Intelligent real-time precise temperature and humidity control system for road slope ecological protection

Abstract

The present invention belongs to the technical field of ecological slope protection engineering, and specifically relates to an intelligent real-time precise control system for temperature and humidity for ecological protection of road slopes, comprising a temperature control system and a humidity control system; the temperature control system comprises a heating cable, a temperature controller and a temperature sensor; the heating cable is laid in the slope surface, and a row of temperature sensors are respectively arranged at the top, middle and bottom of the slope surface; the humidity control system comprises a water collection tank, a humidity controller, a humidity sensor, a main water pipe, a branch water pipe, a vertical pipe, a sprinkler and a water pump; the water collection tank is connected to the branch water pipe through the main water pipe, and the branch water pipe is arranged in the slope; a plurality of vertical pipes are arranged at intervals on the branch water pipe, and the upper ends of the vertical pipes extend out of the soil and are connected to the sprinkler; a row of humidity sensors are respectively arranged at the top, middle and bottom of the slope surface. By adjusting the heat output of the heating cable, the dynamic balance between heat absorption and release by the soil is maintained, thereby achieving the purpose of intelligent real-time regulation of slope soil temperature. By fully considering the impact of temperature changes on water evaporation and vegetation transpiration, the water replenishment amount of the surface soil is calculated, and the water replenishment amount at the vegetation root system is also calculated, and then the watering amount is obtained. By controlling the water output of the sprinkler nozzle, intelligent real-time regulation of slope soil humidity is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of ecological slope protection engineering, and specifically is an intelligent real-time precise control system for temperature and humidity for ecological protection of road slopes. Background Art

[0002] In road slope engineering, grass-planting ecological slope protection technology has been widely used due to its significant effectiveness in improving slope stability and promoting ecological balance. However, this technology still faces urgent challenges: First, in the early stages of ecological slope protection, soil erosion caused by rainfall erosion can lead to partial or substantial loss of plant seeds and seedlings, significantly reducing the effectiveness of vegetation ecological protection. Second, this technology is significantly affected by seasonal climate changes, especially under low temperature and drought conditions. Low soil moisture and temperature may cause the grass to wither and die, resulting in a sharp drop in slope protection effectiveness and even leading to road slope instability. Currently, existing anchor-sprayed mesh protection, geonet grass-planting protection, and ecological concrete slope protection technologies have implemented measures such as laying drainage ditches, strengthening plant root systems, improving soil quality, and incorporating organic materials. However, these technologies have yet to effectively prevent the loss of slope vegetation seeds and seedlings from rainfall erosion or address the extreme imbalance of temperature and humidity within the slope soil under low temperature and drought conditions. Furthermore, their low level of intelligence makes it difficult to achieve real-time regulation of soil temperature and humidity and precise slope stability protection.

[0003] Patent application number 202322538210.3 discloses an ecological slope protection system that automatically circulates rainwater for irrigation. It uses temperature and humidity sensors to monitor the temperature and humidity of the external air, automatically circulating rainwater through a water pump and conductive hose. However, this system fails to consider the coordinated relationship between soil moisture evaporation and water replenishment. Furthermore, the temperature and humidity sensors do not monitor the temperature and humidity of the soil at the root zone of the vegetation. Consequently, it cannot accurately calculate the required water replenishment for the slope soil in real time. Excessive, excessive, or even delayed water replenishment can reduce the stability of the road slope. Patent application number 202410414563.9 discloses a soil and water monitoring device for mountain slope substrates and a construction method for a water-saving irrigation system. This system uses temperature and humidity sensors to monitor soil moisture content, nutrients, and other parameters to dynamically control the water required for vegetation growth. However, this system fails to specifically consider the impact of temperature changes on slope vegetation growth, nor does it account for the heat transfer between cold air and the slope soil under low temperature conditions. Consequently, it fails to accurately regulate the slope soil temperature. The patent application with application number 202410698795.1 discloses a fully automatic irrigation system and method for ecological slope protection, which combines the floor heating system with the drip irrigation system to automatically realize slope water replenishment and anti-freeze protection. However, it does not fully consider the possibility of soil erosion on the slope, especially in the vegetation seed and seedling stages. The slope is basically in an exposed state without vegetation coverage, so it cannot effectively prevent rain erosion. Drip irrigation may cause the roots of vegetation to grow concentratedly in the moist area, affecting the root system's absorption of water.

