Compound ecological restoration system and method for lake agricultural non-point source pollution

Abstract

The invention provides a compound ecological restoration system and method for lake agricultural non-point source pollution, and the system comprises a plurality of pre-reservoirs which are arranged in the marginal area of a lake, and each pre-reservoir comprises a settlement area, a shallow water purification area and a deep water purification area; the plurality of water quality improving wetlands are arranged adjacent to the plurality of pre-reservoirs; a plurality of ecological interception ditches are arranged at the agricultural non-point source pollution inlet lake; the coastal ecological interception zone is arranged around the lake and is arranged in a lake shoreside area; the ecological enclosure is arranged adjacent to the water quality improving wetland, and a submerged plant recovery area is arranged in the ecological enclosure; the submerged plant recovery areas are arranged on the inner side of the ecological enclosure; and the ecological floating islands are uniformly arranged in the lake. According to the method, the treatment effect of lake non-point source pollution can be effectively improved according to the complex and changeable conditions of lake non-point source pollution, and the purpose of treating different types of lakes can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of ecological environment restoration, and in particular to a composite ecological restoration system and method for lake agricultural non-point source pollution. Background Art

[0002] Lakes are one of the key geographical units of the land surface system and an important part of the "mountains, rivers, forests, fields, lakes, grasses and ice" life community. They are irreplaceable in many aspects such as water environment security, flood control and drought relief, water quality purification, and biodiversity protection. Lakes are significantly affected by global environmental changes and human activities in the basin. The non-point source pollution of lakes caused by industrialization, urbanization and agricultural intensification is a common challenge faced by countries around the world.

[0003] In recent years, with the continuous advancement of the comprehensive improvement of the ecological water environment, a large number of applications have been carried out in the fields of lake non-point source pollution and water ecological restoration at home and abroad, and have been recognized by more and more managers. Commonly used methods for the restoration of lake non-point source pollution can be roughly divided into physical methods, chemical methods and biological methods. Physical methods include water diversion and water replacement, dredging, aeration and oxygenation, etc. Chemical methods include adding lime, algae killing, adding iron salts to remove phosphorus, etc. Biological methods include adding microorganisms, planting plants, etc. From the comprehensive effect, ecological governance technology has the advantages of stability, effectiveness, safety, durability and low operating cost.

[0004] Among the existing technologies, due to the uneven distribution of pollution and poor water exchange capacity of lake non-point source pollution, the restoration effect of a single ecological governance technology is difficult to guarantee. There are few projects that use multiple ecological governance technologies in coordination for lake non-point source pollution, and no comprehensive ecological governance technology plan with overall coordination and good restoration effect has been formed. Regarding the applicability of engineering measures, the integrated application of different technical combinations is still insufficient, which leads to a lack of systematic and long-term consideration of technology application and engineering practice. Summary of the invention

[0005] Based on this, the purpose of the present invention is to provide a composite ecological restoration system and method for lake agricultural non-point source pollution, so as to solve the deficiencies in the above-mentioned prior art.

[0006] In a first aspect, the present invention provides a composite ecological restoration system for lake agricultural non-point source pollution, which is applied to lakes, and the system comprises:

[0007] A plurality of pre-reservoirs are arranged at the edge of the lake, and the pre-reservoirs include a sedimentation area, a shallow water purification area, and a deep water purification area;

[0008] A number of water quality improvement wetlands are provided adjacent to the number of the pre-reservoirs;

[0009] A number of ecological interception ditches are set up where agricultural non-point source pollution enters the lake;

[0010] A coastal ecological interception zone is arranged around the lake and is arranged in the shore area of ​​the lake;

[0011] An ecological enclosure is arranged adjacent to the water quality improvement wetland, and a submerged plant restoration area is arranged in the ecological enclosure;

[0012] Several submerged plant restoration areas are arranged inside the ecological enclosure;

[0013] Ecological floating islands are evenly arranged in the lake;

[0014] Among them, the sedimentation area is used to intercept suspended particles in the lake, the shallow water purification area is used to dissolve pollutants in the lake, the deep water purification area is used to purify organic pollutants in the lake, the water quality improvement wetland is used to improve the internal hydraulic conditions of the lake, the ecological interception ditch is used to intercept pollutants discharged into the lake, the coastal ecological interception belt is used to intercept exogenous pollution and repair the shore of the lake, the ecological enclosure is used to reduce the wind and waves of the lake, the submerged water recovery area is used to increase the stability of the lake ecosystem and improve the purification function, and the ecological floating island is used to reduce the pollution load of the lake.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: through the front reservoir and the water quality improvement wetland, it is possible to treat the agricultural and domestic drainage pollution around the lakes with different concentrated point emissions; through the ecological interception ditch and the coastal ecological interception belt, it is possible to treat the non-point source pollution of different linear lakes; through the ecological enclosure, the submerged plant restoration area and the ecological floating island, it is possible to treat the pollution of different surface lake sources, thereby effectively targeting the complex and changeable situation of lake non-point source pollution, improving the control effect of lake non-point source pollution, and achieving the purpose of controlling different types of lakes.

[0016] Furthermore, emergent plants are arranged in the sedimentation area, and the emergent plants include reeds, broad-leaved cattails, water plantains and calamus.

[0017] Furthermore, emergent plants are arranged in the shallow water purification area, the water depth of the shallow water purification area is 0.3m to 1.5m, the bottom of the shallow water purification area is paved with 15cm to 20cm thick porous limestone, and the particle size of the porous limestone is 5mm to 8mm.

[0018] Furthermore, the water depth of the deep water purification area is 1.5m to 2.5m, and emergent plants and floating leaf plants are arranged in the deep water purification area. The emergent plants are reed, wild rice stem, arrowhead, loosestrife, water plantain, water chestnut, water lily and lotus, and the floating leaf plants are water lily, rain lily, water chestnut and water gorge.

