Soil water and evapotranspiration component coordinated measurement method and device, electronic equipment and medium

Abstract

The present application relates to soil water and surface evapotranspiration component remote sensing measurement technical field, especially in soil water and its component and surface evapotranspiration and its component coordination measurement method, system, electronic equipment and medium.It is calculated that the method includes: using the remote sensing image and meteorological data obtained to calculate surface evapotranspiration ratio and surface evapotranspiration, establishes the mathematical equation of the relationship between surface evapotranspiration component and soil water component, and solves the mathematical equation to measure soil water component and surface evapotranspiration component.The present application proposes a kind of soil water and its component and surface evapotranspiration and its component remote sensing collaborative inversion modeling mode, by the correlation mode between soil water and surface evapotranspiration and its component, it can be simply realized that soil water and its component and surface evapotranspiration and its component are jointly measured under fine, coarse spatial resolution, avoid the evapotranspiration component decomposition error caused by improper dry and wet point selection, improve the spatial resolution of soil water remote sensing product, fill the current soil water component remote sensing product blank.

Description

Technical Field

[0001] This invention relates to the field of remote sensing measurement technology for soil water and evapotranspiration components, and in particular to a method, system, electronic device, and medium for the joint measurement of soil water and evapotranspiration components. Background Technology

[0002] Soil water is a crucial component of the terrestrial water cycle, a vital parameter influencing regional and even global energy balance, the material basis for terrestrial ecosystems, and a key variable describing water exchange between the land and atmosphere. Accurate and timely estimation of soil water content is essential for agricultural production, farmland moisture monitoring, and drought assessment. Surface evapotranspiration, the link between water and energy balance and the only physical pathway for soil water to return to the atmosphere, is a key to understanding energy and water exchange between land and atmosphere. It is critical for regional and national water resource management and consumption. Monitoring regional-scale surface evapotranspiration will provide data support for research in agriculture, meteorology, and ecology, while rapidly developing remote sensing technology has made high-precision measurement of regional and even global soil water and surface evapotranspiration possible.

[0003] Currently, remote sensing methods for soil water measurement include optical remote sensing, active and passive microwave sensing, and multi-sensor fusion. Remote sensing monitoring models for surface evapotranspiration can be categorized into empirical models, Penman-Montes model, Priest-Taylor model, energy balance method, and feature space method. While these remote sensing methods are widely used for large-scale monitoring of soil water and surface evapotranspiration, their applicability to soil water remote sensing monitoring needs improvement. They are not yet able to handle situations with arbitrary vegetation cover, and the relationship between remote sensing signals and soil water changes with soil moisture content, environmental conditions, etc. The spatiotemporal heterogeneity of the land surface also reduces the performance of monitoring methods. As for surface evapotranspiration remote sensing monitoring, the estimation of surface evapotranspiration is relatively mature under ideal conditions such as sufficient surface water supply or a relatively homogeneous underlying surface. However, when the underlying surface has soil water deficit or strong heterogeneity, the estimation accuracy of surface evapotranspiration is still not ideal. More importantly, obtaining the components of surface evapotranspiration from heterogeneous underlying surfaces requires determining the wet and dry points, but there is currently a great deal of disagreement on the accurate selection of wet and dry points, which limits the remote sensing acquisition of surface evapotranspiration. Most importantly, the remote sensing monitoring methods for soil water and surface evapotranspiration were developed independently and are unrelated to each other. This ignores the close relationship between soil water and surface evapotranspiration, resulting in the decoupling of the remote sensing monitoring results for soil water and surface evapotranspiration. This makes it difficult to systematically apply the remote sensing monitoring products for soil water and surface evapotranspiration. In addition, the remote sensing monitoring products for soil water usually have low spatial resolution, which is insufficient for widespread application at the field scale.

[0004] Therefore, this invention is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a method, system, electronic device, and medium for the joint measurement of soil water and evapotranspiration components, in order to overcome or partially overcome the technical problems existing in the above-mentioned methods.

[0006] To achieve the above objectives, the technical solution provided by this invention is as follows:

[0007] In a first aspect, embodiments of the present invention provide a method for co-detection of soil water and evapotranspiration components, comprising the following steps:

[0008] S1: Calculate the surface evapotranspiration ratio and surface evapotranspiration using the acquired remote sensing images and meteorological data;

[0009] S2: Establish the mathematical equation relating the evapotranspiration components of S1 to the soil water components;

[0010] S3: Solve the mathematical equation S2 to jointly measure soil water components and evapotranspiration components.

