An integrated method for rapid solidification of mobile sand dunes and planting of economic plants

Abstract

The invention belongs to the field of desert management, and specifically relates to an integrated method for rapid solidification of mobile sand dunes and planting of economic plants, comprising the following steps: step 1, drone aerial seeding: setting a first sand dune reinforcement area perpendicular to the main wind direction, aerial seeding and spraying pelletized desert seeds; step 2, leeward slope reinforcement: after the sand surface of the leeward slope of the sand dune is accumulated to a suitable growth thickness of seeds, a drone is used to spray water-absorbing and moisture-retaining colloid synergistic EICP reinforcement material to solidify the surface of the sand dune; step 3, windward slope reinforcement: drone spraying of growth-promoting water-retaining and high-nutrient matrix covering pelletized desert seeds on the surface of the windward slope of the sand dune to a suitable growth thickness D of the seeds; step 4, inter-dune reinforcement: after the mobile sand dunes of two adjacent dune reinforcement areas are reinforced, aerial seeding and reinforcement of the inter-dune land are carried out; the invention adopts different repair methods for different positions in a targeted manner, can achieve good repair effects, and saves costs.

Description

Technical Field

[0001] The invention belongs to the technical field of desert control, and in particular relates to an integrated method for rapid solidification of mobile sand dunes and planting of economic plants. Background Art

[0002] Sand dunes are a common landform in desert areas. They refer to sand dune-like landforms formed by the transportation and accumulation of wind. According to their mobility, they can be divided into fixed dunes, semi-fixed dunes and mobile dunes. Mobile dunes are widely distributed in desert areas. They are characterized by sparse surface vegetation and typical shapes. They are easy to move under the action of wind, posing a huge threat to transportation, industrial and agricultural construction.

[0003] The main function of sand prevention and control measures is to reduce wind speed and fix surface sand. Common sand control methods include biological sand control, mechanical sand control and chemical sand control. Biological sand control measures are one of the main means of wind prevention and sand control. By utilizing the drought resistance and developed root system of vegetation, it can play a certain role in ecological protection and contribute to soil and water conservation; however, due to the mobility of sand particles on the surface of sand dunes, plants are prone to die due to root exposure in the early stages of growth. Mechanical sand fixation, also known as sand barrier sand fixation, is a barrier made of firewood, straw, clay, branches, laths, pebbles and other materials on the sand surface, which can play a role in fixing mobile sand dunes in a short period of time. However, the grass grid method or other sand fixation barriers require a lot of manual rolling, laying and maintenance, which is labor-intensive and time-consuming, and the overall cost is high. Chemical sand fixation mainly uses by-products of the petrochemical industry such as asphalt emulsions to spray chemical binders on the mobile sand to form a protective shell with a certain strength on the surface of the sand to avoid the direct impact of airflow on the sand surface, so as to achieve the purpose of fixing the mobile sand. However, the sand fixation effect of chemical sand fixation agents is usually not permanent under the influence of wind erosion or ultraviolet rays. They need to be regularly maintained and added, and the management and maintenance costs are relatively high. In short, the existing desert control methods have problems such as high cost, low efficiency, and unstable effect. A more economical and efficient method is urgently needed. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide an integrated method for rapid solidification of mobile sand dunes and planting of economic plants. According to the wind speed and direction monitoring results, the movement of sand dunes can be controlled more accurately. By combining the rapid solidification method and the planting of economic plants, a win-win situation of ecology and economy in desertified areas can be achieved.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A method for integrating rapid solidification of mobile sand dunes and planting of economic plants, comprising the following steps:

[0007] Step 1, drone seeding: set up the first dune reinforcement area perpendicular to the main wind direction, and use drone seeding to spray pelletized desert seeds in this area; predict the time T required for the seeds to accumulate to a suitable growth thickness D on the leeward slope of the moving dunes based on the monitored moving sand dune movement speed, wind direction, and erosion accumulation thickness;

[0008] Step 2: Reinforcement of the leeward slope: When the sand accumulation on the leeward slope of the dune reaches a suitable thickness for seed growth, use drones to spray water-absorbing and moisturizing colloid-enhanced EICP reinforcement materials to solidify the dune surface;

[0009] Step 3: Windward slope reinforcement: Drones are used to spray the growth-promoting, water-retaining, and high-nutrient matrix on the windward slope of the sand dunes to cover the pelletized desert seeds to a thickness D suitable for seed growth;

[0010] Step 4: Reinforcement of inter-dune land: After the reinforcement of the mobile dunes in the two adjacent dune reinforcement areas is completed, the inter-dune land is sown and reinforced; drones are used to first spray pelletized desert seeds, and then water-absorbing and moisturizing colloid synergistic EICP reinforcement materials are sprayed to solidify the inter-dune land;

[0011] Step 5: Repeat steps 1, 2, 3, and 4 in this order to reinforce the next dune reinforcement area.

[0012] Furthermore, the pelletized desert seeds are a mixture of desert shrub seeds and herbaceous plant seeds with high economic efficiency, and the spraying amount is 0.25-1 kg per mu.

[0013] Furthermore, the desert shrub seeds include at least one of Populus chinensis, Artemisia annua, Caragana microsporus, Haloxylon ammodendron, Populus euphratica, Bletilla striata, Calligonum mongolica, and Syngonium wilfordii, and the desert herbaceous plant seeds include at least one of Shadawang, Artemisia ordosica, Sago serrata, Camel thorn, and Sophora alopecuroides.

