of runoff of the target cross section, and specifically includes:

determining the target guarantee rate flow of the section according to the target guarantee rate based on the target section runoff historical data; wherein, the section target guarantee rate flow includes: section target guarantee rate monthly runoff and section target guarantee rate daily runoff; the section target guarantee rate monthly runoff is the monthly average runoff corresponding to the target section under the target guarantee rate; the section target guarantee rate daily runoff is daily average runoff corresponding to each month of the target section at the target guarantee rate;

and determining the annual distribution difference coefficient of the runoff according to the section target guarantee rate monthly runoff and the section target guarantee rate daily runoff.

Specifically, in the target section runoff historical data, a section natural monthly runoff series is marked as Q (i, j), i is a series of years, and j is a month; the series of the section actual measurement daily runoff is marked as Q _c (i, j, k), i being the series of years, j being the month, k being the number of days.

And calculating the flow corresponding to the target guarantee rate of the section at different time intervals (namely the flow of the target guarantee rate of the section) by adopting a quantile method according to the target guarantee rate. The section target guaranteed rate flow comprises the following steps: section target guarantee rate monthly runoff and section target guarantee rate daily runoff.

The section target guarantee rate monthly runoff is the monthly average runoff corresponding to the target section at the target guarantee rate, and in the section natural monthly runoff series, the quantile method is adopted to respectively calculate the flow value corresponding to each monthly runoff of the section at the target guarantee rate P, and the flow value is marked as Q _p (j) The expression is:

in the formula, Q _p (j) Representing the flow corresponding to the j month under the target guarantee rate P; percentile () represents a Percentile function; p represents a target guarantee rate; q (i, j) represents a section natural moon flow series; n is the series of years, generally not less than 20 years.

The section target guarantee rate daily runoff is daily average runoff corresponding to each month of the target section at the target guarantee rate, and flow values corresponding to the daily average runoff of each month of the section at the target guarantee rate P are respectively calculated by adopting a quantile method and are recorded as Q 'based on the section actual measurement daily runoff series' _p (j) The expression is:

of formula (II) Q' _p (j) Representing the average daily flow corresponding to the target guarantee rate P in the j-th month; percentile () represents a Percentile function; p represents a target guarantee rate; q _c (i, j, k) represents the section actual measurement daily runoff series; n is the serial years; m is the total number of days in the series of years.

And calculating the ratio of the average runoff per month and the average runoff per month corresponding to the target guarantee rate according to the target guarantee rate monthly runoff and the target guarantee rate daily runoff of the section, and determining the annual distribution difference coefficient of the runoff.

The expression of the distribution difference coefficient in the runoff year is as follows:

K ₁ (j)＝Q' _p (j)/Q _P (j),j＝1,2,…,1…，12

in the formula, K ₁ (j) Indicating the intra-year distribution coefficient for month j.

According to the dynamic ecological flow calculation method adaptive to the target guarantee rate, through the research on the historical data of the runoff of the target section, the natural hydrological situation change characteristics of a drainage basin are considered, the ratio of the daily average runoff to the monthly average runoff corresponding to the target guarantee rate is defined as the annual distribution difference coefficient of the runoff, the annual distribution difference coefficient of the runoff can effectively reflect the difference of average value changes of the flow in different years, the basic ecological flow data is corrected by combining the annual peak difference coefficient of the runoff, and the rationality and the accuracy of ecological flow calculation can be effectively improved.

Optionally, according to the dynamic calculation method for ecological flow adaptive to the target guarantee rate provided by the present invention, the ecological flow target value is determined based on the annual distribution difference coefficient of runoff and the annual peak-to-peak difference coefficient of runoff, and the method specifically includes:

constructing a hydrological frequency curve of each month according to a frequency curve method based on the historical data of the runoff of the target cross section;

calculating the corresponding flow when the target guarantee rate is met according to the hydrological frequency curve of each month, and determining the lunar standard value of the ecological flow;

correcting the ecological flow monthly reference value based on the runoff annual distribution difference coefficient and the runoff annual withering difference coefficient, and determining the ecological flow monthly target value;

and determining the ecological flow target value based on the ecological flow monthly target value and the target guarantee rate.

Specifically, after the distribution difference coefficient and the runoff annual peak-to-peak difference coefficient are determined based on the runoff year, the basic ecological flow is corrected through the distribution difference coefficient and the runoff annual peak-to-peak difference coefficient in the runoff year.

And constructing a hydrological frequency curve of each month according to a frequency curve method based on the historical data of the runoff of the target section. And calculating the corresponding flow when the target guarantee rate is met based on the hydrological frequency curve of each month and according to the target guarantee rate, and determining the lunar standard value of the ecological flow.

The frequency curve method is a basic method for hydrologic analysis and calculation, namely, a hydrologic frequency curve of each month is constructed by using the average monthly flow or runoff of long-series hydrologic data, the average monthly flow or runoff corresponding to the assessment target frequency P is used as the monthly standard value of the ecological flow of the river control section of the corresponding month and is marked as Q _c (j)。

Based on the runoff annual distribution difference coefficient and the runoff annual abundance differenceThe difference coefficient, the coupling runoff annual and annual variation difference coefficient, the correction ecological flow monthly reference value Q _c (j) Determining the monthly target value Q of the ecological flow _pc (j)。

And (3) correcting and calculating an ecological flow dynamic control target meeting the target cooperative adaptation, wherein the expression is as follows:

Q _pc (j)＝K ₁ (j)×K ₂ (j)×Q _c (j),j＝1,2,…,1…，12

in the formula, K ₁ (j) Represents the intra-year distribution difference coefficient for month j; k ₂ (j) The annual common difference coefficient of runoff in the jth month; q _c (j) The ecological flow monthly standard value of the j month; q _pc (j) And meeting the ecological flow dynamic control target value (ecological flow monthly target value) of the target cooperative adaptation for the j month.

