A method for ecological restoration and management of closed deep-water lakes and reservoirs

Abstract

The present invention discloses an ecological restoration and management method for a closed deepwater lake reservoir, including six steps: rainwater runoff pollution control, lake bottom mud base improvement, lake bottom mud micro-topography remodeling, water ecosystem construction, water landscape fountain pumping system construction, and revetment and ecological environment creation. The present invention comprehensively adopts means such as solving non-point source runoff pollution, micro-modification of deepwater lake terrain, and construction of water ecosystem, which can effectively solve the problems of closed deepwater lake reservoirs, insufficient shallow water area, low survival rate of submerged plants due to insufficient photosynthesis at water depth, and difficulty in building "underwater forests", etc.; it can significantly improve aquatic biodiversity, restore the natural structure and self-purification function of the lake, and at the same time, the lake surface landscape effect can be fully displayed, while improving the water quality of the lake, the ecological benefits and landscape effects are improved, and the management process involved is relatively simple and low in cost, which is suitable for promotion and application.

Description

Technical Field

[0001] The invention belongs to the technical field of water environment management, and in particular relates to an ecological restoration and management method for a closed deep-water lake reservoir. Background Art

[0002] Influenced by the topography, most urban landscape lakes in the southwest are deep "V"-shaped deep-water lakes, which are mainly replenished by rainwater sources. They are closed slow-flowing water bodies with poor fluidity and small water environment capacity, significant water temperature stratification, low dissolved oxygen content in the bottom water, serious endogenous pollution, turbid water, and low apparent transparency. In spring and summer, it is very easy to cause eutrophication in local water bodies in the lake bay area, resulting in weak underwater light, inability of aquatic life and plants to grow smoothly, a significant reduction in the number of beneficial microorganisms, and a lack of water ecosystems in the lake, which in turn leads to low self-purification capacity of the water body and inability to absorb pollutants that flow into the lake with surface runoff during the rainy season and pollutants discharged from point source outlets.

[0003] At present, conventional treatment methods for closed lakes and reservoirs include source control and interception of exogenous pollution, artificial wetlands, and the construction of clean water ecological systems. However, they lack the specificity for the management of mountainous lakes in the southwest region. There are problems such as a large proportion of deep water areas in lakes, insufficient planting area of ​​submerged plants, insufficient coverage, difficulty in planting, and difficulty in survival. At the same time, aeration devices are difficult to lay out and easily stir up the bottom mud, making it difficult to solve problems such as increasing dissolved oxygen and achieving circulating stirring of dead water in deep water areas. The overall management effect is poor and the landscape aesthetics are insufficient. Summary of the invention

[0004] The main purpose of the present invention is to address the problems and shortcomings of the prior art and provide a systematic solution that combines rainwater runoff pollution control, lake bottom mud base improvement, lake bottom mud micro-topography remodeling, water ecosystem construction, water landscape fountain water pumping system construction, revetment and ecological environment creation.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] An ecological restoration and management method for a closed deep-water lake reservoir includes six steps: rainwater runoff pollution control, lake bottom mud base improvement, lake bottom mud micro-topography remodeling, water ecosystem construction, water landscape fountain pumping system construction, and revetment and ecological environment creation; the specific steps include the following:

[0007] 1) Stormwater runoff pollution control;

[0008] Construct a rainwater runoff pollution control system, including interception and purification of rainwater inlets, grass-planted ditches, and lakeside buffer zones. Specifically, set up interception and purification of rainwater inlets, grass-planted ditches, and lakeside buffer zones in the areas where rainwater, fish ponds, farmland, and other areas that generate non-point source runoff pollutants flow through, so as to give full play to the system's function of intercepting and purifying surface runoff pollutants and improve habitat conditions;

[0009] 2) substrate improvement;

[0010] Including substrate disinfection and substrate improvement;

[0011] The bottom disinfection step is to use soil disinfectants to disinfect the soil, remove pathogens, wild fish, and various insect eggs such as golden apple snails in the soil, so as to further remove pollutants in the bottom mud and improve the basic environmental conditions;

[0012] Before the construction of the water ecosystem, a solution of trace nutrient element agent (growth promoter) is added. The content of multiple nutrients is combined into a trace nutrient element increase agent. At the same time, bottom-improving microorganisms are added to improve the substrate to promote the rapid colonization of higher plants, form a developed root system and strong plants, and have stronger resistance to diseases and insect pests; by adding trace elements of calcium, magnesium, iron and other nutrients to balance the distribution of nutrients in the bottom, on the one hand, it provides favorable conditions for the root development of submerged plants and enhances the resistance of plants to the environment; on the other hand, it improves the absorption and utilization rate of submerged plants for nutrients mainly composed of nitrogen and phosphorus in the bottom mud and water bodies;

