CN102900059A - Combined draining and saline controlling system for saline and alkaline land - Google Patents

Abstract

The invention discloses a combined draining and saline controlling system for a saline and alkaline land. The combined draining and saline controlling system comprises underground draining subdrains, surface draining open channels, intra-channel controlling gates, water collecting wells, water pumps and reservoirs, wherein the underground draining subdrains are arranged in a farmland in a staggered mode; the surface draining open channels are perpendicular to the underground draining subdrains; the water collecting wells are arranged at joints of the underground draining subdrains; the water pumps are arranged in the water collecting wells; the reservoirs are arranged at tail ends of the surface draining open channels; and the intra-channel controlling gates are arranged between the surface draining open channels and the reservoirs. According to the combined draining and saline controlling system, a horizontal draining system and a vertical draining system are integrated, so that draining and saline reducing effects are achieved, and the common problems that water is drained unsmoothly, the excavation area is large, collapse easily occurs and the like are solved.

Description

A compound drainage and salt control system for saline-alkali land

technical field

The invention belongs to the technical field of farmland water conservancy engineering, and in particular relates to a compound drainage and salt control system for saline-alkali land.

Background technique

Saline-alkali land often has the problems of poor drainage, soil back-salting and secondary salinization. The drainage effect is not good, which is not conducive to the growth of crops. To prevent salinization of the soil, the groundwater table should be kept at a relatively high depth. Field engineering to control the groundwater level has both horizontal and vertical drainage forms. Among them, horizontal drainage can be divided into two types: open ditch and hidden pipe. The use of open ditch drainage in field engineering requires a large amount of excavation, and there are problems such as easy collapse, easy silt, and easy growth of weeds. The use of hidden pipe drainage in field engineering can reduce the occupation of cultivated land, improve land utilization, and facilitate mechanical farming. However, the underground pipe drainage technology generally uses local material pipes or plastic pipes, and the project cost is relatively high, and the one-time investment is relatively large, so it has not been widely used in my country. In recent years, in many areas in northern my country where the buried depth of groundwater is relatively shallow and the water quality basically meets the requirements for irrigation, drainage has been combined with well irrigation. Practice has proved that well irrigation and well drainage are important measures for comprehensively controlling drought, waterlogging and alkali, and have broad application prospects in areas prone to drought, waterlogging and alkali in northern my country.

Therefore, a new compound drainage and salt control system for saline-alkali land is needed to solve the above problems.

Contents of the invention

Purpose of the invention: The present invention provides a compound drainage and salt control system for saline-alkali land, aiming at the common defects of poor drainage, soil back-salting and secondary salinization in the prior art.

Technical solution: In order to solve the above technical problems, the compound drainage and salt control system for saline-alkali land of the present invention adopts the following technical solution:

A compound drainage and salt control system for saline-alkali land, comprising underground drainage ditches, surface drainage ditches, in-ditch control gates, water collection wells, water pumps and reservoirs, the underground drainage ditches are interlaced with each other in farmland, and the ground drainage ditches and The underground drainage ditches are arranged perpendicular to each other, the water collection well is arranged at the intersection of the underground drainage ditches, the water pump is arranged in the water collection well, and the water storage tank is arranged at the end of the ground drainage open ditch, An in-ditch control gate is set between the surface drainage ditch and the reservoir.

Beneficial effects: the compound drainage and salt control system for saline-alkali land of the present invention integrates the horizontal and vertical drainage systems by designing a drainage system that combines horizontal and vertical drainage systems, which not only achieves the effect of drainage and salt reduction, but also avoids drainage Common problems in the process are poor drainage, large excavation volume, and easy collapse. The invention has simple structure and remarkable effect, is a salt washing system with practical application prospect, and has important popularization and application value. The drainage method combining horizontal culvert drainage and vertical well drainage can significantly reduce the groundwater level, reduce soil salinity, prevent secondary salinization, and promote high-efficiency agricultural production; compared with traditional culvert drainage, underground culvert drainage can effectively Reduce the excavation area of the ground, improve the utilization rate of farmland land, and facilitate mechanical farming, so as to achieve the purpose of efficient use of agricultural land; the horizontal underground ditch drainage and vertical drainage are integrated, the structure is simple, the construction is convenient, and it can be reused.

