River regulation project ecological evaluation method based on river health improvement

Abstract

The invention discloses a river regulation project ecological evaluation method based on river health improvement. The method comprises the following steps: constructing a river regulation project ecological evaluation index system; a standard reference method, a literature reference method, a data analysis method and an expert judgment method are integrated to determine the grading score assignment standard and score assignment of each index; calculating weights of a criterion layer and an index layer by adopting an improved comprehensive weight determination method; and constructing an evaluation model based on a single-index quantification-multi-index integration-multi-criterion integration-neural network method, calculating an evaluation result, and evaluating the ecological level of the river regulation project by referring to an evaluation standard. The river regulation project ecological evaluation method has the beneficial effects that the river health improvement is taken as a target, and the river regulation project ecological evaluation method is provided based on the improved comprehensive weight determination and model construction method. According to the method, the influence degree of the river regulation project on river health can be accurately quantified, and a technical support is provided for health improvement and reconstruction of the regulated river or design optimization of the proposed project.

Description

Technical Field

[0001] The present invention relates to the technical field of ecological water conservancy project evaluation, and in particular to an ecological evaluation method for river regulation projects based on river health improvement. Background Art

[0002] Rivers are important channels for material circulation between terrestrial and aquatic ecosystems, and they have multiple functions such as flood discharge, drainage, navigation, irrigation, and improvement of aquatic ecological environment. While ensuring the basic functions of river channels such as flood discharge and drainage, river regulation projects have brought about many ecological and environmental problems, causing adverse effects on the ecological health of rivers and lakes. For example, regulation measures such as straightening, regularizing cross-sections, and hardening revetments have destroyed the unique meandering of natural rivers, changed the natural pattern of alternating deep pools and shallows, and alternating rapids and slow currents, and caused the degradation of river ecosystems.

[0003] With the proposal of ecological civilization construction, river regulation projects should fully protect river ecosystems, maintain their ecological functions, and improve the ecological health of rivers while considering the safety and economy of water conservancy facilities. Therefore, accurately evaluating the ecological nature of river regulation projects based on river health improvement is of great practical significance for standardizing the ecological construction of river regulation projects and avoiding or minimizing the adverse effects of river regulation on river and lake ecosystems.

[0004] At present, China has carried out many useful explorations in the ecological evaluation of water conservancy projects, but these mainly focus on the ecological evaluation of water conservancy projects such as reservoir projects, ecological coastlines, ecologicalization of water conservancy facilities, water ecological environmental effects of water conservancy projects, and ecological irrigation areas. It is difficult to accurately quantify the ecological effects of river regulation projects based on improving river health.

[0005] Therefore, how to provide an evaluation method that can accurately quantify the ecological performance of river regulation projects aimed at improving river health and provide a data basis for accurately evaluating the effectiveness of project construction is an urgent problem that technical personnel in this field need to solve. Summary of the invention

[0006] In view of the limitations and shortcomings of the existing ecological evaluation methods for river channel regulation projects, the present invention provides an ecological evaluation method for river channel regulation projects based on river health improvement, including an ecological evaluation index system for river channel regulation projects based on river health improvement, weights, classification standards and scoring standards of each sub-index based on the ecological evaluation index system for river channel regulation projects, and an ecological evaluation model for river channel regulation projects based on ecological index. The present invention provides a clear, complete, detailed and quantifiable evaluation system for the ecological evaluation of river channel regulation projects, and provides a simple, easy and economical evaluation method for guiding the ecological design, construction, operation management and long-term tracking and monitoring of ecological restoration effects of river channel regulation projects.

[0007] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: an ecological evaluation method for river regulation projects based on river health improvement, comprising the following steps: Step S1: Establishing an ecological evaluation index system for river regulation projects; Step S2: Divide the ecological evaluation index system of the river regulation project into five levels, and combine the index classification method and the index scoring method to determine the classification and scoring standards and scoring values ​​of each ecological evaluation index; Step S3: using an improved comprehensive weight determination method to calculate the comprehensive weights of various ecological evaluation indicators and determine the weights of the ecological evaluation indicators of the river regulation project; Step S4: constructing an ecological assessment model for river regulation projects; Step S5: Based on the constructed river channel regulation project ecological assessment model, the ecological assessment index of the river channel regulation project is calculated to assess the ecological level of the river channel regulation project; In step S3, the improved comprehensive weight determination method is specifically improved hierarchical analysis method-entropy weight method-independence weight coefficient method-multiplication synthesis normalization method; the steps are: Step S31, using an improved analytic hierarchy process to calculate the subjective weight of each ecological evaluation index; Step S32, using entropy weight method to calculate the objective weight of each ecological evaluation index; Step S33, using the independence weight coefficient method to calculate the objective weight of each ecological evaluation index; Step S34, using the multiplication synthesis normalization method to combine the subjective weight and the objective weight to assign weights.

[0008] Further, in step S1, the ecological evaluation index system of the river regulation project includes a target layer, a criterion layer and an index layer; The target layer includes the ecological status T of the river regulation project; The criteria layer includes the hydrology and water resources B1 indicator layer, the water environment B2 indicator layer, the biological community B3 indicator layer, the biological habitat B4 indicator layer, and the social environment B5 indicator layer; The hydrological and water resources B1 indicator layer is the river and lake water area change rate C1 and the flow process variation degree C2; The water environment B2 indicator layer is the degree of water quality change C3, water body self-purification capacity C4, and lake and reservoir eutrophication C5; The indicator layer of biological community B3 is the bio-integrity index of algae (C6), the bio-integrity index of large benthic animals (C7), the impact on aquatic protected species (C8), and the impact on terrestrial habitats (C9); The indicator layer of biological habitat B4 is natural river channel retention rate C10, revetment near natural degree C11, longitudinal natural connectivity coefficient C12, vegetation coverage rate C13, curvature coefficient change degree C14; The social environment B5 indicator layer is the waterfront landscape facilities completeness C15, landscape comfort C16, and cultural landscape value C17; The three ecological evaluation indicators of lake and reservoir eutrophication C5, waterfront landscape facility completeness C15 and cultural landscape value C17 are alternative indicators, and the river and lake water area change rate C1, flow process variation degree C2, water quality change degree C3, water body self-purification capacity C4, algae biological integrity index C6, large benthic animal biological integrity index C7, impact on aquatic protected species C8, impact on terrestrial biological habitat C9, natural river channel retention rate C10, revetment near-naturalness C11, longitudinal natural connectivity coefficient C12, vegetation coverage C13, curvature coefficient change degree C14 and landscape comfort C16 are required indicators.