[0004] Therefore, the present invention proposes an intelligent real-time precise control system for temperature and humidity for road slope ecological protection, which is of great significance for improving slope stability and strengthening the ecological function of the road environment. Summary of the Invention

[0005] In view of the deficiencies in the existing technology, the technical problem to be solved by the present invention is to provide an intelligent real-time precise control system for temperature and humidity for road slope ecological protection.

[0006] The present invention solves the technical problem by adopting the following technical solutions:

[0007] An intelligent, real-time, precise temperature and humidity control system for road slope ecological protection includes a temperature control system and a humidity control system. The temperature control system includes a heating cable, a temperature controller, and a temperature sensor. The heating cable is laid in a U-shape on the slope surface and is connected to the temperature controller. The surface soil temperature is timely controlled by turning the heating cable on and off to prevent cold air from the external environment from invading the slope soil, thereby affecting vegetation growth. A row of temperature sensors are arranged longitudinally along the road surface at the top, middle, and bottom of the slope surface. The temperature sensors are used to collect the surface soil temperature and are connected to both the temperature controller and the humidity controller of the humidity control system.

[0008] The humidity control system includes a water collection tank, a humidity controller, a humidity sensor, a main water pipe, a branch water pipe, a vertical pipe, a sprinkler nozzle and a water pump; the water collection tank is located at the lower edge of the drainage ditch, the output end of the water pump is connected to one end of the main water pipe, and the other end of the main water pipe is connected to the branch water pipe, and the branch water pipes are evenly arranged in a U shape on the slope; a plurality of vertical pipes are arranged at intervals on the branch water pipe, and the upper ends of the vertical pipes extend out of the soil and are connected to the sprinkler nozzles; a row of humidity sensors are arranged longitudinally along the road surface at the top, middle and bottom of the slope, respectively, and the humidity sensors and water pumps are connected to the humidity controller, and the humidity sensor is used to collect soil humidity at the root system of vegetation; when the moisture content of the surface soil decreases or the soil humidity at the root system of vegetation is lower than the lower limit of soil humidity suitable for vegetation growth, the humidity controller calculates the amount of water to be sprinkled, and then adjusts the water output of each sprinkler nozzle in real time, thereby realizing real-time and precise control of the soil humidity at the root system of vegetation;

[0009] The amount of watering is the sum of the surface soil water supply and the water supply at the vegetation root system; the amount of surface soil water loss caused by evaporation, that is, the surface soil water supply I1, is calculated by the following formula:

[0010]

[0011] Where w is the water use coefficient of land use type, P is rainfall, E0 is potential evapotranspiration, α is surface runoff coefficient, and ΔW is the variable water storage capacity of soil.

[0012] The water supply I2 at the root system of vegetation is calculated by the following formula:

[0013] I2=0.1H h (w1-w2) / η (30)

[0014] Where H h is the depth of vegetation root system, w1 is the upper limit of soil moisture suitable for vegetation growth, w2 is the lower limit of soil moisture suitable for vegetation growth, and η is the utilization coefficient of water supply.

[0015] Furthermore, the theoretical value of the heating cable arrangement interval is calculated according to the following formula:

[0016]

[0017] Where l1 is the spacing of the heating cables, ρ is the resistivity of the heating cables, I is the current carrying capacity of the heating cables, A is the cross-sectional area of ​​the heating cable conductor, k is the thermal conductivity of the soil, is the gradient of surface soil temperature along the slope depth direction, ρ t is the wet bulk density of the soil, ΔT is the change in surface soil temperature, ρ a is the air density, C P is the specific heat of air at constant pressure, T0 is the surface soil temperature, T a is the air temperature, r e is the aerodynamic impedance, L is the latent heat of evaporation, C E is the transfer coefficient that characterizes the latent heat flux, u a is the average wind speed, q s ,q a are the specific humidity of the surface and air, R n is the net radiation flux from the surface, and h1 is the height.

[0018] Furthermore, the arrangement interval of the branch water pipes is calculated by the following formula:

[0019]

[0020] Where l2 is the spacing of the branch water pipes, r is the radius of the spraying range of the sprinkler, and 2r is the spacing of the vertical pipes on the branch water pipes.

