A method for resource utilization of agricultural runoff in plateau lake areas

Abstract

This invention relates to a method for the resource utilization of agricultural runoff in plateau lake areas. The method includes a facility structure comprising: an irrigation runoff canal, a storage tank, a pump, a water conveyance pipe, a reservoir, a wind turbine, a solar photovoltaic system, an energy storage battery, an irrigation conveyance canal, a reservoir release gate, and an ecological absorption device. Multiple irrigation runoff canals are configured and connected by water conveyance pipes. The irrigation conveyance canals are connected to the reservoir and are located on the side of the farmland. This method achieves significant economic and ecological benefits in the management of plateau lakes, solving a series of problems associated with traditional agricultural runoff ecological management models, such as land waste caused by land occupation, increased water costs for local farmers, and secondary pollution caused by sewage overflow during the rainy season. This method is low-cost, technically simple, and easy to operate, enabling the resource utilization of wastewater, reducing agricultural non-point source pollution, and improving water resource utilization efficiency.

Description

Technical Field

[0001] This invention relates to the fields of plateau lake management and agricultural irrigation, specifically a method for the resource utilization of agricultural runoff in plateau lake areas. Background Technology

[0002] As my country's ecological civilization construction continues to advance, plateau lakes, characterized by deep waters, steep banks, numerous inflowing tributaries, and generally fewer outflowing water systems, experience long water exchange cycles and weak self-purification capabilities, making lake protection and management a long and arduous task. While point source pollution has been controlled with ongoing efforts in plateau lake management, agricultural non-point source pollution remains a significant challenge and has not yet been effectively resolved.

[0003] In terms of domestic governance methods, most involve intercepting agricultural runoff and using ecological restoration. While this method has some effect, it requires occupying a large amount of local farmland and has a long treatment cycle. Especially during the rainy season, this method is often affected by rainfall, leading to sewage leakage and reduced effectiveness. Moreover, after the runoff is treated, local farmers are unwilling to use it due to concerns about water volume and electricity prices, ultimately resulting in the wastewater being discharged into lakes.

[0004] To completely solve the pollution problem of plateau lakes caused by agricultural runoff, it is urgent to study a method for the resource utilization of agricultural runoff in plateau lake areas. Summary of the Invention

[0005] The present invention aims to address the aforementioned problems and deficiencies by providing a method for the resource utilization of agricultural runoff in plateau lake areas.

[0006] The present invention is implemented using the following technical solution.

[0007] 1. Provide a set of facilities for the resource utilization of agricultural runoff from plateau lakes. The facilities mainly include: farmland irrigation runoff canal (2), regulating reservoir (3), water pump (5), water conveyance pipe (6), reservoir (7), wind turbine (8), solar photovoltaic (9), energy storage battery (12), irrigation water conveyance canal (13), reservoir sluice gate (14), and ecological absorption device (15).

[0008] The wind turbine (8), solar photovoltaic (9), and energy storage battery (12) are respectively connected to the water pump (5) via wires;

[0009] The water pump (5) is connected to the storage tank (3);

[0010] The farmland irrigation drainage canal (2) is set up in multiple groups and connected to each other by water conveyance pipes (6);

[0011] The farmland irrigation drainage canal (2) is located on the side of the farmland (4);

[0012] The water pump (5) is connected to the reservoir (7) via a water delivery pipe (6);

[0013] The irrigation canal (13) is connected to the reservoir (7); the irrigation canal (13) is located on the side of the farmland (4).

[0014] 2. Collect agricultural irrigation runoff into the farmland irrigation runoff canal (2), and then enter the storage tank (3) through the farmland irrigation runoff canal (2).

[0015] The design of farmland irrigation drainage canals first uses formula (a) to calculate the drainage volume per unit farmland area during the non-rainy season. Then, the drainage volume per unit farmland area during the rainy season and the drainage volume per unit farmland area during the non-rainy season are compared, and the maximum value is taken as the drainage volume per unit farmland area. Finally, formula (b) is used to calculate the water conveyance capacity of different drainage canal bottom widths.

[0016] The canal is designed with a trapezoidal cross-section, with an inner slope ratio of 1:0.5 to 1:0.75. To facilitate the drainage of water accumulated in the farmland on both sides of the canal, the top of the canal is higher than the design water depth but not higher than the ground elevation on both sides.