Determining the monthly target value Q of ecological flow _pc (j) And then, determining the ecological flow target value based on the ecological flow monthly target value, the ecological flow annual assessment standard and the target guarantee rate requirement.

Based on the annual dynamic control target of the ecological flow, the basic ecological flow is calculated by a quantile method, and the expression is as follows:

in the formula, Q _ji Representing basic ecological flow; qpc (j) is an ecological flow dynamic control target value meeting target cooperative adaptation in the jth month; percentile () represents a Percentile function; p represents a target guarantee rate.

According to the ecological flow dynamic calculation method adaptive to the target guarantee rate, provided by the invention, through the research on the historical data of the runoff of the target section, the natural hydrological situation change characteristics of a drainage basin are considered, the annual distribution difference coefficient and the annual common peak difference coefficient of the runoff are defined, the ecological flow dynamic control target (ecological flow dynamic control target value) in different periods of the year is scientifically determined, the target value of the basic ecological flow is specifically refined to the month, and the rationality and the accuracy of the ecological flow calculation can be effectively improved on the basis of the assessment. The problem that in the prior art, the annual difference of runoff is large in years and the annual water quantity is uncertain, so that basic ecological flow with a single numerical value cannot adapt to the natural hydrological situation change characteristics of a drainage basin, and the setting of basic ecological flow data is not scientific is examined.

Optionally, according to the dynamic calculation method of ecological flow adaptive to the target guarantee rate provided by the present invention, after the step of determining the target value of ecological flow based on the annual distribution difference coefficient of runoff and the annual peak-to-peak difference coefficient of runoff, the method further includes:

and determining the actual guarantee rate according to a frequency method based on the ecological flow target value and the flow data of the target section.

Specifically, after the step of calculating the basic ecological flow target value, daily average ecological flow reachability evaluation can be performed by adopting a frequency method from the perspective of the month and the year according to the annual assessment standard and the guarantee rate requirement of the ecological flow.

The frequency method has the following calculation formula:

PR _i ＝A _i /B _i ×100

in the formula: PR _i In order to control the degree of satisfaction of the section ecological flow target,%; a. The _i The number of samples is greater than or equal to the daily average flow of the ecological flow guarantee target in the evaluation period; b _i The total number of day-by-day average flow samples participating in ecological flow guarantee target satisfaction condition evaluation in the evaluation period is obtained.

It is understood that in calculating the actual assurance rate, the data sources may be historical data, simulated data, actual data of the year, and the like. The actual guarantee rate is calculated by taking the historical data as a sample, so that whether the ecological flow target value calculated by the method meets the target guarantee rate or not can be effectively judged, and whether the calculation is wrong or not can be judged. By taking the simulation data as a sample, a drainage basin ecological flow monitoring, early warning, management and protection scheme can be simulated, and feasibility analysis is carried out. The assessment condition of the current-year target section ecological flow can be determined by taking the current-year actual data as a sample. The specific application scenario may be adjusted according to actual requirements, which is not limited in the present invention.

According to the ecological flow dynamic calculation method adaptive to the target guarantee rate, provided by the invention, through the research on the historical data of the runoff of the target section, the natural hydrological situation change characteristics of a basin are considered, the distribution difference coefficient and the annual peak-to-valley difference coefficient of the runoff are defined, the ecological flow dynamic control target at different time intervals in the year is scientifically determined, and the rationality and the accuracy of the ecological flow calculation can be effectively improved. The problem that in the prior art, the annual difference of runoff is large in years and the annual water quantity is uncertain, so that basic ecological flow with a single numerical value cannot adapt to the natural hydrological situation change characteristics of a drainage basin, and the setting of basic ecological flow data is not scientific is examined. And the accessibility of the target ecological flow is evaluated by a frequency method, so that powerful technical support is provided for monitoring, early warning, managing and protecting the drainage basin ecological flow.

Optionally, according to the dynamic calculation method of ecological flow adaptive to the target guarantee rate provided by the present invention, the annual runoff abundance difference coefficient is determined according to the target cross-section flow edge distribution, and specifically includes:

determining the monthly average flow edge distribution of the target section according to an edge distribution function;

determining annual assessment target flow edge distribution according to the monthly average flow edge distribution of the target section;

and determining the runoff annual withering difference coefficient according to the monthly average flow edge distribution of the target section and the annual assessment target flow edge distribution.

Specifically, the target cross-sectional flow edge distribution utilized in the present invention includes: monthly average flow edge distribution of a target section and annual assessment target flow edge distribution.

And based on the historical data of the runoff of the target section, introducing a probability analysis theory, and determining the monthly average flow edge distribution of the target section according to an edge distribution function.

Determining the natural monthly runoff Q (i, j) of the section according to the monthly average flow edge distribution of the target section, and calculating the target guarantee year by year on the basis of the natural monthly runoff Q (i, j) of the sectionThe monthly average flow rate corresponding to the rate is obtained to obtain an annual assessment target flow rate series Q _y (i) And further determining annual assessment target flow edge distribution.

Annual assessment target flow series Q _y (i) The expression is as follows:

in the formula, Q _y (i) Representing the flow corresponding to the target guarantee rate P in the ith year; percentile () represents a Percentile function; p represents a target guarantee rate; q (i, j) represents a section natural moon flow series; n is the series years.