[0021] Furthermore, the potential evapotranspiration E0 is calculated by equations (25) to (29):

[0022]

[0023]

[0024] G=0.07×(T i+1 -T i-1 ) (27)

[0025] γ=0.665×10 -3 ×p (28)

[0026]

[0027] Where λ is the slope of the saturated water vapor pressure-temperature curve, G is the soil heat flux of the month, γ is the psychrometric constant, μ is the wind speed at a height of 2 m, and μ is the wind speed at a height of 2 m. h is the wind speed at height h, e s is the saturated water vapor pressure, e ais the actual water vapor pressure, T i+1 is the average temperature of the surface soil in the last month, T i-1 is the average temperature of the surface soil in the previous month, T avg is the monthly average temperature of the surface soil, and p is the atmospheric pressure.

[0028] Furthermore, the temperature sensor and the humidity sensor are both arranged between the heating cables, and the spacing distance is the same as the arrangement spacing of the heating cables.

[0029] Furthermore, the temperature and humidity control system also includes a power supply system; the power supply system includes solar panels, a support frame and an energy storage device. The support frame is placed at the bottom of the slope, and a solar panel is installed on the upper part of the support frame. The solar panel is connected to the energy storage device.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. This invention fully considers the impact of humidity changes on soil physical and thermodynamic parameters and proposes a theoretical calculation formula for heating cable spacing based on surface energy balance. This effectively avoids over-laying of heating cables and saves costs for ecological slope protection projects. By precisely adjusting the heating power of the heating cables, the dynamic balance between soil absorption and heat release is maintained, achieving intelligent, real-time soil temperature control. This prevents vegetation from freezing to death, prolongs its growth cycle, maintains evergreen vegetation year-round, and enhances the ability of vegetation to protect slopes.

[0032] Taking into full account the impact of temperature changes on soil moisture evaporation and vegetation transpiration, a temperature sensor is used to collect surface soil temperature for calculating surface soil water replenishment. A humidity sensor is used to collect soil moisture at the plant root system for calculating root water replenishment. The sum of the surface soil water replenishment and root water replenishment is the watering rate. The coordinated relationship between soil temperature, evaporation, watering rate, and root water absorption is fully considered to achieve quantitative calculation of watering rate. Then, by controlling the water output of the sprinkler nozzles, the watering rate is precisely adjusted in real time to maintain a dynamic balance between watering rate, evaporation, and soil moisture. This achieves the goal of intelligent, real-time, and precise soil moisture regulation, ensuring that the slope soil moisture state is within the appropriate range for vegetation growth and slope protection. This not only avoids the premature death of vegetation caused by drought, but also promotes the long-term stability of the slope.

[0033] The temperature control system and the humidity control system are interconnected. The surface soil temperature collected by the temperature sensor is fed back to the humidity controller for calculating the amount of water replenished in the surface soil. Information feedback helps to achieve real-time, intelligent and precise control of the temperature and humidity conditions of the road slope.

[0034] 2. The collection trough is used to collect excess rainwater during the rainy season. On the one hand, it prevents the road slope from becoming unstable due to excessive accumulation of rainwater. On the other hand, it provides necessary water for the growth of vegetation roots during the dry season, increases the utilization rate of water resources, and achieves the purpose of protecting the ecological environment.

[0035] 3. Vertical pipes can protect vegetation seeds or seedlings in the early stages of growth from being eroded by rainfall. After the vegetation grows into mature plants, the vertical pipes and vegetation work together to not only reduce the risk of soil erosion on the slopes and maintain the long-term effectiveness of vegetation ecological slope protection, but also their vegetation-like form increases the beauty and ornamental value of the road environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a side view of the road slope where the temperature and humidity control system is installed;

[0037] Figure 2 This is a schematic diagram of the laying of heating cables and temperature sensors;

[0038] Figure 3 This is a schematic diagram of the laying of water pipes and humidity sensors;

[0039] Figure 4 It is a schematic diagram of the structure of the vertical pipe;

[0040] In the figure, 1-drainage ditch; 2-water inlet channel; 3-filter frame; 4-water collection tank; 5-water pump; 6-main water pipe; 7-automatic connecting switch; 8-vertical pipe; 9-heating cable; 10-branch water pipe; 11-humidity controller; 12-temperature controller; 13-energy storage device; 14-support frame; 15-solar panel; 16-humidity sensor; 17-vertical pipe layout position; 18-vegetation cover; 19-sprinkler head; 20-temperature sensor. DETAILED DESCRIPTION

[0041] Specific embodiments are given below in conjunction with the accompanying drawings. The specific embodiments are only used to introduce the technical solutions of the present invention in detail and are not intended to limit the scope of protection of the present application.

