Soil column device and method for simulating soil water-salt leaching effect under drip irrigation condition

Abstract

The invention provides a soil column device and method for realizing soil water-salt leaching effect simulation under a drip irrigation condition. The method comprises the following steps: generating simulated moisture information of different depths in the soil column device; an intelligent moisture sensor and an intelligent salinity concentration sensor are arranged in each soil layer of the soil column device in advance, soil moisture information is collected through the preset intelligent moisture sensor, and then the fitting degree between the simulated moisture information and the soil moisture information is determined; the salinity concentration in the soil column device during drip irrigation is collected through the preset intelligent salinity concentration sensor, and the water-salt permeability coefficient during migration of moisture and salinity in the soil column device is determined according to the soil moisture information and the salinity concentration; adjusting the saturated hydraulic conductivity through the fitting degree; and determining the sensitivity of the saturated hydraulic conductivity of the soil during water-salt leaching according to an adjustment result and the water-salt permeability coefficient. By adopting the scheme provided by the invention, the simulation process of the leaching effect can be adaptively adjusted on the premise that the physical property of the soil is dynamically changed.

Description

Technical Field

[0001] The present application relates to the technical field of soil column experimental detection, and more specifically, to a soil column device and method for simulating soil water-salt leaching under drip irrigation conditions. Background Art

[0002] Soil column experiment is an experimental detection method used to study the migration and transformation processes of substances in soil systems. It is widely used in soil pollution remediation, farmland water and fertilizer management, and groundwater pollution research. During the experiment, the soil response under different environmental conditions can be simulated by controlling factors such as liquid supply rate, soil type, and pollutant concentration; for example, the adsorption, desorption and migration characteristics of heavy metals or organic pollutants in soil can be studied, or the distribution patterns of water and nutrients in soil can be analyzed; the accuracy and repeatability of soil column experiments make it an important tool for understanding soil ecological processes. By combining numerical simulation and chemical analysis, this technology can provide a scientific basis for environmental pollution control and agricultural management.

[0003] The simulation of soil water and salt leaching by soil column device is a method to study the migration laws of water and salt in soil under laboratory conditions. It is widely used in agricultural water and salt management, soil improvement and saline-alkali land management. Based on the soil column device, this technology can accurately simulate the water and salt movement process under natural conditions, and reveal the key influencing factors by controlling experimental variables. In agricultural research, soil column devices are widely used to evaluate the effects of different irrigation and drainage schemes on soil salt leaching efficiency, and provide support for optimizing agricultural water resource utilization and reducing soil secondary salinization; at the same time, this technology is also used to study the migration behavior of pollutants in the soil-groundwater system, and assist in the remediation of contaminated sites and the protection of groundwater resources. In the existing soil column device simulation process, the HYDRUS-1D model is usually used to simulate the soil water and salt leaching of the soil column device. However, in the existing HYDRUS-1D model In the process of simulation, the characteristic parameters of the soil are often determined by combining the basic properties of the soil with empirical equations, thus ignoring the physical properties that change dynamically during the water-salt leaching process (for example, during the water-salt leaching process, the distribution and concentration of soil salt will change with time and water movement). This will lead to a low fit between the simulated moisture content and the measured soil moisture content (that is, the deviation between the simulated moisture content and the measured soil moisture content is large), which makes the simulation results inconsistent with the actual water-salt leaching process in the soil column device; therefore, how to adaptively adjust the simulation process of leaching under the premise of dynamic changes in the physical properties of the soil has become a difficult problem faced by the industry. Summary of the invention

[0004] The present application provides a soil column device and method for simulating soil water-salt leaching under drip irrigation conditions, which can adaptively adjust the simulation process of leaching under the premise of dynamic changes in soil physical properties.

[0005] In a first aspect, the present application provides a method for simulating soil water-salt leaching, comprising the following steps: Based on the distribution of different soil particles in the soil column device, the drip irrigation simulation of the water-salt leaching process is carried out to generate simulated moisture information at different depths in the soil column device; Pre-arrange an intelligent moisture sensor and an intelligent salt concentration sensor in each soil layer of the soil column device, and automatically collect soil moisture information at different depths in the soil column device during drip irrigation through the preset intelligent moisture sensor, so as to determine the fit between the simulated moisture information and the soil moisture information; The salt concentration in the soil column device during drip irrigation is automatically collected by the preset intelligent salt concentration sensor, and the water-salt permeability coefficient during the migration of water and salt in the soil column device is determined according to the soil moisture information and the salt concentration; Adjusting the saturated hydraulic conductivity of the soil when the soil column device performs drip irrigation simulation according to the fit between the simulated moisture information and the soil moisture information; The sensitivity of the saturated hydraulic conductivity of the soil during water-salt leaching is determined based on the adjustment result and the water-salt permeability coefficient.

[0006] In some embodiments, determining the degree of fit between the simulated moisture information and the soil moisture information specifically includes: Determine the fitting deviation between the simulated moisture information and the soil moisture information at each sampling time at the selected depth; Determining the average water content at a selected depth in the soil column device using the soil moisture information; The degree of fit between the simulated moisture information and the soil moisture information is determined by all fitting deviations and the average moisture content.

[0007] In some embodiments, determining the water-salt permeability coefficient when water and salt migrate in the soil column device according to the soil moisture information and the salt concentration specifically includes: Determining the permeability ratio during solute migration by using the soil moisture information and the salt concentration; Obtain the degradation rate of salt in the soil column device; The water-salt permeability coefficient during the migration of water and salt in the soil column device is determined by the permeability ratio and the degradation rate.

