A method for monitoring and generating a scheme for repairing saline-alkali soil

Abstract

The application provides a saline-alkali soil salt-alkali dynamic monitoring and repair scheme generation method, comprising the following steps: collecting temperature values, salt conductivity values, and chloride ion concentrations, sulfate radical concentrations, and carbonate radical concentrations from each layer of soil to obtain real-time layer temperature distribution records and salt distribution records; for inverse temperature dissolved salts that migrate to deep layers, reading temperature values from deep layers to upper layers layer by layer and calculating theoretical saturation conductivity threshold values of each layer, comparing and identifying over-threshold layer positions layer by layer with measured conductivity to determine the crystallization precipitation depth interval of inverse temperature dissolved salts in low-temperature layers; grouping the improvement agent application layer according to the starting depth and the ending depth of each leaching layer, evaluating the coverage rate of each group and the coordinate set of the crystallization and precipitation layer, and obtaining the arrangement scheme of the improvement agent application layer.

Description

Technical Field

[0001] This invention relates to the field of information technology, and in particular to a method for generating dynamic monitoring and remediation schemes for saline-alkali soil. Background Technology

[0002] Soil improvement in saline-alkali land is a crucial research area for ensuring agricultural production and ecological security. In arid and semi-arid regions, the large-scale distribution of saline-alkali soil directly restricts crop growth and sustainable land use. Accurately understanding the dynamic migration patterns of salt is a key factor in improving improvement effectiveness. Currently, most saline-alkali land monitoring and remediation schemes rely mainly on fixed-depth sampling or single-period conductivity observations. These methods often overlook the real-time impact of continuous changes in the soil's internal temperature field on salt transport, leading to systematic biases in judging the actual distribution location of salt. Especially in areas with significant seasonal temperature differences, the contradiction between surface salt accumulation and deep-seated salt deposits is difficult to effectively capture, thus significantly reducing the targeted effectiveness of leaching and improvement measures. Soil salinization is essentially a comprehensive manifestation of the abnormal accumulation of various soluble salts in the soil, rather than the result of a single substance. Based on anionic composition, the main salts in saline-alkali soils can be divided into three main categories: chloride-type (represented by sodium chloride and magnesium chloride), sulfate-type (represented by sodium sulfate and magnesium sulfate), and carbonate-type (represented by sodium carbonate and sodium bicarbonate). Saline-alkali lands of different regions and origins are often dominated by one or a few types of salts, while other salts are present as companion elements. The accumulation of chlorides and sulfates primarily leads to soil salinization, manifested as increased osmotic pressure and inhibition of crop water absorption; the accumulation of carbonates, on the other hand, causes soil alkalization, resulting in a significant increase in soil pH, structural deterioration, and nutrient imbalance. In actual saline-alkali lands, these salts usually coexist in mixtures, and their proportions vary depending on time and location. This means that the management of salinization cannot treat all salts as a uniform whole, but must focus on the essential differences in the physicochemical properties of various salts. Because different salts have fundamental differences in solubility and temperature response characteristics, their migration behaviors also differ significantly under the same environmental conditions. Therefore, a deep understanding of the individual characteristics of each major salt is a prerequisite for understanding the dynamic distribution patterns of salts in complex saline-alkali soils. Temperature gradient, as the core factor driving the movement of soil moisture and salt, directly determines whether salts accumulate upwards or diffuse downwards due to changes in its direction and intensity. However, the solubility of different salts responds significantly differently to temperature. Sodium chloride solubility increases with increasing temperature, while sodium sulfate and sodium carbonate exhibit the characteristic that their solubility increases with decreasing temperature within a certain temperature range. This opposite temperature dependence results in different salts exhibiting opposite migration directions under the same temperature gradient. When the surface temperature is higher than the deep layer, it is conventionally believed that all salts should migrate upwards with evaporation and accumulate at the surface. However, salts with inverse temperature solubility characteristics are more likely to remain dissolved in the lower temperature of the deep layer and continue to migrate downwards until they reach saturation and crystallize in the colder layer. This opposite migration behavior occurs simultaneously in the soil profile, resulting in a complex stratified distribution pattern of salt crystallization and precipitation layers.For example, in saline-alkali land with large diurnal temperature variations in spring, when the surface soil warms rapidly due to sunlight while the deeper layers remain cooler, sodium chloride tends to migrate upwards with capillary water and concentrate and crystallize at the surface. However, sodium sulfate and sodium carbonate, due to the lower temperature and relatively higher solubility at deeper layers, may continue to migrate downwards and precipitate in large quantities at locations where the temperature further decreases in the middle and deeper layers, forming hidden deep salt crystallization zones. This phenomenon, where surface and deep salts migrate in opposite directions and crystallize in an alternating pattern, renders the practice of inferring the overall profile salinity dynamics solely based on surface salinity or average temperature difference ineffective. Leaching depths that are too shallow cannot remove deep salts, while leaching that is too deep wastes water resources and may bring deep salts back to the surface. Similarly, the application of soil amendments is ineffective because the location cannot accurately correspond to the actual crystallization layer. Therefore, accurately identifying the crystallization and precipitation layers of different salts at different depths in the soil profile during temperature gradient changes becomes a key issue for achieving precise stratified leaching and targeted application of soil amendments. Summary of the Invention

[0003] This invention provides a method for generating dynamic monitoring and remediation schemes for saline-alkali soil, mainly including:

[0004] Temperature, salinity conductivity, chloride, sulfate, and carbonate concentrations were collected from various soil layers to obtain real-time layer temperature and salinity distribution records. Based on these records, the solubility of sodium chloride, sodium sulfate, and sodium carbonate salts was identified by fitting chloride, sulfate, and carbonate concentrations to corresponding layer temperatures, thus determining the migration direction of each salt towards the surface or deeper layers under temperature gradients. For salts accumulating towards the surface, the impact of temperature differences on the rate of evaporation-driven salt uplift was quantified to assess the potential crystallization depth when salts migrate and accumulate at high temperatures. The current layer temperature data was extracted and compared layer by layer with the saturated solubility concentration threshold of each salt at that temperature to identify the set of coordinates of crystallization precipitation layers where the salt concentration exceeds the saturation concentration. For inversion-dissolved salts migrating to deeper layers, temperature values ​​are read layer by layer from deep to upward, and the theoretical saturation conductivity threshold for each layer is calculated. This is compared layer by layer with the measured conductivity to identify layers exceeding the threshold, thus determining the crystallization depth range of inversion-dissolved salts in low-temperature layers. By combining real-time layer temperature distribution records and salt distribution records, the crystallization depth of surface-accumulated salts and the precipitation depth range of deep-layer inversion salts are analyzed to identify overlapping and independent regions. Priority leaching levels are assigned to overlapping regions, and different leaching intensities are allocated to independent regions according to salt type, generating the starting and ending depths of each leaching layer. Based on the starting and ending depths of each leaching layer, the modifier application layers are grouped, and the coverage of each group with the coordinate set of the crystallization and precipitation layers is evaluated to obtain the arrangement scheme of the modifier application layers.

