A sandy land arbor-shrub-grass three-dimensional configuration method and system based on water resource carrying capacity

Abstract

The application discloses a kind of based on water resources carrying capacity sandy land arbor shrub three-dimensional configuration method and system, including following six steps: division local type and evaluation available water resources amount;Plant species is divided into deep root water consumption type, medium deep root water-saving type and shallow root fast-growing type three functional types;Water resources carrying capacity threshold calculation;Generation configuration scheme;Water balance simulation verification;Output configuration scheme;Water balance equation macroscopic water resources carrying capacity calculation, plant root system functional type division, microcosmic spatial three-dimensional configuration are quantitatively coupled, avoid soil drying, groundwater level drop and other problems caused by excessive planting from the source, guarantee the long-term stability of vegetation community;Water niche differentiation is carried out in vertical level, significantly improve water use efficiency, avoid interspecific water competition;Customized configuration scheme, technical parameters are clear, strong operability;Simulation verification link is set, reduce field trial and error cost, improve technical reliability.

Description

Technical Field

[0001] This invention relates to the field of environmental ecological transformation, and in particular to a method and system for three-dimensional configuration of trees, shrubs and grasses in sandy areas based on water resource carrying capacity. Background Technology

[0002] The core bottleneck to vegetation restoration in arid and semi-arid regions such as the Hunshandake Sandy Land is water scarcity. The region receives less than 400 mm of rainfall annually, while evaporation far exceeds precipitation. Past efforts often blindly pursued high-density, all-tree afforestation models, leading to excessive soil moisture consumption and severe ecological consequences such as deep soil drying, declining groundwater levels, and large-scale vegetation decline. Therefore, scientifically determining "how much vegetation a piece of land can support, what to plant, and how to combine them" is crucial to ensuring the sustainability of ecological restoration.

[0003] Existing vegetation configuration methods are mostly based on experience or static site condition classification, and have the following main defects: (1) Failure to quantify water resource constraints: There is a lack of accurate calculation of the available water resources in different micro-topographic units, and the configuration density and coverage often exceed the water carrying capacity. (2) Insufficient consideration of interspecific water competition: When matching tree, shrub and grass species, the differences in root water absorption depth and water use strategies of different plants are ignored, resulting in excessive competition among roots in the same layer and reducing water use efficiency. (3) Extensive configuration patterns: The methods fail to propose refined species combinations and planting specifications for different site types such as mobile dunes, semi-fixed sand dunes, fixed sand dunes, and inter-dune lowlands, resulting in unstable governance effects. (4) Disconnection between economic and ecological functions: The methods fail to take into account both ecological restoration and the economic benefits of farmers and herdsmen, making it difficult to maintain the governance results in the long term. Summary of the Invention

[0004] The main objective of this invention is to provide a method and system for three-dimensional configuration of trees, shrubs and grasses in sandy areas based on water resource carrying capacity. This method and system uses water resource carrying capacity as a rigid constraint and three-dimensional configuration of trees, shrubs and grasses based on the differentiation of plant water source ecological niches to achieve sustainable restoration of sandy vegetation.

[0005] To achieve the above objectives, the present invention proposes a first technical solution: a method for three-dimensional configuration of trees, shrubs, and grasses in sandy land based on water resource carrying capacity, comprising the following steps: Step S1: Site type classification and assessment of available water resources; Based on topography, soil moisture and wind erosion intensity, the treatment area was divided into multiple site units, and the water balance method was used to assess the amount of available water resources (Wava) in each site unit during the vegetation growing season. Step S2: Based on the root water absorption depth of each species, they are divided into three functional types: deep-rooted water-consuming type, medium-deep-rooted water-saving type, and shallow-rooted fast-growing type. Step S3: Calculation of water resource carrying capacity threshold; Based on the available water resources (Wava) obtained in step S1, and combined with the transpiration water consumption coefficient of each plant species, the maximum allowable total vegetation cover and the upper limit of planting density for each life form are calculated for different site units; the calculation follows water balance constraints. Where T i The transpiration water consumption of the i-th plant during its growing season (mm·m² / plant), N i The number of plants per unit area; through iterative calculation, the maximum canopy and density thresholds are determined under the condition of ensuring a non-negative soil water balance. Step S4: Generate configuration scheme; For each site unit, based on the core principle of water source ecological niche differentiation, species are selected from the functional types in step S2 according to the configuration rules to form a tree-shrub-grass vertical configuration scheme. Step S5: Moisture balance simulation verification; For each configuration scheme obtained in step S4, the soil moisture balance model is used to simulate the soil moisture budget for one growing season: Where P is the growing season precipitation (mm), which is the local multi-year average; G is the groundwater capillary recharge (mm), which is estimated based on the groundwater level depth and the soil capillary water rise height; R is the surface runoff and deep seepage loss (mm); ET is the total evapotranspiration of the system; ΔS is the change in soil moisture; if ΔS≥0, the scheme is validated; if ΔS<0, the density or species combination is adjusted until water balance is met. Step S6: Output configuration scheme, output a list of tree, shrub and grass configurations that have been verified as feasible in step S5.