[0013] 3) Reshaping of lake sediment microtopography

[0014] The area from the lakeshore to the center of the closed deep-water lake to be repaired and managed is divided into Zone I with a water depth of D < 1m, Zone II with a water depth of 1≤D < 2m, Zone III with a water depth of 2≤D < 2.5m, Zone IV with a water depth of 2.5≤D < 3m, Zone V with a water depth of 3≤D < 3.5m, and Zone VI with a water depth of D > 3.5m.

[0015] Excavate areas I and II to a water depth of 2 to 2.5 m, and use the excavated soil to absorb it in the lake and fill it in areas IV and V, thereby expanding the shallow water area and creating better conditions for the growth of submerged plants.

[0016] The low-lying area of ​​Zone VI is retained, and a deep water area is formed in the center of the lake, with a water depth of 3.5 to 5 meters;

[0017] 4) Construction of water ecosystem;

[0018] A movable submerged plant cultivation device is set up in a low-lying area with a water depth of 3.5-5m in zone VI, which consists of a hollow support column at the upper end, an embedded wedge, an embedded adjusting rod, a supporting floating platform, a planting base, a top floating platform and a light source; wherein the embedded adjusting rod, the supporting floating platform, the planting base, the top floating platform and the light source arranged in sequence from bottom to top form a cultivation and planting area, and a number of support columns are rooted in the bottom mud as the pillars of the entire device, and the entire cultivation and planting area is connected to the support column through the embedded adjusting rod; one end of the embedded adjusting rod is connected to the supporting floating platform and the planting base in sequence to form a bearing area, wherein the top floating platform is further arranged on the bearing area, and a light source is arranged on the upper part thereof; the other end of the embedded adjusting rod is provided with a groove matching the size and shape of the embedded wedge switch, and then the groove is embedded in the hollow part of the upper end of the support column, and is fixed by the embedded wedge switch arranged therein, and at the same time, a number of (more than 2) embedded wedge switches are arranged in the hollow part of the support column along the height direction, and the wedging state of the embedded wedge switch is controlled by the automatic control system to realize the controllable adjustment of the height of the bearing area.

[0019] The cultivation and planting area of ​​the device is supported by a supporting floating platform, which is made of polyethylene foam material and has a certain buoyancy, so that the device can be adjusted up and down according to the water depth. When the embedded wedge is contracted by the automatic control system, the floating platform floats up and then adjusts the embedded wedge switch at the next height to achieve controllable adjustment of the height of the bearing area. The upper part of the floating platform is the planting base (mainly made of stainless steel mesh frame, geotextile is laid in the mesh frame, and 0.2-0.5cm planting soil is laid on the top of the geotextile); submerged plants are planted on top of the planting soil; the top of the cultivation and planting area of ​​the device is the top floating platform, and a light source is installed inside to provide light for the submerged plants and improve their photosynthesis capacity;

[0020] In deep water areas, a mobile submerged plant cultivation device is used to construct a water ecosystem, wherein the water ecosystem includes aquatic plants planted on a planting substrate and aquatic animal communities and microbial communities that are further constructed; it has the advantages of high survival rate, simple structure, and easy maintenance;

[0021] 5) Construction of landscape fountain water pumping system;

[0022] It consists of a fountain water-lifting device, an inlet pipe, an outlet pipe, a circulating water pump, an automatic control system, a solar panel, and a fan room; the circulating water pump and the automatic control system are installed in the fan room on the shore, and the solar panel is installed on the top of the fan room, which is made of stainless steel. The photovoltaic panel converts solar energy into electricity as a power source, which is powered by the automatic control system. The inlet pipe is laid on the bottom of the lake and connected to the circulating water pump through the inlet pipe. The dead water in the deep water area of ​​the lake bottom is transported to the fountain water-lifting aeration device through the inlet pipe and the outlet pipe; it not only circulates and stirs the dead water in the deep water area of ​​the lake bottom, but also creates a water landscape effect while oxygenating the water body.

[0023] The fountain water-lifting device comprises a support platform, a circulation pipeline, and a nozzle from bottom to top. The support platform is made of polyethylene foam material and has a certain buoyancy. The nozzle is connected to the circulation pipeline at a spacing of 0.1 to 0.3 cm, and the circulation pipeline is connected to the outlet pipe. The lake bottom water is transported to the nozzle through the circulation water pump in the fan room to form a fountain landscape effect, and at the same time, the dead water in the lake area is circulated and stirred, which increases the dissolved oxygen and purifies the water quality.