[0017] W TS =αW DE (a)

[0018] In the formula: W TS The amount of water discharged per unit area, in meters. 3 ;

[0019] α is the farmland drainage coefficient;

[0020] W DE For irrigation quotas, m 3

[0021]

[0022] In the formula: Q is the flow rate, m 3 / s;

[0023] R is the hydraulic radius, in meters;

[0024] i represents the longitudinal slope of the channel;

[0025] A is the water flow area, in meters. 2 ;

[0026] n is the roughness coefficient.

[0027] The water storage tank consists of three parts: an inlet system, a level control system, and a communication and automatic control system. Water storage tank size calculation: The water storage tank is fully underground, and its volume is calculated using formula (c).

[0028] v = 1.5V SR AU(c)

[0029] In the formula, v is the volume of the storage tank, m 3 ;

[0030] V SR The required storage capacity per hectare, m 3 / hm 2 ;

[0031] AU represents the cured area, in hectares (hm). 2 (The product of the catchment area and the runoff coefficient).

[0032] 3. When the water level in the regulating reservoir reaches the preset level, the pump (5) will automatically start to pump water to a small irrigation reservoir (7) around the plateau lake. See the automatic start design of the pump station for details. Figure 5 Start-up method: The automatic control system obtains accurate water level data through the level gauge. When the water level reaches the preset pump station start-up water level Z1, the automatic control system connects the pump station start-up switch and the pump station starts pumping water. When the water level drops to the pump station shutdown water level Z2, the automatic control system disconnects the pump station start-up switch and the pump station stops pumping water.

[0033] 4. After the farmland drainage is pumped into the reservoir, in order to ensure that the water quality of the reservoir does not deteriorate, a horizontal chain-type ecological absorption device (15) is installed in the reservoir to treat nitrogen and phosphorus pollutants in the water. The ecological absorption device (15) is installed across both banks of the reservoir. It includes a pair of rotating wheels (16) on each bank. A chain (17) is wound around the rotating wheels (16). A float (19) is installed on the side of the chain (17), and aquatic plants (20) are fixed on the float (19). A handle (18) is installed on the rotating wheel (16); the handle (18) is used to rotate the rotating wheel (16), which drives the chain (17) to move the float (19) to the shore, so that aquatic plants (20) can be placed or collected and replaced inside the float (19) on the shore. The float (19) with aquatic plants (20) installed is connected together by the chain (17) and floats on the water surface. The chain (17) is long enough to cope with water level changes so that the float (19) always floats on the water surface. In addition to ecological absorption method for ecological restoration, the reservoir can collect surface runoff within the reservoir basin into the reservoir, increase the water volume of the reservoir, and further enhance the dilution and purification effect of the water body.

[0034] 5. During the farmland irrigation season, the reservoir sluice gate (14) is controlled to release water. The water flows by gravity into the irrigation canal (13), then into the irrigation canal inside the farmland, and finally into the farmland (4).

[0035] 6. When the amount of farmland runoff is large and the pollution is low during the rainy season, this method will pump the runoff from the farmland into a reservoir in accordance with step 2, which can prevent the runoff from carrying pollutants from the farmland into the lake and causing pollution.

[0036] 7. Based on the measured rainfall data, calculate the amount of water receding per unit area of ​​farmland during the rainy season using formula (d).

[0037] W′ TS =βPA1 (d)

[0038] In the formula, W′ TS The amount of water discharged per unit area, in meters. 3 ;

[0039] β is the farmland rainfall runoff coefficient;

[0040] P represents rainfall in meters (m).

[0041] A1 is a unit area, equal to 1m². 2 .

[0042] 8. To avoid incurring additional electricity costs for local farmers, the entire system adopts a power supply mode that combines photovoltaic power, wind power, and energy storage batteries. Based on local wind and solar conditions, wind power (8) and solar photovoltaic (9) are used to generate electricity to supply the system, while excess electricity is stored in energy storage batteries (12) for use when there is no wind or sunlight.

