Water conservancy bearing capacity assessment method

Abstract

The invention discloses a water conservancy bearing capacity assessment method, which comprises the following steps: respectively acquiring flood control bearing capacity, water resource bearing capacity and water environment bearing capacity of a target area or a target drainage basin in a preset horizontal year, and taking the minimum value of the three as water conservancy bearing capacity; respectively calculating a water conservancy overload degree, a flood control overload degree, a water resource overload degree and a water environment overload degree of a preset horizontal year by adopting the model; when the overload degree is smaller than 1, the corresponding capacity is not overloaded; when the overload degree is not smaller than 1, the corresponding capacity is overloaded, and the capacity comprises flood control bearing capacity, water resource bearing capacity, water environment bearing capacity and water conservancy bearing capacity. According to the method, the flood control bearing capacity, the water resource bearing capacity and the water environment bearing capacity serve as the core to construct the water conservancy bearing capacity calculation model, a corresponding evaluation system framework is provided, and scientific evaluation of the water conservancy bearing capacity is achieved.

Description

Technical Field

[0001] The present application belongs to the field of water conservancy carrying capacity assessment, and specifically relates to a water conservancy carrying capacity assessment method. Background Art

[0002] Water conservancy is an important infrastructure to ensure economic security, ecological security and national security. At present, water shortage, water environment deterioration, frequent floods and other problems in some river basins and regions in my country reflect the abnormal phenomenon that local social and economic development has exceeded the carrying capacity of water conservancy. Weak water conservancy facilities cannot support the sustainable development of local social economy. Therefore, it is necessary to conduct a scientific assessment of water conservancy carrying capacity. Summary of the invention

[0003] The purpose of this application is to provide a method for evaluating water conservancy carrying capacity.

[0004] The technical solution of the present invention is as follows:

[0005] A method for evaluating water conservancy carrying capacity: comprising:

[0006] Obtain the flood control carrying capacity, water resources carrying capacity and water environment carrying capacity of the target area or target basin in the preset level year respectively, and take the minimum value among the three as the water conservancy carrying capacity;

[0007] Adoption Model Calculate the water conservancy overload degree P for the preset level year respectively w (t), flood control overload degree P f (t), water resource overload degree P r (t), water environment overload degree P e (t); where P(t) represents the total population in the preset level year, the actual total population in the current level year, and the predicted total population in the future level year;

[0008] When the overload degree is less than 1, it indicates that the corresponding capacity is not overloaded; when the overload degree is not less than 1, it indicates that the corresponding capacity is overloaded, and the capacities include flood control carrying capacity, water resources carrying capacity, water environment carrying capacity, and water conservancy carrying capacity.

[0009] Furthermore, the above evaluation method also includes:

[0010] Compare the water conservancy overload degree P in the target area in the same level year w (t), flood control overload degree P f (t), water resource overload degree P r (t), water environment overload degree P e (t), find out the overload capacity as a basis for formulating future water conservancy development strategies.

[0011] Furthermore, the above evaluation method also includes: comparing the water conservancy overload degree P of the target area in different level years w (t), flood control overload degree P f (t), water resource overload degree P r (t), water environment overload degree P e (t), predict the changing trend of water conservancy carrying capacity in the target area.

[0012] Furthermore, the calculation model of flood control carrying capacity is Among them, C f (t) represents the flood control carrying capacity of the target area or target basin in the t-th level year, k represents the number of the protection unit or section in the target area or target basin, K represents the total number of protection units or sections, P k represents the target protected population corresponding to the flood control engineering design standard of the kth protection unit or section, β tk It represents the construction compliance rate of the flood control system of the kth protection unit or section in the tth horizontal year.

[0013] Furthermore, the calculation model of water resources carrying capacity is Among them, C r (t) represents the water resources carrying capacity of the target area or target basin in the t-th level year, W a W(t) represents the socio-economic water supply in the t-th year, q(t) represents the per capita water demand in the t-th year, q(t) = W d (t) / P(t),W d P(t) represents the total water demand in the t-th level year, and P(t) represents the total population in the t-th level year.