[0005] Furthermore, temperature, salinity conductivity, chloride ion concentration, sulfate concentration, and carbonate concentration were collected from various soil layers to obtain real-time layer temperature distribution records and salinity distribution records, including:

[0006] Real-time temperature and salinity conductivity values ​​of each layer were collected, and chloride, sulfate and carbonate concentrations were read using ion-selective electrodes.

[0007] The temperature, conductivity, and ion concentration values ​​are labeled and stored layer by layer according to the depth coordinates of the corresponding layers to form the original dataset for layer monitoring.

[0008] Based on the original dataset of the stratigraphic monitoring, the difference between the surface temperature value and the deep temperature value is extracted, and the temperature difference is aligned with the temperature value, conductivity value and ion concentration data of each stratigraphic layer in a time series to obtain the real-time stratigraphic temperature distribution record and the salinity distribution record.

[0009] Furthermore, the soil layers include four layers: surface, shallow, middle, and deep.

[0010] Furthermore, based on real-time stratigraphic temperature and salinity distribution records, the solubility characteristics of sodium chloride, sodium sulfate, and sodium carbonate salts as a function of temperature were identified by fitting chloride, sulfate, and carbonate concentrations with corresponding stratigraphic temperatures. This determined the migration direction of each salt under a temperature gradient, indicating whether it aggregates towards the surface or migrates to deeper layers.

[0011] Extract the temperature values ​​of each layer and the corresponding chloride ion concentration, sulfate concentration, and carbonate concentration;

[0012] The least squares method was used to fit the chloride ion concentration, sulfate concentration and carbonate concentration with the layer temperature, respectively, to obtain the first fitting curve of chloride ion concentration with temperature, the second fitting curve of sulfate concentration with temperature and the third fitting curve of carbonate concentration with temperature.

[0013] Based on the slope direction of the first fitting curve, the second fitting curve and the third fitting curve, the solubility temperature response characteristics of each salt are determined, wherein a positive slope indicates positive temperature solubility and a negative slope indicates inverse temperature solubility.

[0014] Based on the solubility temperature response characteristics and the temperature gradient direction from the surface to the deep layer, the migration direction of each salt is determined, and positive temperature soluble salts are marked to accumulate in the surface layer and negative temperature soluble salts migrate in the deep layer, thus obtaining the migration direction identifier of each salt.

[0015] Furthermore, for salts accumulating on the surface, the potential crystallization depth of salts migrating and accumulating on the high-temperature surface is assessed by quantifying the impact of temperature differences on the rate of evaporation-driven salt uptake. Current layer temperature data is extracted and compared layer by layer with the saturated dissolution concentration threshold of each salt at that temperature to identify the set of coordinates of crystallization precipitation layers where the salt concentration exceeds the saturation concentration, including:

[0016] For positive temperature dissolved salts whose migration direction is identified as gathering towards the surface, the surface temperature value and the temperature value of each depth layer are extracted based on the real-time layer temperature distribution record.

[0017] Look up the saturated solubility concentration threshold of each positive temperature solubility salt at the current stratum temperature from the pre-established salt solubility temperature reference table;

[0018] The saturated dissolution concentration threshold is compared with the measured ion concentration at that layer by layer. Each layer is traversed from the surface to the deep layer to identify the layer where the measured ion concentration exceeds the saturated dissolution concentration threshold.

[0019] The depth coordinates of the layers where the measured ion concentration exceeds the saturation dissolution concentration threshold are extracted and the corresponding salt types are marked. The coordinates of the crystallization precipitation layers of the positive temperature dissolution salts are then summarized to obtain a set of coordinates.

[0020] Furthermore, for positive temperature dissolved salts whose migration direction is identified as gathering towards the surface, after extracting the surface temperature value and the temperature value of each depth layer based on the real-time layer temperature distribution record, the temperature difference between the surface layer and each depth layer is calculated to determine the upward migration rate, and the concentration degree of positive temperature dissolved salts during the migration process to the high temperature surface is evaluated based on the upward migration rate.

[0021] Furthermore, for inversion-dissolved salts migrating to deeper layers, temperature values ​​are read layer by layer from the deepest layer upwards, and the theoretical saturation conductivity threshold for each layer is calculated. This is then compared layer by layer with the measured conductivity to identify layers exceeding the threshold, thus determining the crystallization depth range of inversion-dissolved salts in the low-temperature layers, including:

[0022] Extract the temperature values ​​of deep layers from the real-time layer temperature distribution record, and read the temperature data of each layer layer by layer in the order from deep to surface.

[0023] Based on the pre-established table of temperature reference for the solubility of inverted temperature dissolved salts, the saturated solubility concentrations of sulfate and carbonate corresponding to the temperature of each layer are looked up to obtain the saturated concentration values ​​of inverted temperature salts at each layer.

[0024] Based on the conversion relationship between the inversion salt saturation concentration value and the soil solution conductivity and ion concentration, the theoretical saturation conductivity threshold of each layer is calculated to form a theoretical saturation conductivity threshold sequence for each layer.

[0025] Based on the theoretical saturated conductivity threshold sequence, the measured conductivity values ​​are compared with the corresponding theoretical saturated conductivity thresholds layer by layer from the deep layer to the surface layer. Layers with measured conductivity values ​​exceeding the theoretical saturated conductivity thresholds are identified, the depth coordinates of the super-threshold layers are extracted, and the continuously distributed super-threshold layer segments are determined as the crystallization and precipitation depth range of inversion dissolved salts.

[0026] Furthermore, the method of combining real-time stratigraphic temperature distribution records and salinity distribution records to analyze the crystallization depth of surface-accumulated salts and the precipitation depth range of deep-layer inversion salts, identifying overlapping and independent regions, setting priority leaching levels for overlapping regions, and assigning different leaching intensities to independent regions according to salinity type, generates the starting and ending depths of each leaching layer, including:

[0027] Based on the coordinate set of crystallization and precipitation layers of positive temperature dissolved salts and the crystallization and precipitation depth range of inverse temperature dissolved salts, a superposition and comparison is performed on the depth axis of the soil profile.

[0028] Layers with overlapping depth coordinates are identified as overlapping regions, and segments containing only a single salt crystal layer are identified as independent regions.