Furthermore, the underground drainage ditch includes a soil backfill layer and a straw filling layer, and the soil backfill layer is arranged above the straw filling layer. Rice, wheat or corn stalks can generally be used for filling the lower part. Straw instead of plastic hidden pipes reduces the project investment on the one hand, and on the other hand, it can obtain local materials, which solves the unfavorable phenomenon that rice and wheat straws in the farmland have nowhere to be placed for a long time and are incinerated at will. Moreover, straw burial can increase soil fertility and ensure high agricultural production and income. It can be seen that the straw filling technology not only reduces the project investment, but also prevents environmental pollution and resource waste. The straw covering thickness is equal to the width of the ditch bottom, which is 0.3-0.5m. The straw must be bundled into a column with a diameter of 0.3-0.5m before laying, and then the straw should be buried to the bottom of the ditch and compacted tightly. Finally, backfill the soil to the plow layer.

Furthermore, the section of the underground drainage ditch is trapezoidal, the depth of the underground drainage ditch is 1.2-1.5m, and the width of the bottom of the underground drainage ditch is 0.3-0.5m. The underground drainage ditch adopts a trapezoidal cross-section and must be excavated in advance, and the excavation depth shall meet the requirements for controlling the groundwater level. The spacing of the underground drainage ditch depends on the soil texture and permeability coefficient. Generally, 12-15m for clay soil, 15-20m for loam soil, and 20-30m for sandy loam. The underground drainage ditch will serve as the main drainage channel for groundwater, and the gradient of the underground ditch is similar to the ground slope along the ditch to avoid excessive excavation. The intersecting underground drainage ditches are perpendicular to each other. Reasonable layout and even drainage.

Furthermore, the depth of the water collection wells is 15-20m, the wellhead diameter of the water collection wells is 0.5-0.8m, and the distance between adjacent water collection wells is 40-50m. The wells are roughly arranged in a square. The well wall adopts the pipe string combining the well wall pipe and the water filter pipe, and is vertically installed in the pre-drilled well hole. The well wall pipe is installed at the aquifer, and the filter pipe is installed at the aquifer. A layer of filter screen is set at the connection between the underground drainage ditch and the vertical shaft to filter sand, gravel and weeds in the water. The outlet pipe at the end adopts a plastic reducer. Clay balls are used to stop water at the connection between the underground ditch and the shaft to prevent leakage. The annular gap between the well pipe and the well hole is filled with screened gravel or other artificial fillers to filter water and block sand. The bottom of the water collection well is a settling pipe, which is used to settle the silt flowing into the well.

Furthermore, the water pump is a submersible pump. When washing salt in a large area, the submersible pump is used to pump the groundwater in the collection well to the storage tank to empty the storage capacity and lower the groundwater level.

Furthermore, the control gate in the ditch is a culvert gate. The control gate in the ditch is arranged vertically to the center line of the surface drainage ditch, and is set at the end of the surface drainage ditch, using culvert gates. The control gate is mainly used to control the water level in the ditch to prevent excessive loss of irrigation water.

Furthermore, the surface drainage ditch has a trapezoidal cross section. The daily water level in the ditch is lower than the burial depth of groundwater required by the farmland, generally 1.0-1.5m above the ground. The present invention aims at the demand for salt control, and the daily water level must be kept at 2.2-2.6m. The drainage water level in the ditch depends on the water level in the discharge area of the system. In the present invention, water storage ponds and dams are arranged at the ends of each long ditch as discharge bearing areas, and a waterlogging drainage method based on self-drainage is adopted. Therefore, the drainage water level is determined according to the design flow of drainage. The underground drainage ditch connects the outlet pipe to the surface drainage ditch. The outlet pipe is made of plastic reducing pipe, and the pipe is wrapped or filled with outsourcing filter material to prevent soil particles from entering the underground pipe, so as to avoid sedimentation and hidden pipe blockage, stabilize the surrounding soil, and improve The water seepage capacity of the underground pipe channel to improve the drainage function.

Furthermore, it also includes a first water outlet pipe and a first filter net, the first water outlet pipe communicates with the underground drainage ditch and the underground drainage open ditch, and the first filter net is arranged between the first water outlet pipe and the underground drainage open ditch. The junction of the underground drainage ditch. Used to filter sand and weeds in the water.

