Comprehensive sand prevention and control system for arid region

Abstract

The invention provides a comprehensive desertification prevention and control system for an arid region, and relates to the technical field of environmental governance, the comprehensive desertification prevention and control system comprises a sand blocking unit, a straw grid unit, a vegetation unit and a biological crust layer unit, and the sand blocking unit is arranged on the same side of the vegetation unit, the straw grid unit and the biological crust layer unit and located in the windward direction; the straw grid units are arranged around the vegetation units, the biological crust layer units are arranged in an area defined by the straw grid units and cover the earth surface, and the biological crust layer units are arranged around the vegetation units. The desertification prevention and control effect is improved by selecting shrub types with high hydraulic safety and low growth rate and combining physical and biological skinning technologies.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental governance, and in particular to a comprehensive sand prevention and control system for arid areas. Background Art

[0002] With the impact of industrialization and climate change, the frequency and intensity of droughts have increased, and the global desertification problem is becoming increasingly serious. Desertification leads to land degradation, ecosystem destruction and biodiversity loss. In order to cope with the challenge brought by desertification, a variety of sand control technologies have been used. However, although traditional sand control methods, such as afforestation and physical covering, have achieved certain results, there are still problems such as single sand control methods, primitive means and low technical content, which cannot comprehensively solve the desertification problem. Therefore, there is an urgent need for a new sand control technology that is more efficient, systematic, economical and environmentally friendly.

[0003] The traditional method of single plant sand fixation is mainly through planting drought-resistant shrubs and plants such as Salix psammophila and Tamarix chinensis, using their roots to fix sand, reduce wind erosion, and restore vegetation. However, these plants require a stable water source, but it is difficult to ensure sufficient water supply in arid areas. Due to the strong surface evaporation in arid areas, some plants are not adapted to the specific desert environment, resulting in unstable vegetation coverage. Therefore, it is particularly important to select drought-resistant shrubs with strong ecological adaptability. Wheat straw grid sand fixation is a physical method that increases the surface roughness, slows down wind speed, and prevents sand loss by laying straw grids on the sand. However, relying solely on physical structures may affect the natural characteristics of the soil, and in the long run, the straw grids may be destroyed by wind erosion or sand burial, requiring regular replacement and maintenance, resulting in high costs and difficult maintenance. Summary of the invention

[0004] The purpose of the present invention includes providing a comprehensive sand prevention and control system in arid areas, which improves the effect of sand prevention and control by selecting shrub species with higher hydraulic safety and low growth rate and combining physical and biological crusting technology.

[0005] The embodiments of the present invention can be implemented as follows:

[0006] In a first aspect, the present invention provides a comprehensive sand prevention and control system for arid areas, comprising:

[0007] A sand-blocking unit, a grass grid unit, a vegetation unit and a biological crust layer unit, wherein the sand-blocking unit is arranged on the same side of the vegetation unit, the grass grid unit and the biological crust layer unit and is located in the windward direction; the grass grid unit is arranged around the vegetation unit, the biological crust layer unit is arranged in the area enclosed by the grass grid unit and covers the ground surface, and the biological crust layer unit is arranged around the vegetation unit.

[0008] In an optional embodiment, the sand blocking unit includes a barrier, which is vertically arranged and located on the windward side of the vegetation unit, the grass grid unit and the biological crust layer unit.

[0009] In an optional embodiment, the barrier includes a frame and a sand-blocking net, the frame is used to be fixed to the ground, the sand-blocking net includes a stacked high-absorbent polymer layer and a UV-resistant polymer fiber layer, the high-absorbent polymer layer is adhered to the frame, and the polymer fiber layer is located on a side of the high-absorbent polymer layer away from the frame.

[0010] In an optional embodiment, the straw grid unit includes a plurality of straw grid bodies formed by weaving wheat straw, the plurality of straw grid bodies are arranged adjacent to each other, and each of the straw grid bodies encloses a sand-proof space for accommodating a vegetation unit and a biocrust layer unit.

[0011] In an optional embodiment, the biological crust layer unit includes a colony layer and a composite biological soil crust layer, the colony layer covers the soil surface within the area enclosed by the grass grid unit and around the root system of the vegetation unit, and the composite biological soil crust layer covers the surface of the colony layer.