It is understood that the edge distribution is typically selected from the group consisting of Pearson type III (P-III), exponential (EXP), extreme Value (GEV), and lognormal distribution (lognormal normal distribution, LOGN), etc., the specific type of edge distribution can be selected according to practical requirements in the practical application process of the present invention, which is not limited by the present invention.

Defining the difference coefficient of annual common blight as K ₂ And the conditional probability is the conditional probability of the annual assessment target reaching the standard, is comprehensively determined by the co-occurrence probability of the combined distribution of the monthly flow and the annual assessment target flow, and represents the difference of the rich and lean change of the runoff between the annual periods.

According to the monthly average flow edge distribution and the annual assessment target flow edge distribution of the target section, the co-occurrence probability P of the monthly average flow and the annual assessment target flow joint distribution is solved by a mathematical method ₁ [Q(i,j),Q _y (i)]And further calculating the conditional probability of reaching the standard of the annual assessment target, and determining the runoff annual common withering difference coefficient.

It can be understood that the specific method for calculating the co-occurrence probability of the monthly average flow and the annual assessment target flow joint distribution and the conditional probability of reaching the standard of the annual assessment target after determining the monthly average flow edge distribution and the annual assessment target flow edge distribution of the target section can be selected according to the actual situation, and the invention is not limited to this.

According to the ecological flow dynamic calculation method adaptive to the target guarantee rate, provided by the invention, through the research on the historical data of the runoff of the target section, the natural hydrological situation change characteristics of a drainage basin are considered, the annual rich-lean difference coefficient is defined and is the conditional probability of reaching the standard of the annual assessment target, the conditional probability is comprehensively determined by the co-occurrence probability of the combined distribution of the monthly average flow and the annual assessment target flow, and the difference of the rich-lean change of the runoff among the years is represented. The annual rich water difference coefficient can effectively reflect the difference of the flow of the rich water period and the flow of the low water period in one year, and the basic ecological flow data is corrected by combining the runoff annual rich water difference coefficient, so that the reasonability and the accuracy of ecological flow calculation can be effectively improved.

Optionally, according to the dynamic calculation method for ecological flow adaptive to the target guarantee rate provided by the present invention, the monthly average flow edge distribution of the target section is determined according to an edge distribution function, which specifically includes:

determining the edge distribution of a plurality of monthly average flows according to an edge distribution function;

determining the optimal distribution as the monthly average flow edge distribution of the target section in the monthly average flow edge distributions according to a preset fitting accuracy evaluation rule; the preset fitting precision evaluation rule is determined based on a K-S method, a least square method and a minimum information criterion method.

Specifically, in order to further improve the accuracy of the edge distribution fitting, the invention presets a fitting precision evaluation rule for screening and determining the optimal distribution.

And determining the edge distribution of the average flow for a plurality of months according to the edge distribution function. It will be appreciated that in the present invention, a number of different edge distribution functions are employed to determine the monthly mean flow edge distribution. In practical applications of the present invention, the specific number and type of the edge distribution functions used may be set according to practical situations, which is not limited by the present invention.

And calculating the precision evaluation index of the monthly average flow edge distribution of each month according to a preset fitting precision evaluation rule, and determining the optimal distribution as the monthly average flow edge distribution of the target section in a plurality of monthly average flow edge distributions according to the precision evaluation index.

It should be noted that the preset fitting accuracy evaluation rule is determined based on a Kolmogorov-Smimov (K-S) method, a least square method (OLS) and a minimum information criterion (AIC), for example, only one of the K-S method, the least square method and the minimum information criterion method is selected as an evaluation index, or optionally 2 or more comprehensive evaluations (weighted synthesis, etc.), and a specific calculation method of the preset fitting accuracy evaluation rule may be set according to an actual requirement, which is not limited by the present invention.

Taking the preset fitting precision evaluation rule as a K-S method, a least square method and a minimum information criterion method for comprehensive determination as an example, the invention is explained as follows:

assuming that the cross-sectional flow series is Q (i, j) and the fitting series is Q' (i, j), the accuracy evaluation indexes are as follows:

wherein C represents a comprehensive evaluation target; n is the length of the series of years; k is the number of parameters of edge distribution; j is the month.

Selecting 4-5 edge distributions for precision evaluation, and selecting the distribution corresponding to the minimum value of the comprehensive evaluation target as the optimal distribution, wherein the expression is as follows:

in the formula, C _z Is the minimum value of the comprehensive evaluation target; n is the total number of edge distributions; c _i (j) Represents the comprehensive evaluation target of the ith distribution in the jth month.

According to the scheme, the preset fitting accuracy evaluation rule is comprehensively designed by adopting a K-S method, a least square method and a minimum information criterion method, compared with a single evaluation mode, the edge distribution quality can be compared more comprehensively, and the edge distribution with the best comprehensive performance is selected as the monthly average flow edge distribution of the target section.

According to the dynamic ecological flow calculation method adaptive to the target guarantee rate, when the runoff annual peak-to-peak difference coefficient is calculated, the preset fitting precision evaluation rule is adopted to screen the edge distribution of the average flow of a plurality of months, the optimal distribution is determined to be the target section month average flow edge distribution, the accuracy of edge distribution fitting can be effectively improved, the capability of representing the difference of the runoff annual peak-to-peak change by the runoff annual peak-to-peak difference coefficient is further improved, and the reasonability and the accuracy of ecological flow calculation are further improved.

Optionally, according to the dynamic calculation method of ecological flow adaptive to the target guarantee rate provided by the present invention, the annual run-up difference coefficient of runoff is determined according to the monthly average flow edge distribution of the target section and the annual assessment target flow edge distribution, and specifically includes:

according to the monthly average flow edge distribution of the target section and the annual assessment target flow edge distribution, constructing two-dimensional combined probability distribution of months and years, and determining a combined probability distribution model base;

determining a joint probability distribution function library according to a copula function based on the joint probability distribution model library;

based on a joint probability distribution function library, calculating the co-occurrence probability of joint distribution of the monthly average flow and the annual assessment target flow, and determining the runoff annual withering difference coefficient.