Furthermore, it also includes a second water outlet pipe and a second filter net, the second water outlet pipe communicates with the underground drainage ditch and the water collection well, and the second filter net is arranged between the second water outlet pipe and the Describe the connection of underground drainage ditch. Used to filter sand and weeds in the water.

Furthermore, the well wall of the water collection well includes a well wall pipe and a water filter pipe, the well wall pipe is installed at the soil aquifer, and the water filter pipe is installed at the soil aquifer.

Description of drawings

Fig. 1 is the structural representation of the compound drainage system for saline-alkali land of the present invention;

The sectional view of the underground drainage ditch of the present invention of Fig. 2;

The sectional view of the water collecting well of Fig. 3 of the present invention;

Fig. 4 is a cross-sectional view of the connection between the underground drainage ditch and the ground drainage open ditch of the present invention.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment, further illustrate the present invention, should be understood that these embodiments are only for illustrating the present invention and are not intended to limit the scope of the present invention, after having read the present invention, those skilled in the art will understand various aspects of the present invention Modifications in equivalent forms all fall within the scope defined by the appended claims of this application.

Please refer to Fig. 1, Fig. 2, Fig. 3 and Fig. 4, a kind of compound drainage and salt control system for saline-alkali land of the present invention comprises an underground drainage ditch 1, a water collection well 2, a ground drainage ditch 3, a reservoir 4, and Control gate 5 and water pump. The underground drainage ditches 1 are arranged in the farmland 13 in a criss-cross pattern. Wherein, the section of the underground drainage ditch 1 is a trapezoidal section. The underground drainage ditch 1 includes a soil backfill layer 7 and a straw filling layer 6 , and the soil backfill layer 7 is arranged above the straw filling layer 6 . Rice, wheat or corn stalks can generally be used for filling the lower part. Straw instead of plastic hidden pipes reduces the project investment on the one hand, and on the other hand, it can obtain local materials, which solves the unfavorable phenomenon that rice and wheat straws in the farmland have nowhere to be placed for a long time and are incinerated at will. Moreover, straw burial can increase soil fertility and ensure high agricultural production and income. It can be seen that the straw filling technology not only reduces the project investment, but also prevents environmental pollution and resource waste. The depth of the underground drainage ditch 1 is 1.2-1.5m, and the width of the bottom of the underground drainage ditch 1 is 0.3-0.5m. The underground drainage ditch 1 adopts a trapezoidal section and must be excavated in advance, and the excavation depth shall meet the requirements for controlling the groundwater level. The spacing of the underground drainage ditch 1 depends on the soil texture and the permeability coefficient. Generally, 12-15m for clay soil, 15-20m for loam soil, and 20-30m for sandy loam. The underground drainage ditch 1 will serve as the main drainage channel for groundwater, and the gradient of the underground ditch is similar to the ground slope along the ditch, so as not to excavate too deep. The straw covering thickness is equal to the width of the ditch bottom, which is 0.3-0.5m. The straw must be bundled into a column with a diameter of 0.3-0.5m before laying, and then the straw should be buried to the bottom of the ditch and compacted tightly. Finally, backfill the soil to the plow layer. Wherein, the intersecting underground drainage ditches 1 are perpendicular to each other, the layout is reasonable, and the drainage is uniform.

The surface drainage ditch 3 and the underground drainage ditch 1 are arranged vertically to each other. The section of the ground drainage open ditch 3 is a trapezoidal section. The daily water level in the ditch is lower than the burial depth of groundwater required by the farmland, generally 1.0-1.5m above the ground. The present invention aims at the demand for salt control, and the daily water level must be kept at 2.2-2.6m. The drainage water level in the ditch depends on the water level in the discharge area of the system. In the present invention, water storage ponds and dams are arranged at the ends of each long ditch as discharge bearing areas, and a waterlogging drainage method based on self-drainage is adopted. Therefore, the drainage water level is determined according to the design flow of drainage. The junction of the underground drainage ditch 1 and the ground drainage ditch 3 is provided with a first filter 11, and the first filter 11 is arranged at the junction of the first water outlet pipe 12 and the underground drainage ditch 1 to filter gravel and weeds in the water . The underground drainage ditch 1 is connected to the first water outlet pipe 12 and leads to the ground drainage open ditch 3, and the first water outlet pipe 12 adopts a plastic reducing pipe. The pipes of the first outlet pipe 12 are wrapped or filled with outsourcing filter materials to prevent soil particles from entering the underground drainage ditch 1, so as to avoid sedimentation and blockage of the hidden pipe, stabilize the surrounding soil, improve the water seepage capacity of the hidden pipe channel, and improve the drainage function.