[0008] In some embodiments, determining the permeability ratio during solute migration by using the soil moisture information and the salt concentration specifically includes: Determine the moisture change between each soil moisture content and the adjacent soil moisture content corresponding to the selected depth in the soil column device through the soil moisture information; determining the amount of salt variation between each salt concentration and an adjacent salt concentration at a selected depth in the soil column device; The permeability ratio for solute migration is determined by the total water change and the total salt change.

[0009] In some embodiments, determining the water-salt permeability coefficient during the migration of water and salt in the soil column device by using the permeability ratio and the degradation rate specifically includes: Determine the salt migration ratio in the soil through the degradation rate; The water-salt permeability coefficient during the migration of water and salt in the soil column device is determined based on the salt migration ratio and the permeability ratio.

[0010] In some embodiments, adjusting the saturated hydraulic conductivity of the soil by the soil column device when performing drip irrigation simulation based on the fit between the simulated moisture information and the soil moisture information specifically includes: Setting a fitting threshold for the drip irrigation simulation; Obtain the saturated hydraulic conductivity of the soil in the soil column device when performing drip irrigation simulation; determining a transitional saturated hydraulic conductivity based on a fit between the simulated moisture information and the soil moisture information and the saturated hydraulic conductivity; Determining the optimal fit of the drip irrigation simulation through the transition saturated hydraulic conductivity; When the optimized fitting degree is greater than or equal to the fitting degree threshold, the transitional saturated hydraulic conductivity is used as an adjustment result of the saturated hydraulic conductivity of the soil when the soil column device performs drip irrigation simulation.

[0011] In some embodiments, determining the sensitivity of the saturated hydraulic conductivity of the soil to water-salt leaching according to the adjustment result and the water-salt permeability coefficient specifically includes: Obtaining the adjustment result of the saturated hydraulic conductivity of the soil when the soil column device performs drip irrigation simulation; determining a hydraulic conductivity offset according to the adjustment result; Determining the disturbance amount of the water-salt permeability coefficient; The sensitivity of the saturated hydraulic conductivity of the soil during water-salt leaching is determined based on the hydraulic conductivity offset and the disturbance amount of the water-salt permeability coefficient.

[0012] In a second aspect, the present application provides a soil column device for simulating soil water-salt leaching under drip irrigation conditions, including a soil water-salt leaching simulation unit, wherein the soil water-salt leaching simulation unit includes: A generation module is used to simulate the water-salt leaching process by drip irrigation based on the distribution of different soil particles in the soil column device, and then generate simulated moisture information at different depths in the soil column device; A processing module, which is used to automatically collect soil moisture information at different depths in the soil column device during drip irrigation by using the preset intelligent moisture sensor after setting the intelligent moisture sensor and the intelligent salt concentration sensor in each soil layer of the soil column device, and then determine the fit between the simulated moisture information and the soil moisture information; The processing module is also used to automatically collect the salt concentration in the soil column device during drip irrigation through the preset intelligent salt concentration sensor, and determine the water-salt permeability coefficient during the migration of water and salt in the soil column device according to the soil moisture information and the salt concentration; The processing module is further used to adjust the saturated hydraulic conductivity of the soil when the soil column device performs drip irrigation simulation according to the fit between the simulated moisture information and the soil moisture information; The execution module is used to determine the sensitivity of the saturated hydraulic conductivity of the soil during water-salt leaching according to the adjustment result and the water-salt permeability coefficient.

[0013] In a third aspect, the present application provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above-mentioned soil water-salt leaching simulation method when executing the computer program.

[0014] In a fourth aspect, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above-mentioned soil water-salt leaching simulation method are implemented.

[0015] The technical solution provided by the embodiments disclosed in this application has the following beneficial effects: In the soil column device and method for simulating the water-salt leaching effect of soil under drip irrigation conditions provided in the present application, the water-salt leaching process is simulated by drip irrigation through the distribution of different soil particles in the soil column device, and then simulated moisture information at different depths in the soil column device is generated; intelligent moisture sensors and intelligent salt concentration sensors are pre-set in each soil layer of the soil column device, and the soil moisture information at different depths in the soil column device during drip irrigation is automatically collected by the preset intelligent moisture sensor, and then the fit between the simulated moisture information and the soil moisture information is determined; the salt concentration in the soil column device during drip irrigation is automatically collected by the preset intelligent salt concentration sensor, and the water-salt permeability coefficient during the migration of water and salt in the soil column device is determined according to the soil moisture information and the salt concentration; the saturated hydraulic conductivity of the soil of the soil column device during drip irrigation simulation is adjusted according to the fit between the simulated moisture information and the soil moisture information; the sensitivity of the saturated hydraulic conductivity of the soil during water-salt leaching is determined according to the adjustment result and the water-salt permeability coefficient.