Specifically, after monthly average flow edge distribution and annual assessment target flow edge distribution of a target section are determined, a joint probability distribution model base is constructed, namely two-dimensional joint probability distribution is respectively established for each monthly series and each annual assessment target flow series, so that a model base covering 12 joint probability distributions is constructed.

And determining a joint probability distribution function library based on the joint probability distribution model library according to a copula function. And introducing copula function construction into a joint probability distribution model. The copula function is a multi-dimensional joint distribution function over the [0,1] domain, allowing linking of a number of combined models of arbitrary form edge probability distributions.

In the practical application of the present invention, the specific type and number (the number is more than the optimal distribution) of the copula functions can be set according to the practical requirement, which is not limited in the present invention.

Taking two dimensions as an example, let F _X (x)＝u，F _Y (Y) = v, representing functions of cumulatively distributed random variables X and Y, respectively, the copula function is expressed as follows:

F(x,y)＝C _θ (F _X (x),F _Y (y))＝C _θ (u,v)

wherein F (x, y) represents the joint distribution of random variables x and y; c _θ Is a copula function; f _X (x) And F _Y (y) is the edge distribution function of the random variables x and y.

The Copula function comprises single parameter functions of Clayton, frank and Gumble, and the expression is as follows:

in the formula, theta is a parameter of the copula function; u and v are edge distribution functions of randomly varying x and y.

The two-dimensional copula function parameter theta is estimated by using Kendal correlation coefficient, and the expression is as follows:

in the formula, theta is a parameter of the copula function; tau is Kendal correlation coefficient; d ₁ () Is a debye function of the first type.

It can be understood that, in the embodiment of the present invention, the accuracy evaluation can be performed on the functions of Clayton, frank and Gumble, and the distribution corresponding to the minimum value of the comprehensive evaluation target is selected as the optimal distribution. The specific method of precision evaluation is the same as the above-mentioned method of determining the optimal distribution according to the preset fitting precision evaluation rule, and this is not described in detail in the present invention.

According to the ecological flow examination and management requirements, the premise that the monthly average flow guarantee rate reaches the standard is to meet the annual target flow examination standard. The annual assessment of the monthly assessment which reaches the standard also inevitably reaches the standard, so the statistical analysis can be understood as the conditional probability of the joint distribution. Based on a joint probability distribution function library, calculating the co-occurrence probability of the joint distribution of the monthly average flow and the annual assessment target flow, and determining the runoff annual withering difference coefficient

The edge distribution of the monthly average flow of the cross section is set as F _X [Q(i,j)]= u (j), edge distribution of annual assessment target flow is F _Y [Qy(i)]= v, then the co-occurrence probability of the two is:

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wherein C is a copula function; p is ₁ [Q(i,j),Q _y (i)]The coincidence probability of the monthly average flow and the annual assessment target flow is obtained.

Defining annual common blight difference coefficient K ₂ The expression is the conditional probability of the annual assessment target reaching the standard, and is as follows:

in the formula, K ₂ (j) The annual common difference coefficient of runoff in the jth month; u (j) is the edge distribution of the j-th monthly flow, and v is the edge distribution of the annual assessment target flow.

According to the ecological flow dynamic calculation method adaptive to the target guarantee rate, provided by the invention, through researching target section runoff historical data, the natural hydrological situation change characteristics of a basin are considered, an annual rich-lean difference coefficient is defined and is a conditional probability of reaching the standard of an annual assessment target, the conditional probability is comprehensively determined by the co-occurrence probability of joint distribution of monthly flow and annual assessment target flow, and the difference of the rich-lean change of runoff among years is represented. The annual rich water difference coefficient can effectively reflect the difference of the flow of the rich water period and the flow of the low water period in one year, and the basic ecological flow data is corrected by combining the runoff annual rich water difference coefficient, so that the reasonability and the accuracy of ecological flow calculation can be effectively improved.

The specific steps of the invention are explained in conjunction with the practical application:

in this example, four sections of the river reach to be studied in different watersheds are selected and respectively marked as a, B, C and D. In the assessment practice of the water conservancy department on ecological flow management at the present stage, the assessment requirements of the four research river reach are annual assessment, the assessment rate is not lower than 90% and is taken as an assessment limit value, namely, the assessment target assessment rate P =90%.

Collecting and organizing the long series of natural monthly runoff and the actually measured daily runoff series of the target section. Setting the series of natural monthly runoff of the section as Q (i, j), wherein i is a series of years, and j is a month; the series of the section actual measurement daily runoff is marked as Q _c (i, j, k), i being the series of years, j being the month, k being the day.

Each series of section runoff is 1956-2016, and the series year length is 61 years. The natural monthly runoff of the section considers water quantity reduction such as reservoir regulation, external drainage of a river channel and the like; the published hydrological yearbook is directly extracted from the actually measured runoff of the section and is the actually measured value of the hydrological station near the section.

Based on the natural monthly runoff series of the section, respectively calculating the flow value of each monthly runoff of the section under the target guarantee rate P by adopting a quantile method, and recording as Q _p (j) The expression is:

in the formula, Q _p (j) The average monthly flow corresponding to the jth month under the target guarantee rate P is shown; percentile () represents a Percentile function; p represents a target guarantee rate; q (i, j) represents a section natural lunar runoff series; n is the series years.