[0024] 6) Construction of revetment and ecological environment;

[0025] Construct a species diversity habitat system, use tree stumps or stones to build porous habitats, provide fish systems with hibernation, reproduction, and hiding places, establish mudflats to provide amphibians and birds with hunting, resting, and breeding places, and provide habitats for microorganisms and attached organisms.

[0026] In the above scheme, the interception and purification rainwater outlet adopts a two-layer concentric cylindrical structure, including a rainwater grate, a stainless steel interceptor, a purified rainwater overflow port, an inner columnar purification area and an outer filter area covered on its outer side. The stainless steel interceptor is a stainless steel bar frame with a spacing of 5 to 10 mm, which is used to intercept larger pollutants such as leaves and garbage entering the rainwater outlet to prevent clogging of the lower purification and filtration area. The inner purification area and the outer filtration area are filled with different filter materials respectively. The inner purification area is composed of a cylindrical stainless steel container filled with composite lightweight filter material and with small holes on the side. After purification, the water flows out from the side with a 1mm aperture into the outer filtration area. The filter material includes lightweight volcanic rock and ceramsite, and the filter material particle size is 1.2 to 4mm; it has biodegradable function and is easy to clean mud and sand. The outer filter area is filled with coarse sand filter material, including one or more of gravel and pebbles, with a filter material particle size of 8 to 16 mm; it mainly filters and purifies rainwater and plays a role in water storage. The working principle of the interception and purification rainwater outlet device is: rainwater enters the stainless steel interceptor, the inner purification area, and the outer filter area in turn through the rainwater grate, and is gradually purified, and finally seeps into the ground to replenish groundwater. When the amount of rainwater reaches a certain level, it is discharged from the purified rainwater overflow outlet.

[0027] Preferably, the grass-planted ditch is a surface ditch with vegetation, which consists of seven parts from top to bottom: plants, aquifer, covering layer, planting soil layer, sand layer, and gravel layer, and has the functions of purifying, infiltrating, and storing rainwater.

[0028] Preferably, the width of the lakeside buffer zone is controlled between 4 and 10 m, and the plants in the buffer zone are, from the shore to the lake, a shrub belt, an emergent plant belt, and a floating leaf plant belt, and the planting areas are on the shore, at a water depth of 0-0.4 m, and at a water depth of 0.4-1.0 m.

[0029] In the above scheme, the designed dosage of the soil disinfectant used in step 2) is 20-50 g / m 2; Use direct spraying or even spraying after melting the lake water.

[0030] In the above scheme, the trace nutrient element agent in step 2) includes trace nutrient elements and enzyme substances, and its main components are trace elements such as magnesium, iron, copper, manganese, zinc, cobalt, molybdenum, and enzyme substances; its dosage is 10-30g / m 2 The dosage of the bottom modification microbial agent is 30~80g / m 2 .

[0031] In the above scheme, the aquatic plants in step 4) include floating leaf plants, emergent plants, and submerged plants.

[0032] In the above scheme, the floating leaf plants include water chestnut, Euryale ferox, water lily, water chestnut, water lily, etc.; the emergent plants include lotus, reed, cattail, canna, windmill grass, wild rice stem, etc.; the water purification mechanism of the submerged plants mainly includes physical action, enrichment action, biochemical action, degradation action and inhibition and allelopathic action on algae; the planting varieties include evergreen dwarf Vallisneria, Malayan Potamogeton, Comb-toothed Potamogeton, Micro-toothed Potamogeton, Vertebrata hydrilla, Ceratophyllum, Water Chestnut, etc., and the planting density is 100-200 plants / m 2 .

[0033] In the above scheme, the aquatic animal community mainly includes benthic animal community construction, fish community construction, and zooplankton community construction; the benthic animal community construction step mainly includes adding copper rust ring edge snails, adhesive back toothless clams, shrimps, etc., with a density of 5-80g / m 2 The release method is: temporarily raise them in shallow water for 1-3 days, and then release them after they adapt to the water environment. The fish community construction mainly adds mandarin fish, yellow catfish, silver carp, etc., and the release density is 1-3 fish / 100m 2 The method of release is direct supplementation. At the same time, when fish are temporarily raised and domesticated, aquatic complex vitamins (mainly vitamin A, vitamin B1, vitamin B2, vitamin C, vitamin E and other complex vitamins) are used, and the release density is 1-3kg / 200 fish. The steps of constructing the zooplankton community mainly include adding cladocerans and copepods, and the release density is 50-100ml / m 2 Or 500-1000 / L; the release method is to temporarily raise them in shallow water areas and then release them after they adapt to the water environment.