[0043] The beneficial effects of this invention are as follows:

[0044] 1. This method has achieved significant economic and ecological benefits in the management of plateau lakes, and has solved a series of problems in the traditional farmland drainage ecological management model, such as the waste of land resources caused by land occupation, the increase of water costs for local farmers, and secondary pollution caused by sewage overflow during the rainy season.

[0045] 2. This method is low in cost, easy to operate, and can realize the resource utilization of wastewater, reduce agricultural non-point source pollution, and improve the efficiency of water resource utilization.

[0046] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0047] Figure 1 Schematic diagram of agricultural runoff resource utilization in plateau lake areas;

[0048] Figure 2 Schematic diagram of the reservoir's ecological absorption device;

[0049] Figure 3 Top view of the ecological absorption device;

[0050] Figure 4 Cross-sectional view of the ecological absorption device;

[0051] Figure 5 Automatic start-up design drawing for pump station.

[0052] In the diagram, 1: Plateau lake; 2: Irrigation drainage canal; 3: Storage tank; 4: Farmland; 5: Water pump; 6: Water pipe; 7: Reservoir; 8: Wind turbine; 9: Solar photovoltaic; 10: Utility pole; 11: Utility wire; 12: Energy storage battery; 13: Irrigation canal; 14: Reservoir sluice gate; 15: Ecological absorption device; 16: Rotary wheel; 17: Chain; 18: Handle; 19: Float; 20: Aquatic plants. Detailed Implementation

[0053] See Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown.

[0054] 1. Agricultural irrigation runoff is collected in the farmland irrigation runoff channel (2) and then enters the storage tank (3) through the farmland irrigation runoff channel (2).

[0055] 2. When the water level in the regulating reservoir reaches the preset level, the pump (5) will automatically start to pump water to a small irrigation reservoir (7) around the plateau lake. See the automatic start design of the pump station for details. Figure 5 Start-up method: The automatic control system obtains accurate water level data through the level gauge. When the water level reaches the preset pump station start-up water level Z1, the automatic control system connects the pump station start-up switch and the pump station starts pumping water. When the water level drops to the pump station shutdown water level Z2, the automatic control system disconnects the pump station start-up switch and the pump station stops pumping water.

[0056] 3. After farmland drainage is pumped into the reservoir, to ensure that the water quality of the reservoir does not deteriorate, a horizontal chain-type ecological absorption device (15) is installed in the reservoir to treat pollutants such as nitrogen and phosphorus in the water. The device is installed across both banks of the reservoir. The handle (18) is used to rotate the wheel (16), which drives the chain (17) to move the float (19) to the shore, making it convenient to place or collect and replace aquatic plants (20) on the float on the shore. The float with aquatic plants is connected together by the chain and floats on the water surface. The chain is long enough to cope with water level changes so that the float always floats on the water surface. In addition to ecological absorption for ecological restoration, the reservoir can collect surface runoff within the reservoir's watershed and increase the water volume of the reservoir, thereby further enhancing the dilution and purification effect of the water body.

[0057] 4. During the irrigation season, the reservoir release gate (14) is controlled to release water. The water flows by gravity into the irrigation canal (13), then into the irrigation canal inside the farmland, and finally into the farmland (4).

[0058] 5. When the amount of farmland runoff is large and the pollution is low during the rainy season, this method will follow step 2 to pump the runoff from the farmland into the reservoir, which can prevent the runoff from carrying pollutants from the farmland into the lake and causing pollution.

[0059] 6. To avoid incurring additional electricity costs for local farmers, the entire system adopts a power supply mode that combines photovoltaic power, wind power, and energy storage batteries. Based on local wind and solar conditions, the system is powered by a combination of wind turbines (8) and solar photovoltaics (9), while excess electricity is stored in energy storage batteries (12) for future power supply when there is no wind or sunlight.