[0014] Furthermore, the water-absorbing and moisturizing colloid synergistic EICP reinforcement material is formed by mixing urease with an activity of 4-9 mmol / (L·min) and a binder with a concentration of 0.1-0.4 mol / L in a volume ratio of 1:1; the binder is a mixture of a calcium salt solution and a urea solution with equal molar concentrations.

[0015] Furthermore, the water-absorbing and moisture-retaining colloid synergistic EICP reinforcement material also contains 0.03-0.2% of Artemisia sphaerocephala glue in the total weight of the binder.

[0016] Furthermore, the raw materials of the growth-promoting, water-retaining and high-nutrient matrix include, by weight: 60-80 parts of in-situ desert sand, 5-15 parts of loess, 5-15 parts of activated carbon, 1-5 parts of soybean powder, and 20-50 parts of water-absorbing and moisture-retaining colloid synergistic EICP reinforcement material.

[0017] Furthermore, the suitable growth thickness of seeds is 0.5~5cm.

[0018] Furthermore, the spraying rate of the water-absorbing and moisturizing colloid EICP reinforcement material on the leeward slope and inter-hill land is 2~6L / m 2 .

[0019] Furthermore, the growth-promoting, water-retaining and high-nutrient matrix is ​​also added with pelletized desert seeds at a rate of 0.5 to 1 times the aerial sowing amount.

[0020] Furthermore, the prediction process of the time T required for the sand surface on the leeward slope of the moving sand dune to accumulate to the thickness D suitable for seed growth is as follows:

[0021] Step 1: Use high-resolution remote sensing images to determine the movement of sand dunes in different periods and analyze the morphological changes and movement paths of sand dunes; group the image data by month or week, and calculate the movement distance and direction of sand dunes in each time period;

[0022] Step 2: Collect continuous wind speed records from weather stations, average the wind speed data monthly or weekly, and identify seasonal variations in wind speed; ensure that the data covers at least 2 years to capture long-term wind speed variations;

[0023] Step 3: Build a model: Build a relationship model between the distance the sand dunes move and the wind speed and direction to predict the movement rate of the sand dunes:

[0024] V s = a × W s b (sin( c × θ) )+cos( d × θ )+ e (1),

[0025] in, V s is the movement rate of the dune, W s is the wind speed, θ It's the wind direction. a, b, c, d and e is the parameter to be fitted;

[0026] The time T required for the target deposition thickness D is:

[0027] T=D / ( V s ×tan( a )) (2),

[0028] Where D is the target stacking thickness,V s Predicted dune movement rate, a It is the natural angle of repose of the sand dune.

[0029] The beneficial effects of the present invention are:

[0030] The present invention is suitable for crescent-shaped sand dunes with a moving speed of 4 to 30 meters per year. The movement of the sand dunes can be controlled more accurately according to the moving characteristics of the moving sand dunes. According to the differences in the degree of wind erosion of the sand dunes, the moving sand dunes can be divided into the windward slope, leeward slope and inter-dune area of ​​the sand dunes. Different repair methods are used for different locations in a targeted manner, which can achieve good repair effects and save costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them:

[0032] Figure 1 Schematic diagram of the principle of sand dune movement.

[0033] Figure 2 It is a schematic diagram of the layout of the sand dune reinforcement area according to an embodiment of the present invention.

[0034] Figure 3 Schematic diagram of a flow chart of an embodiment of the present invention.

[0035] Figure 4 This is the result of the germination rate of Verification Example 1 of the present invention.

[0036] Figure 5 This is the average plant height result of Verification Example 1 of the present invention.

[0037] Figure 6 This is the erosion depth result of Experimental Example 1 of the present invention.

[0038] Figure 7 This is the moisture content result of Experimental Example 1 of the present invention.

[0039] Figure 8 This is the layout diagram of the control group of Experimental Example 1 of the present invention.

[0040] Fig. 9 This is a graph showing the experimental group results of Experimental Example 1 of the present invention.

[0041] Fig.10 This is a diagram of the germination results of desert seeds in the experimental group of Experimental Example 1 of the present invention.

[0042] Fig.11 It is a graph showing the experimental group results of Experimental Example 2 of the present invention.

[0043] Fig.12 It is the result diagram of the control group of Experimental Example 2 of the present invention.

[0044] Fig.13 It is a graph showing the experimental group results of Experimental Example 3 of the present invention.

[0045] Fig.14 It is the result diagram of the control group of Experimental Example 3 of the present invention.

[0046] Fig.15 This is a diagram showing the germination results of desert seeds in Experimental Example 3 of the present invention. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0048] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0049] First, let me explain the principle of sand dune movement. Taking the crescent-shaped sand dune as an example, the windward slope is affected by the wind, and the sand on the surface of the windward slope jumps and rolls to the top of the leeward slope. The sand on the leeward slope continues to accumulate until it slides down. The accumulated sand slides to the bottom of the dune, causing the dune to grow forward and then be blown to both sides by the eddy current to accumulate, forming a crescent-shaped sand dune.

[0050] The present invention utilizes the sandy soil layer accumulated on the leeward slope as the seed covering soil on the leeward slope, eliminating the need for artificial covering soil, and sprays water-retaining colloid synergistic EICP reinforcement materials; after aerial seeding of seeds on the windward slope, a growth-promoting water-retaining high-nutrient matrix is ​​sprayed, which can significantly improve the germination rate and survival rate of seeds compared with simple aerial seeding.