[0034] In the above scheme, during the construction of the microbial community, the density of microorganisms is 30-60g / m 2 The microbial flora is screened and cultivated from indigenous microorganisms, with a specification of >10 billion live bacteria / g; it is composed of complex microbial flora such as photosynthetic bacteria, Bacillus, nitrifying bacteria, acidophilic bacteria, etc.; it is activated on-site before being released, and then artificially sprayed on the entire lake surface.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1) The system method of the present invention adopts means such as solving non-point source runoff pollution, micro-modification of deep-water lake terrain, and construction of aquatic ecosystems (creating a submerged plant planting platform in the central lake area), which can effectively solve the problems of closed deep-water lakes and reservoirs, insufficient shallow water areas, and low survival rates of submerged plants due to insufficient photosynthesis at depth, making it difficult to build an "underwater forest". It can improve aquatic biodiversity, restore the natural structure and self-purification function of the lake, and at the same time, fully display the lake surface landscape effect, improve the lake water quality, and enhance the ecological benefits and landscape effects;

[0037] 2) The interception and purification rainwater inlet adopted by the present invention not only plays the role of transferring rainwater, but also intercepts and purifies pollutants in surface runoff through purification and filtration, thereby improving habitat conditions, by improving the structure and filling of the rainwater inlet in the prior art;

[0038] 3) The present invention micro-modifies deep-water lakes according to their topographical characteristics, and adopts a movable submerged plant cultivation device to increase the planting area of ​​shallow-water plants, and the coverage of submerged plants is increased by more than 70%; it solves the problems of low survival rate of submerged plants in deep-water areas and easy hypoxia; by planting submerged plants to form an "underwater forest", nitrogen and phosphorus in the water body are reduced, algae growth is inhibited, and eutrophication of the water body is avoided; at the same time, a shelter is provided for aquatic animals to build an ecological chain balance system and improve the transparency of closed water bodies; the present invention adopts an aeration device that can improve high efficiency;

[0039] 4) By adopting the fountain pumping system and stirring the dead water in the deep water area through the circulating pump, the problems of the aeration device used in conventional lakes and reservoirs, such as the difficulty in maintenance and the easy floating of bottom mud, can be solved, and it can also increase the dissolved oxygen and improve the landscape effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a cross-sectional schematic diagram of a closed deep-water lake ecological restoration and management system according to an embodiment of the present invention; wherein 1 is a rainwater interception and purification outlet, 2 is a grass-planting ditch, 3 is a lakeside buffer zone, 4 is a movable submerged plant cultivation device, 5 is a fountain water pumping device, 6 is a water inlet pipe, 7 is a water outlet pipe, 8 is a circulating water pump, 9 is an automatic control system, 10 is a solar panel, and 11 is a fan room;

[0041] Figure 2Schematic diagram of the structure of the intercepting and purifying rainwater outlet device in Example 1 of the present invention; wherein (a) is a cross-sectional schematic diagram of the intercepting and purifying rainwater outlet device, and (b) is a schematic diagram of the structure of the purified rainwater overflow outlet; 1-1 is a rainwater grate, 1-2 is a stainless steel interceptor, 1-3 is an inner purification area, 1-4 is an outer filtration area, and 1-5 is a purified rainwater overflow outlet;

[0042] Figure 3 Schematic diagram of the structure of the movable submerged plant cultivation device in Example 1 of the present invention; wherein 4-1 is a support column, 4-2 is an embedded wedge, 4-3 is an embedded adjustment rod, 4-4 is a support floating platform, 4-5 is a planting base, 4-6 is a top floating platform, and 4-7 is a light source;

[0043] Figure 4 It is a schematic diagram of the structure of the fountain water pumping device described in Example 1 of the present invention; wherein 5-1 is a supporting platform, 5-2 is a circulation pipeline, and 5-3 is a nozzle. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0045] Example 1

[0046] An ecological restoration and management method for closed deep-water lakes and reservoirs. The urban landscape lake in a city in Sichuan Province is a typical deep "V"-shaped closed lake. The water depth in the deep water area is 4 to 6 meters. There is no external water supply source at present, and it is only replenished by rainwater. The lake body has poor fluidity, the lake water is gray and green, there are many algae, and the transparency is less than 30cm, resulting in sunlight unable to penetrate the lake surface. There are oil films and garbage floating on the local water surface of the shore, and dead branches and leaves are deposited in the water body; the underwater light is weak, the water is not active, plants cannot grow smoothly, the number of beneficial microorganisms is greatly reduced, and the water ecosystem in the lake is missing, resulting in a low self-purification capacity of the water body, which cannot absorb pollutants that flow into the lake with surface runoff during the rainy season;