[0016] It can be seen that in the present application, the water-salt leaching process is simulated by drip irrigation through the distribution of different soil particles in the soil column device, and then the simulated moisture information at different depths in the soil column device is generated, and then an intelligent moisture sensor and an intelligent salt concentration sensor are set in each soil layer of the soil column device, and the soil moisture information at different depths in the soil column device during drip irrigation is automatically collected by the preset intelligent moisture sensor, and then the consistency between the simulated moisture information and the soil moisture information is determined, that is, the degree of fit, so as to dynamically capture the deviation between the simulation and the actual, and then, the degree of fit is used as a feedback parameter, so that the simulation model can be based on the real-time changes in soil moisture content. Iterative optimization is performed (i.e., the saturated hydraulic conductivity of the soil is adjusted when the soil column device is performing drip irrigation simulation). Then, the water-salt permeability coefficient is dynamically calculated by real-time monitoring of the salt concentration and combining with the moisture information, thereby improving the simulation ability of the solute migration behavior and making the model adapt to the changes in the water-salt ratio in the soil. Finally, the sensitivity of the saturated hydraulic conductivity of the soil during water-salt leaching is determined based on the adjustment result and the water-salt permeability coefficient, thereby identifying the key parameters and processes that affect the leaching effect, so that the simulation process has an adaptive adjustment mechanism. In summary, this scheme can adaptively adjust the simulation process of leaching under the premise of dynamic changes in the physical properties of the soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of a process of simulating a method for soil water-salt leaching according to some embodiments of the present application; Figure 2 is a schematic diagram of a process for generating simulated moisture information according to some embodiments of the present application; Figure 3is a schematic diagram of a process for determining a degree of fit according to some embodiments of the present application; Figure 4 is a schematic structural diagram of a soil water-salt leaching simulation unit according to some embodiments of the present application; Figure 5 It is a diagram of the internal structure of a computer device for implementing a method for simulating soil water-salt leaching as shown in some embodiments of the present application. DETAILED DESCRIPTION

[0018] In order to better understand the technical solution in this embodiment, the technical solution in this embodiment will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0019] refer to Figure 1 , which is a schematic flow chart of a soil water-salt leaching simulation method according to some embodiments of the present application. The soil water-salt leaching simulation method 100 mainly includes the following steps: In step 101, drip irrigation is performed to simulate the water-salt leaching process based on the distribution of different soil particles in the soil column device, thereby generating simulated moisture information at different depths in the soil column device.

[0020] Preferably, the soil particles in the soil column device can be settled in the liquid, and the distribution of soil particles in each layer after different time intervals can be measured, and then the physical properties of the soil can be deduced from the distribution of the soil particles, and the simulation parameters (soil volume moisture content, soil permeability coefficient, residual moisture content, saturated moisture content, saturated permeability coefficient and inverse of air intake suction) during drip irrigation simulation can be derived in combination with empirical formulas. Figure 2 As shown, this figure is a schematic diagram of the process of generating simulated moisture information shown in some embodiments of the present application. After all simulation parameters are taken as input, the HYDRUS-1D model in the prior art is used to describe the soil moisture characteristic curve in the soil column device. Finally, the uniform moisture content in the soil column device is used as the initial condition, and the input water flow of the drip irrigation device is used as the boundary condition. The Richards equation and numerical solution technology are combined to generate the simulated moisture content at different depths in the soil column device, and then all the simulated moisture contents are used as the simulated moisture information at different depths in the soil column device. In other embodiments, other methods can also be used to generate, which is not limited here.

[0021] In step 102, intelligent moisture sensors and intelligent salt concentration sensors are pre-set in each soil layer of the soil column device, and the preset intelligent moisture sensors are used to automatically collect soil moisture information at different depths in the soil column device during drip irrigation, thereby determining the degree of fit between the simulated moisture information and the soil moisture information.

[0022] It should be noted that after the drip irrigation of the soil column device begins, the present application pre-sets intelligent moisture sensors and intelligent salt concentration sensors at different depths (such as 10 cm, 30 cm, 50 cm, etc.) in the soil column device, that is, in each soil layer. The intelligent moisture sensor collects the soil moisture content in the soil in real time with a predetermined sampling period, so that the collected soil moisture content is used as the soil moisture information at different depths in the soil column device. In other embodiments, other methods can also be used to determine, which is not limited here. In addition, the predetermined sampling period is 3 minutes, and the data dimension between the simulated moisture information and the soil moisture information is the same.

[0023] It should be noted that the present application selects 30 cm depth in the soil column device as the selected depth, thereby retaining most of the information under the premise of reducing the computational complexity. Figure 3 As shown, this figure is a schematic diagram of a process of determining the degree of fit shown in some embodiments of the present application. The degree of fit between the simulated moisture information and the soil moisture information can be determined by the following steps: First, in 1021, the fitting deviation between the simulated moisture information and the soil moisture information at each sampling time at the selected depth is determined; Then, in 1022, the average water content at the selected depth in the soil column device is determined by using the soil moisture information; Finally, in 1023, the degree of fit between the simulated moisture information and the soil moisture information is determined through all fitting deviations and the average moisture content.

[0024] In specific implementation, determining the fitting deviation amount between the simulated moisture information and the soil moisture information at the selected depth at each sampling time can be achieved in the following manner, namely: first, selecting a sampling time, obtaining the simulated moisture content corresponding to the simulated moisture information at the selected depth in the soil column device at the sampling time and the soil moisture content corresponding to the soil moisture information, then taking the difference between the simulated moisture content and the soil moisture content as the fitting deviation amount between the simulated moisture information and the soil moisture information at the sampling time, repeating the above steps, determining the fitting deviation amount between the simulated moisture information and the soil moisture information at the remaining sampling times, thereby obtaining the fitting deviation amount between the simulated moisture information and the soil moisture information at the selected depth at each sampling time; as a preferred embodiment, determining the average moisture content at the selected depth in the soil column device through the soil moisture information can be achieved in the following manner, namely: first, obtaining the soil moisture content corresponding to the soil moisture information at the selected depth in the soil column device at all sampling times, then taking the average value of all soil moisture contents as the average moisture content, and in other embodiments, other methods can also be used for determination, which is not limited here.