[0006] Optionally, in step S1, the treatment area is divided into four types of site units: mobile sand dunes, semi-fixed sand dunes, fixed sand dunes, and inter-dune lowlands.

[0007] Optionally, in step S1, the available water resources (Wava) of each site unit during the vegetation growing season are evaluated using the following formula: Where: P—Growing season precipitation (mm), using the local multi-year average; G—Groundwater capillary recharge (mm), estimated based on groundwater level depth and soil capillary water rise height; R—Surface runoff and deep seepage loss (mm). Es—Evaporation rate of bare soil (mm).

[0008] Optionally, in step S2, the deep-rooted water-consuming type has a main root depth greater than 150 cm and mainly utilizes deep soil water or groundwater; the medium-deep-rooted water-saving type has a main root depth of 60–150 cm and mainly utilizes medium-deep soil water; the shallow-rooted fast-growing type has a main root depth of 0–60 cm and mainly utilizes shallow soil water formed by precipitation infiltration.

[0009] Optionally, in step S3, the life form includes trees and shrubs.

[0010] Optionally, in step S4, the configuration rules include: ① The same configuration unit must simultaneously include functional types with different root depths to achieve stratified utilization of soil water in deep, medium and shallow layers; ② Trees should only be planted in low-lying areas between hills or in areas where the groundwater depth is less than 4 meters; ③ The configuration density shall not exceed the upper limit of water resource carrying capacity determined in step S3; ④ Based on the differences in micro-topography, patch or strip mosaic configurations are adopted.

[0011] Optionally, the micro-topographical features include the windward slope, the leeward slope, and the slope base.

[0012] Optionally, in step S5, the total evapotranspiration of the system includes vegetation transpiration and soil evaporation.

[0013] Optionally, the list of tree, shrub, and grass configurations includes the dominant species combination, planting density, row and plant spacing, land preparation method, and sand barrier supporting measures for each site type.

[0014] The beneficial effects of this invention are as follows: The method for three-dimensional configuration of trees, shrubs, and grasses in sandy areas based on water resource carrying capacity, as described in this invention, includes the following six steps: classifying site types and assessing available water resources; classifying plant species into three functional types: deep-rooted water-consuming, medium-deep-rooted water-saving, and shallow-rooted fast-growing; calculating water resource carrying capacity thresholds; generating configuration schemes; water balance simulation verification; and outputting configuration schemes. The method uses a water balance equation to quantitatively couple the macroscopic water resource carrying capacity calculation, plant root system functional type classification, and microscopic spatial three-dimensional configuration, using water resource carrying capacity as a rigid constraint to prevent soil drying and groundwater level decline caused by over-planting, thus ensuring the long-term stability of the vegetation community. Functional type classification is based on root depth, and deep-shallow root species are mixed to form vertical water source niche differentiation, significantly improving water use efficiency and avoiding interspecific water competition. Customized configuration schemes are proposed for different micro-topographic units, with clear technical parameters, strong operability, and guidance for front-line production practices. A simulation verification step is set up to pre-verify the configuration scheme through water balance simulation, reducing the cost of field trial and error and improving technical reliability.