[0029] For the overlapping areas, the rinsing level is marked as a priority level, and for the independent areas, the rinsing intensity level is assigned according to the type of salt contained therein;

[0030] Based on the depth range of the overlapping area and the independent area, and the corresponding rinsing level and rinsing intensity level identifiers, the upper boundary depth of each rinsing area is extracted as the starting depth and the lower boundary depth is extracted as the ending depth to generate the starting depth and ending depth of each rinsing layer.

[0031] Furthermore, the modification application layers are grouped according to the starting and ending depths of each rinsing layer, and the coverage of each group with the coordinate set of the crystallization precipitation layer is evaluated to obtain the arrangement scheme of the modification application layers, including:

[0032] Based on the starting and ending depths of each rinsing layer, the rinsing layers are grouped according to the continuity of the depth interval and the consistency of the rinsing level. Rinsing layers with the same rinsing priority and the same rinsing intensity level and adjacent depth intervals are grouped into the same application layer group.

[0033] For each group of soil amendment application layers, its depth range is compared with the coordinate set of crystallization and precipitation layers of thermophilic salts and the crystallization and precipitation depth range of inverted-temperature salts. The ratio of the depth of the covered crystallization layer to the total thickness of the two types of salt crystallization layers in the soil profile is calculated to obtain the coverage ratio of each group.

[0034] Based on the coverage ratio of each group, groups with a coverage ratio higher than the threshold are marked as high-coverage application layers, and groups with a coverage ratio lower than the threshold are marked as low-coverage application layers. Based on the marking results and their depth range, the arrangement scheme of the modifier application layers is obtained.

[0035] Furthermore, the arrangement scheme for the application layers of the modifier includes the application depth range, recommended application dosage, and type of modifier for each group.

[0036] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects:

[0037] This invention discloses a method for dynamic monitoring and remediation of saline-alkali soil. Addressing the migration and crystallization of salts in soil under temperature gradients, the method collects temperature, salt conductivity, and ion concentration data from various layers. It analyzes the temperature difference between the surface and deep layers, fits the characteristics of salt solubility changes with temperature, and determines the direction of salt accumulation towards the surface or migration to the deeper layers. For surface-accumulated salts, the method quantifies the impact of temperature differences on the rate of evaporation-driven salt uplift and identifies the coordinates of crystallization and precipitation layers. For deep-layer inversion-dissolved salts, the method compares conductivity thresholds layer by layer to determine the precipitation depth range. Finally, combining distribution records, it identifies overlapping and independent areas, optimizes leaching levels and intensities, and generates a layer layout scheme for soil amendment application. This invention achieves dynamic control of soil salinity distribution and efficient application of soil amendments by accurately identifying the migration direction and crystallization depth of salts, thereby improving soil remediation effects. Attached Figure Description

[0038] Figure 1 This is a flowchart of a method for generating a dynamic monitoring and remediation scheme for saline-alkali soil according to the present invention.

[0039] Figure 2 This is a schematic diagram of a method for generating a dynamic monitoring and remediation scheme for saline-alkali land soil according to the present invention.

[0040] Figure 3 This is another schematic diagram of a method for generating a dynamic monitoring and remediation scheme for saline-alkali land soil according to the present invention. Detailed Implementation

[0041] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] like Figures 1-3 This embodiment of a method for generating a dynamic monitoring and remediation scheme for saline-alkali land soil may specifically include:

[0043] S101. Collect temperature, salinity conductivity, chloride ion concentration, sulfate concentration, and carbonate concentration from each soil layer to obtain real-time layer temperature distribution records and salinity distribution records.

[0044] Temperature sensors and conductivity probes were deployed at four layers—surface, shallow, middle, and deep—of the soil profile to collect real-time temperature and salinity conductivity values ​​for each layer. Simultaneously, chloride, sulfate, and carbonate concentrations were read using ion-selective electrodes. These temperature, conductivity, and ion concentrations were labeled and stored layer by layer according to their depth coordinates, forming a raw dataset for layer monitoring. Based on this raw dataset, the difference between surface and deep layer temperatures was extracted as the surface-deep temperature difference. This temperature difference was then aligned layer by layer with the temperature, conductivity, and ion concentration data for each layer according to time series, yielding real-time layer temperature and salinity distribution records.

[0045] During soil profile monitoring, the strata are divided based on the typical depth range of vertical migration of soil salts. The surface layer corresponds to the range of 0 to 20 cm, the shallow layer corresponds to the range of 20 to 50 cm, the middle layer corresponds to the range of 50 to 100 cm, and the deep layer corresponds to the area below 100 cm. The depth boundaries of each stratum can be adjusted according to the actual soil profile structure.

[0046] In one embodiment, the temperature sensor uses a thermistor probe, which outputs a corresponding electrical signal by sensing the heat change of the soil medium, and converts it into a temperature value after calibration; the conductivity probe uses a four-electrode method to measure the conductivity of the soil solution, and the conductivity is positively correlated with the soil salinity, thereby obtaining the salinity conductivity value of each layer.

[0047] Specifically, an ion-selective electrode is an electrochemical sensor that selectively responds to specific ions. The chloride ion electrode uses a silver chloride sensitive membrane, the sulfate ion electrode uses a lead salt sensitive membrane, and the carbonate ion electrode uses a carbonate sensitive membrane. When the target ion in the soil solution comes into contact with the sensitive membrane, a potential difference is generated. This potential difference is linearly related to the logarithm of the ion concentration, and the concentration value of each ion can be calculated accordingly.

[0048] For example, the surface and deep temperature difference is obtained by reading the surface temperature value and the deep temperature value and calculating the difference between them. This temperature difference reflects the direction and intensity of the vertical temperature gradient of the soil profile; a positive value indicates that the surface temperature is higher than the deep temperature, and a negative value indicates that the surface temperature is lower than the deep temperature. During the data integration stage, the temperature difference, along with the temperature, conductivity, and ion concentration data of each layer, are aligned layer by layer according to the same acquisition time, forming a real-time layer temperature distribution record and salinity distribution record with time as the sequence index and layer depth as the spatial coordinate.

[0049] S102. Based on real-time stratigraphic temperature distribution records and salinity distribution records, the solubility characteristics of sodium chloride, sodium sulfate, and sodium carbonate salts as a function of temperature are identified by fitting the concentrations of chloride ions, sulfate ions, and carbonate ions with the corresponding stratigraphic temperatures, and the migration direction of each salt towards the surface or towards the deeper layers under the temperature gradient is determined.