The series of section monthly runoff is 1956-2016, the series years are 61 years, and the target guarantee rate is 90%. And respectively adopting a quantile method to calculate the monthly average flow corresponding to the condition that the guarantee rate is 90% for 1-12 months.

Based on the section actual measurement daily runoff series, respectively calculating the flow value corresponding to the average flow of each month and day of the section under the target guarantee rate P by adopting a quantile method, and recording as Q' _p (j) The expression is:

of formula (II) to Q' _p (j) Representing the average daily flow corresponding to the target guarantee rate P in the j-th month; percentile () represents a Percentile function; p represents a target guarantee rate; q _c (i, j, k) represents the section actual measurement daily runoff series; n is the serial years; m is the total number of days in the series of years.

The runoff series actually measured on the cross section is 1956-2016, the series years are 61 years, the total number of the series days is 24107 days, and the target guarantee rate is 90%. And respectively adopting a quantile method to calculate the corresponding daily average flow under the condition that the guarantee rate is 90% for 1-12 months.

Distribution difference coefficient in definition year is K ₁ And determining the ratio of the daily average runoff to the monthly average runoff corresponding to the target guarantee rate, and representing the difference of the flow in different time periods. The expression is as follows:

K ₁ (j)＝Q' _p (j)/Q _P (j),j＝1,2,…,12

According to the calculated section daily average flow and the calculated section monthly average flow under the 90% guarantee rate, the ratio is calculated to be used as a runoff annual distribution difference coefficient, and the result is shown in table 1.

TABLE 1 distribution Difference coefficient K in runoff year ₁

Cross section of watershed	1 month	2 month	Month	3	4 month	Month 5	6 month	7 month	8 month	9 month	10 month	11 month	12 month
														A	0.584	0.764	0.554	0.472	0.511	0.520	0.417	0.429	0.599	0.648	0.788	0.758
B	1.216	1.064	1.151	1.374	1.387	1.859	1.629	3.730	1.986	1.360	1.397	1.360
													C	1.221	1.147	0.644	0.880	0.934	0.737	0.237	0.605	0.776	0.974	0.746	1.059
D	1.036	1.032	1.136	1.202	1.046	0.928	0.422	0.770	0.935	1.060	1.370	1.174

And (4) introducing a probability analysis theory and determining the edge distribution of the average flow of each month of the section. The edge distribution is generally selected from pearson type III (P-III), exponential distribution (EXP), extreme value distribution (GEV), and lognormal distribution (LOGN), etc., and the optimal distribution is determined as an edge distribution profile of the monthly mean flow rate by precision evaluation.

And the fitting precision evaluation is comprehensively determined by selecting a K-S method, a least square method and a minimum information criterion. Assuming that the cross-sectional flow series is Q (i, j) and the fitting series is Q' (i, j), the accuracy evaluation indexes are as follows:

Selecting 4 edge (P-III, EXP, GEV and LOGN) distributions for precision evaluation, and selecting the distribution corresponding to the minimum value of the comprehensive evaluation target as the optimal distribution, wherein the expression is as follows:

The results of the comprehensive evaluation indexes of the sections are shown in Table 2. Taking a comprehensive evaluation index C _z The distribution corresponding to the minimum value is taken as the monthly runoff edge distribution. Fig. 2 is a fitting graph of the edge distribution of the runoff flow of 6 months in the a-section provided by the invention, and 4 fitting graphs of the edge distribution of the runoff flow of 6 months in the a-section are shown in fig. 2 as an example.

TABLE 2 comprehensive evaluation index C for monthly runoff edge distribution _z

Calculating the monthly average flow corresponding to the target guarantee rate in years on the basis of the section natural monthly runoff Q (i, j) to obtain an annual assessment target flow series, and recording the annual assessment target flow series as Q _y (i) The expression is as follows:

in the formula, qy (i) represents the flow corresponding to the target guarantee rate P in the ith year; percentile () represents a Percentile function; p represents a target guarantee rate; q (i, j) represents a section natural lunar runoff series; n is the series years.

Four edge distribution lines of Pearson type III (P-III), exponential distribution (EXP), extreme value distribution (GEV) and lognormal distribution (LOGN) are selected for comparison and selection, and the comprehensive evaluation index results of each section are shown in Table 3. Taking a comprehensive evaluation index C _z And taking the distribution corresponding to the minimum value as the edge distribution of the annual assessment target flow. Fig. 3 is an edge distribution fitting graph of annual assessment target flow of a section a provided by the present invention, and taking the edge distribution of annual assessment target flow of a section a as an example, 4 distribution fitting graphs thereof are shown in fig. 3.

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TABLE 3 annual assessment target flow edge distribution comprehensive evaluation index Cz

And (3) constructing a combined probability distribution model base according to the edge distribution of each month average flow and the annual assessment target flow of the section, namely respectively establishing two-dimensional combined probability distribution for each month series and each annual assessment target flow series, thereby constructing a model base covering 12 combined probability distributions.

AssociationThe probability distribution model is built by introducing copula function. The copula function is at [0,1]]A multi-dimensional joint distribution function over a domain allows linking of a plurality of combined models of arbitrarily shaped edge distribution probability distributions. Introducing a two-dimensional copula function and setting a monthly runoff edge distribution F _X (x) = u, edge distribution of annual assessment target flow F _Y (Y) = v, representing functions of cumulatively distributed random variables X and Y, respectively, the copula function is expressed as follows:

F(x,y)＝C _θ (F _X (x),F _Y (y))＝C _θ (u,v)

The Copula function in the example selects the functions of Clayton, frank and Gumble, and the expression is as follows:

Clayton, frank and Gumble functions are selected for comparison and selection, the distribution corresponding to the minimum value of the comprehensive evaluation target is selected as the optimal distribution, and the comprehensive evaluation index results of all sections in the example are shown in Table 4. From the combined distribution comprehensive evaluation index evaluation value, the precision difference of the 3 copula function models is not large, and the Clayton function is uniformly selected for subsequent calculation in the example. Fig. 4 is a combined distribution fitting graph of the section 6-month runoff and the annual assessment target flow provided by the invention, taking the combined distribution of the section a 6-month runoff and the annual assessment target flow as an example, and 3 distribution fitting graphs are shown in fig. 4.