[0009] Furthermore, in step S2, the index grading method is specifically: standard reference method, literature citation method, data analysis method and expert judgment method; the index scoring method is specifically: data analysis method, standard reference method, expert judgment method and literature reference method; Determine the grading and scoring standards and scoring values ​​for each ecological evaluation indicator; there are 17 ecological evaluation indicators, and each indicator is divided into 5 levels according to different levels of conditions.

[0010] Furthermore, in step S31, the subjective weight of each ecological evaluation index is calculated using the improved hierarchical analysis method, and the specific steps are as follows: Step S311, establish a hierarchical structure model; use the five-scale method to divide the judgment level into five levels: equally important, slightly important, obviously important, strongly important and extremely important, and construct a comparison matrix A according to formula (1) and formula (2); (1); (2); Among them, A is the comparison matrix; is the matrix element, i.e., the scale value, indicating the importance of the i-th indicator compared with the j-th indicator; i=1, 2, 3, ⋯, n; j==1, 2, 3, ⋯, n; n is the number of evaluation indicators; Indicates the importance of the first indicator compared to the first indicator, Indicates the importance of the first indicator compared to the second indicator. Indicates the importance of the first indicator compared to the nth indicator. Indicates the importance of the second indicator compared to the first indicator. Indicates the importance of the second indicator compared to the second indicator, Indicates the importance of the second indicator compared to the nth indicator. Indicates the importance of the nth indicator compared to the first indicator. Indicates the importance of the nth indicator compared to the second indicator. It indicates the degree of importance of the nth indicator compared to the nth indicator; Step S312, calculating the importance ranking index of the indicator according to formula (3); (3); in, is the importance ranking index of the i-th indicator, that is, the matrix elements in the comparison matrix A sum; Step S313, calculating the elements of the judgment matrix B using the importance ranking index according to formula (4); (4); in, It represents the element obtained by calculating the importance ranking index of the i-th indicator and the j-th indicator in the judgment matrix B; Represents the importance ranking index of the i-th indicator The maximum value in Represents the importance ranking index of the i-th indicator The minimum value among them; d represents the comparison scale of importance ranking index; Represents the importance ranking index of the jth indicator; in, , , ; Step S314, calculating the elements of the optimal transfer matrix C of the judgment matrix B according to formula (5); (5); in, represents the elements of the optimal transfer matrix C, Indicates the difference between the i-th index and the The elements obtained by calculating the importance ranking index of the indicators; Indicates the difference between the jth index and the The elements obtained by calculating the importance ranking index of indicators; k=1, 2, 3, ⋯, n; Step S315, calculating the index weight of the hierarchical analysis method according to formula (6); (6); in, is the indicator weight of hierarchical analysis method.

[0011] Furthermore, in step S32, the objective weight of each ecological evaluation index is calculated using the entropy weight method, and the specific steps are as follows: Step S321, constructing the original data matrix of ecological evaluation indicators, as shown in formula (7); (7); in, is the original data matrix; is the score value of the i-th indicator of the g-th evaluation item; q is the number of items to be evaluated; g=1,2,3,⋯,q; i=1,2,3,⋯,n; is the score value of the first indicator of the first evaluation item; is the score value of the second indicator of the first evaluation item; is the score value of the nth indicator of the first evaluation item; is the score value of the first indicator of the second evaluation item; is the score value of the second indicator of the second evaluation item; is the score value of the nth indicator of the second evaluation item; is the score value of the first indicator of the qth evaluation item; is the score value of the second indicator of the qth evaluation item; is the score value of the nth indicator of the qth evaluation item; Step S322, normalizing the positive ecological evaluation index according to formula (8) or the negative ecological evaluation index according to formula (9); (8); (9); in, is the normalized data of positive ecological evaluation indicators. It is the normalized data of negative ecological evaluation index; represents the minimum value among all the scoring values ​​of the i-th indicator, Represents the maximum value of all score values ​​of the i-th indicator; It represents the score value of the first item to be evaluated under the i-th indicator. It represents the score value of the qth item to be evaluated under the i-th indicator; Step S323, calculating the proportion of the ecological evaluation index according to formula (10); (10); in, is the proportion of the score of the gth item to be evaluated under the i-th indicator to the total score of all the scores of the i-th indicator; g=1,2,3,⋯,q; i=1,2,3,⋯,n; Step S324, calculating the entropy value of the ecological evaluation index according to formula (11); (11); in, is the entropy value of the i-th indicator; Step S325, calculating the information entropy redundancy according to formula (12); (12); in, is the information entropy redundancy; Step S326, calculating the index weight according to formula (13); (13); in, is the indicator weight of the entropy weight method.

[0012] Furthermore, in step S33, the objective weight of each ecological evaluation index is calculated using the independence weight coefficient method; the specific steps are: Step S331, constructing the original data matrix of ecological evaluation indicators according to formula (7); (7); Step S332, calculating the complex correlation coefficient of each ecological evaluation index according to formula (14); (14); in, is the multiple correlation coefficient between the ith evaluation index and other indicators; is the score value of the i-th evaluation indicator; is the score value of the original data matrix H without the i-th evaluation index The residual matrix of is the average value of the original data matrix H; Step S333, calculating the weight of each ecological evaluation index according to formula (15); (15); in, is the indicator weight of the independence weight coefficient method.