[0014] Furthermore, the calculation model of water environment carrying capacity is Among them, W n (t) represents the pollutant assimilating capacity of the water body in the t-th year, and s(t) represents the per capita amount of pollutants entering the river in the t-th year.

[0015] Furthermore, the per capita pollutant inflow into the river in the t-th level year s(t) = W T (t) / P(t), where W T (t) represents the total amount of pollutants entering the river in the t-level year, and P(t) represents the total population in the t-level year;

[0016] The total amount of pollutants entering the river in the tth level year W T (t) = W Tp (t)+W Tn (t), where W Tp (t) and W Tn (t) represents the total amount of point source pollutants and non-point source pollutants entering the river respectively;

[0017] Point source pollutants entering the river The total amount of non-point source pollutants entering the river Among them, Q i (t) represents the amount of sewage from the i-th type of point source entering the river in the t-th level year, C i (t) represents the pollutant concentration in the i-th type of point source sewage in the t-th level year, I represents the total number of point source pollution types, Q j (t) represents the amount of non-point source sewage of type j entering the river in the t-th level year, C j (t) represents the pollutant concentration in the jth type of non-point source wastewater in the tth horizontal year, and J represents the total number of non-power pollution types.

[0018] Furthermore, the water body's pollutant assimilation capacity W in the t-th level year is n (t)=(C s -C 0 *exp(-KL / u))*q 0 *exp(KL / 2u), where C s and C 0 They represent the target water quality concentration requirements of the control section and the pollutant concentration of the upper section of the river, K represents the comprehensive degradation coefficient of pollutants; L represents the length of the river section, q 0 represents the design flow of the river section, and u represents the design flow velocity under the design flow of the river section.

[0019] Compared with the prior art, this application has the following characteristics:

[0020] This application constructs a water conservancy carrying capacity calculation model with flood control carrying capacity, water resources carrying capacity, and water environment carrying capacity as the core, and proposes a corresponding evaluation system framework to achieve a scientific assessment of water conservancy carrying capacity.

[0021] This application method was applied to evaluate the water conservancy carrying capacity of 14 cities in Liaoning Province. By analyzing the water conservancy carrying capacity in the current year and different future years, the following information and guidance can be obtained:

[0022] As shown in Table 1, the water conservancy carrying capacity of Liaoning Province is insufficient in the current situation, and the construction of water resource protection system and flood control system are the main factors restricting the water conservancy carrying capacity; as shown in Tables 2 and 3, in the future, the water conservancy carrying capacity will gradually increase, and there will be no obvious shortcomings in the water conservancy engineering system, and it will achieve coordinated development with the social economy.

[0023] The evaluation results of Liaoning Province's water conservancy carrying capacity obtained by this application method are consistent with the actual situation and development goals of Liaoning Province, indicating that this application method is reasonable and effective, and can be used as an evaluation method for regional or river basin water conservancy construction, and can provide reference and reference for the formulation of water conservancy development strategies. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the process of this application. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the technical solutions and beneficial effects of the present application, the specific implementation methods of the present application will be provided below.

[0026] (1) Construct a water conservancy carrying capacity calculation model;

[0027] The constructed water conservancy carrying capacity calculation model is as follows:

[0028] C w (t) = min(C f (t),C r (t),C e (t)) (1)

[0029] In formula (1), C w (t), C f (t), C r (t), C e (t) are the water conservancy carrying capacity, flood control carrying capacity, water resources carrying capacity and water environment carrying capacity of the region or basin in the tth horizontal year.

[0030] Flood control capacity C f The calculation model of (t) is as follows:

[0031]

[0032] In formula (2), k represents the number of the protection unit or section in the region or basin, K is the total number of protection units or sections, and P k is the target population to be protected corresponding to the design standard of the flood control project of the kth protection unit or section, unit: 10,000 people, which can be determined by referring to the national technical standards such as "Flood Control Standard" (GB50201-94), "Design Code for Embankment Engineering" (GB50286-98), "Design Code for Flood Control Engineering in Cities and Cities" (CJJ50-92); β tk It is the construction compliance rate of the kth protection unit or section flood control system in the tth horizontal year. It is the actual survey value for the current horizontal year and is set according to the planning requirements for the future horizontal year.