TABLE 4 Combined distribution comprehensive evaluation index Cz

Defining the difference coefficient of annual common blight as K ₂ The method is comprehensively determined by the co-occurrence probability of the combined distribution of the monthly average flow and the annual assessment target flow, and represents the difference of the rich and lean change of the runoff between the annual periods.

According to the ecological flow assessment management requirements, annual assessment of monthly assessment which reaches the standard also necessarily reaches the standard, so that statistics can be understood as the conditional probability of joint distribution. The edge distribution of the section monthly average flow is set as F _X [Q(i,j)]= u (j), edge distribution of annual assessment target flow is F _Y [Qy(i)]= v, then the co-occurrence probability of the two is:

wherein C is a copula function; p ₁ [Q(i,j),Q _y (i)]The coincidence probability of the monthly average flow and the annual assessment target flow is obtained.

If the annual assessment standard reaching rate target is 90%, calculating the joint conditional probability as the annual abundance difference coefficient of the monthly runoff according to the constructed joint probability distribution function library and by taking the annual assessment target standard reaching as a condition, wherein the calculation result is shown in the table 5.

TABLE 5 runoff annual common Fenggu difference coefficient K2

Cross section of watershed	1 month	2 month	3 month	4 month	Month 5	6 month	7 month	8 month	9 month	10 month	11 month	12 month
													A	0.940	0.954	0.917	0.926	0.926	0.906	0.916	0.903	0.902	0.901	0.930	0.921
B	0.928	0.926	0.904	0.909	0.906	0.903	0.901	0.898	0.903	0.907	0.907	0.912
													C	0.925	0.927	0.923	0.919	0.917	0.921	0.909	0.907	0.905	0.906	0.910	0.910
D	0.925	0.924	0.917	0.916	0.918	0.913	0.912	0.914	0.911	0.912	0.915	0.914

Calculating an ecological flow monthly reference value by adopting a frequency curve method, constructing a monthly hydrological frequency curve by using monthly average flow or runoff of long-series hydrological data, taking the monthly average flow or runoff corresponding to the evaluation target frequency of 90 percent as a river control section ecological flow monthly reference value of a corresponding month, and recording as Q _c (j) Example computational results are shown in table 6.

TABLE 6 monthly standard value unit of ecological flow in m3/s

Coupling the annual and annual variation difference coefficient of runoff, and correcting and calculating an ecological flow dynamic control target meeting the target cooperative adaptation, wherein the expression is as follows:

Q _pc (j)＝K ₁ (j)×K ₂ (j)×Q _c (j),j＝1,2,…,12

in the formula, K ₁ (j) Represents the intra-year distribution difference coefficient for month j; k ₂ (j) The annual common difference coefficient of runoff in the jth month; q _c (j) The ecological flow monthly reference value of the j month; q _pc (j) And meeting the ecological flow dynamic control target value of the target cooperative adaptation for the jth month.

According to annual assessment standards and guarantee rate requirements of ecological flow, a quantile method is adopted to calculate basic ecological flow by relying on a dynamic control target of the ecological flow in the year, and the expression is as follows:

in the formula, Q _ji Representing a basic ecological flow; q _pc (j) Meeting the ecological flow dynamic control target value of the target cooperative adaptation in the jth month; percentile () represents a Percentile function; p represents the target guarantee rate.

The calculated basic ecological flow results are shown in table 7. Fig. 5 is an ecological flow dynamic control target with a section a meeting target cooperative adaptation provided by the present invention, and taking the section a as an example, the ecological flow dynamic control target meeting target cooperative adaptation is shown in fig. 5.

TABLE 7 ecological flow dynamic control target value unit m3/s satisfying target cooperative adaptation

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And (4) performing daily average ecological flow reachability evaluation by adopting a frequency method from the perspective of month and year according to the ecological flow dynamic control target value and the basic ecological flow of the target cooperative adaptation. The frequency method has the following calculation formula:

PR _i ＝A _i /B _i ×100

in the formula: PRI is the target satisfaction degree of the ecological flow of the control section,%; a. The _i The number of samples is equal to or greater than the daily average flow of the ecological flow guarantee target in the evaluation period; b is _i For participating in the life within the evaluation periodAnd the daily average flow sample total number of the condition-meeting situation evaluation of the dynamic flow guarantee target.

The invention adopts 61-year (1956-2016) section daily flow series, and makes accessibility evaluation from long series year, month and year, the section ecological flow and the evaluation result are shown in tables 8 and 9, and fig. 6 is a box type diagram of different section ecological flow dynamic control target year-round guarantee rate.

The chart shows that the basic ecological flow value is closer to the current repeated results of water administration departments, the long-series annual and monthly scale target guarantee rates are both greater than 90%, the median of the annual guarantee rates over 90% all meet the requirements of examination and management, and the ecological flow dynamic control target calculated by the method is more reasonable.