[0051] like Figure 3 As shown, a method for integrating rapid solidification of mobile sand dunes and planting of economic plants comprises the following steps:

[0052] Step 1: Drone seeding: Figure 2 As shown in the figure, the first dune reinforcement area is set up perpendicular to the main wind direction, and pelletized desert seeds are sown in this area by drone flying. The time T required for the seeds to accumulate to a suitable growth thickness D on the leeward slope of the moving dunes is predicted based on the monitored moving sand dune moving speed, wind direction, and erosion accumulation thickness. The required time T is generally 2 to 4 days.

[0053] Step 2: Reinforcement of the leeward slope: When the sand accumulation on the leeward slope of the dune reaches a suitable thickness for seed growth, use drones to spray water-absorbing and moisturizing colloids to strengthen the surface of the dune. Figure 2 As shown in the figure, the leeward slope of the moving sand dune presents wind-blown sand deposition. Therefore, the surface of the dune can be solidified only after the wind-blown sand is accumulated to a suitable thickness D for seed growth. This eliminates the trouble of artificial grass grids or holes. The seed surface is covered with a sand layer and solidified to ensure more seed germination.

[0054] Step 3, windward slope reinforcement: The windward slope of the sand dune is eroded by wind and sand, and the seed coverage thickness is insufficient. Therefore, the surface of the windward slope of the sand dune is sprayed with a high-nutrient matrix to promote growth and retain water. The pelletized desert seeds are covered to a suitable seed growth thickness D; the spraying thickness of the spraying matrix is ​​suitable for the germination and growth of desert plants, generally 0.5~5cm;

[0055] Step 4: Reinforcement of inter-dune land: After the mobile dunes in two adjacent dune reinforcement areas have been reinforced, seeding and reinforcement of inter-dune land will be carried out; drones will be used to spray pelletized desert seeds first, and then water-absorbing and moisturizing colloid EICP reinforcement materials will be sprayed to solidify the inter-dune land; Figure 1 As shown, interdune land refers to the flat sandy land between the first row of dunes and the second row of dunes;

[0056] Step 5: Repeat steps 1, 2, 3, and 4 to reinforce the next dune reinforcement area until the dune reinforcement of all the plots to be treated is completed;

[0057] There is little water on site, so the treatment time is generally chosen about a month before the rainy season. As long as the rainfall is more than 10mm, basic aerial seeding can survive; for example, for the Kubuqi Desert in Ordos, there is more rain in June, July and August, so it is generally better to sow in April and May. When spraying water-absorbing and moisturizing colloid synergistic EICP reinforcement materials, use large-capacity drones for spraying; when spraying to promote the growth of water-retaining and high-nutrient matrix, the low positions of the sand dunes can be sprayed by guest soil sprayers or other equipment with pumps and nozzles (if the lift of guest soil sprayers and other equipment meets the needs, they can continue to be used for spraying on the high windward slope), and the higher positions are sprayed by drones driven by nozzles, and the nozzles are connected to the storage truck. Figure 3 Schematic diagram of the construction method of progressive curing of the present invention, Figure 3 Step 2 in the diagram schematically shows the drone spraying the water-absorbing and moisturizing colloid EICP reinforcement material. Figure 3Step 3 in the diagram schematically shows a storage vehicle and a drone towing a pipe. To prevent the pipe from being dragged onto the ground and affecting the surface effect, pay attention to spraying from top to bottom when constructing the water-retaining and high-nutrient substrate on the windward slope.

[0058] Furthermore, the spraying rate of the water-absorbing and moisturizing colloid EICP reinforcement material on the leeward slope and inter-hill area is 2~6L / m 2 .

[0059] This method is applicable to a speed of 4 to 30 m / year. Reason: Assuming that the dune shape remains unchanged and only moves horizontally by 4 m, the angle of repose is 32°, and the thickness of the sand layer on the leeward side is 4×100 / 365×tan32°=0.68 cm, which meets the general soil cover thickness requirement for seeds (0.5 to 5 cm).

[0060] The present invention does not need to adopt mechanical sand fixation measures such as grass grids, thus saving a lot of manpower; at the same time, the leeward slope utilizes the accumulation of wind and sand to form the surface soil covering the seeds, and the windward slope utilizes the sprayed water-retaining and high-nutrient matrix to provide the surface soil covering for the seeds, thereby constructing a good environment for seed germination and avoiding the death of plants due to root exposure in the early stage of growth; the water-absorbing and moisturizing colloid synergistic EICP reinforcement material and the components of the growth-promoting water-retaining and high-nutrient matrix are harmless to the environment.

[0061] Furthermore, the pelletized desert seeds are a mixture of desert shrub seeds and herbaceous plant seeds with higher economic value, and the spraying amount is 0.25-1 kg per mu; for example, in the sprayed mixed seeds, the weight ratio of Miscanthus annuus: Artemisia sphaerocephala: Artemisia selengensis: Artemisia argyi is 1:1:2:2, and the spraying amount per mu is 0.53 kg.