[0013] Furthermore, in step S34, the subjective weight and the objective weight are combined and weighted by using the multiplication synthesis normalization method; the specific steps are: The comprehensive weight of each ecological evaluation index is calculated according to formula (16); (16); in, is the comprehensive weight of the i-th indicator; is the indicator weight of the hierarchical analysis method; is the indicator weight of the entropy weight method; is the indicator weight of the independence weight coefficient method.

[0014] Furthermore, in step S4, an ecological assessment model for river regulation projects is constructed; specifically: Step S41, quantifying a single indicator using interval linear interpolation or direct scoring method according to the comprehensive method of single indicator quantification - multi-indicator synthesis - multi-criteria integration - neural network; Step S42, calculating the ecological level of the criterion layer according to formula (17)-formula (22), and using the calculation result of the criterion layer as the input variable of the BP neural network, and the expected output is the ecological comprehensive score of the river regulation project; (17); (18); (19); (20); (twenty one); (twenty two); Among them, HY is the hydrological and water resources evaluation score; WE is the water environment evaluation score; BI is the biological community evaluation score; BH is the biological habitat evaluation score; SE is the social environment evaluation score; EC is the ecological comprehensive score of the river regulation project; is the comprehensive weight of the i-th indicator; , , , , They are the evaluation scores of each indicator corresponding to the five criteria layers of hydrology and water resources, water environment, biological community, biological habitat, and social environment, with a value range of 0 to 100; β1 is the weight of the hydrology and water resources criterion layer; β2 is the weight of the water environment criterion layer; β3 is the weight of the biological community criterion layer; β4 is the weight of the biological habitat criterion layer; β5 is the weight of the social environment criterion layer; Step S43, taking the hydrological and water resources evaluation score HY, the water environment evaluation score WE, the biological community evaluation score BI, the biological habitat evaluation score BH, and the social environment evaluation score SE as input variables, constructing a three-layer BP neural network model consisting of five input nodes and one hidden layer, taking the ecological comprehensive score EC of the river regulation project as the expected output, the calculation process of the three-layer BP neural network model is expressed as follows: (twenty three); (twenty four); (25); in, for Adjusted input variables; It is The input variables of each neuron; is the learning rate; is the gradient of the performance function; is the hidden layer; Z is the output layer; is the transfer function of the hidden layer or output layer; is the weight between the input layer and the hidden layer, that is, The input variable and The weights of the neurons in the hidden layer; is the weight between the hidden layer and the output layer; , are the thresholds of the hidden layer and the output layer respectively; Step S44, determining the number of hidden layer nodes, using formulas (26) and (27): (26); (27); Among them, l represents the optimal number of hidden layer nodes; σ, are the number of nodes in the input layer and the output layer respectively, A random number between 1 and 10; Step S45, the logsig function is used between the input layer and the hidden layer, and the Tansig function is used between the hidden layer and the output layer as the transfer coefficient; the expressions are as follows: (28); (29); Among them, the domain of the logsig function is real numbers, and the range is 0 to 1; the domain of the Tansig function is real numbers, the input layer is any value, and the range is -1 to 1; e is a mathematical constant.

[0015] The beneficial effects of the present invention are as follows: the present invention aims to improve the health of rivers, and constructs an evaluation index system according to the connotation and requirements of river health, and adapts measures to local conditions; adopts an improved comprehensive weight determination method, combines subjective weights with objective weights, and comprehensively determines the index weights; adopts an evaluation model that combines single indicator quantification-multiple indicator synthesis-multiple criteria integration-neural network methods to evaluate the ecology of river regulation projects, and proposes an ecological evaluation method for river regulation projects. This method can accurately quantify the degree of impact of river regulation projects on the ecological health of rivers, and provide technical support for the health improvement and transformation of regulated rivers or the design optimization of planned projects. At the same time, the present invention makes up for the shortcomings of long-term tracking and monitoring technology for the ecological restoration effects of river regulation projects, and fills the gap in comprehensive evaluation methods for the ecology of river regulation projects with the goal of improving river health. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a flow chart of ecological assessment of the river regulation project of the present invention; Figure 2 Three-layer BP neural network model. DETAILED DESCRIPTION

[0017] In order to make the technical means, creative features, objectives and effects of the present invention easy to understand, the present invention is further described below in conjunction with specific implementation methods. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0018] like Figure 1 As shown, the present invention works and is implemented as follows: an ecological evaluation method for river regulation projects based on river health improvement, comprising the following steps: Step S1: Establishing an ecological evaluation index system for river regulation projects; Step S2: Divide the ecological evaluation index system of the river regulation project into five levels, and combine the index classification method and the index scoring method to determine the classification and scoring standards and scoring values ​​of each ecological evaluation index; Step S3: using an improved comprehensive weight determination method to calculate the comprehensive weights of various ecological evaluation indicators and determine the weights of the ecological evaluation indicators of the river regulation project; Step S4: constructing an ecological assessment model for river regulation projects; Step S5: Based on the constructed river channel regulation project ecological assessment model, the ecological evaluation index of the river channel regulation project is calculated to assess the ecological level of the river channel regulation project.

