A method for optimizing the layout of channel dam systems in small watersheds

Abstract

The present invention discloses a method for optimizing the layout of a small watershed channel dam system, which belongs to the field of water conservancy engineering, and includes: determining the radiation area of ​​the small watershed, obtaining the main stream watershed and the tributary watershed along the main stream watershed in the radiation area, and marking the existing dam bodies on the main stream watershed and the tributary watershed; constructing a relationship model between the characteristic parameters of dam construction and downstream benefits; screening out all high-quality dam bodies and low-quality dam bodies on the main stream watershed and the tributary watershed; fitting the relationship model; outputting the characteristic parameters that need to be optimized for the low-quality dam bodies, repairing and optimizing the low-quality dam bodies; obtaining the characteristic function and corresponding characteristic parameters of the dam body constructed upstream of the watershed section, and constructing the dam body. A more scientific and reasonable dam system layout plan can be obtained, which can improve the long-term flood control capacity, ecological restoration capacity and water resource utilization rate of the dam system, and is of great significance for improving the ecological environment of the small watershed and promoting regional economic development.

Description

Technical Field

[0001] The invention relates to the field of water conservancy projects, and in particular to a method for optimizing the layout of a channel dam system in a small watershed. Background Art

[0002] The purpose of the small watershed dam system is to intercept and store floods and sediment in the channel, improve the ecological and economic environment of the small watershed, and improve the development and utilization of water and soil resources. Large (backbone dams), medium and small silt dams are scientifically arranged in the channels at all levels of the small watershed to form an organically combined, functionally coordinated, tree-shaped small watershed channel sediment interception and water storage engineering system and water and soil resource development and utilization system. In the management of small watersheds, the layout of the channel dam system is of great significance for flood control, silt interception and planting; the traditional dam system layout method is often based on experience and intuitive judgment, lacking scientificity and systematicity; in recent years, although the construction of silt dams has been vigorously developed, there is still room for improvement in the optimization of dam system layout. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, the present invention provides a method for optimizing the layout of a channel dam system in a small watershed, thereby improving the flood control capacity, ecological optimization capacity and water resource utilization rate of the dam system.

[0004] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0005] A method for optimizing the layout of a small watershed channel dam system is provided, comprising:

[0006] Step S1: determine the radiation area of ​​the small watershed, obtain the main stream watershed and the tributary watershed along the main stream watershed within the radiation area, and mark the existing dam bodies on the main stream watershed and the tributary watershed;

[0007] Step S2: construct a relationship model between the characteristic parameters of dam construction and downstream benefits based on the ecological coefficient s, safety coefficient f and benefit coefficient a of the downstream of the dam;

[0008] F(x)=η1s+η2f+η3a;

[0009] Among them, F(x) is the characteristic function of dam construction, x is the characteristic parameter of dam construction, η1, η2, η3 are the weight coefficients of ecology, safety and benefit respectively;

[0010] Step S3: Set the standard value s of the ecological coefficient in the main stream basin or tributary basin 标准 , standard value of safety factor f 标准 And the standard value of the benefit coefficient a 标准 , select all high-quality dams in the main stream and tributary basins, and the ecological coefficient s, safety factor f and benefit coefficient a of the downstream of the high-quality dams are all less than the standard value s 标准 , standard value f标准 and the standard value a 标准 ;

[0011] Step S4: according to the characteristic functions of all high-quality dam bodies, as well as the ecological coefficient s, safety factor f and benefit coefficient a corresponding to the high-quality dam bodies, input them into the relationship model, fit the weight coefficients η1, η2, η3, and take the average value of the weight coefficients η1, η2, η3 to obtain the fitted relationship model;

[0012] Step S5: According to the inferior dam bodies in the existing radiation area except the high-quality dam bodies, the ecological coefficient s, safety factor f and benefit coefficient a corresponding to the inferior dam bodies are input into the fitted relationship model, and the characteristic parameters that need to be optimized for the inferior dam bodies are output. According to the optimized characteristic parameters, the current characteristic parameters of the inferior dam bodies are compared to repair and optimize the inferior dam bodies;

[0013] According to the basin section of the main stream or tributary where the dam is to be built in the radiation area, the target ecological coefficient s1, target safety factor f1 and target benefit coefficient a1 required to be achieved in the basin section are calculated, and the target ecological coefficient s1, target safety factor f1 and target benefit coefficient a1 are input into the fitted relationship model to obtain the characteristic function and corresponding characteristic parameters of the dam construction upstream of the basin section, and the dam is constructed.