[0025] In specific implementation, the degree of fit between the simulated moisture information and the soil moisture information can be determined by all fitting deviations and the average moisture content in the following manner, namely: first, the square values ​​of all fitting deviations are added and compared with the sum of the square differences between each soil moisture content in the soil moisture information and the average moisture content, and then, 1 is subtracted from the above result as the degree of fit between the simulated moisture information and the soil moisture information. In other embodiments, other methods may be used to determine the degree of fit, which is not limited here.

[0026] It should be noted that the fitting deviation described in the present application refers to the difference between the simulated moisture content corresponding to each sampling time and the measured soil moisture content at the selected depth in the soil column device, which reflects the degree of difference between the simulated moisture content and the corresponding soil moisture content. The larger the fitting deviation, the higher the degree of difference between the simulated moisture content and the corresponding soil moisture content, and the smaller the fitting deviation, the lower the degree of difference between the simulated moisture content and the corresponding soil moisture content; in addition, the degree of fit between the soil moisture contents reflects the degree of consistency between the simulated moisture content and the corresponding soil moisture content. The larger the degree of fit, the higher the degree of consistency between the simulated moisture content and the corresponding soil moisture content, and the smaller the degree of fit, the lower the degree of consistency between the simulated moisture content and the corresponding soil moisture content.

[0027] In step 103, the salt concentration in the soil column device during drip irrigation is automatically collected by the preset intelligent salt concentration sensor, and the water-salt permeability coefficient during the migration of water and salt in the soil column device is determined according to the soil moisture information and the salt concentration.

[0028] It should be noted that the intelligent salt concentration sensor calculates the salt concentration by measuring the conductivity of the soil solution. In addition, the data dimension of the salt concentration is the same as the data dimension of the soil moisture content. In addition, it should be noted that the present application selects a depth of 30 cm in the soil column device as the selected depth, thereby retaining most of the information under the premise of reducing the calculation complexity; in some embodiments, the water-salt permeability coefficient when water and salt migrate in the soil column device according to the soil moisture information and the salt concentration can be determined by the following steps: Determining the permeability ratio during solute migration by using the soil moisture information and the salt concentration; Obtain the degradation rate of salt in the soil column device; The water-salt permeability coefficient during the migration of water and salt in the soil column device is determined by the permeability ratio and the degradation rate.

[0029] In some embodiments, determining the permeability ratio during solute migration by using the soil moisture information and the salt concentration can be achieved by using the following steps: Determine the moisture change between each soil moisture content and the adjacent soil moisture content corresponding to the selected depth in the soil column device through the soil moisture information; determining the amount of salt variation between each salt concentration and an adjacent salt concentration at a selected depth in the soil column device; The permeability ratio for solute migration is determined by the total water change and the total salt change.

[0030] In specific implementation, the following method is used to determine the moisture change amount between each soil moisture content and the adjacent moisture content corresponding to the selected depth in the soil column device through the soil moisture information, namely: first, the soil moisture content at the next sampling moment of each soil moisture content in the soil moisture information is used as the adjacent moisture content of each soil moisture content, and then the absolute value of the difference between each soil moisture content and the corresponding adjacent moisture content is used as the moisture change amount, thereby obtaining the moisture change amount between each soil moisture content and the adjacent moisture content corresponding to the selected depth in the soil column device; as a preferred embodiment, the following method is used to determine the salt change amount between each salt concentration and the corresponding adjacent salt concentration at the selected depth in the soil column device, namely: first, the salt concentration at the next sampling moment of each salt concentration is used as the adjacent salt concentration of each salt concentration, and then the absolute value of the difference between each salt concentration and the corresponding adjacent salt concentration is used as the salt change amount, thereby obtaining the salt change amount between each salt concentration and the adjacent salt concentration at the selected depth in the soil column device.

[0031] It should be noted that the moisture change reflects the degree of change of the soil moisture content in the soil column device at adjacent sampling times. The larger the moisture change, the higher the degree of change of the soil moisture content in the soil column device at adjacent sampling times. The smaller the moisture change, the lower the degree of change of the soil moisture content in the soil column device at adjacent sampling times. Similarly, the salt change reflects the degree of change of the salt concentration in the soil column device at adjacent sampling times. The larger the salt change, the higher the degree of change of the salt concentration in the soil column device at adjacent sampling times. The smaller the salt change, the lower the salt concentration in the soil column device at adjacent sampling times. The lower the degree of change of the salt concentration in the device at adjacent sampling moments; therefore, the permeability ratio described in the present application, that is, the relative rate of migration of water and salt in the soil in the soil column device, the larger the permeability ratio, the faster the migration rate of water in the soil relative to the salt, and the smaller the permeability ratio, the faster the migration rate of salt in the soil relative to the water; in specific implementation, determining the permeability ratio during solute migration by all water changes and all salt changes can be achieved in the following manner, namely: comparing the sum of all water changes with the sum of all salt changes as the permeability ratio during solute migration.

[0032] It should be noted that before drip irrigation begins, the present application measures the initial salt concentration of the soil column device at a selected depth through a conductivity sensor, obtains the salt concentration of all sampling moments at the selected depth in the soil column device, and then selects the salt concentration at a sampling moment, subtracts the salt concentration at the previous sampling moment from the salt concentration at the sampling moment, and compares the result with the salt concentration at the current sampling moment, repeats the above steps, determines the result corresponding to the salt concentration at each sampling moment, and finally, takes the average value of all the results corresponding to the salt concentration as the degradation rate of salt in the soil during drip irrigation. Other methods may also be used to achieve this in other embodiments, which are not limited here.