[0033] It should be noted that the flood control carrying capacity is not limited to the calculation using the above model (2). It can also be calculated using the evaluation results of the comprehensive flood control capacity of the regional or river basin flood control system, or the actual flood control level of the flood control system evaluated by the evaluation results. The flood control carrying capacity C can be directly determined by looking up the Flood Control Standards. f (t).

[0034] Water resources carrying capacity Cr The calculation model of (t) is as follows:

[0035]

[0036] In formula (3), W a (t) is the socio-economic water supply in the t-th level year (unit: 10,000 m 3 );q(t) is the per capita water demand in the t-th level year, unit: m 3 / person, q(t)=W d (t) / P(t);W d (t) is the total water demand in the tth level year, unit: 10,000 m 3 ; P(t) is the predicted total population in the t-th level year, unit: ten thousand people, and the current year is the actual population.

[0037] W a (t) It is mainly subject to two factors: (1) the availability of local water resources. The availability of water resources is the remaining amount of water after deducting the sustainable water demand suitable for the ecological environment from the total amount of local water resources, reflecting the natural endowment conditions of water resources and ecological protection requirements of a region or basin; (2) social, economic, and technical factors and conditions. It is mainly affected by engineering economics and technology. With the improvement of engineering control capabilities, the improvement of water resources development and utilization, and the introduction of external water transfer, the amount of water available for social and economic use will increase. Water resources available for social and economic use include local water, external water transfer, and unconventional water. At the same time, the net consumption of local water resources by the social economy cannot exceed the limit of the availability of local water resources. Due to the complexity of the hydraulic relationship between water sources, water supply projects, and water users in the system of reasonable allocation and efficient utilization of water resources, the general social and economic water availability needs to be obtained through systematic analysis of water resources allocation models. Regions or basins that have carried out relevant planning and research can directly refer to existing results.

[0038] For current conditions, q(t) is the current per capita water consumption; for future planning years, the water resources planning outline or evaluation guidelines can be referred to to predict the total water demand and population size under future planning conditions to obtain q(t). In addition, corresponding planning results can also be referred to.

[0039] Water environment carrying capacity C e The calculation model of (t) is as follows:

[0040]

[0041] s(t)=W T (t) / P(t) (5)

[0042] W n (t)=(C s -C 0*exp(-KL / u))*q 0 *exp(KL / 2u) (6)

[0043] W T (t) = W Tp (t)+W Tn (t) (7)

[0044]

[0045] In formulas (4)-(9), W n (t) is the water body's assimilative capacity for a certain pollutant in the t-level year, unit: t; the main pollutants in my country's water bodies are COD and ammonia nitrogen; s(t) is the per capita amount of pollutants entering the river in the t-level year, unit: t / 10,000 people; W T (t) is the total amount of pollutants entering the river in the t-th level year, unit: t.

[0046] Pollution holding capacity of water body W n (t) refers to the maximum amount of pollutants that the water body of a functional area can accommodate per unit time, based on the given water quality target value, design water volume, location of sewage outlet and sewage discharge method of the functional area, on the premise of meeting the water area function requirements. It can be obtained by calculation or from the water environment protection plan of the region or basin.

[0047] In this specific implementation, a one-dimensional steady-state model is used to estimate the pollution holding capacity W of the water body. n (t), see formula (6), where C s , C 0 are the pollutant concentration required for the river section (unit: mg / L) and the pollutant concentration in the upper section of the river section (unit: mg / L); K is the comprehensive degradation coefficient of pollutants; L is the length of the river section, unit: km; q 0 Design flow rate of the river section, unit: m 3 / s; u is the design flow velocity under the design flow of the river section, unit: m / s.