[0047] It mainly includes six steps: rainwater runoff pollution control, lake bottom mud base improvement, lake bottom mud micro-topography reshaping, water ecosystem construction, water landscape fountain pumping system construction, revetment and ecological environment creation. The specific control and restoration methods include the following steps:

[0048] 1) In the areas where non-point source runoff pollutants generated by rainwater, fish ponds, farmland, etc. flow through, rainwater interception and purification outlets 1, grass-planting ditches 2, and lakeside buffer zones 3 are set up in sequence to give full play to the system's function of intercepting and purifying surface runoff pollutants and improve habitat conditions;

[0049] Among them, the interception and purification rainwater outlet 1 adopts a two-layer concentric cylinder structure design (see the structural diagram for details). Figure 2 ), comprising a rainwater grate 1-1, a stainless steel interceptor 1-2, a purified rainwater overflow port 1-5, an inner columnar purification area 1-3 and an outer filter area 1-4 covered on its outer side, which are arranged in sequence from top to bottom; wherein the stainless steel interceptor 1-2 adopts a stainless steel strip mesh with a mesh size of 3mm×10mm, which is used to intercept larger pollutants such as leaves and garbage entering the rainwater inlet to prevent clogging of the lower purification and filtration area; the inner purification area 1-3 and the outer filter area 1-4 are filled with different filter materials respectively, and the inner purification area 1-3 is filled with a composite lightweight filter material and a cylindrical stainless steel container with small holes on the side surface. After purification, the water flows out from the side with a 1mm aperture into the outer filter area, and the composite light filter material is used to filter the water. The light filter material is obtained by mixing light volcanic rock and ceramsite at a volume ratio of 2:1; the filter material particle size is 1.2-4mm, has biodegradability, and is easy to clean mud and sand; the outer filter area 1-4 is filled with coarse sand filter material (mixed with gravel and pebbles at a volume ratio of 1:1, with a filter material particle size of 8-16mm), which mainly filters and purifies rainwater and plays a role in water storage; the interception and purification rainwater outlet device has the following working principle: rainwater enters the stainless steel interceptor 1-2, the inner filter area 1-3, and the outer purification area 1-4 in turn through the rainwater grate 1-1, is gradually purified, and finally infiltrates into the ground to replenish groundwater. When the amount of rainwater reaches a certain level, it is discharged from the purified rainwater overflow port 1-5;

[0050] The grass-planted ditch 2 is a surface ditch with vegetation, which is mainly composed of seven parts from top to bottom: plants, aquifer, cover layer, planting soil layer, sand layer, and gravel layer, and has the functions of rainwater purification, infiltration, and storage;

[0051] The width of the lakeside buffer zone 3 is controlled between 4 and 10 meters. The plants in the buffer zone are planted in order from the shore to the lake: shrub grass belt, emergent plant belt, and floating leaf plant belt. The planting areas are on the shore, at a water depth of 0 to 0.4 meters, and at a water depth of 0.4-1.0 meters.

[0052] 2) Substrate improvement, including substrate disinfection and substrate improvement.

[0053] The bottom disinfection step is to use soil disinfectants to disinfect the soil, remove the original pathogens, wild fish, and various insect eggs such as golden apple snails in the soil, so as to further remove pollutants in the bottom mud and improve the basic environmental conditions. The designed dosage of soil disinfectants is 30g / m 2 ; The method of evenly spraying after the lake water is melted;

[0054] The step of improving the bottom soil mainly balances the distribution of nutrients in the bottom soil by adding trace elements of calcium, magnesium, iron and other nutrients, which, on the one hand, provides favorable conditions for the root development of submerged plants and enhances the resistance of plants to the environment; on the other hand, it improves the absorption and utilization rate of submerged plants for nutrients mainly composed of nitrogen and phosphorus in the bottom mud and water bodies; before the construction of the water ecosystem, the present invention uses a reasonably proportioned trace nutrient element agent solution (growth-promoting liquid) and a variety of nutrient content to form a trace nutrient element increase agent, and at the same time, introduces bottom-modifying microorganisms to improve the substrate, so as to promote the rapid colonization of higher plants, form a developed root system and a sturdy plant, and have a stronger resistance to diseases and insect pests; among them, the trace nutrient element agent (commercially available Bio-Feng Baite enzyme, main ingredients trace elements, lipase, amylase, protease, etc.; dosage 20g / m 2 , the amount of bottom modification microbial agent (commercially available Beijing Keyuanhuan micro-sludge degradation agent) is 50g / m 2 ;