[0012] In an optional embodiment, the components of the colony layer are rhizobia, pseudomonas, vibrio, bacillus subtilis, trichoderma and cyanobacteria, wherein the component ratios are as follows, by weight: 20-30 parts of rhizobia, 10-15 parts of pseudomonas, 15-25 parts of vibrio, 10-15 parts of trichoderma, and 5-10 parts of cyanobacteria.

[0013] In an optional embodiment, the composite biological soil crust layer is prepared by experimentally culturing a composition consisting of cyanobacteria, mosses and lichens.

[0014] In an optional embodiment, when conducting experimental culture, the culture temperature is set to 25±2° C., the light cycle is set to 11-13 h, and the culture time is set to 8-14 days.

[0015] In an optional embodiment, the composite biological soil crust layer is covered on the surface of the bacterial colony layer by spraying.

[0016] In an optional embodiment, when spraying the composite biological soil crust layer, first level the soil in the area surrounded by the grass grid unit to remove stones and weeds; before 8 a.m. or after 18 p.m., spray the cultivated composite biological soil crust layer at a dry weight of 5 to 10 g / m 2 Spray the amount of spray on the surface of the colony layer.

[0017] The beneficial effects of the comprehensive sand prevention and control system for arid areas provided by the embodiment of the present invention include:

[0018] In summary, the comprehensive sand control and sand control system for arid areas provided by this embodiment is formed by combining vegetation units composed of shrub species with advantages in hydraulic safety and growth rate, sand blocking units made of nanofiber composite materials, and biological crust units to form a multi-level, complementary sand control and sand control system to achieve efficient control of desertified areas. A sand fixation method combining vegetation, physics and biological crusts is adopted to build a complementary relationship and form an efficient ecological restoration system. The vegetation unit fixes the soil through its root system, provides shade and organic matter, helps to improve the surrounding environment, and creates favorable conditions for the formation and development of the biological crust unit. The biological crust unit is formed on the soil surface around the vegetation unit, which can reduce water evaporation, increase the water retention capacity of the soil, and provide nutrients through processes such as nitrogen fixation, thereby promoting the growth of shrubs. Through the fixation of the grass grid unit, this combination can effectively reduce soil erosion and increase soil stability, especially in areas with frequent wind and sand activities, a more solid protective barrier can be formed, forming a multi-level, complementary desertification control model, effectively improving the desert control effect, and facilitating ecological environmental restoration. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A schematic diagram of the structure of the comprehensive sand prevention and control system for arid areas provided in this embodiment;

[0021] Figure 2 A bar graph of hydraulic safety margin values ​​for different shrubs provided for this example;

[0022] Figure 3 A bar graph of turgor loss points for different shrubs provided for this example;

[0023] Figure 4 Bar graph of photosynthetic rates of different shrubs provided for this example.

[0024] Icons: 100-sand blocking unit; 200-grass grid unit; 300-vegetation unit; 400-biological crust unit. DETAILED DESCRIPTION

[0025] In the prior art, desert control has always been a key focus project in environmental management. In order to reduce desertification, single measures such as vegetation coverage and sand-fixing barrier setting are generally adopted. Although certain effects have been achieved, the desertification control effect is not good due to the single measures.

[0026] In view of this, the designer provides a comprehensive sand prevention and control system for arid areas. By effectively combining multiple sand fixation methods, the innovative use of a comprehensive shrub vegetation-physical-biological crust sand prevention and control system has effectively improved the effect of desertification control.

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0030] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear to indicate an orientation or position relationship, they are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0031] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0032] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0033] Please combine Figure 1In this embodiment, the comprehensive sand prevention and control system for arid areas includes a sand blocking unit 100, a grass grid unit 200, a vegetation unit 300 and a biological crust layer unit 400. The sand blocking unit 100 is arranged on the same side of the vegetation unit 300, the grass grid unit 200 and the biological crust layer unit 400 and is located in the windward direction; the grass grid unit 200 is arranged around the vegetation unit 300, the biological crust layer unit 400 is arranged in the area enclosed by the grass grid unit 200 and covers the ground surface, and the biological crust layer unit 400 is arranged around the vegetation unit 300.