[0011] In one embodiment, step S1: calculating the surface evapotranspiration ratio and surface evapotranspiration using acquired remote sensing images and meteorological data includes the following steps:

[0012] S11: Calculate the surface evapotranspiration ratio using acquired remote sensing imagery and meteorological data, specifically:

[0013]

[0014] In the formula, T a e represents air temperature a T represents a The saturated vapor pressure of air at time e r T represents a The actual water vapor pressure of the air at that time, G m G represents the canopy impedance when vegetation is at potential evaporation. a R represents the aerodynamic impedance of the vegetation canopy, LAI represents the leaf area index of the vegetation, and R represents the aerodynamic impedance of the vegetation canopy. n T represents net radiative flux, C represents air volumetric heat capacity, and T represents the total radiative flux. V This indicates the canopy temperature when the vegetation is fully covered.

[0015] S12: Surface evapotranspiration is calculated based on the surface evapotranspiration ratio in S11, specifically as follows:

[0016] ET=β[R n -(1-f v )G s ]

[0017] In the formula, ET represents surface evapotranspiration, f v G represents vegetation cover. s This represents soil heat flux.

[0018] In one embodiment, S2: establishing a mathematical equation relating the evapotranspiration components of S1 to the soil water components includes the following steps:

[0019] S21: Surface evapotranspiration is expressed as the sum of vegetation cover-weighted evapotranspiration components, specifically:

[0020] ET = (1-f v E+f v T

[0021] In the formula, E represents soil evaporation, the evapotranspiration component in ET, and T represents vegetation transpiration, the evapotranspiration component in ET.

[0022] S22: Soil water is expressed as the sum of vegetation cover-weighted bare soil water and root zone water, specifically:

[0023] θ(x,y)=θ S (x,y)(1-f V (x,y))+θ V (x,y)f V (x,y)

[0024]

[0025] In the formula, θ represents the soil water remote sensing observation product, (x, y) represents the pixel position in θ, and θ S (x, y) represents the moisture content of the bare soil component at (x, y), θ V (x, y) represents the soil composition at (x, y) within the vegetation root zone, f V f represents the vegetation cover with spatial resolution equal to θ. V (x, y) represents the vegetation cover at (x, y), I and J represent the number of rows and columns of ET pixels covered by a single pixel in θ, respectively, (i, j) represents the pixel position in ET within the spatial range covered by (x, y), f v f represents the vegetation cover with the same spatial resolution as ET. v (i, j) represents the vegetation cover at (i, j), Θ s (i, j) represents the moisture content of the bare soil at (i, j), Θ v (i, j) represents the root zone water content at (i, j);

[0026] S23: Establish the mathematical equation between the evapotranspiration component of S21 and the soil water component of S22, specifically:

[0027]

[0028] In the formula, ET(x,y) represents the average value of surface evapotranspiration of the pixels in ET within the spatial range covered by (x,y), E(i,j) represents soil evaporation at (i,j), T(i,j) represents vegetation transpiration at (i,j), and ET(i,j) represents surface evapotranspiration at (i,j).

[0029] The above equation is a strict physical relationship equation between soil moisture components and surface evapotranspiration components, based on the assumption that soil moisture and surface evapotranspiration can be expressed as the linear weighted sum of their respective components according to surface vegetation cover. This equation correlates bare soil moisture and root zone moisture components under fine spatial resolution and bare soil evapotranspiration and vegetation transpiration components under fine spatial resolution under coarse spatial resolution by summing and averaging. It can express the relationship pattern between local surface soil moisture and its components and surface evapotranspiration and its components under fine spatial resolution, as well as the relationship pattern between heterogeneous surface soil moisture and its components and surface evapotranspiration and its components under coarse spatial resolution.

[0030] S24: Simplify the mathematical equation between surface evapotranspiration components and soil water components in S23, specifically:

[0031]

[0032] The above equation is a simplified mathematical equation between surface evapotranspiration and soil moisture components in S23, based on the assumption that bare soil moisture is the sole source of water for bare soil evaporation and root zone moisture is the sole source of water for vegetation transpiration. This simplifies the influence of root zone soil moisture on bare soil evaporation and the influence of bare soil moisture on vegetation transpiration. Under the condition that most of the soil moisture in the land surface is unsaturated, it is reasonable to assume that bare soil moisture is the sole source of water for bare soil evaporation and root zone moisture is the sole source of water for vegetation transpiration when there is no rainfall. This is because under the condition of unsaturated soil moisture, the lateral movement of soil moisture is very weak and can be ignored. Under this condition, it is reasonable to consider bare soil moisture as the only water source affecting bare soil evaporation. In this way, the mathematical equation between bare soil moisture and bare soil evaporation can be established at fine spatial resolution as shown in the above equation.