[0062] Furthermore, the desert shrub seeds include at least one of Populus fasciata, Artemisia annua, Caragana korshinskii, Haloxylon ammodendron, Populus euphratica, Bletilla striata, Calligonum mongolica, and Syngonium wilfordii, and the desert herbaceous plant seeds include at least one of Artemisia sudachii, Artemisia ordosica, Miscanthus annuus, Camel thorn, and Sophora alopecuroides; usually, plants such as Artemisia ordosica, Populus fasciata, and Artemisia sutchuenensis can be harvested as animal feed, most of which have medicinal value, and the seeds can also be collected and sold, which is highly economical.

[0063] Furthermore, the water-absorbing and moisturizing colloid synergistic EICP reinforcement material is prepared by mixing urease with an activity of 4 to 9 mmol / (L·min) and a binder with a concentration of 0.1 to 0.4 mol / L in a volume ratio of 1:1; the binder is obtained by mixing a calcium salt solution and a urea solution with equal molar concentrations; wherein the calcium salt can be calcium chloride, calcium nitrate, or calcium acetate; and the urease used can be extracted from beans such as soybeans or sword beans.

[0064] Preferably, the water-absorbing and moisturizing colloid synergistic EICP reinforcement material also contains 0.03-0.2% of Artemisia sphaerocephala glue as the total weight of the binder; Artemisia sphaerocephala glue is a natural plant glue with high viscosity and good water absorption, water retention and thermal stability, and is easily decomposed by microorganisms, is environmentally friendly, can accelerate biological crusting, and can promote the stability of the sand dune surface.

[0065] Furthermore, the raw materials of the growth-promoting water-retaining high-nutrient matrix include, by weight: 60-80 parts of in-situ desert sand, 5-15 parts of loess, 5-15 parts of activated carbon, 1-5 parts of soybean powder, and 20-50 parts of water-absorbing and moisture-retaining colloid synergistic EICP reinforcement materials. The particle size of desert sand is generally less than 0.5 mm, so the particle size of loess, activated carbon, and soybean powder should be less than 0.5 mm, otherwise uneven mixing is likely to occur. Loess is cheap and easy to obtain, and rich in sticky minerals, which can increase the viscosity and nutrients of the soil; biochar has the properties of looseness, porosity, and high specific surface area, and is an environmentally friendly soil conditioner; biochar can improve the water holding capacity of the soil; soybean powder (or sword bean powder) is the residue after the soybean powder raw material is extracted by urease, and it can be used as waste to increase the organic matter content of desert soil. In a specific example of a growth-promoting, water-retaining, high-nutrient matrix, it includes 60 parts of in-situ desert sand, 10 parts of loess, 5 parts of activated carbon, 2 parts of soybean powder, and 30 parts of water-absorbing and moisture-retaining colloid synergistic EICP reinforcement material.

[0066] Preferably, the growth-promoting water-retaining high-nutrient matrix is ​​also added with 0.5 to 1 times the amount of pelletized desert seeds for aerial sowing; in the process of waiting for the sand on the leeward slope to accumulate, the windward slope is blown away by the wind, not only the sand but also the pelletized desert seeds. Therefore, in step 3, the growth-promoting water-retaining high-nutrient matrix sprayed is mixed with a certain amount of pelletized desert seeds to ensure the planting density on the windward slope. In step 1, if the windward slope is bypassed during aerial sowing, the difficulty of drone path planning will be greatly increased. Therefore, when the drone is sowing, the pelletized desert seeds are sprayed on the strip-shaped dune reinforcement area as a whole.

[0067] Predicting the path of moving sand dunes is an existing technology, which usually includes historical data analysis, the layout of monitoring equipment, and the prediction and calculation of movement paths and wind erosion and wind accumulation. Historical data analysis mainly includes the dune pictures of the site's high-resolution remote sensing images at different times, and the analysis of the wind speed data of the site's meteorological station to establish a calculation model for the dune movement rate and wind speed; the layout of the monitoring equipment generally used includes wind erosion measuring rods, sand collectors, anemometer layout, and aerial photography drones, which are mainly used for the actual dune movement and erosion accumulation depth calculation on site. The intelligent monitoring and calculation method for the movement of sand dunes on site mainly includes the calculation of the dune movement speed and the erosion and accumulation thickness calculation model. For example, patents CN118196614A, CN102622656A, CN113887499B, and CN117576485B all disclose methods for dune identification or model construction.

[0068] In the present invention, the prediction process of the time T required for the accumulation of sand on the leeward slope of the moving sand dune to reach the suitable growth thickness D of the seeds is as follows:

[0069] Step 1: Use high-resolution remote sensing images to determine the movement of sand dunes at different times and analyze the morphological changes and movement paths of sand dunes; use image processing software (such as ArcGIS, ENVI) to analyze the contours, slopes, and volume changes of sand dunes; mark the landmark points of sand dunes (such as the leading edge or trailing edge) and track the position changes of these points at different time points; in order to improve the calculation accuracy, group the image data by month or week, and calculate the movement distance and direction of the sand dunes in each time period;

[0070] Calculation of movement distance: When calculating the movement distance of the sand dunes, the time period is divided into weeks or months according to the image data; the movement distance of the sand dunes at each time point is calculated using the formula (3) ΔX(t)=X(t2)-X(t1), where ΔX(t) is the movement distance of the sand dunes in the time period [t1, t2];

[0071] Calculate the movement rate of the dune in the time period [t1, t2] ΔV s ,

[0072] ΔV s = ΔX(t) / Δt (4),

[0073] in, Δt is the duration of the dune in the time period [t1, t2], Δt Take a week or a month;

[0074] Step 2: Collect continuous wind speed records from weather stations, preferably at a high frequency (e.g. hourly or daily). Ensure that the data covers at least 2 years to capture long-term wind speed changes. Average the wind speed data monthly or weekly to identify seasonal patterns in wind speed, such as how wind speed changes in different seasons.