[0034] Based on the above, the comprehensive sand prevention and control system for arid areas provided by this embodiment has at least the following advantages:

[0035] By combining the vegetation unit 300 composed of shrub species with advantages in hydraulic safety and growth rate, the sand-blocking unit 100 made of nanofiber composite materials, and the biological crust unit 400, a multi-level, complementary sand control system is formed to achieve efficient control of desertified areas. The sand fixation method combining vegetation, physics and biological crusts is adopted to build a complementary relationship and form an efficient ecological restoration system. The vegetation unit 300 fixes the soil through its root system, provides shade and organic matter, helps to improve the surrounding environment, and creates favorable conditions for the formation and development of the biological crust unit 400. The biological crust unit 400 is formed on the soil surface around the vegetation unit 300, which can reduce water evaporation, increase the water retention capacity of the soil, and provide nutrients through processes such as nitrogen fixation, thereby promoting the growth of shrubs. By fixing the grass grid unit 200, this combination can effectively reduce soil erosion and increase soil stability, especially in areas with frequent wind and sand activities, and can form a more solid protective barrier, forming a multi-level and complementary desertification control model, effectively improving the desert control effect and facilitating the restoration of the ecological environment.

[0036] The following embodiments illustrate the details of the comprehensive sand prevention and control system for arid areas provided by the present application by way of examples.

[0037] In this embodiment, the sand blocking unit 100 optionally includes a barrier, which is used to block wind and sand. The barrier is vertically arranged, similar to forming a wall, and is arranged on the windward side of the vegetation unit 300, the grass grid unit 200, and the biocrust layer unit 400. The size and windward angle of the barrier are set as needed, and can block the wind and sand blowing toward the vegetation unit 300, the grass grid unit 200, and the biocrust layer unit 400 to the maximum extent.

[0038] For example, in one embodiment, the barrier includes a frame and a sand-blocking net, the frame is used to be fixed to the ground surface, the sand-blocking net includes a super absorbent polymer layer and a UV-resistant polymer fiber layer arranged in layers, the super absorbent polymer layer is attached to the frame, and the polymer fiber layer is located on the side of the super absorbent polymer layer away from the frame. That is, the super absorbent polymer is the inner layer, and the polymer fiber layer is the outer layer. The combination of the two has good weather resistance and wind erosion resistance, and can maintain structural integrity under extreme weather conditions. In addition, the barrier is designed as a multi-layer structure, the outer layer uses UV-resistant polymer fibers, which can effectively resist wind and sand invasion, and the inner layer uses super absorbent polymers, which have a significant water retention effect. In this way, the direct erosion of wind on sand is reduced mainly by blocking and changing wind direction, reducing the wind erosion rate, thereby reducing the loss and migration of sand. The height and density of the sand barrier need to be designed according to specific environmental conditions and sand control goals to achieve the best wind and sand prevention effect. In addition, the layout of the sand barrier also needs to take into account the terrain and the dominant wind direction to maximize its wind and sand prevention function.

[0039] In the present embodiment, optionally, the vegetation unit 300 may include shrub species that have advantages in hydraulic safety and growth rate to ensure the efficient survival and soil fixation ability of the shrubs in extremely arid environments. Specifically, when screening shrubs, the screening criteria are as follows: hydraulic safety margin (HSM)>1.75, turgor loss point (TLP)<-4.0, photosynthetic rate<25. In the present embodiment, the shrubs may be, but are not limited to, Caragana plants, which can not only survive and flourish under conditions of extremely limited water, but also have deep and wide root systems that can effectively fix sand and reduce the risk of wind erosion. In addition to the physical effect of roots fixing sand, shrubs can also provide necessary shade, reduce surface temperature, while improving soil structure, increasing soil organic matter content, and creating favorable conditions for the formation of the biocrust unit 400 and the survival of other organisms.

[0040] In addition, in order to maximize the benefits of the shrub vegetation layer, the planting layout should be scientifically planned. First, natural factors such as topography, wind direction and sunshine should be taken into account to ensure that each plant can play its role in the most suitable position. For example, shrub rows can be arranged according to the dominant wind direction to form a natural wind barrier. In addition, the shrub planting density should be carefully designed to ensure sufficient coverage to prevent wind and sand fixation, while avoiding resource competition due to over-dense planting. In the actual application process, in order to ensure long-term sand control effects, regular irrigation (through water-saving methods such as drip irrigation in extremely arid areas), fertilization to maintain plant growth, as well as timely pruning and disease and pest control are required.