The water collection well 2 is arranged at the junction of the underground drainage ditch 1 . The depth of the water collection wells 2 is 15-20m, the wellhead diameter of the water collection wells 2 is 0.5-0.8m, and the distance between adjacent water collection wells 2 is 40-50m. The collection wells are arranged in a square. The wellhead of the water collection well 2 is provided with a well platform 8, and the well wall of the water collection well 2 adopts a pipe string combining a well wall pipe 9 and a water filter pipe 10, and is vertically installed in a pre-drilled well hole. The well wall pipe 9 is installed at the soil water-resisting layer, and the water filter pipe 10 is installed at the soil aquifer. The underground drainage ditch 1 is connected to the water collection well 2 through the second water outlet pipe 121, and a layer of second filter screen 111 is arranged at the junction of the underground drainage dark ditch 1 and the water collection well 2, and the second filter screen 111 is arranged on the second water outlet pipe 121 and the underground The joint of the drainage ditch 1 is used to filter gravel and weeds in the water. The second water outlet pipe 121 adopts a plastic reducing pipe. Clay balls are used to stop water at the junction of the underground drainage ditch 1 and the water collection well 2 to prevent leakage. The annular gap between the well pipe and the well hole is filled with screened gravel or other artificial fillers to filter water and block sand. The lowermost end of the water collecting well 2 is a settling pipe, which is used for settling the silt flowing into the well.

The water pump is arranged in the sump 2. Among them, the water pump is a submersible pump. When washing salt in a large area, the submersible pump is used to pump and drain the groundwater in the water collection well 2 to the reservoir 4 to empty the storage capacity and lower the groundwater level.

The reservoir 4 is arranged at the end of the surface drainage ditch 3 . The reservoir 4 is excavated at the end of the farm ditch to accommodate the discharge of the drainage system. The reservoir 4 should be arranged at or near the lowest end of the drainage area for centralized drainage. When the drainage system removes the daily flow, the water level should not cause backwater in the drainage system to ensure normal drainage; when the system washes salt in a large area or in the flood season, the storage ponds and dams have sufficient storage capacity to accommodate the discharge of the drainage system in time the full amount of water.

Between the surface drainage ditch 3 and the reservoir 4, an in-ditch control gate is arranged. The control gate 5 in the ditch is a culvert gate. The control gate 5 in the ditch is arranged vertically to the center line of the surface drainage ditch 3, and is set at the end of the surface drainage ditch 3, and adopts a culvert gate. The control gate is mainly used to control the water level in the ditch to prevent excessive loss of irrigation water.

Compound drainage and salt control method in saline-alkali land:

1. When washing salt in a large area, the control gate 5 in the ditch is opened, and the water in the reservoir 4 is pumped into the farmland 13 with a submersible pump. Daily rainfall runoff composition. When washing salt, a large amount of fresh water or brackish water seeps into the underground drainage ditch 1 from the soil surface and is discharged along the straw filling layer 6. Part of the water body is discharged into the ground drainage ditch 3 and then flows back to the reservoir 4, and the other part of the water body is drained along the underground drainage The dark ditch 1 is discharged into the water collection well 2. After washing the salt, the water yield in the sump 2 is drawn back to the reservoir 4 with a submersible pump. The amount of water in the reservoir 4 is replenished by ground fresh water and rainfall runoff or lateral seepage of ditches, and its salinity will gradually decrease. Through regular large-scale salt washing, the saline groundwater can be gradually discharged, the groundwater can be desalinated, and soil desalination can be promoted.

2. During daily irrigation, close the control gate 5 in the ditch, and use the submersible pump to pour the fresh water or brackish water in the reservoir 4 into the farmland 13, and the irrigation water will infiltrate through the soil surface and partly flow into the soil plan wet layer. The underground drainage ditch 1, this part of return water will be discharged into the surface drainage ditch 3 along the underground ditch 1. Since the control gate 5 in the ditch is in the closed state, the water level in the surface drainage ditch 3 is connected to the water level in the underground drainage ditch 1, which can reduce the leakage of irrigation water and improve the utilization efficiency of irrigation water. Part of the residual irrigation water will gradually flow into the water collection well 2 along the underground drainage ditch 1 . After the irrigation is completed, the control gate 5 in the ditch is opened, and the water yield in the surface drainage ditch 3 is discharged into the reservoir 4 .