[0019] Furthermore, the water quality improvement wetland is provided with a planting area, in which emergent plants, floating-leaf plants and submerged plants of different plant heights are arranged, and a permeable enclosure is provided outside the planting area, and the permeable enclosure is made of a fishing net.

[0020] Furthermore, the cross-section of the ecological interception ditch is a trapezoidal cross-section, and planting platforms are provided on both sides of the top of the ecological interception ditch. The height of the planting platform is 0.5m to 1m, and the water side of the planting platform adopts an ecological bag slope protection, and the thickness of the ecological bag slope protection is 0.15m.

[0021] Furthermore, the slope ratio of the two slopes of the ecological interception ditch is 1:2-3, and aquatic plants are arranged on both slopes.

[0022] Furthermore, the coastal ecological interception zone is composed of emergent plants and wetland herbaceous plants, the ecological floating island is composed of double-layer fishing nets and wide floating plates, and the submerged plant restoration area is composed of evergreen dwarf submerged plants and pollution-resistant pioneer species.

[0023] Furthermore, the ecological enclosure is made of PVC coated cloth.

[0024] In a second aspect, the present invention further provides a composite ecological restoration method for lake agricultural non-point source pollution, which is applied to the above-mentioned composite ecological restoration system for lake agricultural non-point source pollution, and the method comprises:

[0025] Build several pre-reservoirs in the lake, build sedimentation areas, shallow water purification areas and deep water purification areas in the pre-reservoirs, and build water quality improvement wetlands through landscape matching adjacent to the pre-reservoirs, so that the sedimentation areas, shallow water purification areas, deep water purification areas and water quality improvement wetlands included in the pre-reservoirs form ecological restoration of point-type pollution sources;

[0026] Constructing ecological interception ditches at the entrances of agricultural non-point source pollution to the lakes;

[0027] By planting emergent plants and wetland herbs on the lake, the emergent plants and wetland herbs form a coastal ecological interception zone, and the ecological interception zone is set in the shore area of ​​the lake, and the ecological interception ditch and the coastal ecological interception zone form a linear pollution source ecological restoration;

[0028] An ecological enclosure is formed in the lake by arranging PVC coated cloth in the lake, and several different plants are planted in the lake to form a submerged plant restoration area in the lake, wherein the submerged plant restoration area is constructed inside the ecological enclosure;

[0029] An ecological floating island is constructed in the lake using soilless cultivation and aquatic plants as the main body, wherein the ecological restoration of a surface pollution source is formed through the ecological enclosure, the submerged plant restoration area and the ecological floating island. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of a composite ecological restoration system for lake agricultural non-point source pollution in the first embodiment of the present invention;

[0031] Figure 2 It is a schematic diagram of the structure of the pre-storehouse in the first embodiment of the present invention;

[0032] Figure 3 It is a schematic structural diagram of a water quality improvement wetland in the first embodiment of the present invention;

[0033] Figure 4 It is a schematic diagram of the structure of the ecological enclosure in the first embodiment of the present invention;

[0034] Figure 5 It is a schematic structural diagram of the submerged plant restoration area in the first embodiment of the present invention;

[0035] Figure 6 It is a schematic diagram of the structure of the ecological floating island in the first embodiment of the present invention;

[0036] Figure 7 for Figure 6 Cross-sectional view at AA in the middle.

[0037] Description of main component symbols:

[0038] 10. Pre-storage area; 11. Settling area; 12. Shallow water purification area; 13. Deep water purification area;

[0039] 20. Water quality improvement wetland; 21. Planting area; 22. Permeable enclosure;

[0040] 30. Ecological interception ditch; 31. Planting platform;

[0041] 40. Coastal ecological interception zone;

[0042] 50. Ecological enclosure;

[0043] 60. Submerged plant restoration area;

[0044] 70. Ecological floating island;

[0045] 80. Lake.

[0046] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0047] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0048] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0050] Embodiment 1

[0051] See also Figures 1 to 7 , shown is a composite ecological restoration system for surface source pollution of a lake 80 in the first embodiment of the present invention, the system includes a front reservoir 10, a water quality improvement wetland 20, an ecological interception ditch 30, a coastal ecological interception belt 40, an ecological enclosure 50, a submerged plant restoration area 60 and an ecological floating island 70.

[0052] There are several pre-reservoirs 10, and several of the pre-reservoirs 10 are arranged in the edge area of ​​the lake 80. Several of the pre-reservoirs 10 include a sedimentation area 11, a shallow water purification area 12 and a deep water purification area 13. There are several water quality improvement wetlands 20, and they are arranged adjacent to the several pre-reservoirs 10. There are several ecological interception ditches 30, and they are arranged at the place where agricultural non-point source pollution enters the lake 80. The coastal ecological interception belt 40 is arranged around the lake 80 and is arranged in the shore area of ​​the lake 80. The ecological enclosure 50 is adjacent to the water quality improvement wetland 20. A submerged plant restoration area is arranged in the ecological enclosure 50. There are several submerged plant restoration areas 60, and several of the submerged plant restoration areas 60 are arranged on the inner side of the ecological enclosure 50. The ecological floating islands 70 are evenly arranged in the lake 80, wherein the sedimentation area 11 is used to intercept suspended particles in the lake 80, the shallow water purification area 12 is used to dissolve pollutants in the lake 80, the deep water purification area 13 is used to purify organic pollutants in the lake 80, the water quality improvement wetland 20 is used to improve the internal hydraulic conditions of the lake 80, the ecological interception ditch 30 is used to intercept pollutants discharged into the lake 80, the coastal ecological interception belt 40 is used to intercept exogenous pollution and repair the shore of the lake 80, the ecological enclosure 50 is used to reduce the wind and waves of the lake 80, the submerged water recovery area 60 is used to increase the stability of the ecosystem of the lake 80 and improve the purification function, and the ecological floating islands 70 are used to reduce the pollution load of the lake 80.