[0014] Furthermore, the method for calculating the ecological coefficient s downstream of the dam is:

[0015] Determine the ecological radiation area downstream of the dam and calculate the annual plant growth area in the ecological radiation area during the historical period is the plant growth area in the nth year in the historical year segment, n is the year in the historical year segment, and the fluctuation coefficient λ of the plant growth area in the historical year segment is calculated;

[0016]

[0017] in, is the plant growth area in the i-th year within the historical year period, where i is the year number;

[0018] Select several sampling areas for plant growth in the ecological radiation area, collect plant samples in the sampling areas, and calculate the growth coefficient γ of the plants in the sampling areas;

[0019]

[0020] Among them, E is the number of plant samples in the sampling area, e is the number of plant samples in the sampling area, L e is the root length of the plant sample, L′ is the standard value of the root length of the plant sample, R eis the root diffusion radius of the plant sample, R′ is the standard value of the root diffusion radius of the plant sample, r e is the trunk spread radius of the plant sample, r′ is the standard value of the trunk spread radius of the plant sample;

[0021] The growth coefficients (γ1,γ2,…,γ M ), γ M is the growth coefficient of the Mth sampling area, M is the total amount of the sampling area, and the growth coefficient of the ecological radiation area is calculated γ m is the growth coefficient of the mth sampling area, and m is the number of the sampling area;

[0022] After obtaining the growth coefficient of each year in the historical year period, calculate the fluctuation coefficient of the growth coefficient in the historical year period

[0023]

[0024] in, is the growth coefficient of the i-th year in the historical year period;

[0025] Using the growth coefficient and the fluctuation coefficient λ to calculate the ecological coefficient s downstream of the dam;

[0026]

[0027] Among them, k1 and k2 are the volatility coefficients respectively. and the influence weight of the fluctuation coefficient λ on the ecological coefficient.

[0028] Furthermore, the method for calculating the safety factor f downstream of the dam is:

[0029]

[0030] Among them, F1 is the vertical load of the dam body, f1 is the friction coefficient on the foundation surface of the dam body, L1 is the design length of the dam body, c1 is the cohesion on the foundation surface of the dam body, F2 is the lateral load of the dam body, U is the number of flood disasters suffered by the downstream of the dam body in the historical years, u is the number of flood disasters, S u is the area affected by the uth flood disaster, l u is the extension length of the u-th flood disaster, S′ is the safe encroachment area of ​​the flood peak downstream of the dam body in the historical year segment, l′ is the safe extension length of the flood peak downstream of the dam body in the historical year segment, η4 ​​and η5 are the influence weights of the dam structure safety and flood disaster safety on the safety of the dam downstream, K1 is the annual attenuation coefficient of the dam stability, N is the service life of the dam body, and W is the stability threshold of the dam body.

[0031] Furthermore, the method for calculating the benefit coefficient a downstream of the dam is:

[0032]

[0033] Among them, X is the water supply when the annual average water storage height downstream of the dam reaches the minimum warning water level, and ε is the annual water demand for agriculture, industry and residents downstream of the dam.

[0034] The beneficial effects of the present invention are:

[0035] According to the actual dam data in the small watershed and the corresponding downstream flood control, ecological and benefit data, a relationship model between the characteristic parameters of dam construction and downstream benefits is established, the coefficients of flood control, ecological and benefit data downstream of the dam are calculated, the existing dams are divided into high-quality dams and low-quality dams, the relationship model is fitted using the existing high-quality dams, and the characteristic parameters of the low-quality dams that need to be repaired and the characteristic parameters of the newly built dams are calculated using the fitted relationship model. By adopting the small watershed channel dam system optimization layout method of the present invention, a more scientific and reasonable dam system layout plan can be obtained, which can improve the long-term flood control capacity, ecological restoration capacity and water resource utilization rate of the dam system, which is of great significance for improving the ecological environment of the small watershed and promoting regional economic development. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Flow chart of the optimal layout method for channel dam systems in small watersheds. DETAILED DESCRIPTION