[0055] 3) Reshaping of lake sediment microtopography

[0056] After optimizing the growth environment of aquatic organisms through the improvement of the bottom mud, the lake bottom was reshaped in step three. The main measures were as follows: the area from the lakeshore to the center of the lake was divided into Zone I with a water depth of D<1m, Zone II with a water depth of 1≤D<2m, Zone III with a water depth of 2≤D<2.5m, Zone IV with a water depth of 2.5≤D<3m, Zone V with a water depth of 3≤D<3.5m, and Zone VI with a water depth of D>3.5m; part of Zone I and Zone II was excavated to a water depth of 2-2.5m, and the soil was self-absorbed in the lake, and the excavated soil was backfilled to Zones IV and V, thereby expanding the water area of ​​the shallow water area and creating better conditions for the growth of submerged plants; at the same time, the low-lying area of ​​Zone VI was retained to form a deep water area in the center of the lake with a water depth of 3.5-5m;

[0057] 4) Construction of water ecosystem;

[0058] A movable submerged plant cultivation device is set up in the low-lying area with a water depth of 3.5-5m in Zone VI (see the structural diagram for details). Figure 3), which consists of a support column 4-1, an embedded wedge 4-2, an embedded adjustment rod 4-3, a support floating platform 4-4, a planting base 4-5, a top floating platform 4-6, and a light source area 4-7. The movable submerged plant cultivation device 4 is installed in the low-lying area of ​​the lake center zone VI, and is rooted in the bottom mud through four supporting columns as the pillars of the entire device. One end of the embedded adjusting rod 4-3 is connected with the supporting floating platform 4-4 and the planting base 4-5 in sequence to form a bearing area, wherein a top floating platform 4-6 is further arranged on the side of the bearing area, and a light source 4-7 is arranged on its upper part; the other end of the embedded adjusting rod 4-3 is provided with a groove matching the size and shape of the embedded wedge switch 4-2, and then it is embedded in the hollow part of the upper end of the supporting column 4-1, and is fixed by the embedded wedge switch 4-2 arranged therein, and at the same time, three embedded wedge switches 4-2 are arranged in the hollow part of the supporting column 4-1 along the height direction, and the embedded wedge 4-2 is switched on and off by the 9 automatic control system and the planting base 4-5 liquid level linkage, and the liquid level is monitored by an ultrasonic water level monitor. When the liquid level is monitored

[0059] When the depth is >2.5m, the embedded wedge contracts, and the culture device floats up along with the embedded adjusting rod 4-3 under the action of buoyancy. When the water level of the planting base 4-5 reaches 2.5m, the embedded wedge opens to fix the culture device. The embedded adjusting rod 4-3 is connected to the floating platform 4-4, and the culture planting area of ​​the device is supported by the floating platform 4-4. The floating platform is made of polyethylene foam material and has a certain buoyancy, which is convenient for the device to be adjusted up and down according to the water depth. A planting base 4-5 is set on the upper part of the floating platform 4-4. First, a stainless steel mesh frame is used and a geotextile is laid in the mesh frame, and then 0.2-0.5cm of planting soil is laid on the top of the geotextile. The top of the culture planting area of ​​the device is a top floating platform, and a light source 4-7 is installed inside to provide light for submerged plants and enhance photosynthesis capacity;

[0060] Aquatic plants are planted on the planting base 4-5, and aquatic animal communities and microbial communities are constructed; aquatic plants include floating leaf plants, emergent plants, and submerged plants;

[0061] Among them, floating-leaf plants include water lilies and duckweed; emergent plants include lotus, cattail and canna; submerged plants’ water purification mechanism mainly includes physical action, enrichment, biochemical action, degradation, inhibition of algae and allelopathic action; the planting varieties include evergreen dwarf Vallisneria, Ceratophyllum and Water Chestnut, with a planting density of 150 plants / m 2 .