[0053] In this embodiment, a composite ecological restoration method for lake agricultural non-point source pollution applied to a composite ecological restoration system for lake agricultural non-point source pollution is also proposed, and the method includes steps S1 to S5:

[0054] S1, construct several pre-reservoirs in the lake, construct a sedimentation area, a shallow water purification area and a deep water purification area in the pre-reservoirs, and construct a water quality improvement wetland in the vicinity of the pre-reservoirs in consideration of landscape matching, so that the sedimentation area, shallow water purification area, deep water purification area and water quality improvement wetland included in the pre-reservoirs form a point-type pollution source ecological restoration;

[0055] S2, constructing an ecological interception ditch at the entrance of agricultural non-point source pollution of the lake;

[0056] S3, planting emergent plants and wetland herbs on the lake, so that the emergent plants and the wetland herbs form a coastal ecological interception belt, and the ecological interception belt is set in the shore area of ​​the lake, and the ecological interception ditch and the coastal ecological interception belt form a linear pollution source ecological restoration;

[0057] S4, forming an ecological enclosure in the lake by arranging PVC coated cloth in the lake, and planting several different plants in the lake to form a submerged plant restoration area in the lake, wherein the submerged plant restoration area is constructed inside the ecological enclosure;

[0058] S5, constructing an ecological floating island in the lake by using soilless cultivation and aquatic plants as the main body, wherein the ecological restoration of the surface pollution source is formed through the ecological enclosure, the submerged plant restoration area and the ecological floating island.

[0059] It should be noted that the pre-storage reservoir 10 and the water quality improvement wetland 20 are provided to form a point-type restoration, and the suspended particles in the lake 80 are intercepted by the sedimentation area 11, the shallow water purification area 12 can dissolve the pollutants in the lake 80, and the deep water purification area 13 can purify the organic pollutants in the lake 80;

[0060] It is worth noting that the construction of the sedimentation area 11 is to create a habitat by utilizing the existing lake 80, plant emergent plants with developed root systems, and intercept suspended particles in the lake 80 by utilizing the adsorption effect of the emergent plant roots and the gravity sedimentation effect. In this embodiment, the sedimentation area 11 is arranged with emergent plants, and the emergent plants in the sedimentation area 11 are reeds and wild rice stems;

[0061] It is worth noting that the shallow water purification area 12 is arranged with emergent plants, which are reeds, broad-leaved cattails, water plantains and calamus, and the water depth of the shallow water purification area 12 is 0.3m, and 15cm thick porous limestone is laid, and the particle size of the limestone is 5mm. In the specific implementation, the pollutants are efficiently degraded under various forms of purification such as filtration sedimentation, adsorption and other physical effects, microbial biodegradation, nitrification and denitrification, and plant absorption;

[0062] It is worth noting that the deep water purification area 13 has a water depth of 1.5 m, and emergent plants and floating leaf plants are arranged in the deep water purification area 13. In this embodiment, the emergent plants are reeds, wild rice stems, arrowheads, loosestrife, water plantain, water chestnut, water lily and lotus, and the floating leaf plants are water lilies, rain lilies, water chestnuts and water gorgeus, which can purify nitrogen, phosphorus and organic pollutants in the lake 80.

[0063] It is worth noting that the water quality improvement wetland 20 is matched with the landscape, and emergent plants, floating leaf plants and submerged plants of different heights are arranged in the planting area 21. In this embodiment, the floating leaf plants are water lilies, water chestnuts and water caltrops, the emergent plants are reeds and wild rice stems, and the submerged plants are duckweed. In addition, a layer of permeable enclosure 22 made of a fishing net is set on the outside of the planting area 21 to reduce the adverse effects of large engineering areas on the growth of submerged plants.

[0064] It should be noted that the ecological interception ditch 30 and the coastal ecological interception belt 40 can form a linear restoration of the lake 80. In the specific implementation, the ecological interception ditch 30 selects a suitable ditch according to local conditions, carries out slope and channel bottom transformation, sets up water interception bank, ecological permeable dam, etc., and plants aquatic plants on the ditch bottom slope to intercept linear discharge of pollutants entering the main body of the lake 80; the coastal ecological interception belt 40 selects a suitable water area along the coast of the lake 80, and forms a linear ecological interception belt that intercepts rainstorm erosion, blocks exogenous pollution and has landscape functions by planting emergent plants and wetland herbs. At the same time, the slopes exposed in the restoration area due to lack of vegetation are regreened;

[0065] It is worth noting that the cross-section of the ecological interception ditch 30 is a trapezoidal cross-section. Planting platforms 31 are arranged on both sides of the top of the ecological interception ditch 30. The height of the planting platform 31 is 0.5m. The water-facing side of the planting platform 31 adopts an ecological bag slope protection. The thickness of the ecological bag slope protection is 0.15m. In the specific implementation, the ecological interception ditch 30 adopts a trapezoidal cross-section, and a 0.5m high aquatic plant planting platform 31 is arranged on both sides of the ditch. The water-facing side of the platform adopts an ecological bag slope protection (each layer is 0.15m thick) for protection, backfilling, and planted with emergent plants on the top of the platform. This section is suitable for existing ditches with steeper slopes on both sides; in other optional embodiments, the ecological interception ditch 30 adopts a trapezoidal cross-section, the slope ratio of the slopes on both sides is 1:2, and aquatic plants are planted on the entire cross-section of the ditch. This section is suitable for existing ditches with gentler slopes on both sides.