[0037] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0038] like Figure 1 As shown, a method for optimizing the layout of a channel dam system in a small watershed includes:

[0039] Step S1: determine the radiation area of ​​the small watershed, obtain the main stream watershed and the tributary watershed along the main stream watershed within the radiation area, and mark the existing dam bodies on the main stream watershed and the tributary watershed;

[0040] Small-basin dam system engineering refers to an engineering system that is coordinated with each other, consisting of a large number of dam bodies such as backbone dams, production dams, pond dams, etc. in the channels and basins of small watersheds. In the small-basin dam system, different types of single dams play different roles. Since the controlling backbone dam engineering is arranged in the small-basin dam system, each single dam can be used in conjunction with the division of labor requirements, which greatly improves the water and sand utilization capacity.

[0041] Step S2: construct a relationship model between the characteristic parameters of dam construction and downstream benefits based on the ecological coefficient s, safety coefficient f and benefit coefficient a of the downstream of the dam;

[0042] F(x)=η1s+η2f+η3a;

[0043] Among them, F(x) is the characteristic function of dam construction, x is the characteristic parameter of dam construction, η1, η2, η3 are the weight coefficients of ecology, safety and benefit respectively;

[0044] The characteristic parameters of dam construction include dam crest width, dam height, upstream and downstream slope data, dam volume, construction cost, etc. The characteristic function of dam construction can be established based on a univariate multivariate function. Parameters such as dam crest width, dam height, upstream and downstream slope data, dam volume, etc. represent the overall performance of the dam body and also correspond to cost control.

[0045] Step S3: Set the standard value s of the ecological coefficient in the main stream basin or tributary basin 标准 , standard value of safety factor f 标准 And the standard value of the benefit coefficient a 标准 , select all high-quality dams in the main stream and tributary basins, and the ecological coefficient s, safety factor f and benefit coefficient a of the downstream of the high-quality dams are all less than the standard value s 标准 , standard value f 标准 and the standard value a 标准 ;

[0046] Step S4: according to the characteristic functions of all high-quality dam bodies, as well as the ecological coefficient s, safety factor f and benefit coefficient a corresponding to the high-quality dam bodies, input them into the relationship model, fit the weight coefficients η1, η2, η3, and take the average value of the weight coefficients η1, η2, η3 to obtain the fitted relationship model;

[0047] Step S5: According to the inferior dam bodies in the existing radiation area except the high-quality dam bodies, the ecological coefficient s, safety factor f and benefit coefficient a corresponding to the inferior dam bodies are input into the fitted relationship model, and the characteristic parameters that need to be optimized for the inferior dam bodies are output. According to the optimized characteristic parameters, the current characteristic parameters of the inferior dam bodies are compared to repair and optimize the inferior dam bodies;

[0048] According to the basin section of the main stream or tributary where the dam is to be built in the radiation area, the target ecological coefficient s1, target safety factor f1 and target benefit coefficient a1 required to be achieved in the basin section are calculated, and the target ecological coefficient s1, target safety factor f1 and target benefit coefficient a1 are input into the fitted relationship model to obtain the characteristic function and corresponding characteristic parameters of the dam construction upstream of the basin section, and the dam is constructed.

[0049] The method for calculating the ecological coefficient s downstream of the dam is:

[0050] Determine the ecological radiation area downstream of the dam and calculate the annual plant growth area in the ecological radiation area during the historical period is the plant growth area in the nth year in the historical year segment, n is the year in the historical year segment, and the fluctuation coefficient λ of the plant growth area in the historical year segment is calculated;

[0051]

[0052] in, is the plant growth area in the i-th year within the historical year period, where i is the year number;

[0053] Select several sampling areas for plant growth in the ecological radiation area, collect plant samples in the sampling areas, and calculate the growth coefficient γ of the plants in the sampling areas;

[0054]

[0055] Among them, E is the number of plant samples in the sampling area, e is the number of plant samples in the sampling area, and L e is the root length of the plant sample, L′ is the standard value of the root length of the plant sample, R e is the root diffusion radius of the plant sample, R′ is the standard value of the root diffusion radius of the plant sample, r e is the trunk spread radius of the plant sample, r′ is the standard value of the trunk spread radius of the plant sample;