[0033] S25: Establish the mathematical equation relating bare soil evaporation and bare soil moisture, specifically:

[0034] E(i,j)=α(i,j)E p (i,j)

[0035]

[0036] In the formula, θ w (i, j) represents the wilting water content of the soil at (i, j), θ s (i, j) represents the saturated water content of the soil at (i, j), E p(i,j) represents the potential evapotranspiration at (i,j), and α(i,j) represents the ratio of the difference between the bare soil moisture and the bare soil wilting water content to the difference between the bare soil saturation water content and the bare soil wilting water content. It represents the proportion of water in the bare soil component that supplies bare soil evaporation and expresses the limiting effect of bare soil moisture saturation on bare soil evaporation. Therefore, bare soil evaporation is defined as the product of potential evapotranspiration and the limiting factor α(i,j).

[0037] In one embodiment, S3: solving the mathematical equation of S2 to jointly measure soil water components and evapotranspiration components includes the following steps:

[0038] S31: The mathematical equations of S24 and S25 are combined to jointly measure soil water and evapotranspiration components at fine spatial resolution, specifically:

[0039]

[0040] Θ s (i,j)=θ w (i,j)Γ

[0041]

[0042] S32: Based on S31, co-measurement of soil water components and evapotranspiration components at coarse spatial resolution, specifically:

[0043]

[0044] In the formula, E S (x, y) represents the evaporation of bare soil at (x, y) with the same spatial resolution as θ, and T V (x, y) represents vegetation transpiration at (x, y) with the same spatial resolution as θ.

[0045] In a second aspect, embodiments of the present invention provide a soil water and evapotranspiration co-measurement device for performing a soil water and evapotranspiration co-measurement method as described in the first aspect above, comprising: an input module, a surface evapotranspiration module, a communication module, a co-measurement module, and an output module;

[0046] The input module is used to collect meteorological data, remote sensing soil moisture, remote sensing surface temperature, soil water-holding physical properties, and other data.

[0047] The surface evapotranspiration module is used to perform the calculation of surface evapotranspiration ratio and surface evapotranspiration using the acquired remote sensing images and meteorological data as described in the first aspect above.

[0048] The connection module is used to execute the mathematical equation described in the first aspect above for establishing the connection between the evapotranspiration components and soil water components described in the first aspect above;

[0049] The co-measurement module is used to perform the solution of the mathematical equations described in the first aspect above in order to co-measure soil water components and evapotranspiration components.

[0050] The output module is used to output the process and results of co-monitoring soil water components and evapotranspiration components.

[0051] Thirdly, embodiments of the present invention provide an electronic device for co-measuring soil water and evapotranspiration components, including a sensor, a memory, and a processor. The sensor is used to acquire meteorological and remote sensing data. The memory stores a computer program and the meteorological and remote sensing data acquired by the sensor. When the processor executes the computer program to process the meteorological and remote sensing data acquired by the sensor, it implements the steps of the soil water and evapotranspiration component co-measuring method described in the first aspect.

[0052] Fourthly, embodiments of the present invention provide a computer-readable storage medium for co-measuring soil water and evapotranspiration components, wherein a computer program is stored thereon, and when the computer program is executed by a processor, it implements the steps of the co-measuring method for soil water and evapotranspiration components described in the first aspect.

[0053] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0054] 1) A modeling model for remote sensing co-inversion of soil water and its components and surface evapotranspiration and its components is proposed, which can easily realize the joint measurement of soil water and its components and surface evapotranspiration and its components.

[0055] 2) Soil water remote sensing products typically have low spatial resolution. This invention improves the spatial resolution of soil water remote sensing products by establishing a physical connection between soil water and surface evapotranspiration.

[0056] 3) Soil water remote sensing products usually cannot provide component information. This invention realizes the component decomposition of soil water remote sensing products through a mathematical model between bare soil evaporation and bare soil moisture.

[0057] 4) By leveraging the correlation model between soil water and surface evapotranspiration and its components, this invention achieves component decomposition of surface evapotranspiration, avoiding the uncertainty caused by wet and dry points in traditional remote sensing evapotranspiration models.