[0075] Calculation of the vector components of wind speed and direction:

[0076] V xi =W i ×cos(θ i ×Π / 180) (5),

[0077] V yi =W i ×sin(θ i ×Π / 180) (6),

[0078] Where: Vxi is the wind speed vector in the X direction, V yi is the wind speed vector in the Y direction, W i is the wind speed, θ i ×Π / 180 means converting wind direction into radians (θ i ×Π / 180 is deg2rad(wind_directions), deg2rad is a function, the function of rad2deg function is to convert the unit of angle from radians to degrees);

[0079] The average wind speed and direction for the composite week are:

[0080] W s =((∑ n i=1 V xi / n) 2 +(∑ n i=1 V yi / n) 2 ) 1 / 2

[0081] θ =arctan2((∑ n i=1 V xi / n), (∑ n i=1 V yi / n))

[0082] Step 3: Build the model:

[0083] Step 3.1, data preprocessing: clean the data, handle missing values ​​and outliers in the wind speed, wind direction and dune movement distance data, and ensure data alignment;

[0084] Step 3.2: Establish a relationship model between the distance dunes move and wind speed and direction to predict the movement rate of dunes; use an extended power law model to include the influence of wind direction. Wind direction is periodic and can be modeled using sine and cosine functions:

[0085] V s = a × W s b (sin( c × θ) )+cos( d × θ )+ e (1),

[0086] in, V sis the movement rate of the dune, W s is the wind speed, θ It's the wind direction. a, b, c, d and e is the parameter to be fitted;

[0087] The time T required for the target deposition thickness D is:

[0088] T=D / ( V s ×tan( a )) (2),

[0089] Where D is the target stacking thickness, V s Predicted dune movement rate, a It is the natural angle of repose of the dune;

[0090] Step 4: Calibrate the model based on the on-site erosion needle, wind speed, and wind direction monitoring results, and apply the calibrated model to the actual dune movement prediction; calculate the time required to reach the seed coverage thickness based on the on-site measured wind speed and wind direction, so as to formulate seed sowing and dune reinforcement strategies.

[0091] For example, suppose the measured data of wind speed, wind direction and sand dune movement distance in a desert in one year are as follows:

[0092] Table 1 Measurement data of wind speed, wind direction and sand dune movement distance in a certain desert in one year

[0093]

[0094] Through matlab parameter fitting, we get: a =0.04, b =1.51, c =0.07, d =0.2, e =0.24; then:

[0095] V s = 0.04 × W s 1.51 (sin( 0.07θ) )+cos( 0.2θ )+ 0.24 (1) ，

[0096] Assuming that the average wind speed monitored on site for one week is 8m / s and the main wind direction is 30°, then calculate V s=0.985m / 30days=3.28cm / day;

[0097] The time T required for the target accumulation thickness of 2 cm is:

[0098] T=D / ( V s ×tan( 32° ))=2cm / (3.28cm / day*0.649)=0.94day=22.5h≈23h.

[0099] Verification Example 1

[0100] The purpose of this verification example 1 is to compare the effect of the amount of Artemisia sphaerocephala glue on the use effect of water-absorbing and moisture-retaining colloid-enhanced EICP reinforcement materials in indoor experiments.

[0101] Sample preparation: A plant growth test reinforced with desert sand was conducted in a transparent acrylic box with a size of 16cm×16cm×5cm. First, the dried desert particles were slowly poured into the acrylic box to make the desert sand in a loose pile state. The desert immersion depth (the depth of the sand introduced into the acrylic box) reached 4cm. The surface was scraped flat with a ruler, and 49 pelletized desert seeds with full particles (commercially available pelletized Shadawang seeds) were evenly arranged on it. Then a layer of 1cm thick desert sand was applied to completely cover the seeds, and finally the surface was scraped flat with a ruler.

[0102] Preparation of water-absorbing and moisturizing colloid synergistic EICP reinforcement material: A urease solution with an activity of 7.5 mmol / (L·min) was prepared, and a cementing liquid with a concentration of 0.1 mol / l (the cementing liquid is a CaCl2 solution and a urea solution with equal molar concentrations) was prepared. The effect of adding 0, 0.03, and 0.05% L Artemisia sphaerocephala glue (for experimental groups CS1, CS1-A0.3, and CS1-A0.5) to the cementing liquid was tested; sample CS0 was sprayed with only the same volume of pure water solution. The cementing liquid and urease solution were mixed in a ratio of 1:1 to prepare the water-absorbing and moisturizing colloid synergistic EICP reinforcement material.

[0103] Spray reinforcement and curing germination: Spray reinforcement material at 2.5L / m 2 The sample surface was sprayed with a spraying amount of 160 g, and then the sample was cured at a room temperature of 25° C. for 1 day. The plant was watered on the second day with a watering amount of 160 g, and then watered every three days and the germination rate and plant height were recorded.