[0066] It should be noted that the surface restoration of the lake 80 can be formed through the ecological enclosure 50, the submerged plant restoration area 60 and the ecological floating island 70. In the specific implementation, the ecological restoration of the surface pollution source includes habitat improvement, ecological enclosure 50, submerged plant restoration area 60, aquatic animal regulation and ecological floating island 70; the habitat improvement construction creates a good environment for the underwater forest construction by clearing water debris, preventing and controlling fish and improving water transparency; the ecological enclosure layout controls the flow of the lake 80 in a baffled manner by arranging PVC coated cloth, fully utilizing the regional clean water volume, reducing the disturbance of wind and waves to submerged plants, and improving the survival rate of plants; the submerged plant restoration area 60 is constructed with water purification The waterscape is mainly composed of underwater landscape. By matching submerged plant species that grow in different seasons and at different water depths, biological stability is increased to improve the purification function and achieve the effect of evergreen lake body in all seasons. The aquatic animal regulation improves the food chain and food web structure of the artificial ecosystem by artificially raising aquatic animals, stabilizes the balance of the ecosystem and realizes the biodiversity of the water body. The construction of the ecological floating island 70 is based on aquatic plants, uses the principle of soilless cultivation technology, applies the symbiotic relationship between species, makes full use of the water body space and nutritional niche, and constructs a "floating water purification habitat platform" in the lake 80, reduces the pollution load in the water body, greatly improves the transparency of the water body, and is arranged as close to the inner side of the ecological enclosure as possible.

[0067] It is worth noting that the water body cleaning for habitat improvement uses a combination of harvesters and manual labor to remove rotten plants, weeds and other solid waste in the lake area. After preliminary drying and dehydration, the waste is bagged and transported out in a centralized manner. Fish control for habitat improvement includes early manual intervention and later community regulation. Fish removal uses physical methods such as gillnets and trawls to remove fish, focusing on removing herbivorous fish and benthic omnivorous fish. To improve water transparency in habitat improvement, new, efficient and non-toxic modified diatomaceous earth is added to the 21 areas of submerged plant planting areas at a rate of 50-150g / m 2 , put it back and forth 2-3 times, and destabilize the positively and negatively charged colloidal particles at the same time, thereby greatly improving the water treatment effect; the submerged plant restoration area 60 is mainly composed of evergreen dwarf submerged plants, supplemented by pollution-tolerant pioneer species, requiring the plant community to have strong pollution tolerance, fast growth, strong reproductive ability and good ecological benefits.

[0068] In addition, through the automatic water quality monitoring station, aquatic biological community optimization and daily inspections; the establishment of the automatic water quality monitoring station, in the early stage of the completion of the ecosystem construction, scientific monitoring of various water indicators, through data analysis, timely discovery of system construction problems, so as to take timely countermeasures; aquatic biological community optimization, by monitoring the growth status, diversity ratio, distribution range, biomass and dominant species of aquatic plants area by area, and formulating a control plan based on data analysis, taking measures such as harvesting, thinning, replanting and transplanting to maintain the balance of aquatic plant species in the system; daily inspections, regular inspections of the lake, timely understanding of the project situation, regular summary of interim results, and compilation of inspection records. Emergency protection measures for water quality mutations can also be formulated to prevent various emergencies from causing damage to the lake ecosystem and minimize environmental risks. By specifically solving various point, line and surface pollution conditions of 80 surface source pollution in the lake, the present invention is long-term effective, suitable for promotion, environmentally friendly, clean, safe and reliable.

[0069] It is worth mentioning that an automatic water quality monitoring station has been set up. The equipment type is a micro station. The monitoring indicators are chemical oxygen demand, ammonia nitrogen, total nitrogen, and total phosphorus. It is powered by solar energy. Daily inspections include using Secchi disks to measure water transparency, inspecting the growth of aquatic plants, observing the number and types of aquatic animals in the water, and responding to alien species in a timely manner and taking corresponding measures, including observing whether there are any abnormalities in aquatic plants and aquatic animals. If there are any abnormalities, take photos, record them, and take emergency measures in a timely manner.

[0070] Maintain emergency plans. When a large amount of sewage suddenly enters the lake, first investigate the source of the sewage, collect and analyze data on the composition, concentration and amount of pollutants, and then propose corresponding solutions. When the turbidity exceeds the assimilable capacity of the ecosystem, take timely measures to reduce turbidity;

[0071] Maintain emergency plans. When oil film appears on the water surface, block the formation of oil film from the source, control the scope of oil film generation, avoid further spread of oil film and its impact on submerged plants and fish, and use oil film and water surface floating object collectors to collect fine floating objects such as grease and catkins, thereby reducing the pollution release of floating objects and improving the water surface sensory experience.

[0072] Embodiment 2

[0073] The difference between the second embodiment of the present invention and the first embodiment is that:

[0074] The emergent plants in the settlement area 11 are mainly reeds, with a plant height of 80-120 cm and a planting density of 36 plants / m 2 The planting area is 12.19% of the area of ​​​​the settlement area 11; the broad-leaved cattail, the plant height is 60-100cm, and the planting density is 25 plants / m 2 The planting area is 8.01% of the area of ​​​​the settlement area 11; the calamus, the plant height is 60-100cm, and the planting density is 25 plants / m 2 , the planting area is 11.20% of the area of ​​settlement area 11;

[0075] The water depth of the shallow water purification area 12 is 1.5m. The emergent plants constructed in the shallow water purification area 12 are water plantains, with a plant height of 80-120cm and a planting density of 36 plants / m 2 , the planting area is 94.55% of the area of ​​shallow water purification area 12;

[0076] The emergent plants in the deep water purification area 13 are reeds, with a plant height of 80-120 cm and a planting density of 36 plants / m 2 The planting area is 2.68% of the deep water purification area 13; wild rice, plant height is 80-120cm, planting density is 16 plants / m 2 The planting area is 16.28% of the area of ​​the deep water purification area 13; the floating leaf plants in the deep water purification area 13 are water lilies, and the planting density is 2 plants / m 2 The planting area is 3.55% of the area of ​​deep water purification area 13; the planting density of water chestnut is 4 plants / m 2 The planting area is 8.45% of the area of ​​deep water purification area 13; Gorgon fruit, the planting density is 1 plant / 5m 2 , the planting area accounts for 10.59% of the area of ​​deep water purification area 13.