TABLE 8 comparison of results of ecological flow in section

TABLE 9 evaluation results of section accessibility of ecological flux

The invention provides an ecological flow dynamic control method and system based on target cooperative adaptation aiming at the defects and practical requirements of the prior art, the existing assessment standard is taken as an adaptation target, the annual change characteristic of runoff is introduced, and the ecological flow dynamic control method and system based on the target cooperative adaptation are constructed based on the big data mining and probability theory technology, so that the reasonable determination of the ecological flow dynamic target is realized.

Fig. 7 is a schematic structural diagram of an ecological flow dynamic calculation system adapted to a target assurance rate, as shown in fig. 7, the present invention further provides an ecological flow dynamic calculation system adapted to a target assurance rate, including: an allocation difference calculating unit 701, a rich difference calculating unit 702 and an ecological flow calculating unit 703;

the distribution difference calculating unit 701 is used for determining a distribution difference coefficient within a runoff year according to a target guarantee rate based on the historical data of the runoff of the target section; wherein the distribution difference coefficient in runoff year is the ratio of daily average runoff to monthly average runoff corresponding to the target section at the target guarantee rate;

a rich-lean difference calculating unit 702, configured to determine a runoff annual rich-lean difference coefficient according to target cross-section flow edge distribution; wherein the runoff annual withering difference coefficient represents the difference of runoff annual withering change;

the ecological flow calculating unit 703 is configured to determine an ecological flow target value based on the intra-year distribution difference coefficient and the inter-year rich-low difference coefficient of the runoff.

Specifically, a section of a researched river reach is selected, and ecological flow management and assessment requirements and a guarantee rate limit value of a target section are determined. In the comprehensive assessment practice of ecological flow management at the present stage, the assessment requirements are annual assessment, the guarantee rate is taken as an assessment index, and the guarantee rate is not lower than 90% and is taken as an assessment limit value. In the invention, the guarantee rate of the assessment target is recorded as P, and different values can be set according to the assessment requirement on the guarantee rate and the assessment time.

After the research section is determined, target section runoff historical data including target section long series natural runoff and actual measurement daily runoff series are collected and collated. Setting the series of natural monthly runoff of the section as Q (i, j), wherein i is a series of years, and j is a month; the series of the section actual measurement daily runoff is marked as Q _c (i, j, k), i being the series of years, j being the month, k being the number of days. Generally, the years of the historical data series are not less than 20 years, and the specific time length can be adjusted according to actual conditions.

After the historical data and the target guarantee rate of the runoff of the target section are determined, a distribution difference calculation unit 701 is used for calculating the ratio of the daily average runoff and the monthly average runoff corresponding to the runoff at the target guarantee rate in different periods of the section by adopting a quantile method based on the historical data of the runoff of the target section, determining the annual distribution difference coefficient of the runoff, and defining the annual distribution difference coefficient as K ₁ 。

A kungfu difference calculating unit 702 for determining the kungfu difference by introducing probability analysis theoryDetermining the annual peak difference coefficient of runoff according to the edge distribution of the target section flow, and defining the annual peak difference coefficient as K ₂ 。

And the ecological flow calculating unit 703 is configured to correct and calculate an ecological flow dynamic control target meeting the target collaborative adaptation based on the runoff intra-year distribution difference coefficient and the runoff annual peak-to-peak difference coefficient, and coupled with the runoff intra-year and annual change difference coefficient, and determine an ecological flow target value.

According to the ecological flow dynamic calculation system adaptive to the target guarantee rate, provided by the invention, through the research on the historical data of the runoff of the target section, the natural hydrological situation change characteristics of a drainage basin are considered, the annual distribution difference coefficient and the annual peak-to-peak difference coefficient of the runoff are defined, the ecological flow dynamic control target in different time periods in the year is scientifically determined, and the rationality and the accuracy of ecological flow calculation can be effectively improved. The problem that in the prior art, the annual difference of runoff is large in years and the annual water quantity is uncertain, so that basic ecological flow with a single numerical value cannot adapt to the natural hydrological situation change characteristics of a drainage basin, and the setting of basic ecological flow data is not scientific is examined.

It should be noted that, the ecological traffic dynamic calculation system adapted to the target assurance rate provided by the present invention is used for executing the ecological traffic dynamic calculation method adapted to the target assurance rate, and a specific implementation manner thereof is consistent with the method implementation manner, and is not described herein again.

Fig. 8 is a schematic physical structure diagram of an electronic device provided in the present invention, and as shown in fig. 8, the electronic device may include: a processor (processor) 801, a communication interface (communication interface) 802, a memory (memory) 803 and a communication bus 804, wherein the processor 801, the communication interface 802 and the memory 803 complete communication with each other through the communication bus 804. The processor 801 may call logic instructions in the memory 803 to perform an ecological traffic dynamic calculation method of adapting a target guaranteed rate, the method comprising: determining a distribution difference coefficient of runoff in a year according to a target guarantee rate based on the historical data of the runoff of the target section; wherein the distribution difference coefficient in runoff year is the ratio of daily average runoff to monthly average runoff corresponding to the target section at the target guarantee rate; determining the annual runoff withering difference coefficient according to the target section flow edge distribution; wherein the runoff annual withering difference coefficient represents the difference of runoff annual withering change; and determining an ecological flow target value based on the runoff annual distribution difference coefficient and the runoff annual withering difference coefficient.

In addition, the logic instructions in the memory 803 may be implemented in the form of software functional units and stored in a computer readable storage medium when the logic instructions are sold or used as independent products. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk, an optical disk, or other various media capable of storing program codes.