[0050] Based on real-time stratigraphic temperature and salinity distribution records, the temperature values ​​and corresponding chloride, sulfate, and carbonate concentrations for each stratigraphic level were extracted. Least squares curve fitting was performed on each ion concentration versus stratigraphic temperature, with stratigraphic temperature as the independent variable and ion concentration as the dependent variable. This yielded a first fitted curve for chloride concentration versus temperature, a second fitted curve for sulfate concentration versus temperature, and a third fitted curve for carbonate concentration versus temperature. Based on the slopes of these three fitted curves, the temperature response characteristics of each salt's solubility were determined. If the slope of the fitted curve was positive, the corresponding salt was identified as thermophilic, meaning its solubility increases with increasing temperature. If the slope of the fitted curve was negative, the corresponding salt was identified as thermophilic, meaning its solubility increases with decreasing temperature. Based on the solubility temperature response characteristics and the temperature gradient direction from the surface to the deep layer, the migration direction of each salt is determined. For positive temperature solubility salts, their migration direction is marked as aggregation towards the surface, and for inverse temperature solubility salts, their migration direction is marked as migration towards the deep layer, thus obtaining the migration direction identifier of each salt.

[0051] In the monitoring of saline-alkali soils, the solubility response characteristics of different salts to temperature changes exhibit fundamental differences, which directly determine the migration behavior of salts in the soil profile. By fitting real-time collected stratigraphic temperature and ion concentration data, the solubility temperature response characteristics of each salt can be identified, thereby determining its migration direction under the influence of temperature gradients.

[0052] Specifically, the least squares method is a mathematical method for determining the parameters of a fitted curve by minimizing the sum of squared residuals between observed and fitted values. In this embodiment, the temperature value of each layer is used as the independent variable, and the ion concentration of the corresponding layer is used as the dependent variable. Curve fitting is performed on chloride, sulfate, and carbonate ions respectively, and the resulting fitted curves reflect the overall trend of each ion concentration changing with temperature.

[0053] In one embodiment, for chloride ions corresponding to sodium chloride, the chloride ion concentration shows an increasing trend as the soil temperature changes from a low-temperature layer to a high-temperature layer, with a positive slope in the fitted curve, indicating that the solubility of sodium chloride increases with increasing temperature, classifying it as a thermophilic salt. Conversely, for sulfate ions corresponding to sodium sulfate, the sulfate ion concentration shows a decreasing trend within the same temperature range, with a negative slope in the fitted curve, indicating that sodium sulfate has higher solubility at lower temperatures, classifying it as a thermotropically dissolving salt. Carbonate ions corresponding to sodium carbonate also exhibit similar thermotropically dissolving characteristics.

[0054] It should be noted that for positive temperature dissolved salts, when the surface temperature is higher than that of the deeper layers, the dissolved salts tend to migrate towards the higher-temperature surface with capillary water and concentrate and accumulate at the surface due to evaporation. In contrast, for inverted temperature dissolved salts, due to their relatively higher solubility in the lower-temperature environment of the deeper layers, the dissolved salts are more likely to remain in the deeper soil solution and continue to migrate to even deeper layers.

[0055] For example, in saline-alkali land during spring, when the daytime surface soil temperature rises while the deep soil temperature remains low, the temperature gradient direction points from the high surface temperature to the low deep temperature. At this time, thermophilic sodium chloride accumulates in the surface, while thermophilic sodium sulfate and sodium carbonate migrate to the deeper layers; the migration directions of the two types of salts are opposite. Based on the correspondence between the slope characteristics of the fitted curves and the temperature gradient direction, each salt is assigned a migration direction identifier, which records the migration trend of each salt under the current temperature gradient conditions.

[0056] S103. For salts accumulating on the surface, the potential crystallization depth of salts migrating and accumulating on the high-temperature surface is assessed by quantifying the effect of temperature differences on the rate of salt migration driven by evaporation. The current layer temperature data is extracted and compared layer by layer with the saturated dissolution concentration threshold of each salt at that temperature to identify the set of coordinates of crystallization precipitation layers where the salt concentration exceeds the saturation concentration.

[0057] For positive-temperature dissolved salts whose migration direction is identified as surface accumulation, surface temperature and temperature values ​​at each depth are extracted from real-time stratum temperature distribution records. The temperature difference between the surface and each depth layer is calculated. A larger temperature difference indicates a stronger evaporation-driven effect on salt migration to the surface. Based on this, it is assumed that the upward migration rate is directly proportional to the temperature difference, and the calculation formula is as follows: Where V is the upward movement rate, The temperature difference is represented by k, a proportionality coefficient of 0.1, used for preliminary quantitative assessment. The concentration degree of thermophilic salts migrating to the high-temperature surface is assessed based on the upward migration rate; a higher rate indicates a more significant concentration effect. The saturated dissolution concentration threshold for each thermophilic salt at the current stratum temperature is retrieved from a pre-established salt solubility temperature comparison table. This saturated dissolution concentration threshold is paired with the measured ion concentration at that stratum to form a concentration comparison data set for each stratum. Based on this concentration comparison data set, each stratum is traversed layer by layer from the surface to the depth. If the measured ion concentration at a certain stratum exceeds the corresponding saturated dissolution concentration threshold, that stratum is determined to be a potential crystallization precipitation stratum. The depth coordinates of the potential crystallization precipitation stratum are extracted and the corresponding salt type is labeled. All potential crystallization precipitation stratums that meet the concentration exceeding the threshold condition are arranged and summarized in depth order to obtain the coordinate set of the crystallization precipitation stratum of thermophilic salts.

[0058] During the improvement of saline-alkali soils, thermophilic salts tend to migrate and accumulate towards the high-temperature surface layer under the influence of temperature gradients. When the salt concentration at a certain layer exceeds the saturation concentration under that temperature condition, the dissolved salts will precipitate and form crystals. Accurately identifying the depth coordinates of these crystallization precipitate layers is crucial for developing targeted leaching programs.

[0059] Specifically, the evaporation-driven upward migration rate is a physical quantity characterizing the intensity of soil moisture carrying salts towards the surface. When the surface temperature is higher than the deep layer temperature, the evaporation rate of surface soil moisture accelerates, and deep soil moisture replenishes the surface through capillary action, with dissolved salts migrating upwards along with the moisture. The greater the temperature difference between the surface and a certain depth layer, the stronger the evaporation-driven effect, the higher the rate of salt migration and accumulation towards the surface, and the more significant the concentration along the migration path.

[0060] In one embodiment, for sodium chloride, a typical thermophilic salt, when the surface temperature is 35 degrees Celsius and the shallow temperature is 25 degrees Celsius, there is a 10-degree Celsius temperature difference between the surface and the shallow layer. This temperature difference drives soil moisture to carry chloride ions to the surface, and the chloride ions gradually concentrate during the migration to the surface.