[0077] Embodiment 3

[0078] The difference between the third embodiment of the present invention and the above embodiment is that:

[0079] The emergent plants in the settlement area 11 are mainly reeds, with a plant height of 80-120 cm and a planting density of 36 plants / m 2 , the planting area is 21.32% of the area of ​​settlement area 11;

[0080] The emergent plants in the shallow water purification area 12 are water plantains, with a plant height of 80-120 cm and a planting density of 36 plants / m 2 , the planting area is 26.49% of the area of ​​shallow water purification area 12;

[0081] The emergent plants in the deep water purification area 13 are reeds, with a plant height of 80-120 cm and a planting density of 36 plants / m 2 The planting area is 19.76% of the area of ​​deep water purification area 13; wild rice, plant height is 80-120cm, planting density is 16 plants / m 2 , the planting area is 14.26% of the area of ​​deep water purification area 13; Sagittaria, plant height is 60-100cm, planting density is 16 plants / m 2 The planting area is 10.37% of the area of ​​the deep water purification area 13; the floating leaf plants in the deep water purification area 13 are water chestnuts, and the planting density is 4 plants / m 2 The planting area is 13.09% of the area of ​​deep water purification area 13; Gorgon fruit, planting density is 1 plant / 5m 2 , the planting area is 8.23% of the area of ​​deep water purification area 13.

[0082] Embodiment 4

[0083] The fourth embodiment of the present invention is different from the above embodiment in that:

[0084] The emergent plants in the settlement area 11 are mainly water plantain, with a plant height of 80-120 cm and a planting density of 36 plants / m 2 The planting area is 28.00% of the area of ​​settlement area 11; Typha latifolia, plant height is 60-100cm, planting density is 25 plants / m 2 The planting area is 7.44% of the area of ​​​​the settlement area 11; the calamus, the plant height is 60-100cm, and the planting density is 25 plants / m 2 , the planting area is 6.39% of the area of ​​settlement area 11;

[0085] The emergent plants used in the shallow water purification area 12 are broad-leaved cattails, with a plant height of 60-100 cm and a planting density of 25 plants / m 2 The planting area is 32.14% of the area of ​​​​the settlement area 11; the height of the fish grass is 30-60cm, and the planting density is 16 plants / m2 The planting area is 19.11% of the area of ​​​​the settlement area 11; the height of the plant is 30-60cm, and the planting density is 25 plants / m 2 , the planting area is 14.29% of the area of ​​​​the settlement area 11; Lythrum salicaria, the plant height is 30-60cm, and the planting density is 16 plants / m 2 The planting area is 10.57% of the area of ​​​​the settlement area 11; the height of aquatic canna is 30-60cm, and the planting density is 16 plants / m 2 , the planting area is 8.30% of the area of ​​settlement area 11;

[0086] The emergent plants in the deep water purification area 13 are lotus, with a plant height of 80-120 cm and a planting density of 1 plant / m 2 The planting area is 9.64% of the area of ​​deep water purification area 13; Lythrum salicaria, plant height is 30-60cm, planting density is 16 plants / m 2 The planting area is 12.11% of the area of ​​deep water purification area 13; water plantain, plant height is 80-120cm, planting density is 36 plants / m 2 The planting area is 9.13% of the area of ​​deep water purification area 13; Pickerel grass, plant height is 30-60cm, planting density is 16 plants / m 2 The planting area is 9.32% of the area of ​​deep water purification area 13; the height of the plant is 30-60cm, and the planting density is 25 plants / m 2 The planting area is 11.63% of the area of ​​the deep water purification area 13; the floating leaf plants in the deep water purification area 13 are water lilies, and the planting density is 16 plants / m 2 The planting area is 6.65% of the deep water purification area 13; the planting density of Yujiuhua is 16 plants / m 2 The planting area is 6.65% of the deep water purification area 13; Nymphoides, the planting density is 16 plants / m 2 , the planting area is 13.04% of the area of ​​deep water purification area 13.

[0087] The water quality improvement wetland 20 is constructed by planting emergent plants, floating-leaf plants and submerged plants of different plant heights through landscape matching to improve the hydraulic conditions inside the wetland.

[0088] Embodiment 5

[0089] The difference between the fifth embodiment of the present invention and the above-mentioned embodiment is that:

[0090] The emergent plants used in the water quality improvement wetland 20 are lotus, with a plant height of 80-120 cm and a planting density of 1 plant / m 2, the planting area is 10.34% of the wetland area; reed, plant height is 80-120cm, planting density is 36 plants / m 2 , the planting area is 4.86% of the wetland area; water plantain, plant height is 80-120cm, planting density is 36 plants / m 2 , the planting area is 2.37% of the wetland area; Typha latifolia, plant height is 60-100cm, planting density is 25 plants / m 2 , the planting area is 1.39% of the wetland area; aquatic canna, plant height is 30-60cm, planting density is 16 plants / m 2 , the planting area is 0.89% of the wetland area; Lythrum salicaria, plant height is 30-60cm, planting density is 16 plants / m 2 , the planting area is 1.03% of the wetland area; Iris calamus, plant height is 30-60cm, planting density is 25 plants / m 2 The planting area is 1.89% of the wetland area; the floating leaf plants used in the construction of the water quality improvement wetland 20 are yellow flower water dragons, and the planting density is 16 plants / m 2 The planting area is 4.52% of the wetland area; the water lotus is used, and the planting density is 25 plants / m 2 The planting area is 2.50% of the wetland area; water lilies are used, and the planting density is 2 plants / m 2 The planting area is 1.86% of the wetland area; Nymphoides is used, and the planting density is 16 plants / m 2 , the planting area accounts for 2.50% of the wetland area.