[0042] The present invention provides an intelligent real-time precise control system for temperature and humidity for road slope ecological protection (hereinafter referred to as the system, see Figures 1 to 4 ), including temperature control system and humidity control system.

[0043] The temperature control system includes a heating cable 9, a temperature controller 12, and a temperature sensor 20. The heating cable 9 is laid flat on the roadside slope at a depth h1 and arranged in a U-shape from the upper edge to the lower edge of the slope, with an interval of l1 between them. It is used to heat the slope soil within a heating range of 25-40°C. A row of temperature sensors 20 are arranged longitudinally along the road surface at the top, middle, and bottom of the slope. The temperature sensors 20 are spaced apart between the heating cables at an interval of l1, and in this embodiment, are buried at a depth of 5 cm. They are used to collect the surface soil temperature. Both the heating cable 9 and the temperature sensor 20 are connected to the temperature controller 12. The temperature sensor 20 converts the surface soil temperature information into an electrical signal and transmits it to the temperature controller 12. The temperature controller 12 averages the surface soil temperatures measured by all temperature sensors 20. When the surface soil temperature is lower than the optimal temperature required for vegetation growth, the temperature controller 12 controls the heating cable 9 to turn on and heat the soil. The heating cable 9 is turned off when the surface soil temperature reaches the optimal temperature required for vegetation growth. The temperature sensor 20 is also connected to the humidity controller 11 of the humidity control system, and feeds the collected surface soil temperature back to the humidity controller 11 for calculating the amount of water replenished in the surface soil.

[0044] Considering the influence of humidity changes on soil physical and thermodynamic parameters, the arrangement interval l1 of the heating cables is derived from the surface energy balance equation. The specific process is as follows:

[0045] The surface energy balance equation is:

[0046] R n =G0+H+LE (1)

[0047] Where R n is the net radiation flux of the surface (MJ / m 2 ); G0 is the soil heat flux (MJ / m 2 ); H is the sensible heat flux (MJ / m 2 ); LE is the latent heat flux (MJ / m 2 );

[0048] The calculation formula of soil heat flux G0 is:

[0049]

[0050] Where, ρ s is the soil density (g / cm 3 );C V is the volumetric heat capacity of the soil (J / (cm 3 ·℃); k is the thermal conductivity of soil (J / (cm·s·℃)); is the gradient of surface soil temperature along the depth direction of the slope (℃ / cm);

[0051] Soil density ρ s The calculation formula is:

[0052]

[0053] Where M is the mass of wet soil (g); V is the total volume of soil (cm 3 );

[0054] Volumetric heat capacity of soil C V The calculation formula is:

[0055] C V =ρ b (c s +c w W) (4)

[0056] Where, ρ b is the dry bulk density of the soil (mN / cm 3 );c s 、c w is the specific heat capacity of the solid and liquid phases of the soil (J / g·℃); W is the mass water content of the soil (%);

[0057] The calculation formula of soil thermal conductivity k is:

[0058]

[0059] Where θ V is the volumetric moisture content of the soil (%); parameters A1, B1, C1, D1 and E1 can be calculated based on the dry bulk density and clay content of the soil, see formula (6) to formula (10);

[0060] A1=0.65-0.78ρ b +0.60ρ b 2 (6)

[0061] B1=1.06ρ b (7)

[0062]

[0063] D1=0.03+0.1ρ b 2 (9)

[0064] E1=4 (10)

[0065] Where m c is the clay content (%);

[0066] The calculation formula of sensible heat flux H is:

[0067] H=ρa C P (T0-T a ) / r e (11)

[0068] Where, ρ a is the air density (kg / m 3 );C P is the specific heat of air at constant pressure (1005Jkg -1 K -1 ); T0 is the surface soil temperature (K); T a is the air temperature (K); r e is the aerodynamic impedance (s / m);

[0069] The calculation formula of latent heat flux LE is:

[0070] LE=ρ a LC E u a (q s -q a ) (12)

