A method and system for monitoring vertical water flux in soil
By acquiring real-time soil depth data and soil water potential, soil hydraulic transmission parameters are inverted, and the soil moisture balance surface is automatically identified. This solves the problem of simultaneous monitoring of evapotranspiration and seepage processes in existing technologies, and realizes dynamic inversion of vertical water transport and accurate interface identification.
Patent Information
- Application Number
- CN202610791545.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-03
- Publication Date
- 2026-08-25
AI Technical Summary
Existing technologies cannot simultaneously capture evapotranspiration and infiltration processes in opposite directions in soil profiles, resulting in disruption of the continuity of water transport monitoring and significant deviations between measured and true values.
By acquiring real-time data on soil moisture content and soil water potential at different soil depths, soil hydraulic conduction parameters are inverted, vertical water flux is calculated, and the location of the soil moisture balance surface is automatically identified. The interface moves dynamically with environmental changes, enabling simultaneous monitoring of evapotranspiration and seepage.
It enables dynamic inversion of the vertical water transport process, continuously and dynamically characterizes the soil water transport mechanism, accurately identifies the interface between evapotranspiration and infiltration, and overcomes the shortcomings of discrete static flux estimation in traditional methods.
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Figure CN122631864A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of water flux monitoring and application technology, specifically relating to a method and system for monitoring vertical soil water flux. Background Technology
[0002] Soil moisture migration in flat terrain is mainly manifested through two typical processes: upward evapotranspiration and downward infiltration. Evapotranspiration flux is mainly affected by meteorological conditions, soil moisture content, and water potential gradient, while infiltration flux is controlled by rainfall, irrigation, and soil hydraulic conductivity. Accurately understanding the vertical distribution of soil moisture and quantitatively describing the "driving force" and "direction" of moisture migration can enable precision irrigation, prevent ineffective water loss caused by deep infiltration, and provide core hydrological characteristic data for characterizing farmland eco-hydrological processes.
[0003] Traditional observation methods generally measure evapotranspiration and seepage processes separately, resulting in two independent measurement technology systems. One type focuses on evapotranspiration monitoring using energy balance and lyometry methods. The energy balance method calculates latent heat flux through the conservation of energy by measuring net radiation, soil heat flux, and sensible heat flux. However, this method is only applicable to sites with uniform surface energy flux and lacks quantitative simulation of deep water movement. The lyometry method constructs a closed soil column or large lyometry device to measure the difference in water inflow and outflow to estimate evapotranspiration or seepage. However, this system is closed at the bottom, leaving only drainage holes, often resulting in a lack of connection between the tested soil and the natural soil beneath the experimental field, hindering the free flow of water. The second type focuses on seepage measurement using soil permeameter technology. Existing permeameters mainly include negative pressure permeameters, free permeameter cylinders, and weighing permeameter systems. These collect seepage water samples at the bottom of the soil and calculate the flux, enabling relatively accurate measurement of deep infiltration. However, these devices can only reflect seepage flux and cannot reflect the upper-layer evaporation process and its dynamic transition relationship with seepage. Especially during the water redistribution stage from rainfall to the dry season, evaporation and seepage usually coexist or alternately dominate, and traditional seepage meters cannot identify the location of the critical transition surface.
[0004] Existing technologies rely on functionally independent equipment, which, while possessing a strong foundation in physical measurement, cannot simultaneously capture the evapotranspiration (upward) and infiltration (downward) processes in opposite directions within the soil profile. This disrupts the continuity of water transport monitoring and easily leads to significant deviations between measured and true values. Summary of the Invention
[0005] To address the shortcomings of existing technologies in monitoring vertical soil moisture transport, this invention provides a method and system for monitoring vertical soil moisture flux.
[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for monitoring soil vertical moisture flux includes the following steps: Real-time acquisition of soil moisture content and soil water potential data at different soil depths; Soil hydraulic transport parameters at different soil depths are inverted based on soil moisture content and soil water potential data at different soil depths; vertical water flux at each depth layer is calculated based on soil moisture content, soil water potential data, and soil hydraulic transport parameters at different depth layers. Determine whether the direction of vertical water flux in each depth layer changes with depth within the profile. If the direction of vertical water flux changes between two adjacent soil layers, the position of the soil moisture balance surface ZFP is obtained based on the vertical water flux of the two adjacent soil layers and the corresponding soil depth. Evapotranspiration flux and seepage flux were calculated based on soil moisture content and soil water potential data at different depths. Specifically, when the soil depth is less than the ZFP depth, the vertical water flux of the soil layer is upward and is considered evapotranspiration flux; when the soil depth is greater than the ZFP depth, the vertical water flux of the soil layer is downward and is considered seepage flux.