[0048] W T (t) is the total amount of pollutants entering the river. In this specific implementation, the total amount of pollutants entering the river is decomposed into the amount of point source pollutants entering the river and the amount of non-point source pollutants entering the river for calculation according to the source of pollutants, see formulas (7)-(9). Tp (t), W Tn (t) are the amount of point source pollutants entering the river (unit: t) and the total amount of non-point source pollutants entering the river (unit: t), which can be determined by referring to existing survey and planning results or estimated through the Manual of Pollutant Emission Statistical Survey and Pollution Emission Accounting Methods and Coefficients. i(t) is the amount of sewage from the i-th type of point source entering the river in the t-th level year (unit: 10,000 tons), i = 1, 2, representing urban domestic and industrial wastewater, respectively, obtained through investigation of sewage outlets or public data from statistical departments; C i (t) is the pollutant concentration in the i-th type point source sewage (unit: mg / L), determined through water quality survey; Q j (t) is the amount of non-point source sewage of type j entering the river in the t-th level year (10,000 tons), which can be estimated through the Manual of Pollution Emission Accounting Methods and Coefficients for Emission Source Statistical Survey or other relevant documents or determined through field surveys, j = 1, 2, 3, 4, representing rural domestic sewage, rural free-range livestock sewage, rural runoff, and urban runoff, respectively; C j (t) is the pollutant concentration of the jth type of non-point source sewage in the tth level year (unit: mg / L). Part of the point source sewage is treated in the sewage treatment plant before entering the river, and the untreated part is directly discharged into the river. They should be treated differently when calculating the amount of pollutants entering the river; non-point source sewage is discharged into the river as untreated.

[0049] (II) Establishing an evaluation system:

[0050] The water conservancy overload degree is constructed to evaluate the water conservancy carrying capacity, as follows:

[0051]

[0052] In formula (10): P w (t), P f (t), P r (t), P e (t) are the water conservancy overload, flood control overload, water resources overload and water environment overload of the region or basin in the tth horizontal year.

[0053] When the overload degree is less than 1, it indicates no overload, and the smaller the overload value, the greater the carrying potential; when the overload degree is greater than 1, it indicates overload, and the larger the overload value, the more serious the overload.

[0054] This application uses the above evaluation system to evaluate the water conservancy carrying capacity, including:

[0055] (1) Calculation of water conservancy carrying capacity

[0056] The natural conditions of water resources and socio-economic development indicators are input into the water conservancy carrying capacity calculation model, and the flood control carrying capacity, water resource carrying capacity and water environment carrying capacity of the target area or target basin in different levels are calculated respectively, and the minimum value of the three is taken as the water conservancy carrying capacity.

[0057] (2) Evaluation of water conservancy carrying capacity

[0058] Compare the water conservancy carrying capacity of each level year with the actual or predicted population, determine whether the water conservancy engineering system is overloaded, find out the shortcomings that restrict the water conservancy carrying capacity, and provide a basis for formulating future water conservancy development strategies.

[0059] Example

[0060] The hydraulic carrying capacity of Liaoning Province was evaluated by this application method. Taking the cities in Liaoning Province as calculation units, 2010 was selected as the current base year, and 2020 and 2030 were selected as different level years in the future, and the hydraulic carrying capacity of 14 cities in Liaoning Province was calculated and evaluated.

[0061] (1) Flood control capacity

[0062] ① Protection population target P corresponding to the design standard 0 :

[0063] The flood control carrying capacity of each city is calculated in two parts: urban area and non-urban area. For urban areas, the flood control planning of general basins and regions will make specific provisions for urban flood control standards and design protection population, so as to determine the protection population target corresponding to the urban design standards. For non-urban areas, the protection population target corresponding to the design standards is determined based on the flood control standards of the basins to which they belong and the local embankment flood control standards.

[0064] ②Flood control system construction compliance rate β:

[0065] The flood control engineering system in Liaoning is mainly composed of reservoirs and dikes. According to the results of the first water conservancy survey in Liaoning Province, the reservoirs with flood control tasks in Liaoning Province are currently operating well. The main factor that determines the carrying capacity of the flood control engineering system is the dike condition. Therefore, this article uses the dike compliance rate as the flood control system construction compliance rate. The current annual dike compliance rate data comes from the "Liaoning Province First Water Conservancy Census Report". In the future level year, the urban dike compliance rate is set to be 100%, and the non-urban dike compliance rate is set to be 75%.