[0091] Embodiment 6

[0092] The difference between the sixth embodiment of the present invention and the above-mentioned embodiment is that:

[0093] The emergent plants used in the construction of the water quality improvement wetland 20 are wild rice stems, with a plant height of 80-120 cm and a planting density of 16 plants / m 2 , the planting area is 8.95% of the wetland area; water plantain, plant height is 80-120cm, planting density is 36 plants / m 2 , the planting area is 5.03% of the wetland area; reed, plant height is 80-120cm, planting density is 36 plants / m 2 The planting area is 12.96% of the wetland area; the height of calamus is 60-100cm, and the planting density is 25 plants / m 2 , the planting area is 3.93% of the wetland area; Sagittaria, plant height is 60-100cm, planting density is 16 plants / m 2, the planting area is 9.13% of the wetland area; Typha latifolia, plant height is 60-100cm, planting density is 25 plants / m 2 , the planting area is 1.49% of the wetland area; aquatic canna, plant height is 30-60cm, planting density is 16 plants / m 2 , the planting area is 0.23% of the wetland area; Lythrum salicaria, plant height is 30-60cm, planting density is 16 plants / m 2 , the planting area is 1.43% of the wetland area; Pickerel grass, plant height is 30-60cm, planting density is 16 plants / m 2 The planting area is 0.77% of the wetland area; the floating leaf plants used in the construction of the water quality improvement wetland 20 are water chestnuts, and the planting density is 4 plants / m 2 The planting area is 9.00% of the wetland area; water lilies are used, and the planting density is 2 plants / m 2 The planting area is 10.21% of the wetland area; the submerged plants used in the construction of the water quality improvement wetland 20 are hornwort, and the planting density is 100-120 plants / m 2 The planting area is 6.95% of the wetland area; the planting density of Hydrilla verticillata is 100-120 plants / m 2 The planting area is 3.76% of the wetland area; the planting density of spike foxtail algae is 100-120 plants / m 2 The planting area is 6.58% of the wetland area; the planting density of water chestnut is 100-120 plants / m 2 , the planting area accounts for 6.26% of the wetland area

[0094] Embodiment 7

[0095] The difference between the seventh embodiment of the present invention and the above-mentioned embodiment is that:

[0096] Ecological interception ditch 30 and coastal ecological interception belt 40; the construction of the ecological interception ditch 30 is to select appropriate ditches according to local conditions, carry out slope and channel bottom transformation, set up water barriers, plant aquatic plants on the ditch bottom slope, and intercept linear pollutants entering the main body of the lake 80; the coastal ecological interception belt 40 is selected in suitable waters along the coast of the lake 80, and by planting emergent plants and wetland herbs, a linear ecological interception belt that intercepts rainstorm erosion, blocks exogenous pollution and has landscape functions is formed, and at the same time, the slopes exposed in the restoration area due to lack of vegetation are regreened;

[0097] The water retaining sill constructed in the ecological interception ditch 30 has an average height of 0.2m, a longitudinal top width of 0.3m, vertical front and back sides, a 0.2m thick and 0.9m long C20 concrete bottom plate at the bottom, and the transverse width of the water retaining sill is the same as the width of the channel bottom;

[0098] The aquatic plants planted in the ecological interception ditch 30 mainly include reeds, lotus, cattail, calamus, loosestrife, and aquatic canna;

[0099] It is worth mentioning that the slope restoration adopts three-dimensional reinforced mesh mat and high-performance ecological base material spray greening technology; the three-dimensional reinforced mesh mat is a reinforced three-dimensional geotextile mat, which is formed by extruding three-dimensional polypropylene material onto the machine-woven hexagonal double-twisted steel wire mesh surface; the high-performance ecological base material spray greening technology is through the scientific formulation of high-performance ecological base materials with the functions of improving soil environment, covering, heat preservation, water retention, accelerating plant growth and root formation, and using liquid spraying construction, it can achieve the effect of rapid formation and long-term greening; the high-performance ecological base material includes fine hot-melt wood fibers, interlocking artificial fibers, high molecular polymers and water-retaining bases, microporous particles and growth promoters.

[0100] Embodiment 8

[0101] The eighth embodiment of the present invention is different from the above-mentioned embodiment in that:

[0102] The ecological interception ditch 30 adopts a trapezoidal cross section, and a 1.0m high aquatic plant planting platform 31 is set on both sides of the ditch. The water side of the platform is protected by ecological bag slope protection (each layer is 0.15m thick), backfilled with earth, and aquatic plants are planted on the top of the platform. This section is suitable for existing ditches with steep slopes on both sides.

[0103] Embodiment 9

[0104] The ninth embodiment of the present invention is different from the above-mentioned embodiment in that:

[0105] The slope ratio of the two banks is 1:3, and aquatic plants are planted on the entire cross section of the ecological interception ditch 30. This embodiment is suitable for existing ditches with gentle slopes on both banks.

[0106] The coastal ecological interception zone 40 adopts a natural gentle slope section, and emergent plants and floating leaf plants are mainly arranged in the area of ​​natural revetment of the water body.

[0107] Densely packed pine piles are driven into the outside of the existing retaining wall. The pine piles are 1.6-3.6m long and not less than 0.12m in diameter. They are arranged in continuous and dense rows. A 2.0m wide planting platform 31 is set between the pine piles and the existing bank slope. The internal eco-bags are backfilled with soil, and emergent plants are planted along the existing bank slope and the top of the planting platform 31.

[0108] Embodiment 10

[0109] The difference between the tenth embodiment of the present invention and the above-mentioned embodiment is that:

[0110] For habitat improvement, water bodies are cleaned up by using a combination of harvesters and manual labor to remove water hyacinths, apple snails, weeds, roots and stems of decaying plants, fishing nets, floating objects, large pieces of gravel and other solid waste in the lake area. After preliminary drying and dehydration, the waste is bagged and transported out in a centralized manner.