[0071] Where, L is the latent heat of vaporization (J); C E is the transfer coefficient characterizing the latent heat flux; u a is the average wind speed (m / s); q s ,q a are the specific humidity of the surface and air, respectively (g / kg);

[0072] The latent heat of evaporation L is a function of the air temperature and can be expressed as:

[0073] L=2.5008×10 6 -2.3×10 3 T a (13)

[0074] Where, T a is the air temperature (°C);

[0075] Volumetric heat capacity of soil C V It can also be expressed as:

[0076]

[0077] Where Q is the heat absorbed by the soil (J); m is the mass of the soil per unit length with a width of l1 and a height of h1 (kg); ΔT is the change in surface soil temperature (°C); ρ t is the wet bulk density of soil (N / m 3 );

[0078] From equations (1), (2), (11) and (12), we can obtain:

[0079]

[0080] The heat Q absorbed by the soil refers to the heat generated by the heating cable per unit length per unit time, which is expressed as:

[0081]

[0082] Where ρ is the resistivity of the heating cable; I is the current carrying capacity of the heating cable (A); A is the cross-sectional area of ​​the heating cable conductor (mm 2 );

[0083] From equations (14), (15) and (16), we can obtain:

[0084]

[0085] It is also known that:

[0086] m=ρ s v=ρ s h1l1 (18)

[0087] Where v is the volume of soil per unit length with a width of l1 and a height of h1 (m 3 );

[0088] From equations (17) and (18), the arrangement interval l1 of the heating cable can be expressed as:

[0089]

[0090] According to formula (19), the layout interval of heating cables can be quantitatively calculated. However, since the variables involved in formula (2) will also change with different seasons, it is necessary to comprehensively consider the local climatic conditions on the basis of theoretical calculation to determine the values ​​of each variable, so as to determine the layout interval l1 of the heating cables.

[0091] The humidity control system includes a water collection tank 4, a humidity controller 11, a humidity sensor 16, a main water pipe 6, a branch water pipe 10, a vertical pipe 8, a sprinkler head 19 and a water pump 5; the water collection tank 4 is located at the lower edge of the drainage ditch 1 on both sides of the road surface, and is used to collect water on the road surface during rainy season; the water pump 5 is located in the water collection tank 4, and the output end of the water pump 5 is connected to one end of the main water pipe 6, and the other end of the main water pipe 6 passes through the water collection tank 4 and is connected to the branch water pipe 10. The branch water pipes 10 are evenly arranged in a U shape along the upper edge to the lower edge of the slope. In the slope, the depth of burial is set to h2, and it is located above the heating cable 9. The arrangement interval of the branch water pipe 10 is l2; a vertical pipe 8 is installed on the branch water pipe 10 at every interval l3. The total height of the vertical pipe is H, which is divided into an above-ground part and an underground part. The height of the above-ground part vertically above the slope surface is H1, and the above-ground part of the vertical pipe of the vegetation-like form is green. A sprinkler head 19 is installed at the end of the above-ground part of each vertical pipe 8 for spraying water; the water pump 5 transports the water in the water collection tank 4 to the vertical pipe 8, and then The water is evenly sprayed onto the surface of the vegetation through the sprinkler nozzle 19; most of the roots of the grassland plants are concentrated in the soil layer within 20-30 cm, so a row of humidity sensors 16 are arranged longitudinally along the road surface at the top, middle and bottom of the slope, with a burial depth of 20-30 cm. The humidity sensors 16 are located between adjacent heating cables and the interval is l1, which is used to collect the soil humidity at the roots of the vegetation; the humidity sensor 16 and the water pump 5 are both connected to the humidity controller 11, and the humidity sensor 16 measures the soil humidity at the roots of the vegetation. The information is converted into an electrical signal and transmitted to the humidity controller 11. The humidity controller 11 averages the soil moisture measured by all humidity sensors 16. When the moisture content of the surface soil decreases or the soil moisture at the roots of the vegetation is lower than the lower limit of the soil moisture suitable for vegetation growth, the humidity controller 11 calculates the watering amount and controls the water pump 5 to start, transporting the water in the water collection tank 4 to each vertical pipe 8, and evenly spraying it onto the soil surface through the sprinkler nozzles 19 until the sum of the water output of all sprinkler nozzles 19 is equal to the watering amount, and then the water pump 5 is turned off.