[0104] Experimental conclusion: The experimental results are as follows Figure 4As shown in the figure, 12 days after adding 0.03% and 0.05% wormwood glue, the germination rate of plants was basically the same as that of untreated desert sand, indicating that the normal dosage of the sand fixation agent used this time would not affect the growth of plants, and the germination rate after adding wormwood glue was higher than that of the group without adding wormwood glue (CS1), indicating that the use of wormwood glue can improve the seed germination rate to a certain extent. Figure 5 As shown, the average growth height of the samples with added wormwood glue is higher than that of the samples without addition or only treated with water. The moisture content measurement shows that the experimental group with added wormwood glue has a higher moisture content, especially the plants in the experimental group CS1 have the highest height, which proves that the water retention performance of this experimental material is better than that of the treatment reinforced with urease + binder alone.

[0105] Experimental Example 1

[0106] This experimental example 1 aims to test the effect of the amount of Artemisia sphaerocephala glue on the use of water-absorbing and moisturizing colloid EICP reinforcement materials in the original desert environment. It also gives the experimental results of inter-hill reinforcement.

[0107] The field test was conducted in the Kubuqi Desert in Ordos. A pristine desert that had not been treated was selected for the test. 18 test areas were divided, each with an area of ​​5m 2 , a walkway is set between two adjacent test areas. Figure 8 As shown, fixed rods were inserted into the sand and then ropes were used to frame each experimental area.

[0108] Preparation of water-absorbing and moisturizing colloid synergistic EICP reinforcement material: A urease solution with an activity of about 7.0mmol / (L·min) was prepared, and a binder with a concentration of 0.1mol / l was prepared (the binder was a CaCl2 solution and a urea solution with equal molar concentrations). 0, 0.03g / L, 0.05%, 0.1%, and 0.15% Artemisia sphaerocephala glue (corresponding to samples CS1, CS1-A0.3, CS-A0.5, CS-A1, and CS-A1.5) were added to the binder to test a total of five reinforcement groups, and each reinforcement group was tested three times. A control group CS0 was set up, which was only sprayed with the same volume of aqueous solution. The binder and urease solution were mixed in a ratio of 1:1 to prepare a water-absorbing and moisturizing colloid synergistic EICP reinforcement material.

[0109] Spray reinforcement and effect test: Insert two erosion needles in each test area to measure the erosion depth, and choose to spray reinforcement after 4 pm on a sunny day to avoid rapid evaporation of the cementing solution. 2The spraying amount was sprayed on the surface of the prepared sample, and then solidified under natural conditions. After 2 weeks of reinforcement, the average moisture content at a depth of 5 cm was measured using a portable soil moisture meter, and the average erosion depth of the erosion needles in the reinforcement area was measured.

[0110] Experimental conclusion: Figure 6 As shown in the figure, after adding sand glue, the erosion depth of the reinforced area was significantly reduced from 25mm (CS0) in the unreinforced area to 0 (CS-A1.5), which improved the anti-erosion ability of desert sand. Figure 7 As shown, the moisture content of the treated area increased from 4.5% (CS0) without reinforcement to 7.3% (CS-A1.5), which increased the water storage capacity of the desert sand and was beneficial to plant growth. Figure 8 The photo of the control group CS0 after two weeks of use of the water-absorbing and moisturizing colloid enhanced EICP reinforcement material. From the photo, it can be seen that the desert seed desert sand in the control group is in a flowing state, while the reinforced sand shows better stability and the shell layer is more obvious. Fig. 9 The figure shows the germination of desert seeds in the CS-A1.0 group 14 days after sowing. It can be seen that the plants have germinated significantly (sprouting and breaking the shell). The shell layer protects the sand from being blown away and does not affect the germination of the seeds. Fig.10 This is the germination of desert seeds after 14 days. Fig. 9 The test areas on both sides are untreated walkways, and it can be seen that the surface sand in the test areas on both sides has obvious flowing waves.

[0111] Experimental Example 2

[0112] This experimental example 2 is intended to test the experimental results of the water-absorbing and moisture-retaining colloid enhanced EICP reinforcement material in the leeward slope reinforcement.

[0113] The field test was conducted in the Kubuqi Desert in Ordos. The test was carried out on the leeward side of the dune. The sand slope angle was 30° and six test areas were divided. Each test area was 5m 2 , a walkway is set between two adjacent test areas. As in Experimental Example 1, the test area is set by inserting fixed rods into the sand and then using ropes to frame each test area.

[0114] Seed sowing: The experiment used pelleted Shadawang seeds. Because Shadawang seeds are herbaceous plants with fast germination and growth rates, the seeds were sown at a spray rate of 0.25 kg per mu by broadcasting. After sowing, the accumulation thickness of the area was recorded by erosion needle.

[0115] Preparation of water-absorbing and moisturizing colloid EICP reinforcement material: A urease solution with an activity of about 7.0mmol / (L·min) was prepared, and a cementing liquid with a concentration of 0.1mol / l was prepared (the cementing liquid was a CaCl2 solution and a urea solution with equal molar concentrations). 0.1% Artemisia sphaerocephala glue (corresponding to sample CS1-A1) was added to the cementing liquid for testing, with a total of 1 reinforcement group, and a control group CS0 was set up, which was to spray only the same volume of aqueous solution on the sand surface. Each group was tested three times.

[0116] Spray reinforcement and effect test: Two erosion needles were inserted in each test area to measure the erosion depth. Two days after seed sowing, the accumulation thickness of the experimental area was measured by the erosion needle monitoring results to be 10-30mm. Spray reinforcement was carried out after 4 pm on a sunny day to avoid rapid evaporation of the cementing solution. The reinforcement material was added at 3L / m 2 Spray the sample surface with a spraying amount of , and solidify it under natural conditions after spraying.