[0019] Further, in step S1, the ecological evaluation index system of the river regulation project includes a target layer, a criterion layer and an index layer; The target layer includes the ecological status T of the river regulation project; The criteria layer includes the hydrology and water resources B1 indicator layer, the water environment B2 indicator layer, the biological community B3 indicator layer, the biological habitat B4 indicator layer, and the social environment B5 indicator layer; The hydrological and water resources B1 indicator layer is the river and lake water area change rate C1 and the flow process variation degree C2; The water environment B2 indicator layer is the degree of water quality change C3, water body self-purification capacity C4, and lake and reservoir eutrophication C5; The indicator layer of biological community B3 is the bio-integrity index of algae (C6), the bio-integrity index of large benthic animals (C7), the impact on aquatic protected species (C8), and the impact on terrestrial habitats (C9); The indicator layer of biological habitat B4 is natural river channel retention rate C10, revetment near natural degree C11, longitudinal natural connectivity coefficient C12, vegetation coverage rate C13, curvature coefficient change degree C14; The social environment B5 indicator layer is the waterfront landscape facilities completeness C15, landscape comfort C16, and cultural landscape value C17; The three ecological evaluation indicators of lake and reservoir eutrophication C5, waterfront landscape facility completeness C15 and cultural landscape value C17 are alternative indicators, and the river and lake water area change rate C1, flow process variation degree C2, water quality change degree C3, water body self-purification capacity C4, algae biological integrity index C6, large benthic animal biological integrity index C7, impact on aquatic protected species C8, impact on terrestrial biological habitat C9, natural river channel retention rate C10, revetment near-naturalness C11, longitudinal natural connectivity coefficient C12, vegetation coverage C13, curvature coefficient change degree C14 and landscape comfort C16 are required indicators.

[0020] Furthermore, in step S2, the index grading method is specifically: standard reference method, literature citation method, data analysis method and expert judgment method; the index scoring method is specifically: data analysis method, standard reference method, expert judgment method and literature reference method; Determine the grading standards and scoring values ​​for each ecological evaluation indicator; there are 17 ecological evaluation indicators, and each indicator is divided into 5 levels according to different levels of conditions.

[0021] Further, in step S3, the improved comprehensive weight determination method is improved hierarchical analysis method-entropy weight method-independence weight coefficient method-multiplication synthesis normalization method; specifically: Step S31, using an improved analytic hierarchy process to calculate the subjective weight of each ecological evaluation index; Step S32, using entropy weight method to calculate the objective weight of each ecological evaluation index; Step S33, using the independence weight coefficient method to calculate the objective weight of each ecological evaluation index; The objective weighting method, which combines the entropy weight method with the independence weight coefficient method, can solve the problem of high information sensitivity of the entropy weight method, reduce the deviation caused by repeated indicator information, and make the evaluation results more accurate, practical and scientific. Step S34, using the multiplication synthesis normalization method to combine the subjective weight and the objective weight to assign weights.

[0022] Further, in step S31, the subjective weight of each ecological evaluation index is calculated using the improved analytic hierarchy process, and the specific steps are as follows: Step S311, establish a hierarchical structure model; use the five-scale method to divide the judgment level into five levels: equally important, slightly important, obviously important, strongly important and extremely important, and construct a comparison matrix A according to formula (1) and formula (2); (1); (2); Among them, A is the comparison matrix; is the matrix element, i.e., the scale value, indicating the importance of the i-th indicator compared with the j-th indicator; i=1,2,3, ⋯,n; j=1,2,3, ⋯,n; n is the number of evaluation indicators; Indicates the importance of the first indicator compared to the first indicator, Indicates the importance of the first indicator compared to the second indicator. Indicates the importance of the first indicator compared to the nth indicator. Indicates the importance of the second indicator compared to the first indicator. Indicates the importance of the second indicator compared to the second indicator, Indicates the importance of the second indicator compared to the nth indicator. Indicates the importance of the nth indicator compared to the first indicator. Indicates the importance of the nth indicator compared to the second indicator. It indicates the degree of importance of the nth indicator compared to the nth indicator; Step S312, calculating the importance ranking index of the indicator according to formula (3); (3); in, is the importance ranking index of the i-th indicator, that is, the matrix elements in the comparison matrix A sum; Step S313, calculating the elements of the judgment matrix B using the importance ranking index according to formula (4); (4); , , ; in, It represents the element obtained by calculating the importance ranking index of the i-th indicator and the j-th indicator in the judgment matrix B; Represents the importance ranking index of the i-th indicator The maximum value in Represents the importance ranking index of the i-th indicator The minimum value among them; d represents the comparison scale of importance ranking index; Represents the importance ranking index of the jth indicator; Step S314, calculating the elements of the optimal transfer matrix C of the judgment matrix B according to formula (5); (5); in, represents the elements of the optimal transfer matrix C, Indicates the difference between the i-th index and the The elements obtained by calculating the importance ranking index of the indicators; Indicates the difference between the i-th index and the The elements obtained by calculating the importance ranking index of indicators; k=1,2,3, ⋯,n; Step S315, calculating the index weight of the hierarchical analysis method according to formula (6); (6); in, is the indicator weight of hierarchical analysis method.

[0023] Furthermore, in step S32, the objective weight of each ecological evaluation index is calculated using the entropy weight method, and the specific steps are as follows: Step S321, constructing the original data matrix of ecological evaluation indicators, as shown in formula (7); (7); in, is the original data matrix; is the score value of the i-th indicator of the g-th evaluation item; q is the number of items to be evaluated; g=1,2,3, ⋯,q; i=1,2,3, ⋯,n; is the score value of the first indicator of the first evaluation item; is the score value of the second indicator of the first evaluation item; is the score value of the nth indicator of the first evaluation item; is the score value of the first indicator of the second evaluation item; is the score value of the second indicator of the second evaluation item; is the score value of the nth indicator of the second evaluation item; is the score value of the first indicator of the qth evaluation item; is the score value of the second indicator of the qth evaluation item; is the score value of the nth indicator of the qth evaluation item; Step S322, normalizing the positive ecological evaluation index according to formula (8) or the negative ecological evaluation index according to formula (9); (8); (9); in, is the normalized data of positive ecological evaluation indicators. It is the normalized data of negative ecological evaluation index; represents the minimum value among all the scoring values ​​of the i-th indicator, Represents the maximum value of all score values ​​of the i-th indicator; represents the score value of the first item to be evaluated under the i-th indicator, It represents the score value of the qth item to be evaluated under the i-th indicator; Step S323, calculating the proportion of the ecological evaluation index according to formula (10); (10); in, is the proportion of the score of the gth item to be evaluated under the i-th indicator to the total score of all the scores of the i-th indicator; g=1,2,3, ⋯,q; i=1,2,3, ⋯,n; Step S324, calculating the entropy value of the ecological evaluation index according to formula (11); (11); in, is the entropy value of the i-th indicator; Step S325, calculating the information entropy redundancy according to formula (12); (12); in, is the information entropy redundancy; Step S326, calculating the index weight according to formula (13); (13); in, is the indicator weight of the entropy weight method.