[0092] The water collection trough 4 is a rectangular water trough, the length of which is consistent with the longitudinal length of the road surface, with a width of 0.5-2m and a depth of 0.5-1m. The wall thickness of the water collection trough is 2-10cm, and the material is fiberglass, which is used to store water; the cross-section of the water inlet channel of the water collection trough is square with a side length of 10-30cm; a filter frame is installed in the water inlet channel 2 of the water collection trough 4, which is a filtering device. The filter frame is 0.5-1.5m long, 10-30cm wide, 10-30cm high, and 0.14-0.5mm thick. The filter frame is made of corrosion-resistant stainless steel, and its main function is to intercept larger suspended matter and particulate impurities; the filter frame is filled with filter fiber sponge, which fits tightly to the inside of the filter frame to form an efficient filter layer. The fiber sponge is not only easy to clean and replace, but also has an adsorption effect on its surface, which can capture tiny particles, thereby enhancing the interception effect of the filter frame. In addition, the porous structure of the fiber sponge gives it good water absorption and moisturizing capabilities. In dry and rainy climates, the fiber sponge in the filter frame can play a moisturizing role and prevent the evaporation of water in the water collection tank.

[0093] Water pump 5 is a single-stage, double-suction, horizontal centrifugal pump primarily used to transport water from the sump. The rotation of the pump shaft drives the impeller, causing water to move radially from the center of the impeller outward to the water pipe. The water pipe is made of PVC with an outer diameter of 50 mm and is primarily used for water transportation. Humidity sensor 16 is a capacitive humidity sensor. As the humidity of the slope soil increases, its capacitance increases, and vice versa, it decreases. This allows the sensor to accurately measure the soil moisture at the root zone of vegetation on the slope.

[0094] The vertical pipe 8 is made of stainless steel with an outer diameter of 25mm. The above-ground part is connected to the sprinkler, which adopts a refractive fixed long-range sprinkler. The vertical pipe is mainly used to transport water from the branch water pipe to the sprinkler nozzle to ensure that the water flow can be sprayed on the plants with appropriate pressure and distribution range; the above-ground part of the vertical pipe is wrapped with a vegetation-like jacket of PE material, which ① helps to reduce the erosion of soil by rainwater, thereby reducing the risk of soil erosion; ② forms a protective layer to play a role in insulation, avoiding the freezing of the water pipe in winter; ③ its color is closer to the color of real vegetation and can blend in with the surrounding environment.

[0095] Assuming the sprinkler's spray radius is r, to ensure uniform irrigation of vegetation, the vertical pipes 8 are installed at a distance of 2r on the branch aqueducts 10, i.e., l3 = 2r. These vertical pipes 8 are alternately arranged on adjacent branch aqueducts 10, forming a continuous triangular arrangement to minimize areas left uncovered. Connecting the positions of three vertical pipes on adjacent branch aqueducts 10 forms an equilateral triangle with a side length of 2r. The height of this triangle is the spacing between the branch aqueducts 10. Thus,:

[0096]

[0097] Where l2 is the spacing of the branch water pipes (m); r is the radius of the spraying range of the sprinkler head (m).

[0098] The watering volume I0 consists of two parts: the surface soil water replenishment volume I1 and the vegetation root water replenishment volume I2. Considering the impact of slope temperature changes on soil water evaporation and vegetation transpiration, the surface soil water replenishment volume I1 is calculated using the soil water balance equation. The calculation steps are as follows:

[0099] The calculation formula for evapotranspiration (including soil water evaporation and vegetation transpiration) is:

[0100]

[0101] Where ET is evapotranspiration (mm); w is the water use coefficient of land use type (reference value: 0.5 for grassland, 0 for artificial surface, bare land and desert); P is rainfall (mm); E0 is potential evapotranspiration (mm);

[0102] From the perspective of the soil water balance equation, evapotranspiration can also be expressed as:

[0103] ET=I1+PR-S+ΔW (22)

[0104] Where I1 is the amount of water replenished by the surface soil; R is the surface runoff; S is the net flux at the lower boundary of the soil (positive downward and negative upward); ΔW is the variable water storage capacity of the soil; all variables in the formula are in mm.