[0061] It should be noted that the salt solubility temperature reference table is a pre-established data lookup table that records the saturated solubility concentration values ​​of various salts under different temperature conditions. For sodium chloride, its saturated solubility concentration is approximately 360 grams per liter at 20 degrees Celsius, approximately 363 grams per liter at 30 degrees Celsius, and approximately 366 grams per liter at 40 degrees Celsius, with solubility increasing slowly with increasing temperature. For sodium sulfate, its solubility increases rapidly with increasing temperature below 32.4 degrees Celsius, but decreases with increasing temperature above this temperature, exhibiting complex temperature response characteristics. By consulting this reference table, the saturated solubility concentration thresholds of each positive temperature solubility salt at the current stratum temperature can be obtained. Furthermore, the construction of the concentration comparison data set is a core step in identifying crystallization precipitation strata. For each monitoring layer, the saturated dissolution concentration threshold corresponding to that layer's temperature is looked up from a salt solubility temperature reference table. This threshold is then paired with the ion concentration measured at that layer using an ion-selective electrode, forming a comparative data set consisting of the layer depth coordinates, the saturated dissolution concentration threshold, and the measured ion concentration. This data set comprehensively records the salt saturation state information for each layer.

[0062] For example, during spring monitoring of saline-alkali land, the surface temperature was 32 degrees Celsius, corresponding to a saturated dissolution concentration threshold of sodium chloride of 362 grams per liter. However, the measured chloride ion concentration on the surface was 380 grams per liter, exceeding the saturated dissolution concentration threshold, indicating that conditions for sodium chloride crystallization and precipitation existed in this layer.

[0063] In one possible implementation, the identification of crystallization precipitation sites is performed by traversing the layers from the surface to the depth. Starting from the surface, the concentration comparison data set of each layer is read sequentially, and the relationship between the measured ion concentration and the saturation dissolution concentration threshold is compared. If the measured ion concentration exceeds the saturation dissolution concentration threshold, the layer is determined to be a potential crystallization precipitation site, and the depth coordinates of the layer are extracted and the corresponding salt type is marked. If the measured ion concentration is below the saturation dissolution concentration threshold, the salt in the layer is still in a dissolved state and does not constitute a crystallization precipitation site.

[0064] Understandably, as thermophilic salts gradually concentrate during their migration to the surface, crystallization and precipitation layers tend to be concentrated in the surface and shallow layers. By arranging and summarizing all potential crystallization and precipitation layers that meet the concentration threshold conditions in descending order of depth, a set of coordinates for thermophilic salt crystallization and precipitation layers is formed. This set clearly records the crystallization distribution location and corresponding depth range of each thermophilic salt in the soil profile.

[0065] S104. For inversion-dissolved salts migrating to deeper layers, temperature values ​​are read layer by layer from the deep layer upwards, and the theoretical saturation conductivity threshold of each layer is calculated. The measured conductivity is compared layer by layer to identify layers exceeding the threshold, and the crystallization depth range of inversion-dissolved salts in low-temperature layers is determined.

[0066] For inversion-dissolved salts whose migration direction is identified as moving towards deeper layers, the temperature values ​​of deeper layers are extracted from real-time stratigraphic temperature distribution records. Temperature data for each layer is read sequentially from deep to surface. Based on a pre-established table of inversion-dissolved salt solubility at temperature, the saturated dissolution concentrations of sulfate and carbonate at each layer are looked up to obtain the saturated concentration values ​​of inversion salts at each layer. According to the conversion relationship between soil solution conductivity and ion concentration, the saturated concentration values ​​of each layer are multiplied by a preset ion conductivity conversion coefficient to obtain the corresponding theoretical saturated conductivity threshold. This theoretical saturated conductivity threshold represents the upper limit of conductivity at which the inversion-dissolved salts reach saturation under the current temperature conditions, forming a sequence of theoretical saturated conductivity thresholds for each layer. Based on the theoretical saturated conductivity threshold sequence, each layer is traversed from deep to surface. The measured conductivity value of each layer is compared with the corresponding theoretical saturated conductivity threshold. If the measured conductivity value of a certain layer exceeds the theoretical saturated conductivity threshold, that layer is determined to be a potential crystallization precipitation layer for inversion-dissolved salts. The depth coordinates of the potential crystallization precipitation layer are extracted. All potential crystallization precipitation layers that meet the conductivity exceeding the threshold condition are arranged in depth order to identify continuously distributed over-threshold layer segments and determine the crystallization precipitation depth range of inversion-dissolved salts in low-temperature layers.

[0067] Temperature inversion-soluble salts are salts whose solubility increases as temperature decreases. Sodium sulfate and sodium carbonate are typical examples in saline-alkali soils. When there is a temperature gradient in the soil profile, with high surface temperature and low depth temperature, the solubility of these salts is actually higher in the low-temperature environment of the deep layer. The dissolved salts tend to migrate to the deeper layers and reach saturation and crystallize in layers where the temperature further decreases.

[0068] Specifically, the table of solubility temperatures for inverted-temperature dissolved salts records the saturated solubility concentrations of sodium sulfate and sodium carbonate under different temperature conditions. Taking sodium sulfate as an example, its saturated solubility concentration is approximately 49 grams per liter at 0 degrees Celsius, approximately 90 grams per liter at 10 degrees Celsius, and approximately 195 grams per liter at 20 degrees Celsius. The solubility increases rapidly with increasing temperature. When the temperature in deeper soil layers is lower, the saturated solubility concentration of sodium sulfate decreases accordingly, and dissolved sulfate ions are more likely to reach saturation and precipitate as crystals.

[0069] In one embodiment, temperature data for each layer is read in a reverse traversal order from deep to surface. This traversal order is designed based on the fact that the crystallization of inverted temperature dissolved salts first occurs in the deepest layers with the lowest temperatures. As the traversal progresses upwards and enters layers with higher temperatures, the solubility threshold increases accordingly, and the probability of crystallization decreases. This traversal order allows for layer-by-layer identification starting from the layer where crystallization is most likely to occur.