[0056] The growth coefficients (γ1,γ2,…,γ M ), γ M is the growth coefficient of the Mth sampling area, M is the total amount of the sampling area, and the growth coefficient of the ecological radiation area is calculated γ m is the growth coefficient of the mth sampling area, and m is the number of the sampling area;

[0057] After obtaining the growth coefficient of each year in the historical year period, calculate the fluctuation coefficient of the growth coefficient in the historical year period

[0058]

[0059] in, is the growth coefficient of the i-th year in the historical year period;

[0060] Using the growth coefficient and the fluctuation coefficient λ to calculate the ecological coefficient s downstream of the dam;

[0061]

[0062] Among them, k1 and k2 are the volatility coefficients respectively. and the influence weight of the fluctuation coefficient λ on the ecological coefficient.

[0063] The size of the ecological coefficient indicates the degree of impact of the dam on the downstream ecology. The larger the ecological coefficient, the worse the downstream ecology is, and the greater the impact of the dam on the downstream ecology.

[0064] The method for calculating the safety factor f downstream of the dam is:

[0065]

[0066] Among them, F1 is the vertical load of the dam body, f1 is the friction coefficient on the foundation surface of the dam body, L1 is the design length of the dam body, c1 is the cohesion on the foundation surface of the dam body, F2 is the lateral load of the dam body, U is the number of flood disasters suffered by the downstream of the dam body in the historical years, u is the number of flood disasters, S u is the area affected by the uth flood disaster, l u is the extension length of the u-th flood disaster, S′ is the safe encroachment area of ​​the flood peak downstream of the dam body in the historical year segment, l′ is the safe extension length of the flood peak downstream of the dam body in the historical year segment, η4 ​​and η5 are the influence weights of dam structure safety and flood disaster safety on the safety of the dam downstream, K1 is the annual attenuation coefficient of dam stability, N is the service life of the dam body, and W is the stability threshold of the dam body.

[0067] The size of the safety factor indicates the impact of the dam on downstream flood control safety. The larger the safety factor, the worse the downstream flood control effect, the greater the impact of the dam on downstream flood control safety, and the worse its own stability.

[0068] The method for calculating the benefit coefficient a downstream of the dam is:

[0069]

[0070] Among them, X is the water supply when the annual average water storage height downstream of the dam reaches the minimum warning water level, and ε is the annual water demand for agriculture, industry and residents downstream of the dam.

[0071] According to the actual dam data in the small watershed and the corresponding downstream flood control, ecological and benefit data, a relationship model between the characteristic parameters of dam construction and downstream benefits is established, the coefficients of flood control, ecological and benefit data downstream of the dam are calculated, the existing dams are divided into high-quality dams and low-quality dams, the relationship model is fitted using the existing high-quality dams, and the characteristic parameters of the low-quality dams that need to be repaired and the characteristic parameters of the newly built dams are calculated using the fitted relationship model. By adopting the small watershed channel dam system optimization layout method of the present invention, a more scientific and reasonable dam system layout plan can be obtained, which can improve the long-term flood control capacity, ecological restoration capacity and water resource utilization rate of the dam system, which is of great significance for improving the ecological environment of the small watershed and promoting regional economic development.