[0024] Furthermore, in step S33, the objective weight of each ecological evaluation index is calculated using the independence weight coefficient method; the specific steps are: Step S331, constructing the original data matrix of ecological evaluation indicators according to formula (7); (7); Step S332, calculating the complex correlation coefficient of each ecological evaluation index according to formula (14); (14); in, is the multiple correlation coefficient between the ith evaluation index and other indicators; is the score value of the i-th evaluation indicator; Remove the i-th evaluation index from the original data matrix H The residual matrix of is the average value of the original data matrix H; Step S333, calculating the weight of each ecological evaluation index according to formula (15); (15); in, is the indicator weight of the independence weight coefficient method.

[0025] Furthermore, in step S34, the subjective weight and the objective weight are combined and weighted by using the multiplication synthesis normalization method; the specific steps are: The comprehensive weight of each ecological evaluation index is calculated according to formula (16); (16); in, is the comprehensive weight of the i-th indicator; is the indicator weight of the hierarchical analysis method; is the indicator weight of the entropy weight method; is the indicator weight of the independence weight coefficient method.

[0026] Furthermore, in step S4, based on the comprehensive method of single index quantification-multi-index synthesis-multi-criteria integration-neural network, an ecological assessment model for river regulation projects is constructed; specifically: Step S41, quantifying a single indicator using interval linear interpolation or direct scoring method according to the comprehensive method of single indicator quantification - multi-indicator synthesis - multi-criteria integration - neural network; Step S42, calculating the ecological level of the criterion layer according to formula (17)-formula (22), and using the calculation result of the criterion layer as the input variable of the BP neural network, and the expected output is the ecological comprehensive score of the river regulation project; (17); (18); (19); (20); (twenty one); (twenty two); Among them, HY is the hydrological and water resources evaluation score; WE is the water environment evaluation score; BI is the biological community evaluation score; BH is the biological habitat evaluation score; SE is the social environment evaluation score; EC is the ecological comprehensive score of the river regulation project; is the comprehensive weight of the i-th indicator; , , , , They are the evaluation scores of each indicator corresponding to the five criteria layers of hydrology and water resources, water environment, biological community, biological habitat, and social environment, with a value range of 0 to 100; β1 is the weight of the hydrology and water resources criterion layer; β2 is the weight of the water environment criterion layer; β3 is the weight of the biological community criterion layer; β4 is the weight of the biological habitat criterion layer; β5 is the weight of the social environment criterion layer; Step S43, using the hydrological and water resources evaluation score HY, the water environment evaluation score WE, the biological community evaluation score BI, the biological habitat evaluation score BH, and the social environment evaluation score SE as input variables, constructing a three-layer BP neural network model consisting of five input nodes and one hidden layer, and taking the ecological comprehensive score EC of the river regulation project as the expected output, such as Figure 2 As shown in the figure, the calculation process of the three-layer BP neural network model is expressed as: (twenty three); (twenty four); (25); in, for Adjusted input variables; It is The input variables of each neuron; is the learning rate; is the gradient of the performance function; is the hidden layer; Z is the output layer; is the transfer function of the hidden layer or output layer; is the weight between the input layer and the hidden layer, that is, The input variable and The weights of the neurons in the hidden layer; is the weight between the hidden layer and the output layer; , are the thresholds of the hidden layer and the output layer respectively; Step S44, determining the number of hidden layer nodes, using formulas (26) and (27): (26); (27); Among them, l represents the optimal number of hidden layer nodes; σ, are the number of nodes in the input layer and the output layer respectively, A random number between 1 and 10; Step S45, the logsig function is used between the input layer and the hidden layer, and the Tansig function is used between the hidden layer and the output layer as the transfer coefficient; the expressions are as follows: (28); (29); Among them, the domain of the logsig function is real numbers, and the range is 0 to 1; the domain of the Tansig function is real numbers, the input layer is any value, and the range is -1 to 1; e is a mathematical constant.

[0027] Furthermore, in step S3, the weights of the evaluation indicators of the ecological river regulation project are determined; specifically, Table 1 is constructed.

[0028] Table 1 is the weight table of evaluation indicators for ecological river regulation projects

[0029] Furthermore, in step S5, the ecological evaluation model of the river regulation project is used to calculate the ecological evaluation index of the river regulation project, and a comprehensive evaluation is performed against the evaluation standards; the evaluation standards are specifically: 90-100 points is good, 80-90 points is better, 60-70 points is fair, 40-60 points is poor, and less than 40 points is poor. Example:

[0030] Based on the improvement of river ecological health, this paper proposes an ecological evaluation method for river regulation projects, conducts ecological evaluation of river regulation projects, and carries out the evaluation process with a river in Jiangxi Province as the research object. The engineering construction content of a river in Jiangxi Province mainly includes embankment projects, dredging projects, slope protection projects, landscape construction and other contents, which are typical river regulation projects. The ecological evaluation method for river regulation projects based on river health improvement is adopted to score the sub-items of the project and evaluate the ecological compliance of the project.

[0031] In this embodiment, the basic data of various evaluation indicators of a river regulation project in Jiangxi Province mainly come from Table 2: Table 2 Sources of basic data on ecological evaluation indicators for river regulation projects in a certain river in Jiangxi Province

[0032] Calculation and scoring of ecological evaluation indicators for a river regulation project in Jiangxi Province: Hydrology and Water Resources B1 River and lake water area change rate C1 After analyzing the engineering design, construction and other data, the project’s river and lake water area change rate score was 100 points.