[0070] It should be noted that there is a direct proportional relationship between soil solution conductivity and ion concentration; the higher the total amount of ions in the solution, the stronger the conductivity and the higher the conductivity value. The ion conductivity conversion factor is a coefficient characterizing the contribution of a unit concentration of ions to conductivity. The conversion factors vary slightly for different ions; the conversion factors for sulfate and carbonate ions can be obtained by calibration using standard solutions. Multiplying the inversion salt saturation concentration value of each layer by the corresponding ion conductivity conversion factor yields the theoretical saturation conductivity threshold that the layer should exhibit under saturation. Furthermore, the construction of the theoretical saturation conductivity threshold sequence provides a benchmark for layer-by-layer comparison. For each monitoring layer, this sequence records the conductivity value that the soil solution should exhibit when the inversion dissolved salts reach saturation under the current layer temperature conditions. If the measured conductivity value of a certain layer exceeds the theoretical saturation conductivity threshold corresponding to that layer, it indicates that the inversion dissolved salt concentration at that layer has exceeded the saturation limit, and conditions for crystallization and precipitation exist.

[0071] For example, in a winter saline-alkali land monitoring scenario, the deep soil temperature is five degrees Celsius, corresponding to a saturated dissolution concentration of sodium sulfate of approximately 55 grams per liter. The theoretical saturated conductivity threshold is a preset value, while the measured conductivity value of this layer significantly exceeds this threshold, indicating that there are conditions for sodium sulfate crystallization in the deep layer. This layer is identified as a potential crystallization precipitation layer.

[0072] In one possible implementation, when multiple consecutive adjacent strata are identified as potential crystallization sites, these strata constitute a continuously distributed super-threshold stratum segment. By identifying the starting and ending depth coordinates of this segment, the crystallization depth range of inversion-dissolved salts can be determined. This depth range clearly identifies the crystallization distribution range of inversion-dissolved salts in the soil profile.

[0073] It is understandable that the crystallization strata of temperature-inverted dissolved salts are concentrated in deep, low-temperature regions, forming a stratified distribution pattern with the surface crystallization strata of temperature-soluble salts. By identifying the crystallization strata of the two types of salts separately, complete spatial distribution information of salt crystals in the soil profile can be obtained, providing a basis for stratification location in formulating stratified leaching schemes.

[0074] S105. By combining real-time layer temperature distribution records and salt distribution records, the crystallization layer depth of surface accumulated salts and the precipitation depth range of deep inversion salts are analyzed. Overlapping areas and independent areas are identified. Priority leaching levels are set for overlapping areas, and different leaching intensities are assigned to independent areas according to salt type. The starting depth and ending depth of each leaching layer are generated.

[0075] Based on the coordinate set of crystallization precipitation layers of thermophilic salts and the crystallization precipitation depth range of inverted-temperature salts, the crystallization layers of the two types of salts are superimposed and compared on the soil profile depth axis. Layers with overlapping depth coordinates are identified as overlapping areas, and segments containing only a single type of salt crystallization layer are identified as independent areas, thus obtaining the depth range of overlapping areas and the depth range of independent areas. For the depth range of the overlapping areas, the leaching level is marked as a priority level; for the depth range of the independent areas, a leaching intensity level is assigned according to the type of salt it contains. If the independent area contains thermophilic salts, a first leaching intensity level is assigned; if the independent area contains inverted-temperature salts, a second leaching intensity level is assigned, thus obtaining the leaching level and leaching intensity level identifier for each area. Based on the depth range of the overlapping areas, the depth range of the independent areas, and the corresponding leaching level and leaching intensity level identifier, the upper boundary depth of each leaching area is extracted as the starting depth, and the lower boundary depth is extracted as the ending depth. After sorting by leaching level priority, the starting depth and ending depth of each leaching layer are generated.

[0076] During the process of improving saline-alkali land, the crystallization layers of thermophilic and thermophilic salts often exhibit different spatial distribution characteristics in the soil profile. There is overlap between the two in certain depth ranges. The difficulty of salt management in such overlapping areas is higher than that in independent areas with a single salt distribution.

[0077] Specifically, overlay comparison is the process of comparing the coordinate set of crystallization precipitation layers of thermophilic salts with the crystallization precipitation depth range of thermophilic salts on the same depth coordinate axis. When a certain depth location falls within both the crystallization layer range of thermophilic salts and the precipitation depth range of thermophilic salts, that depth location is classified as an overlapping region; when a certain depth location belongs to the crystallization layer of only one type of salt and not the other, that depth location is classified as an independent region.

[0078] In one embodiment, if the set of coordinates of the crystallization precipitation layer of the thermophilic salt covers a depth range of 0 to 30 cm, and the crystallization precipitation depth range of the thermophilic salt covers a depth range of 20 to 60 cm, then the 20 to 30 cm depth segment is an overlapping region, the 0 to 20 cm depth segment is an independent region of the thermophilic salt, and the 30 to 60 cm depth segment is an independent region of the thermophilic salt.

[0079] It should be noted that overlapping areas, due to the simultaneous presence of crystallization and precipitation of two types of salts, have a higher complexity in leaching treatment and are therefore marked as priority leaching levels. Independent areas are assigned different leaching intensity levels based on the types of salts they contain: independent areas with positive temperature dissolved salts are assigned the first leaching intensity level, and independent areas with inverted temperature dissolved salts are assigned the second leaching intensity level. These two leaching intensity levels correspond to different leaching water volumes and leaching frequencies. Furthermore, the starting and ending depths of each leaching layer are obtained by extracting the upper and lower boundary depths of each area. Overlapping areas are arranged first by priority leaching level, and independent areas are arranged second by leaching intensity level, forming a complete sequence of leaching layer depths. This sequence clearly records the spatial range and corresponding leaching priority of each leaching layer.

[0080] S106. Based on the starting and ending depths of each rinsing layer, the modifier application layers are grouped, and the coverage of each group and the coordinate set of the crystallization precipitation layer is evaluated to obtain the arrangement scheme of the modifier application layers.

[0081] Based on the starting and ending depths of each leaching layer, the leaching layers are grouped according to the continuity of depth intervals and the consistency of leaching levels. Leaching layers with the same leaching priority, the same leaching intensity level, and adjacent depth intervals are grouped into the same application layer group, resulting in several amendment application layer groups and their corresponding depth ranges. For each amendment application layer group, its depth range is compared with the coordinate set of crystallization layers for thermophilic salts and the crystallization precipitation depth range for inverted-temperature salts. The ratio of the depth of the crystallization layers covering this group to the total thickness of the two types of salt crystallization layers in the entire soil profile is calculated to obtain the coverage ratio of each group. Based on the coverage ratio of each group, if the coverage ratio of a certain group exceeds a preset coverage threshold of 0.5, the group is marked as a high-coverage application layer; if the coverage ratio is lower than the preset coverage threshold of 0.5, the group is marked as a low-coverage application layer. Based on the marking results of the high-coverage and low-coverage application layers and their depth range, a scheme for the application of modifiers is obtained. This scheme includes the application depth range of each group, the recommended application dose (e.g., 10 kg of modifier per meter of depth), and the type of modifier (e.g., an acidic modifier for high-coverage layers).