[0007] Preferably, the inversion of soil hydraulic conduction parameters based on soil moisture content data and soil water potential data at different depths includes the following steps: The soil moisture characteristic curve was calculated using the collected soil moisture content and soil water potential measurements of each layer; the relative saturation of the soil was calculated based on the soil moisture characteristic curve. Soil depth determined by inversion of relative soil saturation z Soil hydraulic conduction parameters at the location.
[0008] Preferably, the vertical water flux at each depth layer is calculated based on water content data, soil water potential data, and soil hydraulic conduction parameters at different depths, specifically using the following formula: ; in, Soil depth z Vertical water flux at the location; Soil water potential; This is a parameter related to soil hydraulic conductivity, which varies with soil moisture content. θ change; This represents the rate of change of soil water potential in the vertical direction.
[0009] Preferably, the location of the soil moisture balance surface is obtained by using linear interpolation based on the vertical water flux of two adjacent soil layers and the corresponding soil depth.
[0010] Preferably, the evapotranspiration flux is specifically obtained by using the decrease in water storage in the evapotranspiration zone of the soil profile where the soil depth is less than the ZFP depth per unit time.
[0011] Preferably, the seepage flux is obtained by utilizing the change in average water content of soil layers with a depth greater than ZFP in the soil profile per unit time.
[0012] This invention also provides a soil vertical moisture flux monitoring system, specifically comprising: The data acquisition module is used to acquire real-time data on soil moisture content and soil water potential at different soil depths.
[0013] The flux calculation module inverts soil hydraulic conduction parameters at different soil depths based on water content and soil water potential data at different soil depths; and calculates the vertical water flux at each depth layer based on water content, soil water potential, and soil hydraulic conduction parameters at different depth layers.
[0014] The vertical interactive analysis module for water flux is used to determine whether the direction of vertical water flux in each depth layer changes with depth within the profile. If the direction of vertical water flux in two adjacent soil layers changes, the position of the soil water balance surface ZFP is obtained based on the vertical water flux of the two adjacent soil layers and the corresponding soil depth. Evapotranspiration flux and seepage flux were calculated based on soil moisture content and soil water potential data at different depths. Specifically, when the soil depth is less than the ZFP depth, the vertical water flux of the soil layer is upward and is considered evapotranspiration flux; when the soil depth is greater than the ZFP depth, the vertical water flux of the soil layer is downward and is considered seepage flux.
[0015] The present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps described in the method for monitoring vertical soil moisture flux.
[0016] The present invention also provides a computer-readable storage medium storing a computer program that, when loaded by a processor, can execute the steps described in the method for monitoring vertical soil moisture flux.
[0017] The soil vertical water flux monitoring method provided by this invention has the following beneficial effects: This invention utilizes data on soil moisture content and soil water potential at different depths to dynamically calculate the vertical water flux at each depth based on physical equations. It automatically identifies the interface (soil moisture balance surface) between soil evaporation and seepage based on the directional changes in the vertical water flux between adjacent soil layers. This interface moves with environmental conditions, allowing for real-time determination of interface depth changes and continuous dynamic characterization of soil moisture transport mechanisms. By calculating the depth of the soil moisture balance surface based on the identified interfaces and calculating the water flux above and below the interfaces in separate zones, it achieves dynamic inversion of the vertical water transport process and simultaneous monitoring of evapotranspiration and seepage. Attached Figure Description
[0018] To more clearly illustrate the embodiments and design schemes of the present invention, the accompanying drawings required for this embodiment will be briefly described below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0019] Figure 1 This is a flowchart of a method for monitoring vertical soil moisture flux according to an embodiment of the present invention.
[0020] Figure 2 This is a schematic diagram of a method for estimating vertical soil moisture flux based on changes in stratified soil moisture and water potential in an embodiment of the present invention. Detailed Implementation
[0021] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.
[0022] Example This invention provides a method for monitoring soil vertical water flux, such as... Figure 1 As shown, the specific steps include: Step 1: Deploy multiple layers of sensors at different soil depths to collect soil moisture content. ) and soil water potential ( Dynamic data.
[0023] Step 2: Based on measured data, calculate the vertical water flux of each soil layer in real time according to Darcy's law. When the flux direction changes (i.e. When the positive and negative values change, a zero flux interface exists. The depth of the soil moisture balance surface is obtained using linear interpolation. z ZFP This is used to distinguish between the upward evaporation and downward seepage processes of soil. For example... Figure 1As shown, the specific processing steps include the following:
[0024] (1) Based on real-time data collection and The simplified one-dimensional Darcy's law was used to calculate the vertical water flux of each soil profile layer. The flux calculation formula is as follows: ; in, Soil depth z Vertical water flux at the location (positive values indicate leakage, negative values indicate evaporation); Soil water potential; Soil depth z The soil hydraulic conductivity parameters vary with soil moisture content; This represents the rate of change of soil water potential in the vertical direction.