[0066] (2) Water resources carrying capacity

[0067] ①Per capita water demand q(t):

[0068] The current per capita water demand can be obtained based on the Liaoning Province Water Resources Bulletin and Statistical Yearbook in 2010. In the future, based on the Liaoning Province Regional Economic Sustainable Development Water Resources Allocation Planning Report and the Liaoning Province National Economic and Social Development Plan, the population size and water quotas of various industries are predicted to determine the future water demand plan and the corresponding per capita water demand.

[0069] ② Socio-economic water supply W a (t):

[0070] Combined with Liaoning Province's plan to build a "water from the east to the west" water resources allocation pattern in the future, a water resources optimization allocation model for Liaoning Province is established. The model is based on the balance of supply and demand and water consumption, and optimizes the water supply process to achieve the goal of minimizing water shortage, maximizing the guarantee rate, and minimizing reservoir water abandonment. The available water resources, engineering storage capacity, water supply capacity, and optimal scheduling between reservoirs are taken into account. Therefore, the water supply obtained by the model can be considered as the social and economic water supply.

[0071] (3) Water environment carrying capacity

[0072] Since Liaoning Province has a clear plan for reducing COD emissions in the future, this embodiment uses COD as a typical pollutant to calculate the water environment carrying capacity.

[0073] ① Water body pollution holding capacity W n (t): The one-dimensional steady-state model is used for calculation. The parameter values ​​and detailed calculation instructions refer to the calculation results of Wei Chenghai and Wei Hongxia on the pollution absorption capacity of water bodies in Liaoning Province (Reference: Wei Chenghai, Wei Hongxia. Analysis of the water environment carrying capacity of Liaoning Province [C]. Proceedings of the 2007 Academic Annual Conference of the Water Resources Professional Committee of the Chinese Society of Hydraulic Engineering, 2007).

[0074] ② Per capita pollutant discharge into the river s(t): Based on the supply and consumption discharge results of the t-level year calculated by the water resources optimization allocation model, the amount of various waste water entering the river in urban and rural areas is obtained. According to the local measured water quality monitoring data and relevant plans, the pollutant concentrations of various waste water are given, and then the pollutant discharge into the river in the t-level year and the per capita pollutant discharge into the river are determined.

[0075] The evaluation results of water conservancy carrying capacity in Liaoning Province at different levels were calculated by the method of the present invention, as shown in Tables 1-3.

[0076] Table 1 Current water conservancy carrying capacity of various cities in Liaoning Province

[0077]

[0078]

[0079] Table 2 Water conservancy carrying capacity of cities in Liaoning Province in 2020

[0080]

[0081]

[0082] Table 3 Water conservancy carrying capacity of cities in Liaoning Province in 2030

[0083]

[0084] As can be seen from Table 1, in the current situation, the water conservancy carrying capacity of all cities in Liaoning Province is overloaded, the existing water conservancy engineering system cannot fully support the needs of national economic development, and water conservancy construction is slightly lagging behind. In the future, the subsystems of water conservancy engineering will gradually become coordinated with the development of the national economy. By 2020, the water resources protection system will be the first to get rid of the overload state, the water resources carrying capacity will also be greatly improved, and the overload situation will be greatly reduced. The main factor restricting the water conservancy carrying capacity is the flood control carrying capacity. There are 5 cities with low flood control carrying capacity due to insufficient flood control standards in planning; by 2030, there will be no obvious shortcomings in the construction of the three major bodies of Liaoning Province's water conservancy carrying capacity - flood control system, water resources allocation system and water resources protection system, and the water conservancy engineering system can better support social and economic development.

[0085] The technical solutions provided by the present invention are not limited to the above-mentioned embodiments. Any technical solutions formed by transformation and substitution using the structure and method of the present invention are within the protection scope of the present invention.