[0111] Fish control for habitat improvement, including early human intervention and later community control. Fish removal uses physical methods such as gillnets and trawls to remove fish, with a focus on removing herbivorous fish and bottom-dwelling omnivorous fish;

[0112] Habitat improvement to improve water transparency, by adding new, efficient, non-toxic modified diatomaceous earth in the submerged plant restoration area 60, with a dosage of 50-150g / m 2 , put it in 2-3 times before and after, and destabilize the positively and negatively charged colloidal particles at the same time, thereby greatly improving the water treatment effect;

[0113] In this embodiment, the ecological enclosure 50 is composed of a float, an enclosure cloth, a connecting buckle, a counterweight and a tensile member; the float is a crossbar type float; the enclosure cloth is a double-sided PVC reinforced plastic cloth, and the height can be selected or customized according to the water depth; the connecting buckle is set to a section every 20m, with quick connection ports at both ends; the counterweight is a counterweight chain, so that the ecological soft enclosure skirt forms an underwater pollution-blocking concave surface in the water flow; the tensile member includes a pull rope, a reinforcement belt and a tension counterweight chain at the top, middle and bottom of the fence;

[0114] Submerged plant restoration area 60 is mainly composed of evergreen dwarf submerged plants, supplemented by pollution-tolerant pioneer species. The plant community is required to have strong pollution tolerance, fast growth, strong reproductive capacity and good ecological benefits;

[0115] The ecological floating island 70 is arranged on the inner side of the ecological enclosure 50; the ecological floating bed is 2m wide and consists of a 1m wide double-layer fishing net and a 1m wide floating plate; the double-layer fishing net is close to the impermeable ecological enclosure 50, and pink-green foxtail algae and round coin grass are mixed every 5m on the double-layer fishing net, and aquatic canna is planted in the culture holes on the floating plate; the double-layer fishing net is fixed by foundation piles, and the lower end of the permeable enclosure 22 is fixed by a counterweight stone cage; the floating plate is fixed by foundation piles, and the foundation piles are galvanized steel pipe piles, including a main pipe and a casing. The main pipe diameter is DN32, the pile length is 3m, and the burial depth is 2m-2.5m depending on the water depth. The casing is "T" shaped; the floating plates are connected by buckles and binding belts, the outer periphery of the floating plate adopts DN63 PB hot-melt pipe plus fixed type, and each group of floating beds is connected by a three-way socket.

[0116] Embodiment 11

[0117] The difference between the eleventh embodiment of the present invention and the above-mentioned embodiment is that:

[0118] In this embodiment, the ecological enclosure 50 is mainly composed of an upper floating body, a lower enclosure, and a bottom weighted gabion. The upper layer is bound with a floating ball, which can rise and fall with the change of water level. The lower layer is made of PVC coated cloth impermeable material, and the bottom is fixed with a gabion. The gabion has a specification of 100mm*100m*100mm and weighs about 10kg. This embodiment is mainly used outside the restoration area to block the influence of water outside the restoration area on the internal effect of the restoration area;

[0119] Embodiment 12

[0120] The difference between the twelfth embodiment of the present invention and the above-mentioned embodiment is that:

[0121] In this embodiment, the ecological enclosure 50 is a permeable enclosure 22, which is mainly composed of a lower layer of fishing nets + bottom weighted gabions. The lower layer of fishing nets is a 10mm pore diameter fishing net permeable material, and the bottom is fixed with gabions. This embodiment is mainly used for the inner side of the repair area.

[0122] Embodiment 13

[0123] The thirteenth embodiment of the present invention is different from the above-mentioned embodiment in that:

[0124] The submerged plant restoration area 60 mainly uses duckweed, with a plant height of 20-50 cm and a planting density of 100-120 plants / m 2 The planting area is 16.69% of the area of ​​submerged plant restoration area 60; Verticillium verticillatum, plant height is 20-50cm, planting density is 100-120 plants / m 2 The planting area is 6.83% of the submerged plant restoration area 60; the evergreen dwarf Vallisneria, the plant height is 20-50cm, and the planting density is 100-120 plants / m 2 The planting area is 34.38% of the area of ​​submerged plant restoration area 60; the spike foxtail algae, the plant height is 20-50cm, and the planting density is 100-120 plants / m 2 The planting area is 11.38% of the area of ​​submerged plant restoration area 60; the improved Vallisneria spinulosa, the plant height is 20-50cm, the planting density is 100-120 plants / m 2 , the planting area is 18.76% of the submerged plant restoration area 60; Water Chestnut, plant height is 20-50cm, planting density is 100-120 plants / m 2 The planting area accounts for 16.69% of the submerged plant restoration area 60.

[0125] The aquatic animal regulation, by releasing carnivorous fish and building large mollusk communities, uses biological manipulation methods to form a complete food chain, build a healthy aquatic ecosystem, and make the aquatic ecosystem more complex and stable. The carnivorous fish are mainly black snakeheads, with a stocking density of 3 fish / 1000m 2 , 200-500g per fish, the number of fish released is 17.65% of the total carnivorous fish; Mandarin fish, the release density is 4 fish / 1000m 2 , 200-500g per fish, the number of fish released is 23.53% of the total carnivorous fish; silver carp, the stocking density is 10 fish / 1000m 2 Each fish weighs 200-500g, and the number of fish released is 58.82% of the total amount of carnivorous fish. The mollusk community mainly uses copper rust ring edge snails, and the release density is 15g / m 2 , 10-20g each, the number of releases is 50.00% of the total mollusc community; river mussels, the release density is 10g / m 2 , 50-200g each, the number of shrimp released is 33.33% of the total mollusc community; the density of freshwater shrimp is 5g / m 2 , 30-50g each, and the number released is 16.67% of the total mollusk population.