[0033] Among them, in some embodiments, determining the water-salt permeability coefficient during the migration of water and salt in the soil column device by using the permeability ratio and the degradation rate can be achieved by the following steps: Determine the salt migration ratio in the soil through the degradation rate; The water-salt permeability coefficient during the migration of water and salt in the soil column device is determined based on the salt migration ratio and the permeability ratio.

[0034] As a preferred embodiment, determining the salt migration ratio in the soil through the degradation rate can be achieved in the following manner, namely: taking the result of subtracting the degradation rate from 1 as the salt migration ratio in the soil; as a preferred embodiment, determining the water-salt permeability coefficient during water and salt migration in the soil column device based on the salt migration ratio and the permeability ratio can be achieved in the following manner, namely: taking the product of the permeability ratio and the salt migration ratio as the water-salt permeability coefficient during water and salt migration in the soil column device. In other embodiments, other methods can also be used, which are not limited here.

[0035] It should be noted that the salt migration ratio described in the present application refers to the ratio of the amount of salt migration in the soil to the initial amount of salt during drip irrigation, which reflects the degree of salt migration in the soil. The larger the salt migration ratio, the higher the degree of salt migration in the soil, and the smaller the salt migration ratio, the lower the degree of salt migration in the soil. In addition, the water-salt permeability coefficient describes the salt removal efficiency caused by leaching during the migration of water and salt in the soil column device. The larger the water-salt permeability coefficient, the higher the salt removal efficiency caused by leaching during the migration of water and salt in the soil column device, and the smaller the water-salt permeability coefficient, the lower the salt removal efficiency caused by leaching during the migration of water and salt in the soil column device.

[0036] In step 104, the saturated hydraulic conductivity of the soil when the soil column device performs drip irrigation simulation is adjusted according to the fit between the simulated moisture information and the soil moisture information.

[0037] In some embodiments, adjusting the saturated hydraulic conductivity of the soil when the soil column device performs drip irrigation simulation by the degree of fit between the simulated moisture information and the soil moisture information can be achieved by the following steps: Setting a fitting threshold for the drip irrigation simulation; Obtain the saturated hydraulic conductivity of the soil in the soil column device when performing drip irrigation simulation; determining a transitional saturated hydraulic conductivity based on a fit between the simulated moisture information and the soil moisture information and the saturated hydraulic conductivity; Determining the optimal fit of the drip irrigation simulation through the transition saturated hydraulic conductivity; When the optimized fitting degree is greater than or equal to the fitting degree threshold, the transitional saturated hydraulic conductivity is used as an adjustment result of the saturated hydraulic conductivity of the soil when the soil column device performs drip irrigation simulation.

[0038] It should be noted that the fit threshold during the drip irrigation simulation can be set based on the simulation accuracy requirements. In some preferred embodiments, in high-precision simulation requirements (for example, laboratories), the fit threshold is set to [0.95, 1); in application scenarios with normal accuracy requirements (for example, engineering applications and agricultural management), the fit threshold is set to [0.85, 0.95). In other embodiments, other methods can be used for setting, which will not be repeated here.

[0039] It should be noted that when the degree of fit is greater than or equal to the degree of fit threshold, the degree of fit is directly used as the optimized degree of fit; in specific implementation, the transitional saturated hydraulic conductivity can be determined based on the degree of fit between the simulated moisture information and the soil moisture information and the saturated hydraulic conductivity. The following method can be used, namely: when the degree of fit between the simulated moisture information and the soil moisture information is less than the degree of fit threshold, the saturated hydraulic conductivity is multiplied by 1.1 as the transitional saturated hydraulic conductivity in this application. In other embodiments, it can also be determined by other methods, which are not limited here.

[0040] In specific implementation, the optimal fitting degree of the drip irrigation simulation determined by the transition saturated hydraulic conductivity can be achieved in the following manner, namely: after the transition saturated hydraulic conductivity is used as the saturated hydraulic conductivity in the simulation parameters again, other simulation parameters are kept unchanged, all simulation parameters are used as input, and the HYDRUS-1D model in the prior art is used to describe the soil moisture characteristic curve in the soil column device. Finally, the uniform moisture content in the soil column device is used as the initial condition, the input water flow of the drip irrigation device is used as the boundary condition, and the simulated moisture content at different depths in the soil column device is generated by combining the Richards equation and the numerical solution technology, and the above-mentioned process of the fitting degree between the simulated moisture information and the soil moisture information is repeated, and the obtained fitting degree is used as the optimized fitting degree in the present application; in addition, in some preferred embodiments, when the optimized fitting degree is less than the fitting degree threshold, the optimized fitting degree is used as the new fitting degree again, and the above-mentioned process of determining the optimized fitting degree is repeated until the optimized fitting degree is greater than or equal to the fitting degree threshold.

[0041] It should be noted that, in the present application, the transitional saturated hydraulic conductivity is taken as a temporary value obtained by adjusting the saturated hydraulic conductivity when the degree of fit is less than the degree of fit threshold, so that the transitional saturated hydraulic conductivity is judged by the optimized degree of fit, that is, when the optimized degree of fit corresponding to the adjustment result of the saturated hydraulic conductivity is greater than or equal to the degree of fit threshold, the transitional saturated hydraulic conductivity is taken as the final value of the saturated hydraulic conductivity, so as to find the most suitable saturated hydraulic conductivity value, thereby improving the reliability of the model.