[0033] Flow process variation degree C2 According to the flow data of a river hydrological station in Jiangxi Province from 1990 to 2022, the average flow over the years is 10.74m 3 / s, average flow in 2022 8.19m 3 / s, according to calculation, the flow process variation is 0.2%, and the score of this indicator is 58 points. According to the on-site investigation and analysis, the main reason for the difference in flow change is rainfall.

[0034] Water environment evaluation index B2 Water quality change degree C3 After the construction, the water quality of a river in Jiangxi Province reached the surface water quality standard III in 2022. The measured results of permanganate index, five-day biochemical oxygen demand, ammonia nitrogen and total phosphorus are shown in Table 3. According to historical monitoring data, the water quality of a river in Jiangxi Province generally reached the III standard in 2018. In summary, after the construction of the water conservancy project in a river in Jiangxi Province, the water quality category of a river in Jiangxi Province was not reduced, but the water quality of a river in Jiangxi Province was improved to a certain extent. Therefore, the water quality change degree score of the project was 100 points.

[0035] Table 3 Water quality after water conservancy project construction (unit: mg / L)

[0036] Water self-purification capacity C4 According to the measured results, the dissolved oxygen content in a river in Jiangxi Province ranges from 6.18 to 9.12 mg / L, with an average of 7.89 mg / L, which is greater than 7.5 mg / L. The score for this indicator is 100 points.

[0037] Biome Evaluation Index B3 Lake and reservoir eutrophication C5: It is an alternative indicator and is not evaluated.

[0038] Biotectonic integrity index of algae C6 According to the reference range of the biotic integrity index (P-IBI) of algae, the grading standards based on the biotic integrity index (P-IBI) of a river in Jiangxi Province were determined to be 1.5, 1.2448, 0.9896, 0.7343, 0.4791 and 0 respectively. Therefore, the biotic integrity index (P-IBI) of the typical monitoring points ranged from 0.8851 to 1.6085. According to the scoring standard, the scoring range of the biotic integrity index (P-IBI) of a river in Jiangxi Province was 53.67-100 points, with an average of 84.23 points.

[0039] Macrobenthic Biotic Integrity Index C7 According to the reference range of the large benthic animal biological integrity index B-IBI, the grading standards based on the large benthic animal biological integrity index B-IBI of a river in Jiangxi Province were determined to be 2.37, 2.096, 1.822, 1.548 and 1.274 respectively. Therefore, the large benthic animal biological integrity index B-IBI of typical monitoring points ranges from 2.30 to 2.75. According to the scoring standard, the large benthic animal biological integrity index B-IBI of a river in Jiangxi Province ranges from 82.15 to 100 points, with an average of 95.50 points.

[0040] Impact on aquatic protected species C8 The affected river sections do not involve aquatic organisms, migratory or semi-migratory fish, and fish that are under national and local key protection, rare and endangered, and unique to the river sections in the development areas, so the project’s impact on aquatic protected species is scored 100 points.

[0041] Impact on terrestrial habitats C9 The construction area of ​​the river regulation project and its impact area do not involve terrestrial species that are under national or local key protection, rare and endangered, or unique to the river sections in the development area, so the project's impact on the habitat of terrestrial protected organisms is scored 100 points.

[0042] Biohabitat B4 Natural river retention rate C10 According to the on-site investigation, an ecological corridor with a total length of 20 km was built, and the natural coastline rate reached 90%, and the score for this indicator was 90 points.

[0043] Near-natural revetment level C11 In addition to the need for hardening for flood control, the construction of a river embankment in Jiangxi Province mainly adopts near-natural revetments, mainly with turf slope protection, and the growth environment of revetment plants is basically undisturbed. This item is scored 80 points.

[0044] Longitudinal natural connectivity coefficient C12 In this project, only the original Hezhou sluice gate was renovated, and no new river-blocking structures that would block water, affect fish migration, and exchange of material and energy between upstream and downstream were built. This item is worth 100 points.

[0045] Vegetation coverage C13 The project has created an ecological river with a high vegetation coverage rate by adopting methods such as turf slope protection, hardened bank slope transformation, and ecological park construction. In general, the river has many types of vegetation, a large area, a relatively complete vegetation structure, and a vegetation coverage rate of 89%. This item is scored 80 points.

[0046] Bending coefficient variation degree C14 According to calculation, the bending coefficient of a river in Jiangxi Province was 1.6 before the construction of a water conservancy project, and it remained 1.6 after the construction. After the construction of the project, the change in the bending coefficient of a river in Jiangxi Province was 0. Therefore, the score for this item was 100 points.

[0047] Social Environment B5 Waterfront landscape facilities completeness C15 The green belt along a river in Jiangxi Province has been planned and designed, has good landscape effects, is equipped with abundant landscape nodes and recreational facilities, is hydrophilic and safe, and scored 100 points.

[0048] Landscape comfort level C16 A river in Jiangxi Province combines river basin management with the improvement of the living environment, promotes the ecological management of the shore and beach and the transformation of shanty towns, and builds a 20-kilometer green ecological corridor along the river. The river landscape is natural and harmonious, and has strong ornamental value. The score for this item is 100 points.

[0049] Cultural landscape value C17 During the management of a river in Jiangxi Province, some cultural landscapes were excavated, but there were relatively few cultural landscapes, so the score for this item was 80 points.

[0050] Comprehensive evaluation of river ecological health According to the ecological assessment model of river regulation projects, the ecological evaluation score of a river water conservancy project in Jiangxi Province in 2022 was 87.7 points. According to the evaluation standard of the ecological evaluation index of river regulation projects, the ecological score of a river regulation project in Jiangxi Province was between 80 and 90, and the evaluation level was II, with good ecology.

[0051] In summary, the ecological evaluation method of river regulation projects based on the improvement of river ecological health can be well applied to the ecological evaluation of river regulation projects.