[0015] This invention proposes a second technical solution for a three-dimensional tree, shrub, and grass configuration system for sandy land based on water resource carrying capacity, comprising: The data acquisition module is used to acquire data on the topography, soil moisture, wind erosion intensity, precipitation, and groundwater depth of the treatment area. The site type classification and water resource calculation module is used to divide the treatment area into multiple site units and use the water balance method to calculate the available water resources (Wava) of each site unit during the vegetation growing season. The functional classification module is used to store root water absorption depth data for each plant species and classify the plant species into three functional types: deep-rooted water-consuming type, medium-deep-rooted water-saving type, and shallow-rooted fast-growing type. The water resource carrying capacity calculation module, based on the available water resource quantity Wava and the single plant transpiration water consumption coefficient of each plant species, performs iterative calculations to satisfy the water balance constraint condition ∑(Ti · Ni) ≤ Wava, and determines the maximum allowable vegetation cover and upper limit of planting density for each site unit. The configuration scheme generation module is used to select species from the three functional types to generate a tree-shrub-grass vertical configuration scheme according to preset configuration rules. The configuration rules include: the same configuration unit must contain species from all three functional types; trees are only configured in low-lying areas between hills or areas where the groundwater depth is less than four meters; and the configuration density does not exceed the upper limit of the planting density. The simulation verification module is used to simulate the soil moisture balance of the generated configuration scheme. When the change in soil moisture ΔS≥0, the scheme is output; otherwise, the configuration scheme generation module is triggered to make adjustments.

[0016] The beneficial effects of this invention are as follows: The three-dimensional tree-shrub-grass configuration system for sandy land based on water resource carrying capacity described in this invention breaks down the complete technical process into a data acquisition module, a site type classification and water resource calculation module, a functional classification module, a water resource carrying capacity calculation module, a configuration scheme generation module, and a simulation verification module. Each module has clear functional boundaries and a well-defined data flow. This architecture allows any module to be independently upgraded, optimized, or replaced. For example, if a more refined water balance model is needed, only the site type classification and water resource calculation module needs to be updated, without reconstructing the entire system—significantly improving the system's maintainability and flexibility in technological iteration. The modules do not operate in isolation but form an orderly data transmission and feedback chain: the Wava value output by the site type classification and water resource calculation module is directly input into the water resource carrying capacity calculation module as a hard constraint condition for the density upper limit; the density threshold output by the water resource carrying capacity calculation module is directly input into the configuration scheme generation module as a mandatory parameter for the configuration rules; the initial scheme output by the configuration scheme generation module enters the simulation verification module for water balance verification, and schemes that fail automatically trigger the configuration scheme generation module for adjustment until ΔS≥0 is satisfied before output. This closed-loop architecture enables the system to automatically generate, verify, and iteratively optimize solutions without human intervention. It reduces the workload of repeated expert calculations in traditional methods to an automated process, significantly improving configuration efficiency and solution reliability. Detailed Implementation

[0017] The present invention will be further illustrated below with reference to embodiments. In the following detailed description, only certain exemplary embodiments of the invention are described by way of illustration. Undoubtedly, those skilled in the art will recognize that various modifications can be made to the described embodiments without departing from the spirit and scope of the invention. Therefore, the description is illustrative in nature and not intended to limit the scope of the claims.