[0117] Experimental conclusion:

[0118] Fig.11 , Fig.12 This is the situation of the CS1-A1 and CS0 test areas after 20 days of testing ( Fig.11 , Fig.12 Because it had just rained, there were many small spots on the surface of the desert, and footprints were obvious. Fig.12 It can be seen that the CS0 shell sand layer is in a flowing state, with obvious corrugations on the surface. The erosion needle monitoring results show that the accumulation thickness of the experimental area is about 50-80mm, and the water content of the sand layer at a depth of 5cm on the leeward slope is 3.1-5.4%. The surface strength of the sand layer measured by the micro-penetrator is 10-30kPa.

[0119] like Fig.11 The sand layer flow in the CS1-A1 shell layer is not obvious. The erosion needle monitoring results show that the accumulation thickness of the experimental area is 5-20mm. After applying the water-absorbing and moisturizing colloid enhanced EICP reinforcement material, the sand layer accumulation is reduced. The reason for this is that the surface of the unreinforced area (CS0) is relatively loose, which makes it easier to capture and accumulate wind and sand from other places, so the accumulation thickness is larger. The reinforced sand layer is more compact, which reduces the accumulation efficiency of sand particles in the leeward area, making it difficult for wind and sand to be captured and accumulated on the surface, indicating that this material can reduce the movement of sand dunes, thereby fixing the sand dunes.

[0120] In addition, the moisture content of the sand layer on the leeward slope at a depth of 5 cm was measured by a portable moisture meter and was found to be 7.4-10.1%, indicating that the use of water-absorbing and moisturizing colloid enhanced EICP reinforcement materials can increase the moisture content of sand, indicating that this material is suitable for leeward slopes and has good effects. The surface strength of the sand layer was measured by a micro-penetrator and was 150-250 kPa, indicating that the use of water-absorbing and moisturizing colloid enhanced EICP reinforcement materials improves the erosion resistance and surface strength of wind sand.

[0121] Experimental Example 3

[0122] The field test was conducted in the Kubuqi Desert in Ordos. The windward slope of the sand dune was selected for the test. The sand slope angle was 20°. Six test areas were divided, each with an area of ​​5m 2 , a walkway is set between two adjacent test areas. As in Experimental Example 1, the test area is set by inserting fixed rods into the sand and then using ropes to frame each test area.

[0123] Preparation of water-absorbing and moisture-retaining colloid-enhanced EICP reinforcement materials: A urease solution with an activity of about 7.0 mmol / (L·min) was prepared, and a binder with a concentration of 0.1 mol / l was prepared (the binder was a CaCl2 solution and a urea solution with equal molar concentrations), and 0.1% Artemisia sphaerocephala glue was added to the binder for testing.

[0124] The raw materials for the growth-promoting, water-retaining and high-nutrient matrix are prepared according to weight portions: 60 parts of in-situ desert sand, 10 parts of loess, 5 parts of activated carbon, 2 parts of soybean powder, and 30 parts of water-absorbing and moisturizing colloid enhancing EICP reinforcement material to prepare the growth-promoting, water-retaining and high-nutrient matrix.

[0125] Seed sowing and spraying reinforcement: This experiment used pelletized Shadawang seeds. Because Shadawang seeds are herbaceous plants with fast germination and growth rates, the seeds were sown at a spraying rate of 0.25kg per mu. Two erosion needles were inserted in each test area for erosion depth measurement. After seed sowing, the growth-promoting water-retaining high-nutrient matrix was evenly sprayed on the surface of the sand layer. Spraying reinforcement was carried out after 4 pm on a sunny day to avoid rapid evaporation of the cementing solution. The spraying thickness of the growth-promoting water-retaining high-nutrient matrix was controlled at 1-2cm. After the reinforcement material was sprayed, it was solidified under natural conditions. A total of 1 reinforcement group TP1 and an untreated control group TP0 were set up, and three repeated test areas were conducted in each group.

[0126] Experimental conclusion:

[0127] Fig.13 , Fig.14 This is the situation of the TP1 and TP0 test areas 14 days after the test. Fig.14It can be seen that the TP0 sand layer without any treatment is in a flowing state, with obvious corrugations on the surface ( Fig.13 , Fig.14 Because the photo was taken after a light rain, there are many pockmarks on the surface of the desert. The erosion needle monitoring results show that the erosion thickness of the experimental area is about 30-45mm, and the portable moisture meter measures the moisture content of the sand layer at a depth of 5cm on the windward slope to be 2.3-4.5%, and the micro-penetrator measures the surface strength of the sand layer to be 20-50kPa.

[0128] like Fig.13 The sand layer in the TP1 shell layer does not flow significantly, and the shell layer is relatively intact. The erosion needle monitoring results show that the erosion thickness in the experimental area is 5-25mm, and the sand layer erosion is significantly reduced. The portable moisture meter measures the moisture content of the sand layer at a depth of 5cm on the windward slope at 5.7-8.9%, indicating that the use of the growth-promoting water-retaining high-nutrient matrix on the surface increases the moisture content of the sand. Fig.15 This is the germination of TP1 and TP0 plants on the windward slope after 20 days. It can be seen from the figure that the use of the growth-promoting, water-retaining, high-nutrient matrix TP1 promoted plant germination, while the untreated TP0 had almost no plant growth. The surface strength of the sand layer measured by the micro-penetrator was between 150-350kPa, indicating that the use of the growth-promoting, water-retaining, high-nutrient matrix improved the anti-erosion ability and surface strength of the wind-blown sand, and the growth-promoting, water-retaining, high-nutrient matrix was conducive to plant growth, indicating that this material is suitable for the windward slope with good results.