[0126] In summary, the composite ecological restoration system for lake 80 surface source pollution in the above-mentioned embodiment of the present invention can treat different point-type slope protection surface source pollution situations through the sedimentation area 11, the shallow water purification area 12, the deep water purification area 13 and the water quality improvement wetland 20, can treat linear lake 80 surface source pollution situations through the ecological interception ditch 30 and the coastal ecological interception belt 40, and can treat different surface lake 80 source pollution situations through the ecological enclosure 50, the submerged plant restoration area 60 and the ecological floating island 70, thereby effectively targeting the complex and changeable situation of lake 80 surface source pollution, improving the control effect of lake 80 surface source pollution, and achieving the purpose of controlling different types of lakes 80.

[0127] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0128] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A composite ecological restoration system for lake agricultural non-point source pollution, applied to lakes, characterized in that: The system comprises: A plurality of pre-reservoirs are arranged at the edge of the lake, and the pre-reservoirs include a sedimentation area, a shallow water purification area, and a deep water purification area; A number of water quality improvement wetlands are provided adjacent to the number of the pre-reservoirs; A number of ecological interception ditches are set up where agricultural non-point source pollution enters the lake; A coastal ecological interception zone is arranged around the lake and is arranged in the shore area of ​​the lake; An ecological enclosure is arranged adjacent to the water quality improvement wetland, and a submerged plant restoration area is arranged in the ecological enclosure; Several submerged plant restoration areas are arranged inside the ecological enclosure; Ecological floating islands are evenly arranged in the lake; Among them, the sedimentation area is used to intercept suspended particles in the lake, the shallow water purification area is used to dissolve pollutants in the lake, the deep water purification area is used to purify organic pollutants in the lake, the water quality improvement wetland is used to improve the internal hydraulic conditions of the lake, the ecological interception ditch is used to intercept pollutants discharged into the lake, the coastal ecological interception belt is used to intercept exogenous pollution and repair the shore of the lake, the ecological enclosure is used to reduce the wind and waves of the lake, the submerged water recovery area is used to increase the stability of the lake ecosystem and improve the purification function, and the ecological floating island is used to reduce the pollution load of the lake.

2. The composite ecological restoration system for lake agricultural non-point source pollution according to claim 1 is characterized in that: Emergent plants are arranged in the sedimentation area, and the emergent plants are reeds, broad-leaved cattails, water plantains and calamus.

3. The composite ecological restoration system for lake agricultural non-point source pollution according to claim 1 is characterized in that: Emergent plants are arranged in the shallow water purification area, the water depth of the shallow water purification area is 0.3m-1.5m, the bottom of the shallow water purification area is paved with 15cm-20cm thick porous limestone, and the particle size of the porous limestone is 5mm-8mm.

4. The composite ecological restoration system for lake agricultural non-point source pollution according to claim 1 is characterized in that: The water depth of the deep water purification area is 1.5m to 2.5m. Emergent plants and floating leaf plants are arranged in the deep water purification area. The emergent plants are reed, wild rice stem, arrowhead, loosestrife, water plantain, water hyacinth, water lily and lotus, and the floating leaf plants are water lily, rain lily, water chestnut and water gorge.

5. The composite ecological restoration system for lake agricultural non-point source pollution according to claim 1 is characterized in that: The water quality improvement wetland is provided with a planting area, in which emergent plants, floating leaf plants and submerged plants of different plant heights are arranged, and a permeable enclosure is arranged outside the planting area, and the permeable enclosure is made of a fishing net.

6. The composite ecological restoration system for lake agricultural non-point source pollution according to claim 1 is characterized in that: The cross-section of the ecological interception ditch is a trapezoidal cross-section. Planting platforms are arranged on both sides of the top of the ecological interception ditch. The height of the planting platforms is 0.5m to 1m. The water side of the planting platform adopts ecological bag slope protection. The thickness of the ecological bag slope protection is 0.15m.

7. The composite ecological restoration system for lake agricultural non-point source pollution according to claim 1 is characterized in that: The slope ratio of the two sides of the ecological interception ditch is 1:2-3, and aquatic plants are arranged on both slopes.

8. The composite ecological restoration system for lake agricultural non-point source pollution according to claim 1 is characterized in that: The coastal ecological interception zone is composed of emergent plants and wetland herbs, the ecological floating island is composed of double-layer fishing nets and wide floating plates, and the submerged plant restoration area is composed of evergreen dwarf submerged plants and pollution-resistant pioneer species.

9. The composite ecological restoration system for lake agricultural non-point source pollution according to claim 1, characterized in that: The ecological enclosure is made of PVC coated cloth.

10. A composite ecological restoration method for lake agricultural non-point source pollution, applied to the composite ecological restoration system for lake agricultural non-point source pollution as claimed in any one of claims 1 to 9, characterized in that: The method comprises: Build several pre-reservoirs in the lake, build sedimentation areas, shallow water purification areas and deep water purification areas in the pre-reservoirs, and build water quality improvement wetlands through landscape matching adjacent to the pre-reservoirs, so that the sedimentation areas, shallow water purification areas, deep water purification areas and water quality improvement wetlands included in the pre-reservoirs form ecological restoration of point-type pollution sources; Constructing ecological interception ditches at the entrances of agricultural non-point source pollution to the lakes; By planting emergent plants and wetland herbs on the lake, the emergent plants and wetland herbs form a coastal ecological interception zone, and the ecological interception zone is set in the shore area of ​​the lake, and the ecological interception ditch and the coastal ecological interception zone form a linear pollution source ecological restoration; An ecological enclosure is formed in the lake by arranging PVC coated cloth in the lake, and several different plants are planted in the lake to form a submerged plant restoration area in the lake, wherein the submerged plant restoration area is constructed inside the ecological enclosure; An ecological floating island is constructed in the lake using soilless cultivation and aquatic plants as the main body, wherein the ecological restoration of a surface pollution source is formed through the ecological enclosure, the submerged plant restoration area and the ecological floating island.

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