[0018] A method for three-dimensional tree, shrub, and grass configuration in sandy areas based on water resource carrying capacity includes the following steps: Step S1: Site type classification and assessment of available water resources; Based on topography, soil moisture, and wind erosion intensity, the treatment area was divided into four site units: mobile dunes, semi-fixed sand dunes, fixed sand dunes, and inter-dune lowlands. The water balance method was used to assess the available water resources (Wava) in each site unit during the vegetation growing season. Where: P—Growing season precipitation (mm), using the local multi-year average; G—Groundwater capillary recharge (mm), estimated based on groundwater level depth and soil capillary water rise height; R—Surface runoff and deep seepage loss (mm). Es—Evaporation rate of bare soil (mm); Step S2: Based on the root water absorption depth of each species, they are divided into three functional types: deep-rooted water-consuming type, medium-deep-rooted water-saving type, and shallow-rooted fast-growing type. Step S3: Calculation of water resource carrying capacity threshold; Based on the available water resources (Wava) obtained in step S1, and combined with the transpiration water consumption coefficient of each plant species, the maximum allowable total vegetation cover and the upper limit of planting density for each life form (including trees and shrubs) are calculated for different site units; the calculation follows water balance constraints. Where T i The transpiration water consumption of the i-th plant during its growing season (mm·m² / plant), N i The number of plants per unit area; through iterative calculation, the maximum canopy and density thresholds are determined under the condition of ensuring a non-negative soil water balance. Step S4: Generate configuration scheme; For each site unit, based on the core principle of water source ecological niche differentiation, species are selected from the functional types in step S2 according to the configuration rules to form a tree-shrub-grass vertical configuration scheme. Step S5: Moisture balance simulation verification; For each configuration scheme obtained in step S4, the soil moisture balance model is used to simulate the soil moisture budget for one growing season: Where ET is the total evapotranspiration of the system and ΔS is the change in soil moisture; if ΔS≥0, the scheme is validated; if ΔS<0, the density or species combination is adjusted until water balance is achieved. Step S6: Output configuration scheme, output a list of tree, shrub and grass configurations that have been verified as feasible in step S5. The list of tree, shrub and grass configurations includes the dominant species combination, planting density, row and plant spacing, land preparation method and sand barrier supporting measures for each site type.

[0019] This configuration method has the following technical effects: 1. It realizes the rigid quantitative coupling of water resource carrying capacity assessment and three-dimensional vegetation configuration, fundamentally solving the industry problem of overloaded water consumption in configuration schemes.

[0020] Traditional planting methods often rely on experience to determine the ratio and density of trees, shrubs, and grasses. Water resource assessment and species selection are often separate processes, and the assessment results cannot effectively constrain planting behavior, leading to frequent failures in practice where plants "survive but don't grow large and eventually die from drought." This method, through the water balance constraint inequality ∑Ti·Ni≤Wava established in step S3, rigorously and mathematically correlates the total available water resources Wava calculated at the macro level with the transpiration water consumption Ti and the number of plants per unit area Ni at the micro level. This ensures that the total planting density of any planting scheme is limited to the water carrying capacity threshold of the site unit. This quantitative coupling mechanism ensures the feasibility of the planting scheme at the physical limits, eliminating the systemic risk of soil moisture deficit and vegetation degradation caused by over-planting.

[0021] 2. Based on the principle of water source ecological niche differentiation, a standardized generation rule of "deep root-medium-deep root-shallow root" three-dimensional configuration was constructed, realizing the efficient utilization of soil moisture in layers and the long-term stability of community structure.

[0022] In step S2 of this configuration method, plant species are objectively divided into three functional types based on root water absorption depth: deep-rooted water-consuming, medium-deep-rooted water-saving, and shallow-rooted fast-growing. Step S4 requires that each configuration unit must simultaneously contain species of all three functional types, forming a vertical differentiation of water source niches. This configuration rule ensures that deep soil water / groundwater, medium-deep soil water, and shallow soil water formed by precipitation infiltration are efficiently utilized by species of their corresponding functional groups, avoiding the intense water competition and community structure imbalance caused by overlapping water source niches in traditional configurations. The three-dimensional structure of trees, shrubs, and grasses generated based on this rule not only has a spatially staggered arrangement but also forms a stable mechanism of complementary coexistence in water utilization, providing structural guarantees for the long-term self-sustaining restoration of the vegetation community.

[0023] 3. A complete technical closed loop of "setting the upper limit of water resource carrying capacity - determining the structure of ecological niche - verifying water balance" has been constructed, which upgrades the configuration scheme from open-loop empirical design to a closed-loop self-optimizing system.