[0025] (2) To achieve accurate inversion of vertical water flux, soil hydraulic conductivity is calibrated based on the soil moisture content and soil water potential measurements collected by soil moisture and soil water potential sensors for each layer. Specifically:
[0026] A moisture characteristic curve was calculated using the collected soil moisture content and soil water potential measurements for each layer; the relative saturation of the soil was then calculated based on the moisture characteristic curve, using the following formula: ; ; in, Soil depth z The relative saturation of the soil at that point Soil depth z Unsaturated soil volumetric water content This refers to the residual soil moisture content. This represents the soil saturation water content. , , These are all model parameters of the Van Genuchten model, which characterizes the soil moisture feature curve.
[0027] Inversion of soil depth z Hydraulic conductivity at the location The curve is calculated using the following formula: ; in, For the saturated hydraulic conductivity of soil, To connect the porosity parameter, a value of 0.5 is typically used. It is a constant. =1-1 / The inversion of each layer Used for calculating Darcy's law in the above formula.
[0028] (3) Vertical water flux of adjacent soil layers If the orientation changes with depth within the profile, then a soil moisture balance surface (ZFP) exists. The depth of the soil moisture balance surface can be obtained using linear interpolation. z ZFP : ; in, and These represent the soil depths. z d , z h Soil water potential at the location; and These represent soil depths. z d , z h Soil volumetric water content at the location; and These represent the soil depths. z d , z h Vertical water flux of soil at a given location.
[0029] (4) Based on the depth of the soil moisture balance surface z ZFP Based on this, the calculation distinguishes between evaporation and leakage, as shown in the schematic diagram below. Figure 2 As shown, z ZFP The above changes in soil moisture are evapotranspiration flux ET. z ZFP The following soil moisture changes are represented by infiltration flux (L). The formula for calculating evapotranspiration flux is:
[0030] ; The formula for calculating leakage flux is: ; in, , It is the surface to z ZFP depth z d At the current moment The next moment Soil volumetric water content, , It is soil z ZFP to the diving layer H depth zh At the current moment The next moment Soil volumetric water content, It is the surface to z ZFP Soil layer thickness, It is soil z ZFP to the diving layer H Soil layer thickness, N 1 is the surface to z ZFP Number of soil moisture monitoring stations within the area N 2 is z ZFP to the diving layer H The number of soil moisture monitoring points within the area is equal, and the spacing between monitoring points in each soil layer is equal.
[0031] The advantages of the soil vertical water flux monitoring method provided by this invention are as follows: (1) By deploying soil moisture content sensors and soil water potential sensors in layers in the soil profile, the water content distribution and water potential status information of each depth layer can be collected in real time, realizing the synchronous recording of water flux transport in two opposite directions, evaporation and seepage, within the same time period, avoiding the time sequence misalignment caused by the traditional instruments that can only measure in one direction and at one point. (2) The conversion interface between evaporation and seepage, i.e., the soil moisture balance surface, is automatically identified according to the change of water potential gradient direction and water flux sign. This method does not require manual intervention and can track the dynamic change of the critical surface position over time in real time, realizing the accurate identification of evaporation and seepage zone calculation. (3) By using the measured soil moisture changes at different depths, the vertical water flux is calculated in layers, realizing the dynamic calculation of the water transport process, overcoming the limitations of traditional methods that can only obtain discrete and static flux estimation.
[0032] The present invention also provides a soil vertical moisture flux monitoring system, comprising: The data acquisition module is used to acquire real-time data on soil moisture content and soil water potential at different soil depths.
[0033] The flux calculation module inverts soil hydraulic conduction parameters at different soil depths based on water content and soil water potential data at different soil depths; and calculates the vertical water flux at each depth layer based on water content, soil water potential, and soil hydraulic conduction parameters at different depth layers.
[0034] The vertical interactive analysis module for water flux is used to determine whether the direction of vertical water flux in each depth layer changes with depth within the profile. If the direction of vertical water flux in two adjacent soil layers changes, the position of the soil water balance surface ZFP is obtained based on the vertical water flux of the two adjacent soil layers and the corresponding soil depth. Evapotranspiration flux and seepage flux were calculated based on soil moisture content and soil water potential data at different depths. Specifically, when the soil depth is less than the ZFP depth, the vertical water flux of the soil layer is upward and is considered evapotranspiration flux; when the soil depth is greater than the ZFP depth, the vertical water flux of the soil layer is downward and is considered seepage flux.
[0035] The modules in the aforementioned soil vertical moisture flux monitoring system can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the computer device's memory as software, so that the processor can call and execute the corresponding operations of each module.
[0036] The present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the steps in an embodiment of a method for monitoring vertical soil moisture flux. Specific implementation methods can be found in the method embodiments, and will not be repeated here.