[0058] 5) This invention enables the coordinated measurement of soil water and surface evapotranspiration and their components at both fine and coarse spatial resolutions. Attached Figure Description

[0059] The accompanying drawings, together with the specification, illustrate embodiments consistent with the present invention. To more clearly explain the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly described below. It is worth noting that those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0060] Figure 1 A schematic flowchart of a method for co-measurement of soil water and evapotranspiration components provided in an embodiment of the present invention;

[0061] Figure 2 A schematic flowchart of another method for co-measurement of soil water and evapotranspiration components provided in an embodiment of the present invention;

[0062] Figure 3 A schematic flowchart of another method for co-measurement of soil water and evapotranspiration components provided in an embodiment of the present invention;

[0063] Figure 4 A schematic flowchart of another method for co-measurement of soil water and evapotranspiration components provided in an embodiment of the present invention;

[0064] Figure 5 This is a schematic diagram of a soil water and evapotranspiration co-measurement device provided in an embodiment of the present invention. Detailed Implementation

[0065] The beneficial effects and implementation steps of the present invention will be further explained below with reference to the accompanying drawings used in the embodiments. It should be noted that the embodiments of the present invention and the steps therein are not strictly executed in sequence, and can be executed in other ways. Therefore, the embodiments shown in this specification are only some embodiments of the present invention, and not all embodiments.

[0066] In one embodiment, such as Figure 1 As shown, Figure 1 A schematic flowchart of a method for co-monitoring soil water and evapotranspiration components provided in an embodiment of the present invention includes the following steps:

[0067] S1: Calculate the surface evapotranspiration ratio and surface evapotranspiration using the acquired remote sensing images and meteorological data;

[0068] S2: Establish the mathematical equation relating the evapotranspiration components of S1 to the soil water components;

[0069] S3: Solve the mathematical equation S2 to jointly measure soil water components and evapotranspiration components.

[0070] This invention simplifies the physical relationship between soil water and its components and surface evapotranspiration and its components, enabling the collaborative estimation of soil water and its components and surface evapotranspiration and its components. This overcomes the isolation of the inversion products of soil water and its components and surface evapotranspiration and its components caused by the independent development of traditional remote sensing models for soil water and surface evapotranspiration and its components. It strengthens the physical relationship in the remote sensing inversion process of soil water and its components and surface evapotranspiration and its components, and provides a guarantee for the collaborative application of the two products at the field scale.

[0071] Based on the above embodiments, in some embodiments of the present invention, further, such as Figure 2 As shown, step S1: Calculating the surface evapotranspiration ratio and surface evapotranspiration using acquired remote sensing images and meteorological data, one implementation method includes the following steps:

[0072] S11: Calculate the surface evapotranspiration ratio using acquired remote sensing imagery and meteorological data, specifically:

[0073]

[0074] In the formula, T a e represents air temperature a T represents a The saturated vapor pressure of air at time e r T represents a The actual water vapor pressure of the air at that time, G m G represents the canopy impedance when vegetation is at potential evaporation. a R represents the aerodynamic impedance of the vegetation canopy, LAI represents the leaf area index of the vegetation, and R represents the aerodynamic impedance of the vegetation canopy. n T represents net radiative flux, C represents air volumetric heat capacity, and T represents the total radiative flux. V This indicates the canopy temperature when the vegetation is fully covered.

[0075] The remote sensing images used include, but are not limited to, land surface temperature, land surface albedo, land surface emissivity, normalized difference vegetation index, and vegetation cover f retrieved from the remote sensing images. v and vegetation cover at the scale f V Soil wilting moisture content θ w Soil saturated water content θ s The parameters include leaf area index (LAI), soil moisture (θ), etc. These remote sensing products can be obtained by inverting remote sensing images and corresponding inversion algorithms, or by downloading the corresponding remote sensing products from the Internet. This invention does not specifically limit the specific source of the surface parameter remote sensing products.

[0076] Meteorological data includes, but is not limited to, solar radiation observations, sky temperature, air temperature, atmospheric pressure, relative humidity, actual water vapor pressure, wind speed, and the observation altitude of wind speed and air temperature.

[0077] The acquisition time of remote sensing products for various surface parameters and the acquisition time of meteorological data should be as close as possible, but they are not required to be synchronized in time. That is, the acquisition times do not need to be at the same moment. The acquisition times should be as close as possible, as long as the difference between the acquisition time of remote sensing products for various surface parameters and the acquisition time of meteorological data is within a reasonable time range. For example, if the difference between the acquisition time of remote sensing products for various surface parameters and the acquisition time of meteorological data is within 3 hours, that is, if the remote sensing products for surface parameters are acquired at 12:00 on October 21, 2018, while the acquisition times of remote sensing products for other surface parameters or meteorological data are between 9:00 and 15:00 on October 21, 2018, then the requirement that the acquisition time of remote sensing products for various surface parameters and the acquisition time of meteorological data should be as close as possible is met. In this regard, the present invention does not impose specific limitations on the time range of the acquisition time difference; those skilled in the art can set it according to specific applications.