[0024] In existing technologies, once a configuration scheme is generated based on experience, it often lacks effective verification methods. The feasibility of the scheme can only be determined years later by observing the survival of the vegetation, resulting in extremely high trial-and-error costs. This configuration method establishes an independent feedback correction loop in step S5: using a water balance model to simulate the soil moisture budget for each configuration scheme during the growing season, with a soil moisture change ΔS≥0 as a rigid verification standard. Schemes that fail verification are automatically adjusted in density or species combination until water balance is achieved before output. This closed-loop design allows the configuration scheme to complete feasibility self-checks and automatic corrections before implementation, intercepting the risk of scheme failure at the design stage and significantly reducing the trial-and-error costs and ecological risks of the project.

[0025] 4. Differentiated configuration schemes were established for different site types, achieving precise desertification control with a "one policy for one site" approach.

[0026] Step S1 of this configuration method divides the treatment area into multiple site units, including mobile dunes, semi-fixed sand dunes, fixed sand dunes, and inter-dune lowlands. Each site unit independently calculates its available water resources (Wava) and independently determines its carrying capacity coverage and density threshold limits. In step S4, differentiated tree, shrub, and grass configuration schemes are generated for each type of site unit. For example, trees are only configured in inter-dune lowlands or areas with shallow groundwater levels, while mobile dunes emphasize the combination of shallow-rooted, fast-growing pioneer species with sand barrier measures. This refined configuration strategy, based on site type as the basic planning unit, avoids the localized water overload or improper configuration caused by the homogenization of the entire treatment area in traditional methods, significantly improving the spatial accuracy and overall success rate of sandy land vegetation restoration.

[0027] 5. The configuration solution output is complete and can directly guide the implementation of the project, with high practicality and operability.

[0028] The configuration list output by step S6 of this configuration method not only includes the dominant species combinations and planting densities for each site type, but also specific construction parameters such as row and plant spacing, land preparation methods, and sand barrier supporting measures. This means that the output of this method does not require secondary conversion or manual interpretation and can be directly used as construction drawings and technical specifications for sand control projects, bridging the "last mile" from scientific methods to engineering practice, and has high practical value and promotion potential.

[0029] According to some embodiments of the present invention, in step S2, the deep-rooted water-consuming type has a main root depth greater than 150cm and mainly utilizes deep soil water or groundwater; the medium-deep-rooted water-saving type has a main root depth of 60-150cm and mainly utilizes medium-deep soil water; the shallow-rooted fast-growing type has a main root depth of 0-60cm and mainly utilizes shallow soil water formed by precipitation infiltration.

[0030] Soil moisture in arid sandy areas exhibits significant stratification in its vertical profile: the 0–60 cm soil layer primarily receives direct recharge from precipitation infiltration, exhibiting drastic moisture fluctuations and serving as the main storage space for shallow soil water; the 60–150 cm soil layer acts as a transitional buffer layer for precipitation infiltration, with relatively stable moisture levels, representing mid-to-deep soil water; and the soil layer below 150 cm approaches or reaches the groundwater level influence zone, with a stable and relatively abundant water supply. The three-level root depth thresholds of this technical solution precisely correspond to the typical depth ranges of these three hydrological functional layers, ensuring accurate matching between the functional classification and the natural stratification of soil moisture in sandy areas. This provides a verifiable and reproducible physical basis for the configuration rule in step S4 that "the same configuration unit must simultaneously contain functional types with different root depths." Deep-rooted, water-consuming species have access to groundwater or deep, stable soil water, and their per-plant transpiration water consumption (Ti) is typically high, with water consumption less affected by rainfall fluctuations. Medium-deep-rooted, water-saving species rely on rainfall infiltration to replenish medium-deep soil water, with moderate water consumption and some water-saving regulation capabilities. Shallow-rooted, fast-growing species utilize only shallow soil water formed by rainfall infiltration, with relatively low transpiration water consumption but significantly affected by the intermittency of rainfall. After classifying species into these three categories, in the iterative calculation of water resource carrying capacity in step S3, differentiated transpiration water consumption coefficients (Ti) can be set according to functional type classification, making the calculation of the upper limit of density more precise and realistic, avoiding the carrying capacity estimation deviation caused by using the same water consumption parameter without differentiating functional types.