[0042] In step 105, the sensitivity of the saturated hydraulic conductivity of the soil during water-salt leaching is determined according to the adjustment result and the water-salt permeability coefficient.

[0043] In some embodiments, determining the sensitivity of the saturated hydraulic conductivity of the soil during water-salt leaching according to the adjustment result and the water-salt permeability coefficient can be achieved by using the following steps: Obtaining the adjustment result of the saturated hydraulic conductivity of the soil when the soil column device performs drip irrigation simulation; determining a hydraulic conductivity offset according to the adjustment result; Determining the disturbance amount of the water-salt permeability coefficient; The sensitivity of the saturated hydraulic conductivity of the soil during water-salt leaching is determined based on the hydraulic conductivity offset and the disturbance amount of the water-salt permeability coefficient.

[0044] In specific implementation, the hydraulic conductivity offset is determined according to the saturated hydraulic conductivity adjustment result of the soil in the drip irrigation simulation in the following manner, namely: after determining the saturated hydraulic conductivity adjustment result of the soil in the drip irrigation simulation minus the saturated hydraulic conductivity result, the result obtained is used as the hydraulic conductivity offset; as a preferred embodiment, the disturbance amount of the water-salt permeability coefficient can be determined in the following manner, namely: first, after the saturated hydraulic conductivity adjustment result of the soil in the drip irrigation simulation is used as a simulation parameter, other simulation parameters are kept unchanged, all simulation parameters are used as input, and the HYDRUS-1D model in the prior art is used to describe the soil moisture characteristic curve in the soil column device; finally, the uniform moisture content in the soil column device is used as the initial condition, the input water flow of the drip irrigation device is used as the boundary condition, and the simulated moisture information of different depths in the soil column device is generated in combination with the Richards equation and the numerical solution technology; after the simulated moisture information is used as the soil moisture information, the above process of determining the water-salt permeability coefficient from the soil moisture information is repeated, and then the absolute value of the difference between the obtained result and the water-salt permeability coefficient is used as the disturbance amount of the water-salt permeability coefficient.

[0045] It should be noted that the hydraulic conductivity offset described in the present application represents the adjustment range of the saturated hydraulic conductivity. The larger the hydraulic conductivity offset, the larger the adjustment range of the saturated hydraulic conductivity. The smaller the hydraulic conductivity offset, the smaller the adjustment range of the saturated hydraulic conductivity. In addition, the disturbance amount of the water-salt permeability coefficient represents the degree of influence of the adjustment of the saturated hydraulic conductivity on the water-salt permeability coefficient. The larger the disturbance amount of the water-salt permeability coefficient, the higher the influence of the adjustment of the saturated hydraulic conductivity on the water-salt permeability coefficient. The smaller the disturbance amount of the water-salt permeability coefficient, the lower the influence of the adjustment of the saturated hydraulic conductivity on the water-salt permeability coefficient.

[0046] It should be noted that the sensitivity of the saturated hydraulic conductivity in the simulation of the water-salt leaching process measures the degree of change of the water-salt permeability coefficient predicted by the model when the saturated hydraulic conductivity changes. The greater the sensitivity, the higher the degree of change of the water-salt permeability coefficient predicted by the model when the saturated hydraulic conductivity changes. The smaller the sensitivity, the lower the degree of change of the water-salt permeability coefficient predicted by the model when the saturated hydraulic conductivity changes. As a preferred embodiment, the sensitivity of the saturated hydraulic conductivity of the soil to water-salt leaching based on the hydraulic conductivity offset and the disturbance of the water-salt permeability coefficient can be achieved in the following manner, namely: first, determining the result of comparing the disturbance of the water-salt permeability coefficient with the hydraulic conductivity offset, then determining the result of comparing the saturated hydraulic conductivity adjustment result with the water-salt permeability coefficient, and finally, taking the product of the above two results as the sensitivity of the saturated hydraulic conductivity of the soil to water-salt leaching.