[0037] Furthermore, the present invention also provides a non-transitory computer-readable storage medium containing instructions, on which a computer program is stored. For example, a memory containing instructions that can be executed by a processor of a computer device to perform the above-described method. For example, the non-transitory computer-readable storage medium may be a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc. When the computer program is executed by the processor, it can implement the steps in an embodiment of a soil vertical moisture flux monitoring method. Specific implementation methods can be found in the method embodiments, which will not be repeated here.
[0038] Those skilled in the art will understand that embodiments of the present invention can provide methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.
[0039] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, as well as combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.
[0040] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.
[0041] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.
[0042] It should be noted that the specific embodiments described above enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way. Therefore, although the present invention has been described in detail in this specification and embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention; and all technical solutions and improvements that do not depart from the spirit and scope of the present invention are covered within the protection scope of the present invention patent. No reference numerals in the claims should be construed as limiting the scope of the claims. Any simple variations or equivalent substitutions of technical solutions that can be readily obtained by those skilled in the art within the scope of the technology disclosed in the present invention are within the protection scope of the present invention.
Claims
1. A method for monitoring soil vertical moisture flux, characterized in that, Includes the following steps: Real-time acquisition of soil moisture content and soil water potential data at different soil depths; Soil hydraulic transport parameters at different soil depths are inverted based on soil moisture content and soil water potential data at different soil depths; vertical water flux at each depth layer is calculated based on soil moisture content, soil water potential data, and soil hydraulic transport parameters at different depth layers. Determine whether the direction of vertical water flux in each depth layer changes with depth within the profile. If the direction of vertical water flux changes between two adjacent soil layers, the position of the soil moisture balance surface ZFP is obtained based on the vertical water flux of the two adjacent soil layers and the corresponding soil depth. Evapotranspiration flux and seepage flux were calculated based on soil moisture content and soil water potential data at different depths. Specifically, when the soil depth is less than the ZFP depth, the vertical water flux of the soil layer is upward and is considered evapotranspiration flux; when the soil depth is greater than the ZFP depth, the vertical water flux of the soil layer is downward and is considered seepage flux.
2. The method for monitoring vertical soil moisture flux according to claim 1, characterized in that, The process of retrieving soil hydraulic transport parameters based on soil moisture content and soil water potential data at different depths includes the following steps: The soil moisture characteristic curve was calculated using the collected soil moisture content and soil water potential measurements of each layer; the relative saturation of the soil was calculated based on the soil moisture characteristic curve. Soil depth determined by inversion of relative soil saturation z Soil hydraulic conduction parameters at the location.
3. The method for monitoring vertical soil moisture flux according to claim 1, characterized in that, The vertical water flux at each depth layer is calculated based on water content data, soil water potential data, and soil hydraulic transport parameters, using the following formula: ； in, Soil depth z Vertical water flux at the location; Soil water potential; This is a parameter related to soil hydraulic conductivity, which varies with soil moisture content. θ change; This represents the rate of change of soil water potential in the vertical direction.
4. The method for monitoring vertical soil moisture flux according to claim 1, characterized in that, The location of the soil moisture balance surface was obtained by using linear interpolation based on the vertical water flux of two adjacent soil layers and the corresponding soil depth.
5. The method for monitoring vertical soil moisture flux according to claim 1, characterized in that, The evapotranspiration flux is specifically obtained by using the decrease in water storage in the evapotranspiration zone of the soil profile where the soil depth is less than the ZFP depth per unit time.
6. The method for monitoring vertical soil moisture flux according to claim 1, characterized in that, The leakage flux is specifically obtained by utilizing the change in average water content of soil layers with a depth greater than ZFP in the soil profile per unit time.
7. A soil vertical moisture flux monitoring system, characterized in that, include: The data acquisition module is used to acquire real-time water content and soil water potential data at different soil depths; The flux calculation module inverts soil hydraulic transport parameters at different soil depths based on water content and soil water potential data at different soil depths; and calculates the vertical water flux at each depth layer based on water content, soil water potential data, and soil hydraulic transport parameters at different depth layers. The vertical interactive analysis module for water flux is used to determine whether the direction of vertical water flux in each depth layer changes with depth within the profile. If the direction of vertical water flux in two adjacent soil layers changes, the position of the soil water balance surface ZFP is obtained based on the vertical water flux of the two adjacent soil layers and the corresponding soil depth. Evapotranspiration flux and seepage flux were calculated based on soil moisture content and soil water potential data at different depths. Specifically, when the soil depth is less than the ZFP depth, the vertical water flux of the soil layer is upward and is considered evapotranspiration flux; when the soil depth is greater than the ZFP depth, the vertical water flux of the soil layer is downward and is considered seepage flux.
8. A computer device, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the method according to any one of claims 1 to 6.
9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is loaded by the processor, it is able to perform the steps of the method according to any one of claims 1 to 6.