[0078] S12: Surface evapotranspiration is calculated based on the surface evapotranspiration ratio in S11, specifically as follows:

[0079] ET=β[R n -(1-f v )G s ]

[0080] In the formula, ET represents surface evapotranspiration, f v G represents vegetation cover. s This represents soil heat flux.

[0081] Based on the above embodiments, in some embodiments of the present invention, further, such as Figure 3 As shown, S2: Establishing a mathematical equation relating the evapotranspiration components of S1 to the soil water components. One implementation method includes the following steps:

[0082] S21: Surface evapotranspiration is expressed as the sum of vegetation cover-weighted evapotranspiration components, specifically:

[0083] ET = (1-f v E+f v T

[0084] In the formula, E represents soil evaporation, the evapotranspiration component in ET, and T represents vegetation transpiration, the evapotranspiration component in ET.

[0085] S22: Soil water is expressed as the sum of vegetation cover-weighted bare soil water and root zone water, specifically:

[0086] θ(x,y)=θ S (x,y)(1-f V (x,y))+θ V (x,y)f V (x,y)

[0087]

[0088] In the formula, θ represents the soil water remote sensing observation product, (x, y) represents the pixel position in θ, and θ S (x, y) represents the moisture content of the bare soil component at (x, y), θ V (x, y) represents the soil composition at (x, y) within the vegetation root zone, f V f represents the vegetation cover with spatial resolution equal to θ. V (x, y) represents the vegetation cover at (x, y), I and J represent the number of rows and columns of ET pixels covered by a single pixel in θ, respectively, (i, j) represents the pixel position in ET within the spatial range covered by (x, y), f v f represents the vegetation cover with the same spatial resolution as ET. v (i, j) represents the vegetation cover at (i, j), Θ s (i, j) represents the moisture content of the bare soil at (i, j), Θ v (i, j) represents the root zone water content at (i, j);

[0089] S23: Establish the mathematical equation between the evapotranspiration component of S21 and the soil water component of S22, specifically:

[0090]

[0091]

[0092] In the formula, ET(x,y) represents the average value of surface evapotranspiration of the pixels in ET within the spatial range covered by (x,y), E(i,j) represents soil evaporation at (i,j), T(i,j) represents vegetation transpiration at (i,j), and ET(i,j) represents surface evapotranspiration at (i,j).

[0093] The above equation is a strict physical relationship equation between soil moisture components and surface evapotranspiration components, based on the assumption that soil moisture and surface evapotranspiration can be expressed as the linear weighted sum of their respective components according to surface vegetation cover. This equation correlates bare soil moisture and root zone moisture components under fine spatial resolution and bare soil evapotranspiration and vegetation transpiration components under fine spatial resolution under coarse spatial resolution by summing and averaging. It can express the relationship pattern between local surface soil moisture and its components and surface evapotranspiration and its components under fine spatial resolution, as well as the relationship pattern between heterogeneous surface soil moisture and its components and surface evapotranspiration and its components under coarse spatial resolution.

[0094] S24: Simplify the mathematical equation between surface evapotranspiration components and soil water components in S23, specifically:

[0095]

[0096] The above equation is a simplified mathematical equation between surface evapotranspiration and soil moisture components in S23, based on the assumption that bare soil moisture is the sole source of water for bare soil evaporation and root zone moisture is the sole source of water for vegetation transpiration. This simplifies the influence of root zone soil moisture on bare soil evaporation and the influence of bare soil moisture on vegetation transpiration. Under the condition that most of the soil moisture in the land surface is unsaturated, it is reasonable to assume that bare soil moisture is the sole source of water for bare soil evaporation and root zone moisture is the sole source of water for vegetation transpiration when there is no rainfall. This is because under the condition of unsaturated soil moisture, the lateral movement of soil moisture is very weak and can be ignored. Under this condition, it is reasonable to consider bare soil moisture as the only water source affecting bare soil evaporation. In this way, the mathematical equation between bare soil moisture and bare soil evaporation can be established at fine spatial resolution as shown in the above equation.