[0047] It should be noted that the saturated hydraulic conductivity is a simulation parameter that directly controls the penetration rate of water and salt in the soil. It determines the speed of water infiltration and directly affects the migration depth and speed of the wetting front. The essence of water-salt leaching is the migration of salt carried by water. Therefore, the speed of water migration directly determines the migration range of salt. For example, in soils with high saturated hydraulic conductivity (such as sand), water carries salt to infiltrate rapidly, and salt is more easily leached to deep layers. In soils with low saturated hydraulic conductivity (such as clay), water moves slowly, and salt may accumulate in the surface or shallow layer and is difficult to be effectively leached. Therefore, after determining the sensitivity of the saturated hydraulic conductivity in the simulation of water-salt leaching process, the application can adjust the simulation method based on the sensitivity, so as to obtain the desired effect. In order to more accurately describe the characteristics of the actual soil, for example, when the sensitivity is high, the inhomogeneity of the soil needs to be considered. Preferably, the spatial random distribution of the sensitivity can be generated by adopting the Kriging interpolation or geostatistical method in the prior art, instead of the uniform assumption, so as to obtain the spatial heterogeneity of the actual soil, thereby improving the accuracy of the water-salt leaching process. In other embodiments, the high sensitivity of the saturated hydraulic conductivity also characterizes the existence of significant nonlinear effects in the water-salt leaching simulation process, that is, the relationship between the moisture content and the salt concentration in the soil is a complex functional relationship. Preferably, the water-salt leaching process can be more accurately described by introducing a coupling model. In other embodiments, other methods can also be used to achieve this, which is not limited here. In addition, in another aspect of the present application, in some embodiments, the present application provides a soil column device for simulating soil water and salt leaching under drip irrigation conditions, the device comprising a soil water and salt leaching simulation unit, referring to Figure 4 , which is a schematic diagram of the structure of a soil water-salt leaching simulation unit according to some embodiments of the present application. The soil water-salt leaching simulation unit 200 includes: a generation module 201, a processing module 202 and an execution module 203, which are described as follows: The generation module 201 in the present application mainly performs drip irrigation simulation on the water-salt leaching process based on the distribution of different soil particles in the soil column device, thereby generating simulated moisture information at different depths in the soil column device; Processing module 202, in the present application, the processing module 202 is mainly used to set an intelligent moisture sensor and an intelligent salt concentration sensor in each soil layer of the soil column device, and automatically collect soil moisture information at different depths in the soil column device during drip irrigation through the preset intelligent moisture sensor, and then determine the fit between the simulated moisture information and the soil moisture information; In addition, the processing module 202 in the present application is also used to automatically collect the salt concentration in the soil column device during drip irrigation through the preset intelligent salt concentration sensor, and determine the water-salt permeability coefficient when the water and salt migrate in the soil column device according to the soil moisture information and the salt concentration; In addition, the processing module 202 in the present application is also used to adjust the saturated hydraulic conductivity of the soil when the soil column device performs drip irrigation simulation according to the fit between the simulated moisture information and the soil moisture information; Execution module 203, in the present application, execution module 203 is mainly used to determine the sensitivity of the saturated hydraulic conductivity of the soil during water-salt leaching based on the adjustment result and the water-salt permeability coefficient.

[0048] In addition, the present application also provides a computer device, which includes a memory and a processor, the memory stores codes, and the processor is configured to obtain the codes and execute the above-mentioned soil water-salt leaching simulation method.

[0049] In some embodiments, reference Figure 5 , which is an internal structure diagram of a computer device for implementing a soil water-salt leaching simulation method according to some embodiments of the present application. The soil water-salt leaching simulation method in the above embodiment can be Figure 5 The computer device 300 shown in the figure is implemented, and the computer device 300 includes at least one processor 301, a communication bus 302, a memory 303 and at least one communication interface 304.

[0050] The processor 301 may be a general-purpose central processing unit (CPU), or an application specific integrated circuit (ASIC) or one or more processors for controlling the execution of the soil water-salt leaching simulation method in the present application.

[0051] The communication bus 302 is used to transmit information between the above components.

[0052] The memory 303 may be a read only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read only memory (EEPROM), a compact disc read only memory (CD ROM) or other optical disc storage, an optical disc storage (including a compressed optical disc, a laser disc, an optical disc, a digital versatile disc, a Blu-ray disc, etc.), a magnetic disk or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of an instruction or data structure and can be accessed by a computer, but is not limited thereto. The memory 303 may exist independently and be connected to the processor 301 via the communication bus 302. The memory 303 may also be integrated with the processor 301.

[0053] The memory 303 is used to store the program code for executing the solution of the present application, and the execution is controlled by the processor 301. The processor 301 is used to execute the program code stored in the memory 303. The program code may include one or more software modules. The soil water-salt leaching simulation method in the above embodiment can be implemented by the processor 301 and one or more software modules in the program code in the memory 303.

[0054] The communication interface 304 uses any transceiver or other device for communicating with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc.

[0055] In a specific implementation, as an embodiment, a computer device may include multiple processors, each of which may be a single-core (single CPU) processor or a multi-core (multi CPU) processor. The processor here may refer to one or more devices, circuits, and / or processing cores for processing data (such as computer program instructions).

[0056] The above-mentioned computer device may be a general-purpose computer device or a special-purpose computer device. In a specific implementation, the computer device may be a desktop computer, a portable computer, a network server, a personal digital assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, a communication device or an embedded device. The embodiment of the present application does not limit the type of computer device.

[0057] In addition, the present application also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the above-mentioned soil water-salt leaching simulation method is implemented.

[0058] In summary, in the soil column device and method for simulating soil water-salt leaching under drip irrigation conditions disclosed in the embodiments of the present application, the water-salt leaching process is simulated by drip irrigation through the distribution of different soil particles in the soil column device, and then simulated moisture information at different depths in the soil column device is generated; intelligent moisture sensors and intelligent salt concentration sensors are pre-set in each soil layer of the soil column device, and the soil moisture information at different depths in the soil column device during drip irrigation is automatically collected by the preset intelligent moisture sensor, and then the fit between the simulated moisture information and the soil moisture information is determined; the salt concentration in the soil column device during drip irrigation is automatically collected by the pre-trial intelligent salt concentration sensor, and the water-salt permeability coefficient during the migration of water and salt in the soil column device is determined according to the soil moisture information and the salt concentration; the saturated hydraulic conductivity of the soil of the soil column device during drip irrigation simulation is adjusted according to the fit between the simulated moisture information and the soil moisture information; the sensitivity of the saturated hydraulic conductivity of the soil during water-salt leaching is determined according to the adjustment result and the water-salt permeability coefficient; the simulation process of leaching can be adaptively adjusted under the premise of dynamic changes in the physical properties of the soil.