In summary, the compound drainage and salt control system for saline-alkali land of the present invention integrates the horizontal and vertical drainage systems by designing a drainage system that combines horizontal and vertical drainage systems, which not only achieves the effect of drainage and salt reduction, but also avoids It solves the common problems such as poor drainage, large excavation volume and easy collapse during the drainage process. The invention has simple structure and remarkable effect, is a salt washing system with practical application prospect, and has important popularization and application value. Its main advantages are as follows:

(1) The drainage method combining horizontal culvert drainage and shaft drainage can significantly reduce the groundwater level, reduce soil salinity, prevent secondary salinization, and promote efficient agricultural production;

(2) Replacing plastic hidden pipes with straw reduces project investment on the one hand, and on the other hand, local materials can be obtained, which solves the unfavorable phenomenon that rice and wheat straws in farmland have nowhere to be placed and incinerated randomly for a long time. Moreover, straw burial can increase soil fertility and ensure high agricultural production and income. It can be seen that the straw filling technology not only reduces the project investment, but also prevents environmental pollution and resource waste;

(3) Compared with the traditional underground pipe drainage, the underground underground ditch drainage can effectively reduce the excavation area, improve the utilization rate of farmland land, and facilitate mechanical farming, so as to achieve the purpose of efficient use of agricultural land;

(4) Integrate horizontal underground ditch drainage and vertical drainage into one, with simple structure, convenient construction, and can be reused.

Claims (10)

1. A compound drainage and salt control system for saline-alkali land, characterized in that it comprises an underground drainage ditch, an open drainage ditch on the surface, a control gate in the ditch, a water collection well, a water pump and a reservoir, and the underground drainage ditch is arranged in a criss-cross pattern in the farmland , the surface drainage ditch and the underground drainage ditch are arranged perpendicular to each other, the water collection well is arranged at the intersection of the underground drainage ditch, the water pump is arranged in the water collection well, and the water storage tank is arranged in the The end of the ground drainage ditch, and the control gate in the ditch is set between the ground drainage ditch and the reservoir. 2. The compound drainage and salt control system for saline-alkali land according to claim 1, wherein the underground drainage ditch includes a soil backfill layer and a straw filling layer, and the soil backfill layer is arranged above the straw filling layer. 3. The compound drainage and salt control system for saline-alkali land as claimed in claim 1, wherein the section of the underground drainage ditch is a trapezoidal section, the depth of the underground drainage ditch is 1.2-1.5m, and the depth of the underground drainage ditch is 1.2-1.5m. The width of the trench bottom is 0.3-0.5m. 4. The compound drainage and salt control system for saline-alkali land as claimed in claim 1, wherein the depth of the water collection well is 15-20m, and the wellhead diameter of the water collection well is 0.5-0.8m, adjacent to the water collection well The distance between them is 40-50m. 5. The compound drainage and salt control system for saline-alkali land according to claim 1, wherein the water pump is a submersible pump. 6. The compound drainage and salt control system for saline-alkali land according to claim 1, wherein the control gate in the ditch is a culvert gate. 7. The compound drainage and salt control system for saline-alkali land according to claim 1, characterized in that, the section of the surface drainage ditch is trapezoidal. 8. The compound drainage and salt control system for saline-alkali land according to claim 1, further comprising a first water outlet pipe and a first filter net, and the first water outlet pipe communicates with the underground drainage ditch and the underground drainage open ditch , the first filter screen is arranged at the junction of the first water outlet pipe and the underground drainage ditch. 9. The compound drainage and salt control system for saline-alkali land according to claim 1, further comprising a second water outlet pipe and a second filter net, the second water outlet pipe communicates with the underground drainage ditch and the water collection well, The second filter screen is arranged at the junction of the second water outlet pipe and the underground drainage ditch. 10. The compound drainage and salt control system for saline-alkali land as claimed in claim 1, wherein the well wall of the water collection well comprises a well wall pipe and a water filter pipe, and the well wall pipe is installed at the soil water-resisting layer, and the The filter pipe is installed at the soil aquifer.

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