[0041] In this embodiment, optionally, the straw grid unit 200 includes a plurality of straw grid bodies formed by weaving straw, and the plurality of straw grid bodies are arranged adjacent to each other, and each straw grid body encloses a sand-proof space for accommodating the vegetation unit 300 and the biocrust layer unit 400. It should be understood that the straw grid body is woven from straw, which not only increases the roughness of the surface and reduces the wind speed, but also maintains soil moisture to a certain extent, providing better conditions for plant growth. The straw grid body is laid on the surface of the vegetation unit 300 to increase the roughness of the surface, reduce wind erosion, and prevent soil loss. The layout of the straw grid needs to be scientifically designed according to the terrain, wind direction and vegetation distribution. Using the intelligent straw grid layout system, the best grid layout plan is automatically generated using terrain analysis and remote sensing technology to maximize its sand-proof performance. The layout uses terrain data and meteorological information to automatically generate the best grid arrangement to ensure maximum sand-proof effect. During construction, the grids should be spaced appropriately to ensure sufficient coverage while avoiding overcrowding that would affect ventilation and water penetration in the lower soil. In addition, the laying of the straw grid body also takes into account the complementarity with the shrub vegetation of the vegetation unit 300, and the shade provided by the shrub vegetation reduces the sun exposure of the straw grid body, thereby extending its service life.

[0042] In this embodiment, optionally, the biological crust layer unit 400 includes a colony layer and a composite biological soil crust layer, the colony layer covers the soil surface in the area enclosed by the grass grid unit 200 and around the root system of the vegetation unit 300, and the composite biological soil crust layer covers the surface of the colony layer.

[0043] Wherein, the composition of the colony layer is rhizobium, pseudomonas, vibrio, bacillus subtilis, trichoderma and cyanobacteria, wherein, according to weight parts, the composition ratio is: rhizobium 20-30 parts, pseudomonas 10-15 parts, vibrio 15-25 parts, trichoderma 10-15 parts, cyanobacteria 5-10 parts. It should be understood that rhizobium is a nitrogen-fixing bacteria, which can form a symbiotic relationship with leguminous plants such as caragana plants in arid and semi-arid areas, helping plants to grow in nitrogen-poor soils. Pseudomonas and vibrio have strong environmental adaptability, can secrete plant growth hormones, promote the growth of plants under adversity, can tolerate drought conditions, and by increasing the growth of plant roots, enhance the resistance of plants to stress; trichoderma fungi can not only decompose organic matter and improve soil structure, but also enhance the disease resistance of plants, cyanobacteria provide organic matter to the soil through photosynthesis, and improve soil fertility through nitrogen fixation. In this way, the colony layer composed of a variety of bacteria can effectively protect the soil and reduce the rate of soil desertification.

[0044] Optionally, the composite biological soil crust layer is prepared by experimental cultivation of a composition composed of cyanobacteria, mosses and lichens. During the experimental cultivation, the cultivation temperature is set to 25±2°C, the photoperiod is set to 11-13h, and the cultivation time is set to 8-14 days. It should be understood that by selecting cyanobacteria, mosses and lichens for cultivation and mixing these biological components, a diverse ecological community can be established that can survive in extreme arid environments and play a role in consolidating soil and conserving water.

[0045] Optionally, the composite biological soil crust layer is covered on the surface of the colony layer by spraying. Specifically, when spraying the composite biological soil crust layer, first level the soil in the area surrounded by the grass grid unit 200, remove stones and weeds; before 8 a.m. or after 18 p.m., spray the cultivated composite biological soil crust layer on the surface of the colony layer at a spraying amount of 5 to 10 g / m2 by dry weight. Regularly monitor the coverage, thickness and biological activity of the composite biological soil crust layer to ensure the stable development of the composite biological soil crust layer. Through continuous observation and analysis of the growth state of the composite biological soil crust layer, its adaptability and effect under different environmental conditions can be timely understood, and adjustments or additional spraying can be made when necessary to ensure that the composite biological soil crust layer can effectively play its role in sand prevention and control.