[0031] In some embodiments of the present invention, in step S4, the configuration rules include: ① The same configuration unit must contain functional types with different root depths to realize the stratified utilization of soil water in deep, medium and shallow layers; a complementary mechanism for stratified water utilization is constructed from the structural design level, eliminating the hidden danger of water competition among species; ② Trees are only planted in low-lying areas between hills or in areas where the groundwater depth is less than 4 meters; the spatial layout of water-intensive species is precisely linked to areas with abundant water resources, avoiding low survival rates and water overload caused by planting trees in water-deficient areas; ③ The configuration density does not exceed the upper limit of water resource carrying capacity determined in step S3; the density control is upgraded from experience-based advice to rigid quantitative constraint, which ensures the carrying capacity of the configuration scheme within the physical limits of water resources from the perspective of total quantity; ④ Based on the differences in micro-topographical features, a patchy or strip-shaped mosaic configuration is adopted; the micro-topographical features include windward slopes, leeward slopes, and slope bases. Integrating the principles of topography-wind-sand dynamics into the spatial layout enhances the windbreak and sand-fixing effectiveness and micro-habitat adaptability of the configuration scheme.

[0032] The four rules work synergistically across four dimensions—water resource allocation, spatial layout, total quantity control, and micro-topographic adaptation—to form a multi-constraint collaborative configuration decision-making system. The simultaneous action of these four rules optimizes the generated configuration scheme in four dimensions: water use efficiency, spatial structure rationality, total quantity controllability, and environmental adaptability, achieving a systemic technical effect that a single rule could not achieve.

[0033] According to some embodiments of the present invention, in step S5, the total system evapotranspiration includes vegetation transpiration and soil evaporation Es. This technical solution calculates the total system evapotranspiration ET in two parts, allowing for targeted adjustments during water deficits. For example, if soil evaporation is too high, surface cover species or sand barrier measures should be added; if vegetation transpiration is too high, the planting density of high water-consuming functional species should be reduced first. This gives the solution modification a clear physical direction, improving the efficiency and scientific nature of the self-optimization process. The three functional species—deep-rooted water-consuming, medium-deep-rooted water-saving, and shallow-rooted fast-growing—exhibit systematic differences in transpiration water consumption characteristics. After separating vegetation transpiration independently from the total system evapotranspiration, a differentiated single-plant transpiration water consumption coefficient Ti can be set for each functional type, and multiplied and accumulated with the planting density Ni of each functional type. Soil evaporation Es is estimated independently based on surface cover and bare soil area. This decoupled calculation method ensures consistency and coherence between the water balance constraint ∑Ti·Ni ≤ Wava in step S3 and the water balance simulation equation P+G=ET+R+ΔS in step S5 in terms of parameter definition and calculation logic. This avoids simulation bias caused by redundant parameter definitions or inconsistent definitions, thus improving the reliability of the verification results. The degree of surface exposure varies significantly among different site types. For example, mobile dunes have low vegetation cover and soil evaporation is dominant, while fixed sand dunes have high vegetation cover and vegetation transpiration is dominant. The proportions and total cover of each functional type also differ in different configuration schemes, leading to significant variations in the composition ratio of vegetation transpiration and soil evaporation in ET. By separating these two components, the water balance model can accurately capture the changes in evapotranspiration composition from sparse vegetation to dense communities. This allows the same model to maintain high simulation accuracy across different site types and configuration schemes, enhancing the versatility of the verification method and the scientific rigor of cross-scheme comparisons.

[0034] A three-dimensional tree-shrub-grass configuration system for sandy land based on water resource carrying capacity includes: The data acquisition module is used to acquire data on the topography, soil moisture, wind erosion intensity, precipitation, and groundwater depth of the treatment area. The site type classification and water resource calculation module is used to divide the treatment area into multiple site units and use the water balance method to calculate the available water resources (Wava) of each site unit during the vegetation growing season. The functional classification module is used to store root water absorption depth data for each plant species and classify the plant species into three functional types: deep-rooted water-consuming type, medium-deep-rooted water-saving type, and shallow-rooted fast-growing type. The water resource carrying capacity calculation module, based on the available water resource quantity Wava and the single plant transpiration water consumption coefficient of each plant species, performs iterative calculations to satisfy the water balance constraint condition ∑(Ti · Ni) ≤ Wava, and determines the maximum allowable vegetation cover and upper limit of planting density for each site unit. The configuration scheme generation module is used to select species from the three functional types to generate a tree-shrub-grass vertical configuration scheme according to preset configuration rules. The configuration rules include: the same configuration unit must contain species from all three functional types; trees are only configured in low-lying areas between hills or areas where the groundwater depth is less than four meters; and the configuration density does not exceed the upper limit of the planting density. The simulation verification module is used to simulate the soil moisture balance of the generated configuration scheme. When the change in soil moisture ΔS≥0, the scheme is output; otherwise, the configuration scheme generation module is triggered to make adjustments.