[0097] S25: Establish the mathematical equation relating bare soil evaporation and bare soil moisture, specifically:

[0098] E(i,j)=α(i,j)E p (i,j)

[0099]

[0100] In the formula, θ w (i, j) represents the wilting water content of the soil at (i, j), θ s (i, j) represents the saturated water content of the soil at (i, j), E p (i,j) represents the potential evapotranspiration at (i,j), and α(i,j) represents the ratio of the difference between the bare soil moisture and the bare soil wilting water content to the difference between the bare soil saturation water content and the bare soil wilting water content. It represents the proportion of water in the bare soil component that supplies bare soil evaporation and expresses the limiting effect of bare soil moisture saturation on bare soil evaporation. Therefore, bare soil evaporation is defined as the product of potential evapotranspiration and the limiting factor α(i,j).

[0101] Based on the above embodiments, in some embodiments of the present invention, further, such as Figure 4 As shown, S3: Solving the mathematical equation S2 to jointly measure soil water components and evapotranspiration components, one method includes the following steps:

[0102] S31: The mathematical equations of S24 and S25 are combined to jointly measure soil water and evapotranspiration components at fine spatial resolution, specifically:

[0103]

[0104] Θ s (i,j)=θ w (i,j)Γ

[0105]

[0106] S32: Based on S31, co-measurement of soil water components and evapotranspiration components at coarse spatial resolution, specifically:

[0107]

[0108] In the formula, E S (x, y) represents the evaporation of bare soil at (x, y) with the same spatial resolution as θ, and T V (x, y) represents vegetation transpiration at (x, y) with the same spatial resolution as θ.

[0109] In summary, remote sensing co-monitoring based on the physical relationship between soil water and its components and surface evapotranspiration and its components can be achieved.

[0110] It is worth noting that, although in Figures 1-4 In the flowcharts described, the steps are connected sequentially by arrows, but this does not mean that these steps must be executed in the exact order of the arrows to complete. Unless otherwise specified, these steps can be executed in different orders to achieve the desired effect, and it is not necessary to strictly follow the order of the arrows to achieve the desired result.

[0111] In one embodiment, such as Figure 5 As shown, a soil water and evapotranspiration co-measurement device is provided for performing a soil water and evapotranspiration co-measurement method described in the above embodiments, including: input module 1, surface evapotranspiration module 2, communication module 3, co-measurement module 4, and output module 5.

[0112] The input module 1 is used to collect meteorological data, remote sensing soil moisture, remote sensing surface temperature, soil water-holding physical properties and other data.

[0113] The surface evapotranspiration module 2 is used to perform the calculation of surface evapotranspiration ratio and surface evapotranspiration using the acquired remote sensing images and meteorological data as described in the above embodiment.

[0114] The connection module 3 is used to execute the mathematical equation described in the above embodiments for establishing the connection between evapotranspiration components and soil water components as described in the above embodiments;

[0115] The co-measurement module 4 is used to perform the above-described embodiment to solve the mathematical equations described in the above-described embodiment in order to co-measure soil water components and evapotranspiration components;

[0116] The output module 5 is used to output the process and results of co-monitoring soil water components and evapotranspiration components.

[0117] This invention provides an electronic device for co-monitoring soil water and evapotranspiration components, comprising: a sensor, a memory, and a processor. The sensor is used to acquire meteorological and remote sensing data. The memory stores a computer program and the meteorological and remote sensing data acquired by the sensor. The processor executes the computer program to process the meteorological and remote sensing data acquired by the sensor. Figures 1 to 4 The technical solutions of any of the illustrated method embodiments are similar in implementation principle and technical effect, and will not be repeated here.

[0118] This invention also provides a computer-readable storage medium for co-monitoring soil water and evapotranspiration components. The medium stores a computer-executable program, which, when executed by a processor, can implement the soil water and evapotranspiration component co-monitoring method provided in this invention. For example, when the computer-executable program is executed by a processor, it can implement… Figures 1 to 4 The technical solutions of any of the illustrated method embodiments are similar in implementation principle and technical effect, and will not be repeated here.

[0119] Those skilled in the art will understand that all flowcharts illustrating the methods in this description can be implemented using computer code instructions related to hardware. This computer code can be stored in a computer-readable storage medium, such as a read-only memory (ROM), hard disk, magnetic tape, floppy disk, USB flash drive, flash memory, or optical storage. When the computer program in the storage medium is read and executed by a computer, it can complete the various steps of the embodiments of the above methods. Furthermore, the computer code used to execute the embodiments provided by this invention can also be stored in volatile memory, for example, random access memory (RAM) or an external cache memory.

[0120] The beneficial effects of the proposed method for co-measurement of soil water and evapotranspiration components are as follows:

[0121] 1) A simple paradigm for systematically estimating soil water and its components and surface evapotranspiration and its components is proposed, which can conveniently and quickly realize the joint inversion of soil water and its components and surface evapotranspiration and its components.