[0062] The steps of constructing the animal community are benthic animal community construction, fish community construction, and zooplankton community construction; the benthic animal community construction mainly adds copper rust ring edge snails, adhesive back toothless clams, shrimps, etc., with a density of 50g / m 2The release method is: temporarily raise them in shallow water for 1-3 days, and then release them after they adapt to the water environment. The fish community construction mainly adds mandarin fish, yellow catfish, silver carp, etc., and the release density is 1 fish / 100m 2 The method of feeding is direct supplementation; at the same time, when the fish are temporarily raised and domesticated, aquatic complex vitamins are used, the main ingredients and their weight percentages are: vitamin A 2%, vitamin B1 1.5%, vitamin B2 1.5%, vitamin C 1.5%, vitamin E 0.5%, vitamin B6 1%, vitamin D30.5%, vitamin B12 1.5%, niacin 10%, sub-powder 80%, and the feeding density is 1kg / 200 tails. The zooplankton community construction mainly adds cladocerans and copepods, and the feeding density is 50ml / m 2 Or 1000 pieces / L; the release method is to temporarily raise them in shallow water areas and then release them after they adapt to the water environment.

[0063] The density of microorganisms in the process of microbial community construction is 40g / m 2 The microbial flora is screened and cultivated from indigenous microorganisms, with a specification of >10 billion live bacteria / g; it is composed of complex microbial flora such as photosynthetic bacteria, Bacillus, nitrifying bacteria, acidophilic bacteria, etc.; it is activated on-site before being released, and then artificially sprayed on the entire lake surface.

[0064] 5) Construction of landscape fountain water pumping system; Figure 1 As shown, the landscape fountain water-lifting system consists of a fountain water-lifting device 5, an inlet pipe 6, an outlet pipe 7, a circulating water pump 8, an automatic control system 9, a solar panel 10, and a fan room 11. The circulating water pump 8 and the automatic control system 9 are installed in a fan room 11 placed on the shore, and the solar panel 10 is installed on the top of the fan room 11. The fan room 11 is made of stainless steel. The photovoltaic panel converts solar energy into electrical energy as a power source, and the power is supplied by the automatic control system. The water inlet pipe is laid on the bottom of the lake, and is connected to the circulating water pump 8 through the inlet pipe 6. The dead water in the deep water area of ​​the lake bottom is transported to the fountain water-lifting aeration device 5 through the inlet pipe 6 and the outlet pipe 7. It not only plays a circulating stirring role on the dead water in the deep water area of ​​the lake bottom, but also realizes the creation of water landscape effects while oxygenating the water body.

[0065] The fountain water pumping device is as follows Figure 4 As shown, it is composed of a support platform 5-1, a circulation pipe 5-2 and a nozzle 5-3 arranged from bottom to top. The support platform is made of polyethylene foam material with a certain buoyancy. The nozzle is connected to the circulation pipe at a distance of 0.2 cm. The circulation pipe 5-2 is connected to the outlet pipe 7. The lake bottom water is transported to the nozzle 5-3 through the circulation water pump in the fan room to form a fountain landscape effect, and at the same time, the dead water in the lake area is circulated and stirred, which increases the dissolved oxygen and purifies the water quality.

[0066] 6) Construction of revetment and ecological environment;

[0067] Construct a species diversity habitat system, use tree stumps or stones to build porous habitats, provide fish systems with hibernation, reproduction, and hiding places, establish mudflats to provide amphibians and birds with hunting, resting, and breeding places, and provide habitats for microorganisms and attached organisms.

[0068] After ecological restoration and management using the above methods, the lake water quality has reached the Class IV water standard for surface water environment (Surface Water Environmental Quality Standard (GB3838-2002)). The specific detection indicators are shown in Table 1.

[0069] Table 1 Test results of water quality indicators before and after treatment using the method described in Example 1

[0070]

[0071] The conventional technologies for deep-water lake and reservoir management described in Table 1 include the following steps: artificial wetland construction, sediment dredging, clean water ecosystem construction and underwater aeration system construction. However, due to the deep water depth and insufficient shallow water area, submerged plants have difficulty surviving, resulting in plant death and secondary pollution, and the water purification effect is poor.

[0072] The above embodiments are only examples for clear explanation, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here, so the obvious changes or modifications derived are still within the protection scope of the invention.