[0052] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An ecological evaluation method for river regulation projects based on river health improvement, characterized by: The following steps are involved: Step S1: Establish an ecological evaluation index system for river regulation projects; Step S2: Divide the ecological evaluation index system of the river regulation project into five levels, and determine the grading and scoring standards and scoring values ​​of each ecological evaluation index by combining the index grading method and the index scoring method; Step S3: using an improved comprehensive weight determination method to calculate the comprehensive weights of each ecological evaluation index and determine the weights of the ecological evaluation indexes of the river regulation project; Step S4: constructing an ecological assessment model for river regulation projects; Step S5: Based on the constructed river channel regulation project ecological assessment model, the ecological evaluation index of the river channel regulation project is calculated to assess the ecological level of the river channel regulation project; In step S3, the improved comprehensive weight determination method is specifically improved hierarchical analysis method-entropy weight method-independence weight coefficient method-multiplication synthesis normalization method; the steps are: Step S31, using an improved analytic hierarchy process to calculate the subjective weight of each ecological evaluation index; Step S32, using entropy weight method to calculate the objective weight of each ecological evaluation index; Step S33, using the independence weight coefficient method to calculate the objective weight of each ecological evaluation index; Step S34, using the multiplication synthesis normalization method to combine the subjective weight and the objective weight to assign weights.

2. The ecological evaluation method for river regulation projects based on river health improvement according to claim 1 is characterized by: In step S1, the ecological evaluation index system of the river regulation project includes a target layer, a criterion layer and an index layer; The target layer includes the ecological status T of the river regulation project; The criteria layer includes the hydrology and water resources B1 indicator layer, the water environment B2 indicator layer, the biological community B3 indicator layer, the biological habitat B4 indicator layer, and the social environment B5 indicator layer; The hydrological and water resources B1 indicator layer is the river and lake water area change rate C1 and the flow process variation degree C2; The water environment B2 indicator layer is the degree of water quality change C3, water body self-purification capacity C4, and lake and reservoir eutrophication C5; The indicator layer of biological community B3 is the bio-integrity index of algae (C6), the bio-integrity index of large benthic animals (C7), the impact on aquatic protected species (C8), and the impact on terrestrial habitats (C9); The indicator layer of biological habitat B4 is natural river channel retention rate C10, revetment near natural degree C11, longitudinal natural connectivity coefficient C12, vegetation coverage rate C13, curvature coefficient change degree C14; The social environment B5 indicator layer is the waterfront landscape facilities completeness C15, landscape comfort C16, and cultural landscape value C17; The three ecological evaluation indicators of lake and reservoir eutrophication C5, waterfront landscape facility completeness C15 and cultural landscape value C17 are alternative indicators, and the river and lake water area change rate C1, flow process variation degree C2, water quality change degree C3, water body self-purification capacity C4, algae biological integrity index C6, large benthic animal biological integrity index C7, impact on aquatic protected species C8, impact on terrestrial biological habitat C9, natural river channel retention rate C10, revetment near-naturalness C11, longitudinal natural connectivity coefficient C12, vegetation coverage C13, curvature coefficient change degree C14 and landscape comfort C16 are required indicators.

3. The ecological evaluation method for river regulation projects based on river health improvement according to claim 2 is characterized by: In step S2, the index grading method is specifically: standard reference method, literature citation method, data analysis method and expert judgment method; the index scoring method is specifically: data analysis method, standard reference method, expert judgment method and literature reference method; Determine the grading standards and scoring values ​​for each ecological evaluation indicator; there are 17 ecological evaluation indicators, and each indicator is divided into 5 levels according to different levels of conditions.

4. The ecological evaluation method for river regulation projects based on river health improvement according to claim 3 is characterized by: In step S31, the subjective weight of each ecological evaluation index is calculated using the improved hierarchical analysis method. The specific steps are as follows: Step S311, establish a hierarchical structure model; use the five-scale method to divide the judgment level into five levels: equally important, slightly important, obviously important, strongly important and extremely important, and construct a comparison matrix A according to formula (1) and formula (2); （1）； （2）； Among them, A is the comparison matrix; is the matrix element, i.e., the scale value, indicating the importance of the i-th indicator compared with the j-th indicator; i=1, 2, 3, ⋯, n; j==1, 2, 3, ⋯, n; n is the number of evaluation indicators; Indicates the importance of the first indicator compared to the first indicator, Indicates the importance of the first indicator compared to the second indicator. Indicates the importance of the first indicator compared to the nth indicator. Indicates the importance of the second indicator compared to the first indicator. Indicates the importance of the second indicator compared to the second indicator, Indicates the importance of the second indicator compared to the nth indicator. Indicates the importance of the nth indicator compared to the first indicator. Indicates the importance of the nth indicator compared to the second indicator. It indicates the degree of importance of the nth indicator compared to the nth indicator; Step S312, calculating the importance ranking index of the indicator according to formula (3); （3）； in, is the importance ranking index of the i-th indicator, that is, the matrix elements in the comparison matrix A sum; Step S313, calculating the elements of the judgment matrix B using the importance ranking index according to formula (4); （4）； in, It represents the element obtained by calculating the importance ranking index of the i-th indicator and the j-th indicator in the judgment matrix B; Represents the importance ranking index of the i-th indicator The maximum value in Represents the importance ranking index of the i-th indicator The minimum value among them; d represents the comparison scale of importance ranking index; Represents the importance ranking index of the jth indicator; in, , , ; Step S314, calculating the elements of the optimal transfer matrix C of the judgment matrix B according to formula (5); （5）； in, represents the elements of the optimal transfer matrix C, Indicates the difference between the i-th index and the The elements obtained by calculating the importance ranking index of the indicators; Indicates the difference between the jth index and the The elements obtained by calculating the importance ranking index of indicators; k=1, 2, 3, ⋯, n; Step S315, calculating the index weight of the hierarchical analysis method according to formula (6); （6）； in, is the indicator weight of hierarchical analysis method.