[0122] 2) The established mathematical relationship between soil water and surface evapotranspiration enabled spatial downscaling of soil water remote sensing observations, enriching the spatial details of soil water remote sensing products.

[0123] 3) By understanding the physical relationship between bare soil evaporation and bare soil moisture, the component decomposition of soil water remote sensing products was realized, filling the current gap in soil water component remote sensing products;

[0124] 4) By establishing mathematical formulas between soil water and its components and surface evapotranspiration and its components, the measurement of soil evaporation and vegetation transpiration was realized, avoiding the decomposition error of evapotranspiration components caused by improper selection of wet and dry points.

[0125] 5) It can achieve the coordinated measurement of soil water and its components and surface evapotranspiration and its components at both fine and coarse spatial resolutions.

[0126] This specification focuses on describing the differences between the various embodiments, and the similarities or similarities between the embodiments can be referred to each other. For the embodiments of apparatus, electronic devices, and media, since they are similar to the method embodiments, the descriptions are relatively simple; for similarities, please refer to the relevant sections of the method embodiments. It should be noted that the embodiments shown in this specification are not intended to limit the scope of patent protection of this invention. Furthermore, some or all combinations of the shown embodiments can be implemented in ways different from the shown embodiments. This invention does not describe all possible combinations of technical features. For those skilled in the art, any equivalent substitutions, modifications, or improvements to some steps and method features in the shown embodiments of this invention, without inventive effort, are all included within the scope of protection of this invention.

Claims

1. A method for co-measurement of soil water and evapotranspiration components, characterized in that, Includes the following steps: S1: Calculate the surface evapotranspiration ratio β and surface evapotranspiration ET using the acquired remote sensing images and meteorological data, specifically as follows: ET=β[R n -(1-f v )G s ] In the formula, T a e represents air temperature a T represents a The saturated vapor pressure of air at time e r T represents a The actual water vapor pressure of the air at that time, G m G represents the canopy impedance when vegetation is at potential evaporation. a R represents the aerodynamic impedance of the vegetation canopy, LAI represents the leaf area index of the vegetation, and R represents the aerodynamic impedance of the vegetation canopy. n T represents net radiative flux, C represents air volumetric heat capacity, and T represents the total radiative flux. V f represents the canopy temperature when the vegetation is fully covered. v G represents vegetation cover. s ET represents soil heat flux, and ET represents surface evapotranspiration. S2: Establish the mathematical equation relating the evapotranspiration components of S1 to the soil water components, specifically: In the formula, Θ s (i,j) represents the bare soil moisture at (i,j), θ(x,y) represents the soil moisture at pixel (x,y) of the soil water remote sensing observation product, E(i,j) represents the soil evaporation at (i,j), and ET(x,y) represents the average surface evaporation of pixels in ET within the spatial range covered by (x,y). S3: Solve the mathematical equation S2 to jointly measure soil water components and evapotranspiration components, specifically: In the formula, θ represents the soil water remote sensing observation product, (x, y) represents the pixel position in θ, I and J represent the number of rows and columns of ET pixels covered by a single pixel in θ, respectively. S (x, y) represents the moisture content of the bare soil component at (x, y), f V f represents the vegetation cover with spatial resolution equal to θ. V (x, y) represents the vegetation cover at (x, y), (i, j) represents the pixel location in ET within the spatial range covered by (x, y), and f v f represents the vegetation cover with the same spatial resolution as ET. v (i, j) represents the vegetation cover at (i, j), θ w (i, j) represents the wilting water content of the soil at (i, j), θ V (x, y) represents the soil composition at (x, y) within the vegetation root zone, E S (x, y) represents the evaporation of bare soil at (x, y) with the same spatial resolution as θ, and T V (x, y) represents vegetation transpiration at (x, y) with the same spatial resolution as θ, E p (i, j) represents the potential evapotranspiration at the surface at (i, j), θ s (i,j) represents the saturated water content of the soil at (i,j), and ET(x,y) represents the mean evapotranspiration of the pixels in ET within the spatial range covered by (x,y).