In another aspect, the present invention further provides a computer program product, the computer program product includes a computer program stored on a non-transitory computer-readable storage medium, the computer program includes program instructions, when the program instructions are executed by a computer, the computer can execute the ecological flow dynamic calculation method for adapting the target guarantee rate provided by the above methods, the method includes: determining a distribution difference coefficient of runoff in a year according to a target guarantee rate based on the historical data of the runoff of the target section; wherein the annual distribution difference coefficient of the runoff is the ratio of daily average runoff to monthly average runoff corresponding to the target section at the target guarantee rate; determining a runoff annual withering difference coefficient according to the target section flow edge distribution; wherein the runoff annual withering difference coefficient represents the difference of runoff annual withering change; and determining an ecological flow target value based on the runoff annual distribution difference coefficient and the runoff annual withering difference coefficient.

In yet another aspect, the present invention further provides a non-transitory computer-readable storage medium, on which a computer program is stored, the computer program being implemented by a processor to perform the ecological flow dynamic calculation method for adapting to the target guarantee rate provided in the above, the method comprising: determining a distribution difference coefficient of runoff in a year according to a target guarantee rate based on target section runoff historical data; wherein the annual distribution difference coefficient of the runoff is the ratio of daily average runoff to monthly average runoff corresponding to the target section at the target guarantee rate; determining a runoff annual withering difference coefficient according to the target section flow edge distribution; wherein the runoff annual withering difference coefficient represents the difference of runoff annual withering change; and determining the ecological flow target value based on the runoff annual distribution difference coefficient and the runoff annual withering difference coefficient.

The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.

Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. With this understanding in mind, the above-described technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium, such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods of the various embodiments or some parts of the embodiments.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. An ecological flow dynamic calculation method adaptive to a target guarantee rate is characterized by comprising the following steps:

and determining an ecological flow target value based on the runoff annual distribution difference coefficient and the runoff annual withering difference coefficient.

2. The method for dynamically calculating ecological flow adaptive to the target guarantee rate according to claim 1, wherein the determining of the annual distribution difference coefficient of runoff based on the historical data of the runoff of the target section according to the target guarantee rate specifically comprises:

determining the target guarantee rate flow of the section according to the target guarantee rate based on the target section runoff historical data; wherein, the section target guarantee rate flow comprises: section target guarantee rate monthly runoff and section target guarantee rate daily runoff; the section target guarantee rate monthly runoff is the corresponding monthly average runoff of the target section under the target guarantee rate; the section target guarantee rate daily runoff is daily average runoff corresponding to each month of the target section at the target guarantee rate;

3. The method for dynamically calculating ecological flow rate adaptive to the target guarantee rate according to claim 1, wherein the determining an ecological flow rate target value based on the runoff annual distribution difference coefficient and the runoff annual peak-to-peak difference coefficient specifically comprises:

calculating corresponding flow when the target guarantee rate is met according to the hydrological frequency curves of each month, and determining a monthly standard value of the ecological flow;

correcting the ecological flow monthly reference value based on the runoff annual distribution difference coefficient and the runoff annual peak difference coefficient, and determining an ecological flow monthly target value;

4. The method for dynamically calculating ecological flow adaptive to the target guarantee rate according to claim 1, wherein after the step of determining the ecological flow target value based on the annual distribution difference coefficient and the annual common and withered difference coefficient of runoff, the method further comprises:

5. The dynamic ecological flow calculation method adaptive to the target assurance rate according to any one of claims 1 to 4, wherein the determining the annual runoff abundance difference coefficient according to the target cross-section flow edge distribution specifically includes:

and determining the runoff annual common withering difference coefficient according to the monthly average flow edge distribution of the target section and the annual assessment target flow edge distribution.

6. The dynamic ecological flow calculation method adapted to the target assurance rate according to claim 5, wherein the determining the monthly average flow edge distribution of the target section according to the edge distribution function specifically comprises:

determining the optimal distribution as the monthly average flow edge distribution of the target section in the monthly average flow edge distributions according to a preset fitting precision evaluation rule; the preset fitting precision evaluation rule is determined based on a K-S method, a least square method and a minimum information criterion method.

7. The method for dynamically calculating ecological flow adaptive to the target assurance rate according to claim 5, wherein the determining the runoff annual peak-to-peak difference coefficient according to the target section monthly average flow edge distribution and the annual assessment target flow edge distribution specifically comprises:

according to the monthly average flow edge distribution of the target section and the annual assessment target flow edge distribution, building two-dimensional combined probability distribution of months and years, and determining a combined probability distribution model base;

based on the joint probability distribution function library, calculating the co-occurrence probability of joint distribution of the monthly average flow and the annual assessment target flow, and determining the runoff annual common abundance difference coefficient.

8. An ecological flow dynamic calculation system adapted to a target assurance rate, comprising: the system comprises a distribution difference calculating unit, a withering difference calculating unit and an ecological flow calculating unit;

the distribution difference calculating unit is used for determining a distribution difference coefficient within a runoff year according to a target guarantee rate based on target section runoff historical data; wherein the annual distribution difference coefficient of the runoff is the ratio of daily average runoff to monthly average runoff corresponding to the target section at the target guarantee rate;

the power difference calculating unit is used for determining the power difference coefficient of the runoff annual line according to the target cross section flow edge distribution; wherein the runoff annual withering difference coefficient represents the difference of runoff annual withering change;

and the ecological flow calculating unit is used for determining an ecological flow target value based on the runoff annual distribution difference coefficient and the runoff annual peak-to-peak difference coefficient.

9. An electronic device, comprising a memory and a processor, wherein the processor and the memory communicate with each other via a bus; the memory stores program instructions executable by the processor, the processor calls the program instructions to perform the ecological flow dynamic calculation method adapted to the target assurance rate according to any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, implements the method for ecological flow dynamic calculation adapted to a target guaranteed rate according to any one of claims 1 to 7.