[0082] In the process of improving saline-alkali soil, the application layer arrangement of the amendment directly affects the improvement effect. Reasonable application layer grouping can enable the amendment to form a good spatial correspondence with the salt crystallization layer, thereby improving the neutralization and replacement efficiency of the amendment on salt.

[0083] Specifically, application layer grouping is the process of grouping leached layers with the same leaching grade and adjacent depth ranges into the same group. The same leaching grade indicates that these layers have the same salinity type or leaching priority, while adjacent depth ranges mean that these layers are continuously distributed in the soil profile. After grouping leached layers that meet these two conditions into the same application layer group, each group corresponds to a continuous depth range, which is the potential application range for the soil amendment.

[0084] In one embodiment, if both the surface rinsing layers of 0 to 15 cm and 15 to 30 cm have a priority rinsing level, then these two layers are grouped into the same application layer group, the depth range of which is 0 to 30 cm.

[0085] It should be noted that the coverage ratio is an indicator of the spatial matching degree between the application layer group and the salt crystallization layer. Positive temperature solubility salts refer to salts whose solubility increases with increasing temperature, and their crystallization and precipitation occur when the temperature decreases; negative temperature solubility salts refer to salts whose solubility decreases with increasing temperature, and their crystallization and precipitation occur when the temperature increases. The depth of the crystallization and precipitation layer for positive temperature solubility salts refers to the depth range of precipitation of this type of salt in the soil due to decreasing temperature, while the depth of crystallization and precipitation for negative temperature solubility salts refers to the depth range of precipitation of this type of salt in the soil due to increasing temperature. The coverage ratio is calculated by summing the crystallization depths of the two types of salts covered within the depth range of a given application layer group, and dividing this sum by the total depth of the crystallization layers of the two types of salts. A higher coverage ratio indicates a greater degree of overlap between the application layer group and the salt crystallization layer, suggesting that the application of the amendment within this group may improve the contact effect with the salt crystals. Furthermore, the coverage ratio is compared with a preset coverage threshold, for example, a threshold of 0.7, determined based on soil salinity distribution and empirical data. Groups with coverage ratios exceeding the threshold are marked as high-coverage application layers, while groups with coverage ratios below the threshold are marked as low-coverage application layers. High-coverage application layers should prioritize the application of amendments with relatively larger application rates, while low-coverage application layers can appropriately reduce the amount of amendments applied or adjust the application strategy.

[0086] If the technical solution of this application involves personal information, the product using this solution has clearly informed the user of the personal information processing rules and obtained the user's voluntary consent before processing the personal information. If sensitive personal information is involved, the user's separate consent has been obtained before processing, and the "express consent" requirement is met. For example, a clear sign is placed at the collection device such as a camera to inform the user that they have entered the collection area, and the user's voluntary entry is considered as consent; or the processing device clearly indicates the processing rules and obtains authorization through pop-up windows or by asking the user to upload information themselves. The personal information processing rules include the processor, the purpose of processing, the processing method, and the types of personal information.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for generating dynamic monitoring and remediation schemes for saline-alkali soil, characterized in that, The method includes: Temperature, salinity conductivity, chloride, sulfate, and carbonate concentrations were collected from various soil layers to obtain real-time layer temperature and salinity distribution records. Based on these records, the solubility of sodium chloride, sodium sulfate, and sodium carbonate salts was identified by fitting chloride, sulfate, and carbonate concentrations to corresponding layer temperatures, thus determining the migration direction of each salt towards the surface or deeper layers under temperature gradients. For salts accumulating towards the surface, the impact of temperature differences on the rate of evaporation-driven salt uplift was quantified to assess the potential crystallization depth when salts migrate and accumulate at high temperatures. The current layer temperature data was extracted and compared layer by layer with the saturated solubility concentration threshold of each salt at that temperature to identify the set of coordinates of crystallization precipitation layers where the salt concentration exceeds the saturation concentration. For inversion-dissolved salts migrating to deeper layers, temperature values ​​are read layer by layer from deep to upward, and the theoretical saturation conductivity threshold for each layer is calculated. This is compared layer by layer with the measured conductivity to identify layers exceeding the threshold, thus determining the crystallization depth range of inversion-dissolved salts in low-temperature layers. By combining real-time layer temperature distribution records and salt distribution records, the crystallization depth of surface-accumulated salts and the precipitation depth range of deep-layer inversion salts are analyzed to identify overlapping and independent regions. Priority leaching levels are assigned to overlapping regions, and different leaching intensities are allocated to independent regions according to salt type, generating the starting and ending depths of each leaching layer. Based on the starting and ending depths of each leaching layer, the modifier application layers are grouped, and the coverage of each group with the coordinate set of the crystallization and precipitation layers is evaluated to obtain the arrangement scheme of the modifier application layers.

2. The method for generating a dynamic monitoring and remediation scheme for saline-alkali land soil according to claim 1, characterized in that, The process involves collecting temperature, salinity, conductivity, chloride, sulfate, and carbonate concentrations from various soil layers to obtain real-time layer temperature and salinity distribution records, including: Real-time temperature and salinity conductivity values ​​of each layer were collected, and chloride, sulfate and carbonate concentrations were read using ion-selective electrodes. The temperature, conductivity, and ion concentration values ​​are labeled and stored layer by layer according to the depth coordinates of the corresponding layers to form the original dataset for layer monitoring. Based on the original dataset of the stratigraphic monitoring, the difference between the surface temperature value and the deep temperature value is extracted, and the temperature difference is aligned with the temperature value, conductivity value and ion concentration data of each stratigraphic layer in a time series to obtain the real-time stratigraphic temperature distribution record and the salinity distribution record.

3. The method for generating a dynamic monitoring and remediation scheme for saline-alkali land soil according to claim 1, characterized in that, The soil layers include four layers: topsoil, shallow soil, middle soil, and deep soil.

4. The method for generating a dynamic monitoring and remediation scheme for saline-alkali land soil according to claim 1, characterized in that, The method involves identifying the solubility of sodium chloride, sodium sulfate, and sodium carbonate salts as a function of temperature by fitting the concentrations of chloride, sulfate, and carbonate ions with the corresponding layer temperatures, based on real-time stratigraphic temperature and salinity distribution records. This process determines the migration direction of each salt under a temperature gradient, indicating whether it accumulates towards the surface or migrates to deeper layers. This includes: Extract the temperature values ​​of each layer and the corresponding chloride ion concentration, sulfate concentration, and carbonate concentration; The least squares method was used to fit the chloride ion concentration, sulfate concentration and carbonate concentration with the layer temperature, respectively, to obtain the first fitting curve of chloride ion concentration with temperature, the second fitting curve of sulfate concentration with temperature and the third fitting curve of carbonate concentration with temperature. Based on the slope direction of the first fitting curve, the second fitting curve and the third fitting curve, the solubility temperature response characteristics of each salt are determined, wherein a positive slope indicates positive temperature solubility and a negative slope indicates inverse temperature solubility. Based on the solubility temperature response characteristics and the temperature gradient direction from the surface to the deep layer, the migration direction of each salt is determined, and positive temperature soluble salts are marked to accumulate in the surface layer and negative temperature soluble salts migrate in the deep layer, thus obtaining the migration direction identifier of each salt.