[0035] This three-dimensional tree, shrub, and grass configuration system for sandy land, based on water resource carrying capacity, has the following beneficial technical effects: 1. Through modular architecture, complex multidisciplinary configuration processes are engineered into deployable and maintainable standardized systems.

[0036] The integrated planting of trees, shrubs, and grasses in sandy areas involves the comprehensive application of knowledge from multiple disciplines such as hydrology, plant ecology, and soil science. Traditional methods heavily rely on on-site collaboration by expert teams, making standardization and promotion difficult. This system breaks down the complete technical process into a data acquisition module, a site type classification and water resource calculation module, a functional classification module, a water resource carrying capacity calculation module, a configuration scheme generation module, and a simulation verification module. Each module has clear functional boundaries and a well-defined data flow. This architecture allows any module to be independently upgraded, optimized, or replaced. For example, if a more refined water balance model is required, only the site type classification and water resource calculation module needs to be updated, without reconstructing the entire system; this significantly improves the system's maintainability and the flexibility of technological iteration.

[0037] 2. Through data linkage and closed-loop feedback between modules, a self-optimizing configuration decision-making mechanism of "evaluation-generation-verification-correction" was constructed.

[0038] The modules do not operate in isolation, but rather form an orderly data transmission and feedback loop: the Wava value output by the site type classification and water resources calculation module is directly input into the water resources carrying capacity calculation module as a hard constraint condition for the density upper limit; the density threshold output by the water resources carrying capacity calculation module is directly input into the configuration scheme generation module as a mandatory parameter for the configuration rules; the initial scheme output by the configuration scheme generation module enters the simulation verification module for water balance verification, and schemes that fail automatically trigger the configuration scheme generation module to make adjustments until ΔS≥0 is satisfied before output. This closed-loop architecture enables the system to automatically complete the generation, verification, and iterative optimization of schemes without human intervention, compressing the workload of repeated trial calculations by experts in traditional methods into an automatic system operation process, significantly improving configuration efficiency and scheme reliability.

[0039] 3. The functional division module provides a standardized species classification basis for the configuration scheme generation module, ensuring the complementary ecological niche logic of the water source in the vertical structure design.

[0040] The functional classification module pre-stores and categorizes plant species into three types: deep-rooted water-consuming, medium-deep-rooted water-saving, and shallow-rooted fast-growing. This allows the configuration scheme generation module to automatically combine species for deep, medium, and shallow soil water utilization based on the rule that "the same configuration unit must contain all three functional types." This standardized interface design between modules ensures that regardless of updates or expansions to the species database of the treatment area, the configuration scheme generation module can always select species from the three functional types to generate a three-dimensional structure of trees, shrubs, and grasses that conforms to the principle of water source ecological niche differentiation, thus ensuring the stability and consistency of the ecological logic of the system's output scheme.

[0041] 4. The water resource carrying capacity calculation module rigidly couples macroscopic water resource quantity with microscopic planting density, providing an insurmountable physical constraint boundary for the configuration scheme.

[0042] The water resource carrying capacity calculation module uses the condition ∑(Ti·Ni) ≤ Wava as its core operation. It mathematically rigidly correlates site type classification with the available water resource quantity Wava output by the water resource calculation module, and with the transpiration water consumption coefficient Ti and the number of plants per unit area Ni for each plant species, all within the same inequality. This module's design ensures that the planting density of any scheme output by the configuration scheme generation module is limited to the physical limit of the site unit's water resource carrying capacity, eliminating the possibility of water deficit after implementation due to excessive density at the system architecture level.