[0129] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. 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 application, and these all belong to the protection scope of the present application.

Claims

1. A method for integrating rapid solidification of mobile sand dunes and planting of economic plants, characterized in that: The following steps are involved: Step 1, drone seeding: set up the first dune reinforcement area perpendicular to the main wind direction, and use drone seeding to spray pelletized desert seeds in this area; predict the time T required for the seeds to accumulate to a suitable growth thickness D on the leeward slope of the moving dunes based on the monitored moving sand dune movement speed, wind direction, and erosion accumulation thickness; Step 2, leeward slope reinforcement: after the sand surface of the leeward slope of the dune has accumulated to a suitable thickness for seed growth, a water-absorbing and moisturizing colloid synergistic EICP reinforcement material is sprayed by drone to solidify the dune surface; the water-absorbing and moisturizing colloid synergistic EICP reinforcement material is prepared by mixing urease with an activity of 4 to 9 mmol / (L·min) and a binder with a concentration of 0.1 to 0.4 mol / L in a volume ratio of 1:1; the binder is a mixture of a calcium salt solution and a urea solution with equal molar concentrations; the water-absorbing and moisturizing colloid synergistic EICP reinforcement material is also added with 0.03 to 0.2% of the total weight of the binder. Step 3: Windward slope reinforcement: Drones are used to spray the growth-promoting, water-retaining, and high-nutrient matrix on the windward slope of the sand dunes to cover the pelletized desert seeds to a thickness D suitable for seed growth; The raw materials of the growth-promoting, water-retaining and high-nutrient matrix include, by weight: 60-80 parts of in-situ desert sand, 5-15 parts of loess, 5-15 parts of activated carbon, 1-5 parts of soybean powder, and 20-50 parts of water-absorbing and moisture-retaining colloid synergistic EICP reinforcement material; Step 4: Reinforcement of inter-dune land: After the reinforcement of the mobile dunes in the two adjacent dune reinforcement areas is completed, the inter-dune land is sown and reinforced; drones are used to first spray pelletized desert seeds, and then water-absorbing and moisturizing colloid synergistic EICP reinforcement materials are sprayed to solidify the inter-dune land; Step 5: Repeat steps 1, 2, 3, and 4 in this order to reinforce the next dune reinforcement area.

2. The integrated method for rapid solidification of mobile sand dunes and planting of economic plants according to claim 1, characterized in that: The pelletized desert seeds are a mixture of desert shrub seeds and herbaceous plant seeds with high economic value, and the spraying amount is 0.25-1 kg per mu.

3. The integrated method for rapid solidification of mobile sand dunes and planting of economic plants according to claim 2, characterized in that: The desert shrub seeds include at least one of Populus chinensis, Artemisia annua, Caragana microsporum, Haloxylon ammodendron, Populus euphratica, Bletilla striata, Calligonum mongolica, and Syngonium wilfordii. The desert herbaceous plant seeds include at least one of Sadawang, Artemisia ordosica, Artemisia sphaerocephala, Camel thorn, and Sophora alopecuroides.

4. The integrated method for rapid solidification of mobile sand dunes and planting of economic plants according to claim 1, characterized in that: The suitable growth thickness of seeds is 0.5~5cm.

5. The integrated method for rapid solidification of mobile sand dunes and planting of economic plants according to claim 1, characterized in that: The spraying rate of water-absorbing and moisturizing colloid EICP reinforcement material on leeward slopes and inter-hill land is 2~6L / m 2 .

6. The integrated method for rapid solidification of mobile sand dunes and planting of economic plants according to claim 1, characterized in that: The growth-promoting, water-retaining and high-nutrient matrix is ​​also added with pelletized desert seeds with an aerial sowing amount of 0.5 to 1 times.

7. The integrated method for rapid solidification of mobile sand dunes and planting of economic plants according to claim 1, characterized in that: The prediction process of the time T required for the sand surface on the leeward slope of the moving sand dune to accumulate to the thickness D suitable for seed growth is as follows: Step 1: Use high-resolution remote sensing images to determine the movement of sand dunes in different periods and analyze the morphological changes and movement paths of sand dunes; group the image data by month or week, and calculate the movement distance and direction of sand dunes in each time period; Step 2: Collect continuous wind speed records from weather stations, average the wind speed data monthly or weekly, and identify seasonal variations in wind speed; ensure that the data covers at least 2 years to capture long-term wind speed variations; Step 3: Build a model: Build a relationship model between the distance the sand dunes move and the wind speed and direction to predict the movement rate of the sand dunes: V s = a × W s b (without( c × θ) )+cos( d × θ )+ e (1) in, V s is the movement rate of the dune, W s is the wind speed, θ It's the wind direction. a, b, c, d and e is the parameter to be fitted; The time T required for the target deposition thickness D is: T=D / ( V s ×tan( a )) (2), Where D is the target stacking thickness, V s Predicted dune movement rate, a It is the natural angle of repose of the sand dune.

Images