Claims

1. A method for evaluating water conservancy carrying capacity, characterized in that it includes: Obtain the flood control carrying capacity, water resources carrying capacity and water environment carrying capacity of the target area or target basin in the preset level year respectively, and take the minimum value among the three as the water conservancy carrying capacity; Adoption Model Calculate the water conservancy overload degree P for the preset level year respectively w (t), flood control overload degree P f (t), water resource overload degree P r (t), water environment overload degree P e (t); where P(t) represents the total population in the preset level year, the actual total population in the current level year, and the predicted total population in the future level year; When the overload degree is less than 1, it indicates that the corresponding capacity is not overloaded; when the overload degree is not less than 1, it indicates that the corresponding capacity is overloaded, and the capacities include flood control carrying capacity, water resources carrying capacity, water environment carrying capacity, and water conservancy carrying capacity.

2. The method for evaluating water conservancy carrying capacity according to claim 1, characterized in that: include: Compare the water conservancy overload degree P in the target area in the same level year w (t), flood control overload degree P f (t), water resource overload degree P r (t), water environment overload degree P e (t), find out the overload capacity as a basis for formulating future water conservancy development strategies.

3. The water conservancy carrying capacity assessment method according to claim 1, characterized in that: include: Comparison of water conservancy overload degree P in target area under different normal years w (t), flood control overload degree P f (t), water resource overload degree P r (t), water environment overload degree P e (t), predict the changing trend of water conservancy carrying capacity in the target area.

4. The water conservancy carrying capacity assessment method according to claim 1, characterized in that: The calculation model of flood control carrying capacity is: Among them, C f (t) represents the flood control carrying capacity of the target area or target basin in the t-th level year, k represents the number of the protection unit or section in the target area or target basin, K represents the total number of protection units or sections, P k represents the target protected population corresponding to the flood control engineering design standard of the kth protection unit or section, β tk It represents the construction compliance rate of the flood control system of the kth protection unit or section in the tth horizontal year.

5. The water conservancy carrying capacity assessment method according to claim 1, characterized in that: The calculation model of water resources carrying capacity is: Among them, C r (t) represents the water resources carrying capacity of the target area or target basin in the t-th level year, W a W(t) represents the socio-economic water supply in the t-th year, q(t) represents the per capita water demand in the t-th year, q(t) = W d (t) / P(t),W d P(t) represents the total water demand in the t-th level year, and P(t) represents the total population in the t-th level year.

6. The method for evaluating water conservancy carrying capacity according to claim 1, characterized in that: The calculation model of the water environment carrying capacity is: Among them, W n (t) represents the pollutant assimilating capacity of the water body in the t-th year, and s(t) represents the per capita amount of pollutants entering the river in the t-th year.

7. The method for evaluating water conservancy carrying capacity according to claim 6, characterized in that: The per capita pollutant inflow into the river in the t-th level year s(t) = W T (t) / P(t), where W T (t) represents the total amount of pollutants entering the river in the t-level year, and P(t) represents the total population in the t-level year; The total amount of pollutants entering the river in the tth level year is W T (t) = W Tp (t)+W Tn (t), where W Tp (t) and W Tn (t) represents the total amount of point source pollutants and non-point source pollutants entering the river respectively; The amount of point source pollutants entering the river The total amount of non-point source pollutants entering the river Among them, Q i (t) represents the amount of sewage from the i-th type of point source entering the river in the t-th level year, C i (t) represents the pollutant concentration in the i-th type of point source sewage in the t-th level year, I represents the total number of point source pollution types, Q j (t) represents the amount of non-point source sewage of type j entering the river in the t-th level year, C j (t) represents the pollutant concentration in the jth type of non-point source wastewater in the tth horizontal year, and J represents the total number of non-power pollution types.

8. The method for evaluating water conservancy carrying capacity according to claim 6, characterized in that: The water body's pollutant assimilation capacity W for the t-th level year n (t)=(C s -C0*exp(-KL / u))*q0*exp(KL / 2u), where C s and C0 represent the target water quality concentration requirements of the control section and the pollutant concentration of the section on the river respectively, K represents the comprehensive degradation coefficient of pollutants; L represents the length of the river section, q0 represents the design flow of the river section, and u represents the design flow velocity under the design flow of the river section.

Images