Claims

1. A method for ecological restoration and management of a closed deep-water lake reservoir, characterized in that: The steps include: 1) Stormwater runoff pollution control; Set up interception and purification rainwater inlets, grass-planted ditches and lakeside buffer zones in the areas where non-point source runoff pollutants are generated; 2) Improvement of lake bottom mud base; Including substrate disinfection and substrate improvement; Among them, soil disinfectants are used to disinfect the soil substrate; in the step of improving the substrate, before the construction of the water ecosystem, a solution of trace nutrient elements is added, and at the same time, bottom-modifying microorganisms are added to improve the substrate; 3) Reshaping of lake sediment microtopography The area from the lakeshore to the center of the closed deep-water lake is divided into Zone I with a water depth of D < 1m, Zone II with a water depth of 1≤D < 2m, Zone III with a water depth of 2≤D < 2.5m, Zone IV with a water depth of 2.5≤D < 3m, Zone V with a water depth of 3≤D < 3.5m, and Zone VI with a water depth of D > 3.5m. Excavate areas I and II to a water depth of 2-2.5m, and use the excavated soil to absorb it in the lake and backfill it into areas IV and V to expand the shallow water area. 4) Construction of water ecosystem; A movable submerged plant cultivation device is set up in the low-lying area with a water depth of 3.5~5m in Zone VI, which consists of a support column, an embedded wedge, an embedded adjustment rod, a support floating platform, a planting base, a top floating platform and a light source; wherein the embedded adjustment rod, the support floating platform, the planting base, the top floating platform and the light source arranged in sequence from bottom to top form a cultivation and planting area, the support column is rooted in the bottom mud as the pillar of the entire device, the cultivation and planting area is connected to the support column by an embedded adjustment rod, and the upper and lower heights between the embedded adjustment rod and the support column are adjusted by an embedded wedge; the embedded wedge is switched on and off by an automatic control system linked to the liquid level of the planting base, and the liquid level is monitored by an ultrasonic water level monitor. When the liquid level is monitored to be >2.5m, the embedded wedge shrinks, and the cultivation device floats up with the embedded adjustment rod under the action of buoyancy. When the water level of the planting base is reached, the embedded wedge is opened to fix the cultivation device; A water ecosystem is constructed by using a movable submerged plant cultivation device set up in a deep water area, wherein the water ecosystem includes aquatic plants planted on a planting substrate and constructed aquatic animal communities and microbial communities; The aquatic plants include floating leaf plants, emergent plants and submerged plants; during the construction of the microbial community, the density of microorganisms is 30-60g / m 2 ; The microbial flora is screened and cultivated from indigenous microorganisms, with a specification of >10 billion live bacteria / g; 5) Construction of landscape fountain water pumping system; The landscape fountain water-lifting system consists of a fountain water-lifting device, an inlet pipe, an outlet pipe, a circulating water pump, an automatic control system, a solar panel, and a fan room; the circulating water pump and the automatic control system are installed in the fan room on the shore, the solar panel is installed on the top of the fan room, and the power is supplied by the automatic control system. The water inlet pipe is laid on the bottom of the lake and connected to the circulating water pump through the inlet pipe, and the dead water in the deep water area of ​​the lake bottom is transported to the fountain water-lifting aeration device through the inlet pipe and the outlet pipe; 6) Construction of revetment and ecological environment; Construct species diversity habitat systems, build porous habitats with tree stumps or boulders, and establish tidal flats.

2. The ecological restoration and management method according to claim 1, characterized in that: The intercepting and purifying rainwater outlet adopts a two-layer concentric cylindrical structure, including a rainwater grate, a stainless steel interceptor, a purified rainwater overflow outlet, an inner columnar purification area and an outer filtering area coated on its outer side, which are arranged in sequence from top to bottom.

3. The ecological restoration and management method according to claim 2 is characterized in that: The inner columnar purification zone adopts a composite lightweight filter material, including lightweight volcanic rock and ceramsite, and the filter material particle size is 1.2-4 mm; the outer filter zone is filled with coarse sand filter material, including one or more of gravel and pebbles, and the filter material particle size is 8-16 mm.

4. The ecological restoration and management method according to claim 1 is characterized in that: The main component of the soil disinfectant used in step 2) is quicklime, and the designed dosage is 20~50g / m 2 ; Micronutrients include micronutrients and enzymes, and the dosage is 10-30g / m 2 ; The dosage of microbial agent for soil modification is 30-80g / m 2 .

5. The ecological restoration and management method according to claim 1 is characterized in that: Step 5) The fountain water-lifting device includes a support platform, a circulation pipe and a nozzle arranged from bottom to top; the nozzle is connected to the circulation pipe at a spacing of 0.1-0.3 cm, and the circulation pipe is connected to the water outlet pipe; the lake bottom water is transported to the nozzle through the circulation water pump in the fan room.

6. The ecological restoration and management method according to claim 1 is characterized in that: The width of the lakeside buffer zone is 4 to 10 meters, and includes a shrub and grass belt, an emergent plant belt, and a floating leaf plant belt arranged in sequence from the lakeshore to the lake.

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