[0105] In formula (22), rainfall P is measured by a rain gauge; the groundwater level is deep and contributes little to evapotranspiration, so the net flux S at the lower boundary of the soil can be assumed to be zero; ΔW can be obtained by measuring the soil moisture content; and the surface runoff R can be calculated by the following formula:

[0106] R=P×α (23)

[0107] Where, α is the surface runoff coefficient. The surface runoff coefficient of grassland ecosystem can be referred to Table 1;

[0108] Table 1 Reference values ​​of surface runoff coefficients for grassland ecosystems

[0109]

[0110] According to equations (21), (22) and (23), the surface soil water replenishment amount I1 is:

[0111]

[0112] Potential evapotranspiration E0 is calculated by equations (25) to (29):

[0113]

[0114] G=0.07×(T i+1 -T i-1 ) (27)

[0115] γ=0.665×10 -3 ×p (28)

[0116]

[0117] Where λ is the slope of the saturated water vapor pressure-temperature curve (kPa / ℃); G is the soil heat flux of the month (MJ / m 2 ); γ is the psychrometric constant (kPa / ℃); μ is the wind speed at a height of 2m (m / s); μ h is the wind speed at height h (m / s); e s is the saturated water vapor pressure (kPa); e a is the actual water vapor pressure (kPa); T i+1 is the average temperature of the surface soil in the last month (℃); T i-1 is the average temperature of the surface soil in the previous month (℃); p is the atmospheric pressure (kPa); T avg is the monthly average temperature of the surface soil (℃), which is calculated from the surface soil temperature collected by the temperature sensor; h is the height (m).

[0118] The water supply at the root system of vegetation I2 (mm) can be calculated by the following formula:

[0119] I2=0.1H h (w1-w2) / η (30)

[0120] Where H h is the depth of vegetation roots (mm); w1 is the upper limit of soil moisture suitable for vegetation growth (%); w2 is the lower limit of soil moisture suitable for vegetation growth (%), η is the utilization coefficient of water replenishment, generally taken as 0.7~0.9.

[0121] Since the humidity of the road slope soil changes with depth, if the humidity sensor is placed on the surface of the soil, the soil humidity at the root of the vegetation cannot be accurately measured; if the humidity sensor is placed in the soil layer at the root of the vegetation, the moisture reduction of the surface of the soil due to evaporation cannot be monitored in time. Therefore, based on the influence of temperature changes on soil moisture evaporation and vegetation transpiration, the present invention uses a temperature sensor to collect the surface soil temperature (this temperature will be transmitted to the humidity controller) to accurately calculate the surface soil water replenishment amount I1, and then combines the soil humidity change value at the root of the vegetation collected by the humidity sensor to accurately calculate the water replenishment amount I2 at the root of the vegetation, and then determine the watering amount (i.e., I0=I1+I2). The watering amount divided by the number of sprinklers is equal to the water output of each sprinkler head. The water output of the sprinkler head is controlled by the humidity controller to achieve uniform distribution and balance of moisture in the entire slope soil.

[0122] The temperature and humidity control system also includes a power supply system, consisting of solar panels 15, a support frame 14, and an energy storage device 13. The support frame 14 is positioned at the base of the slope, with the solar panels 15 mounted on top. The solar panels 15 are connected to the energy storage device 13. The solar panels 15 absorb solar energy and convert it into electricity, which the energy storage device 13 stores for use in the temperature and humidity control systems. The support frame 14 is between 1 and 3 meters tall and constructed of galvanized steel. The solar panels 15 utilize monocrystalline silicon solar cell technology, specifically 265-290W monocrystalline silicon modules.

[0123] Any matters not described in the present invention are applicable to the prior art.