[0059] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0060] Obviously, those skilled in the art may make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A soil water-salt leaching simulation method for simulating soil water-salt leaching in a soil column device under drip irrigation conditions, characterized in that: The steps include: Based on the distribution of different soil particles in the soil column device, the drip irrigation simulation of the water-salt leaching process is carried out to generate simulated moisture information at different depths in the soil column device; Pre-arrange an intelligent moisture sensor and an intelligent salt concentration sensor in each soil layer of the soil column device, and automatically collect soil moisture information at different depths in the soil column device during drip irrigation through the preset intelligent moisture sensor, so as to determine the fit between the simulated moisture information and the soil moisture information; The salt concentration in the soil column device during drip irrigation is automatically collected by the preset intelligent salt concentration sensor, and the water-salt permeability coefficient during the migration of water and salt in the soil column device is determined according to the soil moisture information and the salt concentration; Adjusting the saturated hydraulic conductivity of the soil when the soil column device performs drip irrigation simulation according to the fit between the simulated moisture information and the soil moisture information; The sensitivity of the saturated hydraulic conductivity of the soil during water-salt leaching is determined based on the adjustment result and the water-salt permeability coefficient.

2. The method according to claim 1, characterized in that Determining the degree of fit between the simulated moisture information and the soil moisture information specifically includes: Determine the fitting deviation between the simulated moisture information and the soil moisture information at each sampling time at the selected depth; Determining the average water content at a selected depth in the soil column device using the soil moisture information; The degree of fit between the simulated moisture information and the soil moisture information is determined by all fitting deviations and the average moisture content.

3. The method according to claim 1, characterized in that Determining the water-salt permeability coefficient when water and salt migrate in the soil column device according to the soil moisture information and the salt concentration specifically includes: Determining the permeability ratio during solute migration by using the soil moisture information and the salt concentration; Obtain the degradation rate of salt in the soil column device; The water-salt permeability coefficient during the migration of water and salt in the soil column device is determined by the permeability ratio and the degradation rate.

4. The method according to claim 3, characterized in that Determining the permeability ratio during solute migration by using the soil moisture information and the salt concentration specifically includes: Determine the moisture change between each soil moisture content and the adjacent soil moisture content corresponding to the selected depth in the soil column device through the soil moisture information; determining the amount of salt variation between each salt concentration and an adjacent salt concentration at a selected depth in the soil column device; The permeability ratio for solute migration is determined by the total water change and the total salt change.

5. The method according to claim 3, characterized in that Determining the water-salt permeability coefficient during the migration of water and salt in the soil column device by using the permeability ratio and the degradation rate specifically includes: Determine the salt migration ratio in the soil through the degradation rate; The water-salt permeability coefficient during the migration of water and salt in the soil column device is determined based on the salt migration ratio and the permeability ratio.

6. The method according to claim 1, characterized in that Adjusting the saturated hydraulic conductivity of the soil by the soil column device when performing drip irrigation simulation through the degree of fit between the simulated moisture information and the soil moisture information specifically includes: Setting a fitting threshold for the drip irrigation simulation; Obtain the saturated hydraulic conductivity of the soil in the soil column device when performing drip irrigation simulation; determining a transitional saturated hydraulic conductivity based on a fit between the simulated moisture information and the soil moisture information and the saturated hydraulic conductivity; Determining the optimal fit of the drip irrigation simulation through the transition saturated hydraulic conductivity; When the optimized fitting degree is greater than or equal to the fitting degree threshold, the transitional saturated hydraulic conductivity is used as an adjustment result of the saturated hydraulic conductivity of the soil when the soil column device performs drip irrigation simulation.

7. The method according to claim 1, characterized in that Determining the sensitivity of the saturated hydraulic conductivity of the soil during water-salt leaching based on the adjustment result and the water-salt permeability coefficient specifically includes: Obtaining the adjustment result of the saturated hydraulic conductivity of the soil when the soil column device performs drip irrigation simulation; determining a hydraulic conductivity offset according to the adjustment result; Determining the disturbance amount of the water-salt permeability coefficient; The sensitivity of the saturated hydraulic conductivity of the soil during water-salt leaching is determined based on the hydraulic conductivity offset and the disturbance amount of the water-salt permeability coefficient.

8. A soil column device for simulating soil water and salt leaching under drip irrigation conditions, comprising a soil water and salt leaching simulation unit, characterized in that: The soil water-salt leaching simulation unit comprises: A generation module is used to simulate the water-salt leaching process by drip irrigation based on the distribution of different soil particles in the soil column device, and then generate simulated moisture information at different depths in the soil column device; A processing module, which is used to automatically collect soil moisture information at different depths in the soil column device during drip irrigation by using the preset intelligent moisture sensor after setting the intelligent moisture sensor and the intelligent salt concentration sensor in each soil layer of the soil column device, and then determine the fit between the simulated moisture information and the soil moisture information; The processing module is also used to automatically collect the salt concentration in the soil column device during drip irrigation through the preset intelligent salt concentration sensor, and determine the water-salt permeability coefficient during the migration of water and salt in the soil column device according to the soil moisture information and the salt concentration; The processing module is further used to adjust the saturated hydraulic conductivity of the soil when the soil column device performs drip irrigation simulation according to the fit between the simulated moisture information and the soil moisture information; The execution module is used to determine the sensitivity of the saturated hydraulic conductivity of the soil during water-salt leaching according to the adjustment result and the water-salt permeability coefficient.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the soil water-salt leaching simulation method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the soil water-salt leaching simulation method according to any one of claims 1 to 7 are implemented.

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