Claims

1. A method for optimizing the layout of a small watershed channel dam system, characterized in that: include: Step S1: determine the radiation area of ​​the small watershed, obtain the main stream watershed and the tributary watershed along the main stream watershed within the radiation area, and mark the existing dam bodies on the main stream watershed and the tributary watershed; Step S2: construct a relationship model between the characteristic parameters of dam construction and downstream benefits based on the ecological coefficient s, safety coefficient f and benefit coefficient a of the downstream of the dam; F(x)=η1s+η2f+η3a; Among them, F(x) is the characteristic function of dam construction, x is the characteristic parameter of dam construction, η1, η2, η3 are the weight coefficients of ecology, safety and benefit respectively; Step S3: Set the standard value s of the ecological coefficient in the main stream basin or tributary basin 标准 , standard value of safety factor f 标准 And the standard value of the benefit coefficient a 标准 , select all high-quality dams in the main stream and tributary basins, and the ecological coefficient s, safety factor f and benefit coefficient a of the downstream of the high-quality dams are all less than the standard value s 标准 , standard value f 标准 and the standard value a 标准 ; Step S4: according to the characteristic functions of all high-quality dam bodies, as well as the ecological coefficient s, safety factor f and benefit coefficient a corresponding to the high-quality dam bodies, input them into the relationship model, fit the weight coefficients η1, η2, η3, and take the average value of the weight coefficients η1, η2, η3 to obtain the fitted relationship model; Step S5: According to the inferior dam bodies in the existing radiation area except the high-quality dam bodies, the ecological coefficient s′, safety factor f′ and benefit coefficient a′ corresponding to the inferior dam bodies are input into the fitted relationship model, and the characteristic parameters that need to be optimized for the inferior dam bodies are output. According to the optimized characteristic parameters, the current characteristic parameters of the inferior dam bodies are compared to repair and optimize the inferior dam bodies; According to the river basin section of the main stream or tributary where the dam is to be built in the radiation area, the target ecological coefficient s1, target safety factor f1 and target benefit coefficient a1 to be achieved in the river basin section are calculated, and the target ecological coefficient s1, target safety factor f1 and target benefit coefficient a1 are input into the fitted relationship model to obtain the characteristic function and corresponding characteristic parameters of the dam built upstream of the river basin section, and then the dam is built; The method for calculating the ecological coefficient s downstream of the dam is: Determine the ecological radiation area downstream of the dam and calculate the annual plant growth area in the ecological radiation area during the historical period is the plant growth area in the nth year in the historical year segment, n is the year in the historical year segment, and the fluctuation coefficient λ of the plant growth area in the historical year segment is calculated; in, is the plant growth area in the i-th year within the historical year period, where i is the year number; Select several sampling areas for plant growth in the ecological radiation area, collect plant samples in the sampling areas, and calculate the growth coefficient γ of the plants in the sampling areas; Among them, E is the number of plant samples in the sampling area, e is the number of plant samples in the sampling area, and L e is the root length of the plant sample, L′ is the standard value of the root length of the plant sample, R e is the root diffusion radius of the plant sample, R′ is the standard value of the root diffusion radius of the plant sample, r e is the trunk spread radius of the plant sample, r′ is the standard value of the trunk spread radius of the plant sample; The growth coefficients (γ1,γ2,…,γ M ), γ M is the growth coefficient of the Mth sampling area, M is the total amount of the sampling area, and the growth coefficient of the ecological radiation area is calculated γ m is the growth coefficient of the mth sampling area, and m is the number of the sampling area; After obtaining the growth coefficient of each year in the historical year period, calculate the fluctuation coefficient of the growth coefficient in the historical year period in, is the growth coefficient of the i-th year in the historical year period; Using the growth coefficient and the fluctuation coefficient λ to calculate the ecological coefficient s downstream of the dam; Among them, k1 and k2 are the volatility coefficients respectively. and the weight of the impact of the fluctuation coefficient λ on the ecological coefficient; The method for calculating the safety factor f downstream of the dam is: Among them, F1 is the vertical load of the dam body, f1 is the friction coefficient on the foundation surface of the dam body, L1 is the design length of the dam body, c1 is the cohesion on the foundation surface of the dam body, F2 is the lateral load of the dam body, U is the number of flood disasters suffered by the downstream of the dam body in the historical years, u is the number of flood disasters, S u is the area affected by the uth flood disaster, l u is the extension length of the u-th flood disaster, S′ is the safe encroachment area of ​​the flood peak downstream of the dam body in the historical year segment, l′ is the safe extension length of the flood peak downstream of the dam body in the historical year segment, η4 ​​and η5 are the influence weights of the dam structure safety and flood disaster safety on the safety of the dam body downstream, K1 is the annual attenuation coefficient of the dam body stability, N is the service life of the dam body, and W is the stability threshold of the dam body; The method for calculating the benefit coefficient a downstream of the dam is: Among them, X is the water supply when the annual average water storage height downstream of the dam reaches the minimum warning water level, and ε is the annual water demand for agriculture, industry and residents downstream of the dam.

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