[0060] The above descriptions are merely some specific embodiments of the present invention. Commonly known details or common knowledge in the solutions are not described in detail here (including but not limited to abbreviations, acronyms, and units conventionally used in the art). It should be noted that the above embodiments do not limit the present invention in any way. For those skilled in the art, any technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of the present invention. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for the resource utilization of agricultural runoff in plateau lake areas, characterized in that, Includes: farmland irrigation drainage canal (2), storage tank (3), water pump (5), water conveyance pipe (6), reservoir (7), wind turbine (8), solar photovoltaic (9), energy storage battery (12), irrigation water conveyance canal (13), reservoir sluice gate (14), and ecological absorption device (15); The wind turbine (8), solar photovoltaic (9), and energy storage battery (12) are connected to the water pump (5) via wires; the water pump (5) is connected to the storage tank (3); The farmland irrigation drainage canal (2) is set up in multiple groups and connected to each other by water conveyance pipes (6); The farmland irrigation drainage canal (2) is located on the side of the farmland (4); The water pump (5) is connected to the reservoir (7) via a water delivery pipe (6); The irrigation canal (13) is connected to the reservoir (7); the irrigation canal (13) is located on the side of the farmland (4); The facility includes: a horizontal chain-type ecological absorption device (15) installed in the reservoir to treat nitrogen and phosphorus pollutants in the water; the ecological absorption device (15) is installed across both banks of the reservoir; including a pair of rotating wheels (16) on each bank; a chain (17) is wound around the rotating wheel (16); a float (19) is installed on the side of the chain (17), and aquatic plants (20) are fixedly installed on the float (19); a handle (18) is installed on the rotating wheel (16); The handle (18) is used to rotate the wheel (16), which drives the chain (17) to move the float (19) to the shore, so that aquatic plants (20) can be placed or collected and replaced inside the float (19) on the shore. The float (19) with aquatic plants (20) installed is connected together by the chain (17) and floats on the water surface, so that the float (19) always floats on the water surface. The design of the farmland irrigation drainage canal includes the following steps: First, the drainage volume per unit farmland area during the non-rainy season is calculated using formula (a). The drainage volume per unit farmland area during the rainy season and the drainage volume per unit farmland area during the non-rainy season are compared, and the maximum value is taken as the drainage volume per unit farmland area. Then, the water conveyance capacity of different drainage canal bottom widths is calculated using formula (b). The channel is designed with a trapezoidal cross section, with an inner slope ratio of 1:0.5 to 1:0.

75. To facilitate the drainage of water accumulated in the farmland on both sides of the channel, the top of the channel is higher than the design water depth but not higher than the ground elevation on both sides. W TS = αW DE (a) In the formula: W TS The amount of water discharged per unit area, in meters. 3 ; α is the farmland drainage coefficient; W DE For irrigation quotas, m 3 In the formula: Q is the flow rate, m 3 / s; R is the hydraulic radius, in meters; i represents the longitudinal slope of the channel; A is the water flow area, in meters. 2 ; n is the roughness coefficient; The water storage tank consists of an inlet system, a level control system, and a communication and automatic control system. Storage tank size calculation: The storage tank is fully underground, and the volume of the storage tank is calculated using formula (c); v=1.5V SR AU (c) In the formula, v is the volume of the storage tank, m 3 ; V SR The required storage capacity per hectare, m 3 / hm 2 ; AU represents the cured area, in hectares (hm). 2 The product of the catchment area and the runoff coefficient; The method includes: when the water level in the regulating reservoir (3) reaches the preset water level, the water pump (5) is automatically started to pump the water to a small irrigation reservoir (7) around the plateau lake; Start-up method: The automatic control system obtains accurate water level data through the level gauge. When the water level reaches the preset pump station start-up water level Z1, the automatic control system connects the pump station start-up switch and the pump station starts pumping water. When the water level drops to the pump station shutdown water level Z2, the automatic control system disconnects the pump station start-up switch and the pump station stops pumping water. During the farmland irrigation season, the reservoir's water gate (14) is controlled to release water, which flows by gravity into the irrigation canal (13), then into the farmland's internal irrigation canal, and finally into the farmland (4). When the amount of farmland runoff is large and the pollution is low during the rainy season, pumping the runoff into reservoirs can prevent the runoff from carrying pollutants from the farmland into the lakes and causing pollution. Based on rainfall data measurements, the amount of water receding per unit area of ​​farmland during the rainy season is calculated using formula (d). W ′ TS = βPA1(d) In the formula, W ′ TS The amount of water discharged per unit area, in meters. 3 ; β is the farmland rainfall runoff coefficient; P represents rainfall in meters (m). A1 is a unit area, equal to 1m². 2 .

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