5. The ecological evaluation method for river regulation projects based on river health improvement according to claim 4 is characterized by: In step S32, the objective weight of each ecological evaluation index is calculated using the entropy weight method, and the specific steps are as follows: Step S321, constructing the original data matrix of ecological evaluation indicators, as shown in formula (7); （7）； in, is the original data matrix; is the score value of the i-th indicator of the g-th evaluation item; q is the number of items to be evaluated; g=1,2,3,⋯,q; i=1,2,3,⋯,n; is the score value of the first indicator of the first evaluation item; is the score value of the second indicator of the first evaluation item; is the score value of the nth indicator of the first evaluation item; is the score value of the first indicator of the second evaluation item; is the score value of the second indicator of the second evaluation item; is the score value of the nth indicator of the second evaluation item; is the score value of the first indicator of the qth evaluation item; is the score value of the second indicator of the qth evaluation item; is the score value of the nth indicator of the qth evaluation item; Step S322, normalizing the positive ecological evaluation index according to formula (8) or the negative ecological evaluation index according to formula (9); （8）； （9）； in, is the normalized data of positive ecological evaluation indicators. It is the normalized data of negative ecological evaluation index; represents the minimum value among all the scoring values ​​of the i-th indicator, Represents the maximum value of all score values ​​of the i-th indicator; represents the score value of the first item to be evaluated under the i-th indicator, It represents the score value of the qth item to be evaluated under the i-th indicator; Step S323, calculating the proportion of the ecological evaluation index according to formula (10); （10）； in, is the proportion of the score of the gth item to be evaluated under the i-th indicator to the total score of all the scores of the i-th indicator; g=1,2,3,⋯,q; i=1,2,3,⋯,n; Step S324, calculating the entropy value of the ecological evaluation index according to formula (11); （11）； in, is the entropy value of the i-th indicator; Step S325, calculating the information entropy redundancy according to formula (12); (12)； in, is the information entropy redundancy; Step S326, calculating the index weight according to formula (13); （13）； in, is the indicator weight of the entropy weight method.

6. The ecological evaluation method for river regulation projects based on river health improvement according to claim 5 is characterized by: In step S33, the objective weight of each ecological evaluation index is calculated using the independence weight coefficient method; the specific steps are: Step S331, constructing the original data matrix of ecological evaluation indicators according to formula (7); （7）； Step S332, calculating the complex correlation coefficient of each ecological evaluation index according to formula (14); (14)； in, is the multiple correlation coefficient between the ith evaluation index and other indicators; is the score value of the i-th evaluation indicator; is the score value of the original data matrix H without the i-th evaluation index The residual matrix of is the average value of the original data matrix H; Step S333, calculating the weight of each ecological evaluation index according to formula (15); （15）； in, is the indicator weight of the independence weight coefficient method.

7. The ecological evaluation method for river regulation projects based on river health improvement according to claim 6 is characterized by: In step S34, the subjective weight and the objective weight are combined and weighted by using the multiplication synthesis normalization method; the specific steps are: The comprehensive weight of each ecological evaluation index is calculated according to formula (16); （16）； in, is the comprehensive weight of the i-th indicator; is the indicator weight of the hierarchical analysis method; is the indicator weight of the entropy weight method; is the indicator weight of the independence weight coefficient method.

8. The ecological evaluation method for river regulation projects based on river health improvement according to claim 7 is characterized by: In step S4, an ecological assessment model for river regulation projects is constructed; specifically: Step S41, quantifying a single indicator using interval linear interpolation or direct scoring method according to the comprehensive method of single indicator quantification - multi-indicator synthesis - multi-criteria integration - neural network; Step S42, calculating the ecological level of the criterion layer according to formula (17)-formula (22), and using the calculation result of the criterion layer as the input variable of the BP neural network, and the expected output is the ecological comprehensive score of the river regulation project; （17）； （18）； （19）； （20）； （21）； （22）； Among them, HY is the hydrological and water resources evaluation score; WE is the water environment evaluation score; BI is the biological community evaluation score; BH is the biological habitat evaluation score; SE is the social environment evaluation score; EC is the ecological comprehensive score of the river regulation project; is the comprehensive weight of the i-th indicator; , , , , They are the evaluation scores of each indicator corresponding to the five criteria layers of hydrology and water resources, water environment, biological community, biological habitat, and social environment, with a value range of 0 to 100; β1 is the weight of the hydrology and water resources criterion layer; β2 is the weight of the water environment criterion layer; β3 is the weight of the biological community criterion layer; β4 is the weight of the biological habitat criterion layer; β5 is the weight of the social environment criterion layer; Step S43, taking the hydrological and water resources evaluation score HY, the water environment evaluation score WE, the biological community evaluation score BI, the biological habitat evaluation score BH, and the social environment evaluation score SE as input variables, constructing a three-layer BP neural network model consisting of five input nodes and one hidden layer, taking the ecological comprehensive score EC of the river regulation project as the expected output, the calculation process of the three-layer BP neural network model is expressed as follows: （23）； （24）； （25）； in, for Adjusted input variables; It is The input variables of each neuron; is the learning rate; is the gradient of the performance function; is the hidden layer; Z is the output layer; is the transfer function of the hidden layer or output layer; is the weight between the input layer and the hidden layer, that is, The input variable and The weights of the neurons in the hidden layer; is the weight between the hidden layer and the output layer; , are the thresholds of the hidden layer and the output layer respectively; Step S44, determining the number of hidden layer nodes, using formulas (26) and (27): （26）； （27）； Among them, l represents the optimal number of hidden layer nodes; σ, are the number of nodes in the input layer and the output layer respectively, A random number between 1 and 10; Step S45, the logsig function is used between the input layer and the hidden layer, and the Tansig function is used between the hidden layer and the output layer as the transfer coefficient; the expressions are as follows: （28）； （29）； Among them, the domain of the logsig function is real numbers, and the range is 0 to 1; the domain of the Tansig function is real numbers, the input layer is any value, and the range is -1 to 1; e is a mathematical constant.

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