[0046] The design of the comprehensive sand prevention and control system for arid areas provided in this embodiment has multiple protective measures that are mutually complementary and can effectively improve the control effect of the desertification environment. Specifically:

[0047] 1. By selecting species with high hydraulic security, we ensure that plants can maintain water transport under extreme drought conditions and avoid plant death due to hydraulic failure. Studies have shown that the selected species have high anti-embolism vulnerability and low water loss rate under drought stress, so they have high hydraulic transmission security. In addition, the xylem hydraulic conductivity of these species is significantly lower than that of other common species. This low water transmission efficiency and low growth rate enable them to maintain water balance under conditions of extreme water shortage;

[0048] 2. Combining vegetation, physical structure and biological crust technology, a multi-level, complementary and mutually beneficial sand control system is formed, which greatly improves the comprehensiveness and efficiency of sand control. This system not only uses the roots of shrub vegetation to fix sand, provide necessary shade and organic matter, and improve soil structure, but also increases the surface roughness and slows down wind speed through physical protection measures such as barriers and straw grid bodies, effectively preventing soil erosion. In addition, the formation of the composite biological soil crust layer further enhances the soil's water retention capacity and nutrient supply, promotes the growth of shrub vegetation, and forms a stable ecosystem. This comprehensive management model not only improves the efficiency of sand control, but also promotes the recovery and sustainable development of the ecosystem;

[0049] 3. Mix the microbial enhancer, i.e., the colony layer, with water and spray it around the roots of the soil or shrub layer plants to promote root development and enhance plant growth. The colony layer can be applied regularly to the rhizosphere of shrubs to promote the growth of shrub roots and plants as a whole, accelerate the formation of the composite biological soil crust layer, and provide additional nutritional support. The integrated management of shrubs and composite biological soil crust layers and the application of microbial enhancers ensure that shrub vegetation and composite biological soil crust layers can develop stably in arid environments and form a mutually beneficial ecosystem.

[0050] 4. By rationally selecting shrub species that can adapt to specific arid environments, and customizing biocrust formulations based on soil types and climatic conditions, the system can efficiently address desertification issues in different regions. This flexibility and adaptability means that the present invention is not only applicable to arid and semi-arid regions, but can also adjust sand control measures according to changes in specific environmental conditions to adapt to other desertified areas with similar climatic conditions around the world. This high degree of environmental adaptability ensures the effectiveness of sand control measures while reducing the risk of control failure due to environmental changes. The strategy of using local vegetation and on-site prepared biocrusts significantly reduces the implementation cost of the sand control system. The present invention is more economical and easy to promote and apply in a wide range of areas. In addition, the system has low maintenance costs because once established, the shrub vegetation and biocrust layers are self-sustaining and recoverable, reducing long-term maintenance requirements. This cost-effective design not only makes sand control possible for resource-limited areas, but also helps achieve sustainable development goals and brings long-term economic and environmental benefits to local communities.

[0051] The following is an example of screening shrub vegetation for the comprehensive sand prevention and control system in arid areas of the present application.

[0052] Please combine Figure 2-Figure 4In order to screen high-quality shrubs suitable for arid environments, the present invention adopts a hydraulic safety and growth rate evaluation method. The experiment selected 19 typical desert shrub varieties from different climatic regions, as shown in Table 1. The results show that Caragana, Artemisia ordosica, Periploca salsa, Hippophae rhamnoides, etc. have a higher survival rate. Further hydraulic and physiological characteristics analysis was carried out, and their hydraulic safety (by measuring water potential, hydraulic conductivity, turgor pressure loss point, hydraulic safety margin, etc.) and growth rate (by monitoring the photosynthetic rate, specific leaf area and wood density of the plants, etc.) under drought conditions were determined respectively. Caragana, Prunus mongolica and Calligonum sylvestris plants performed outstandingly in these two indicators, with lower water potential thresholds and higher hydraulic safety, respectively. Moreover, the higher the hydraulic safety and the slower the growth rate of the plant, the stronger the environmental adaptability and stress resistance. In addition, the shrubs maintain low water transfer efficiency and low growth rate to survive, adopting a "conservative" survival strategy. After hydraulic safety and growth rate tests, the most adaptable shrub species of the genus Caragana, such as Caragana korshinskii, Caragana deserticola, Caragana dwarfis and Caragana serrata, were finally screened out and applied to the shrub vegetation layer of the present invention. The experimental results show that the survival rate of these shrubs under simulated drought conditions is as high as over 85%, and the stability of their root systems is significantly improved, and their sand fixation effect is significantly improved. Therefore, these shrub varieties are applied to the comprehensive sand control system of the present invention. Experiments show that they can not only maintain a high survival rate under extreme drought conditions, but also significantly improve the overall sand fixation effect of the system.