5. The method for generating a dynamic monitoring and remediation scheme for saline-alkali land soil according to claim 1, characterized in that, For salts accumulating on the surface, the potential crystallization depth of salts migrating and accumulating on the high-temperature surface is assessed by quantifying the impact of temperature differences on the rate of evaporation-driven salt uptake. The current layer temperature data is extracted and compared layer by layer with the saturated dissolution concentration threshold of each salt at that temperature to identify the set of coordinates of crystallization precipitation layers where the salt concentration exceeds the saturation concentration, including: For positive temperature dissolved salts whose migration direction is identified as gathering towards the surface, the surface temperature value and the temperature value of each depth layer are extracted based on the real-time layer temperature distribution record. Look up the saturated solubility concentration threshold of each positive temperature solubility salt at the current stratum temperature from the pre-established salt solubility temperature reference table; The saturated dissolution concentration threshold is compared with the measured ion concentration at that layer by layer. Each layer is traversed from the surface to the deep layer to identify the layer where the measured ion concentration exceeds the saturated dissolution concentration threshold. The depth coordinates of the layers where the measured ion concentration exceeds the saturation dissolution concentration threshold are extracted and the corresponding salt types are marked. The coordinates of the crystallization precipitation layers of the thermophilic salts are then compiled to obtain a set of coordinates.

6. The method for generating a dynamic monitoring and remediation scheme for saline-alkali land soil according to claim 5, characterized in that, For positive temperature dissolved salts whose migration direction is identified as gathering towards the surface, the surface temperature value and the temperature value of each depth layer are extracted based on the real-time layer temperature distribution record. The temperature difference between the surface layer and each depth layer is calculated to determine the upward migration rate. The concentration of positive temperature dissolved salts during the migration process towards the high temperature surface is evaluated based on the upward migration rate.

7. The method for generating a dynamic monitoring and remediation scheme for saline-alkali land soil according to claim 1, characterized in that, For inversion-dissolved salts migrating to deeper layers, temperature values ​​are read layer by layer from deep to upward, and the theoretical saturation conductivity threshold for each layer is calculated. This is then compared layer by layer with the measured conductivity to identify layers exceeding the threshold, thus determining the crystallization depth range of the inversion-dissolved salts in the low-temperature layers. This includes: Extract the temperature values ​​of deep layers from the real-time layer temperature distribution record, and read the temperature data of each layer layer by layer in the order from deep to surface. Based on the pre-established table of temperature reference for the solubility of inverted temperature dissolved salts, the saturated solubility concentrations of sulfate and carbonate corresponding to the temperature of each layer are looked up to obtain the saturated concentration values ​​of inverted temperature salts at each layer. Based on the conversion relationship between the inversion salt saturation concentration value and the soil solution conductivity and ion concentration, the theoretical saturation conductivity threshold of each layer is calculated to form a theoretical saturation conductivity threshold sequence for each layer. Based on the theoretical saturated conductivity threshold sequence, the measured conductivity values ​​are compared with the corresponding theoretical saturated conductivity thresholds layer by layer from the deep layer to the surface layer. Layers with measured conductivity values ​​exceeding the theoretical saturated conductivity thresholds are identified, the depth coordinates of the super-threshold layers are extracted, and the continuously distributed super-threshold layer segments are determined as the crystallization and precipitation depth range of inversion dissolved salts.

8. The method for generating a dynamic monitoring and remediation scheme for saline-alkali land soil according to claim 1, characterized in that, The method combines real-time stratigraphic temperature distribution records and salinity distribution records to analyze the crystallization depth of surface-accumulated salts and the precipitation depth range of deep-layer inversion salts, identifies overlapping and independent regions, assigns priority leaching levels to overlapping regions, and allocates different leaching intensities to independent regions according to salinity type, generating the starting and ending depths of each leaching layer, including: Based on the coordinate set of crystallization and precipitation layers of positive temperature dissolved salts and the crystallization and precipitation depth range of inverse temperature dissolved salts, a superposition and comparison is performed on the depth axis of the soil profile. Layers with overlapping depth coordinates are identified as overlapping regions, and segments containing only a single salt crystal layer are identified as independent regions. For the overlapping areas, the rinsing level is marked as a priority level, and for the independent areas, the rinsing intensity level is assigned according to the type of salt contained therein; Based on the depth range of the overlapping area and the independent area, and the corresponding rinsing level and rinsing intensity level identifiers, the upper boundary depth of each rinsing area is extracted as the starting depth and the lower boundary depth is extracted as the ending depth to generate the starting depth and ending depth of each rinsing layer.

9. The method for generating a dynamic monitoring and remediation scheme for saline-alkali land soil according to claim 1, characterized in that, The modifier application layers are grouped according to the starting and ending depths of each rinsing layer. The coverage of each group with the coordinate set of the crystallization precipitation layer is evaluated to obtain the arrangement scheme of the modifier application layers, including: Based on the starting and ending depths of each rinsing layer, the rinsing layers are grouped according to the continuity of the depth interval and the consistency of the rinsing level. Rinsing layers with the same rinsing priority and the same rinsing intensity level and adjacent depth intervals are grouped into the same application layer group. For each group of soil amendment application layers, its depth range is compared with the coordinate set of crystallization and precipitation layers of thermophilic salts and the crystallization and precipitation depth range of inverted-temperature salts. The ratio of the depth of the covered crystallization layer to the total thickness of the two types of salt crystallization layers in the soil profile is calculated to obtain the coverage ratio of each group. Based on the coverage ratio of each group, groups with a coverage ratio higher than the threshold are marked as high-coverage application layers, and groups with a coverage ratio lower than the threshold are marked as low-coverage application layers. Based on the marking results and their depth range, the arrangement scheme of the modifier application layers is obtained.

10. The method for generating a dynamic monitoring and remediation scheme for saline-alkali land soil according to claim 1, characterized in that, The arrangement of the modifier application layers includes the application depth range, recommended application dosage, and modifier type for each group.

Images