Claims

1. An intelligent real-time precise temperature and humidity control system for road slope ecological protection, comprising a temperature control system and a humidity control system; characterized in that: The temperature control system includes a heating cable, a temperature controller, and a temperature sensor; the heating cable is laid in a U-shape on the slope surface, and the heating cable is connected to the temperature controller. The surface soil temperature is controlled in real time by controlling the opening and closing of the heating cable; a row of temperature sensors are arranged longitudinally along the road surface at the top, middle, and bottom of the slope surface, respectively. The temperature sensors are used to collect the surface soil temperature and are connected to the temperature controller and the humidity controller of the humidity control system at the same time; The humidity control system includes a water collection tank, a humidity controller, a humidity sensor, a main water pipe, a branch water pipe, a vertical pipe, a sprinkler nozzle and a water pump; the water collection tank is located at the lower edge of the drainage ditch, the output end of the water pump is connected to one end of the main water pipe, and the other end of the main water pipe is connected to the branch water pipe, and the branch water pipes are evenly arranged in a U shape on the slope; a plurality of vertical pipes are arranged at intervals on the branch water pipe, and the upper ends of the vertical pipes extend out of the soil and are connected to the sprinkler nozzles; a row of humidity sensors are arranged longitudinally along the road surface at the top, middle and bottom of the slope, respectively, and the humidity sensors and water pumps are all connected to the humidity controller, and the humidity sensors are used to collect soil humidity at the root system of vegetation; when the moisture content of the surface soil decreases or the soil humidity at the root system of vegetation is lower than the lower limit of soil humidity suitable for vegetation growth, the humidity controller calculates the amount of water to be sprinkled, and then adjusts the water output of each sprinkler nozzle in real time, thereby realizing real-time control of the soil humidity at the root system of vegetation; The amount of watering is the sum of the surface soil water supply and the water supply at the vegetation root system; the surface soil water supply I1 is calculated by the following formula: Where w is the water use coefficient of land use type, P is rainfall, E0 is potential evapotranspiration, α is surface runoff coefficient, and ΔW is the variable water storage capacity of soil. The water supply I2 at the root system of vegetation is calculated by the following formula: I2=0.1H h (w1-w2) / h (30) Where H h is the depth of vegetation root system, w1 is the upper limit of soil moisture suitable for vegetation growth, w2 is the lower limit of soil moisture suitable for vegetation growth, and η is the utilization coefficient of water supply; The theoretical value of the heating cable arrangement interval is calculated according to the following formula: Where l1 is the spacing of the heating cables, ρ is the resistivity of the heating cables, I is the current carrying capacity of the heating cables, A is the cross-sectional area of ​​the heating cable conductor, k is the thermal conductivity of the soil, is the gradient of soil temperature along the depth direction of the slope, T is the monthly average temperature of the soil surface, ρ t is the wet bulk density of the soil, Δt is the change in soil temperature, ρ a is the air density, C P is the specific heat of air at constant pressure, T0 is the surface temperature, T a is the air temperature, r e is the aerodynamic impedance, L is the latent heat of evaporation, C E is the transfer coefficient that characterizes the latent heat flux, u a is the average wind speed, q s ,q a are the specific humidity of the surface and air, R n is the net radiation flux from the surface, and h1 is the height.

2. The intelligent real-time precise control system for temperature and humidity for road slope ecological protection according to claim 1 is characterized in that: The arrangement interval of the branch water pipes is calculated by the following formula: Where l2 is the spacing of the branch water pipes, r is the radius of the spraying range of the sprinkler, and 2r is the spacing of the vertical pipes on the branch water pipes.

3. The intelligent real-time precise control system for temperature and humidity for road slope ecological protection according to claim 1 is characterized in that: Potential evapotranspiration E0 is calculated by equations (25) to (29): G=0.07×(T i+1 -T i-1 ) (27) γ=0.665×10 -3 ×p (28) Where λ is the slope of the saturated water vapor pressure-temperature curve, G is the soil heat flux of the month, γ is the psychrometric constant, μ is the wind speed at a height of 2 m, and μ is the wind speed at a height of 2 m. h is the wind speed at height h, e s is the saturated water vapor pressure, e a is the actual water vapor pressure, T i+1 is the average temperature of the soil surface in the next month, T i-1 is the average temperature of the soil surface in the previous month, T avg is the monthly average temperature of the surface soil, and p is the atmospheric pressure.

4. The intelligent real-time precise control system for temperature and humidity for road slope ecological protection according to claim 1 or 3, characterized in that: The temperature sensor and the humidity sensor are both arranged between the heating cables, and the spacing distance between them is the same as the spacing between the heating cables.

5. The intelligent real-time precise control system for temperature and humidity for road slope ecological protection according to claim 1 is characterized in that: The temperature and humidity control system also includes a power supply system; the power supply system includes solar panels, a support frame and an energy storage device. The support frame is placed at the bottom of the slope, and a solar panel is installed on the top of the support frame. The solar panel is connected to the energy storage device.

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