2. The method according to claim 1, characterized in that, S2 includes the following steps: S21: Surface evapotranspiration is expressed as the sum of vegetation cover-weighted evapotranspiration components, specifically: ET=(1-f v )E+f v T In the formula, E represents soil evaporation, the evapotranspiration component in ET, and T represents vegetation transpiration, the evapotranspiration component in ET. S22: Soil water is expressed as the sum of vegetation cover-weighted bare soil water and root zone water, specifically: θ(x,y)=θ S (x,y)(1-f V (x,y))+θ V (x,y)f V (x,y) In the formula, Θ v (i, j) represents the root zone water content at (i, j); S23: Establish the mathematical equation between the evapotranspiration component of S21 and the soil water component of S22, specifically: In the formula, T(i,j) represents vegetation transpiration at (i,j), and ET(i,j) represents surface evapotranspiration at (i,j). The above equation is a strict physical relationship equation between soil moisture components and surface evapotranspiration components, based on the assumption that soil moisture and surface evapotranspiration can be expressed as the linear weighted sum of their respective components according to surface vegetation cover. This equation correlates bare soil moisture and root zone moisture components under fine spatial resolution and bare soil evapotranspiration and vegetation transpiration components under fine spatial resolution under coarse spatial resolution by summing and averaging. It can express the relationship pattern between local surface soil moisture and its components and surface evapotranspiration and its components under fine spatial resolution, as well as the relationship pattern between heterogeneous surface soil moisture and its components and surface evapotranspiration and its components under coarse spatial resolution. S24: Simplify the mathematical equation between surface evapotranspiration components and soil water components in S23, specifically: The above equation is a simplified mathematical equation between surface evapotranspiration and soil moisture components in S23, based on the assumption that bare soil moisture is the sole source of water for bare soil evaporation and root zone moisture is the sole source of water for vegetation transpiration. This simplifies the influence of root zone soil moisture on bare soil evaporation and the influence of bare soil moisture on vegetation transpiration. Under the condition that most of the soil moisture in the land surface is unsaturated, it is reasonable to assume that bare soil moisture is the sole source of water for bare soil evaporation and root zone moisture is the sole source of water for vegetation transpiration when there is no rainfall. This is because under the condition of unsaturated soil moisture, the lateral movement of soil moisture is very weak and can be ignored. Under this condition, it is reasonable to consider bare soil moisture as the only water source affecting bare soil evaporation. In this way, the mathematical equation between bare soil moisture and bare soil evaporation can be established at fine spatial resolution as shown in the above equation. S25: Establish the mathematical equation relating bare soil evaporation and bare soil moisture, specifically: E(i,j)=α(i,j)E p (i,j) In the formula, α(i,j) represents the ratio of the difference between the bare soil moisture content and the bare soil wilting moisture content to the difference between the bare soil saturation moisture content and the bare soil wilting moisture content. It represents the proportion of water in the bare soil component that supplies bare soil evaporation and expresses the limiting effect of bare soil moisture saturation on bare soil evaporation. Therefore, bare soil evaporation is defined as the product of potential evapotranspiration and the limiting factor α(i,j).

3. The method according to claim 1, characterized in that, Specifically, S3 is: S31: The mathematical equations of S24 and S25 are combined to jointly measure soil water and evapotranspiration components at fine spatial resolution, specifically: I s (i,j)=θ w (i,j)C S32: Based on S31, co-measurement of soil water components and evapotranspiration components at coarse spatial resolution, specifically: In the formula, E S (x, y) represents the evaporation of bare soil at (x, y) with the same spatial resolution as θ, and T V (x, y) represents vegetation transpiration at (x, y) with the same spatial resolution as θ.

4. A device for co-measuring soil water and evapotranspiration components, characterized in that, The method for co-measuring soil water and evapotranspiration components as described in claim 1 includes: an input module, a surface evapotranspiration module, a communication module, a co-measuring module, and an output module; The input module is used to collect meteorological data, remote sensing soil moisture, remote sensing surface temperature, soil water-holding physical properties, and other data. The surface evapotranspiration module is used to calculate the surface evapotranspiration ratio and surface evapotranspiration using the acquired remote sensing images and meteorological data. The connection module is used to establish a mathematical equation relating evapotranspiration components and soil water components. The co-measurement module is used to solve the mathematical equations of the connection module to co-measure soil water components and evapotranspiration components; The output module is used to output the process and results of co-monitoring soil water components and evapotranspiration components.

5. An electronic device for co-monitoring soil water and evapotranspiration components, comprising a sensor, a memory, and a processor, wherein the sensor is used for acquiring meteorological and remote sensing data, and the memory stores a computer program and the meteorological and remote sensing data acquired by the sensor, characterized in that... When the processor executes the computer program to process the meteorological and remote sensing data acquired by the sensor, it implements the steps of the soil water and evapotranspiration co-measurement method according to any one of claims 1 to 3.

6. A computer-readable storage medium for co-monitoring soil water and evapotranspiration components, having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the method for co-measuring soil water and evapotranspiration components as described in any one of claims 1-3.

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