[0053] Table 1 Information of the 19 woody plants studied

[0054]

[0055]

[0056] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A comprehensive sand prevention and control system for arid areas, characterized in that: include: A sand-blocking unit (100), a grass grid unit (200), a vegetation unit (300) and a biological crust layer unit (400), wherein the sand-blocking unit (100) is arranged on the same side of the vegetation unit (300), the grass grid unit (200) and the biological crust layer unit (400) and is located in the windward direction; the grass grid unit (200) is arranged around the vegetation unit (300), the biological crust layer unit (400) is arranged in the area enclosed by the grass grid unit (200) and covers the ground surface, and the biological crust layer unit (400) is arranged around the vegetation unit (300).

2. The comprehensive sand prevention and control system for arid areas according to claim 1 is characterized by: The sand blocking unit (100) comprises a blocking barrier, which is arranged vertically and located on the windward side of the vegetation unit (300), the grass grid unit (200) and the biological crust layer unit (400).

3. The comprehensive sand prevention and control system for arid areas according to claim 2 is characterized by: The barrier comprises a frame and a sand-blocking net, wherein the frame is used to be fixed to the ground surface, and the sand-blocking net comprises a stacked high-absorbent polymer layer and an ultraviolet-resistant polymer fiber layer, wherein the high-absorbent polymer layer is attached to the frame, and the polymer fiber layer is located on a side of the high-absorbent polymer layer away from the frame.

4. The comprehensive sand prevention and control system for arid areas according to claim 1 is characterized by: The straw lattice unit (200) comprises a plurality of straw lattice bodies formed by weaving straw, the plurality of straw lattice bodies are arranged adjacent to each other, and each of the straw lattice bodies encloses a sand-proof space for accommodating a vegetation unit (300) and a biocrust layer unit (400).

5. The comprehensive sand prevention and control system for arid areas according to claim 1 is characterized by: The biological crust layer unit (400) comprises a colony layer and a composite biological soil crust layer, the colony layer covers the soil surface in the area enclosed by the grass grid unit (200) and around the root system of the vegetation unit (300), and the composite biological soil crust layer covers the surface of the colony layer.

6. The comprehensive sand prevention and control system for arid areas according to claim 5 is characterized by: The components of the colony layer are rhizobia, pseudomonas, vibrio, bacillus subtilis, trichoderma and cyanobacteria, wherein, by weight, the component ratios are: 20-30 parts of rhizobia, 10-15 parts of pseudomonas, 15-25 parts of vibrio, 10-15 parts of trichoderma and 5-10 parts of cyanobacteria.

7. The comprehensive sand prevention and control system for arid areas according to claim 5 is characterized by: The composite biological soil crust layer is prepared by experimentally culturing a composition consisting of cyanobacteria, mosses and lichens.

8. The comprehensive sand prevention and control system for arid areas according to claim 7 is characterized by: When conducting experimental cultivation, the cultivation temperature is set to 25±2° C., the light cycle is set to 11-13 h, and the cultivation time is set to 8-14 days.

9. The comprehensive sand prevention and control system for arid areas according to claim 5 is characterized by: The composite biological soil crust layer is covered on the surface of the bacterial colony layer by spraying.

10. The comprehensive sand prevention and control system for arid areas according to claim 9 is characterized by: When spraying the composite biological soil crust layer, the soil in the area surrounded by the grass grid unit (200) is first leveled to remove stones and weeds; before 8 a.m. or after 18 p.m., the cultivated composite biological soil crust layer is sprayed at a dry weight of 5 to 10 g / m 2 Spray the amount of spray on the surface of the colony layer.

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