[0043] 5. The simulation verification module provides a feasibility pre-implementation mechanism for the configuration scheme, intercepting failure risks at the design stage.

[0044] The simulation verification module uses an independent water balance model to simulate the soil moisture budget during the growing season for the configuration schemes, with ΔS≥0 as a clear pass criterion, and forms an automatic feedback loop with the configuration scheme generation module. This design allows any scheme with potential water deficit to be identified and corrected before output, avoiding the high trial-and-error costs of traditional methods where the success or failure of a scheme can only be judged by vegetation survival status after many years of implementation. This makes the quality control of the configuration schemes proactive and automated.

[0045] 6. The system as a whole provides an integrable core engine for the intelligent desertification control and digital ecological restoration platform.

[0046] Each module of this system is fully functional and has clear interfaces. It can serve as an independent core algorithm engine and be integrated into information platforms for desertification control, digital twin systems for ecological restoration, or decision support systems for forestry resource management through API calls or module embedding. It can work in collaboration with external data sources such as remote sensing monitoring, weather forecasting, and real-time soil moisture monitoring to achieve intelligent desertification control decision-making throughout the entire process, from data collection, carrying capacity assessment, scheme generation to verification output. This demonstrates the broad application prospects and integration value of this system in the field of digital ecology.

[0047] The following specific embodiment will further illustrate the screening method of the present invention.

[0048] Example: Tree, shrub, and grass configuration based on water resource carrying capacity on the southern edge of the Hunshandake Sandy Land Step S1: The treatment area was divided into four site types: mobile dunes, semi-fixed sand dunes, fixed sand dunes, and inter-dune lowlands. The available water resources during the growing season for each type were assessed using the water balance formula. The results were as follows: mobile dunes 180–220 mm, semi-fixed sand dunes 240–280 mm, fixed sand dunes 260–300 mm, and inter-dune lowlands 350–450+ mm.

[0049] Step S2: Select 10 suitable plant species: *Cotinus coggygria*, *Caragana microphylla*, *Salix matsudana*, *Ulmus pumila*, *Chenopodium album*, *Prunus armeniaca*, *Leymus chinensis*, *Agropyron cristatum*, *Hemerocallis fulva*, and *Hemerocallis fulva*. These are categorized based on root depth: Deep-rooted, water-intensive type: *Ulmus pumila* (Sandland Ulmus); Medium-deep root water-saving type: *Pterocarya stenoptera*, *Caragana microphylla*, *Saussurea involucrata*; Shallow-rooted, fast-growing varieties: Yellow willow, North China camel hairy quinoa, European plum, sheep grass, ice grass, daylily; Step S3: Calculate the carrying capacity threshold based on the transpiration water consumption coefficient of each plant: maximum coverage of mobile sand dunes is 30-40%, with shrubs ≤80 plants / acre and no trees; coverage of semi-fixed sand dunes is 40-55%, with shrubs ≤110 plants / acre; coverage of fixed sand dunes is 50-65%, with shrubs ≤150 plants / acre; coverage of inter-dune lowlands is 60-75%, with shrubs ≤120 plants / acre and trees ≤45 plants / acre.

[0050] Step S4: Generate 6 configuration schemes as shown in Table 1: Table 1 Technical Schemes for Tree, Shrub and Grass Configuration in Different Site Environments (1) Sand-fixing configuration of mobile dune pioneer (yellow willow + poplar + ice grass) Yellow willow cuttings, density ≤ 80 clumps / mu; poplar twigs sown in holes between strips, density ≤ 40 plants / mu; ice grass strips sown on both sides, row spacing 30 cm. Water source ecological niche differentiation: Yellow willow root system depth 1.5 m, poplar twig depth 1~2 m, ice grass shallow layer 0~40 cm, forming a "deep-medium-shallow" three-layer root system structure.

[0051] (2) Semi-fixed sandy land shrub-grass compound forage configuration (North China camel hair lamb + small-leaved caragana + sheep grass) The plant spacing for *Chenopodium album* is 0.5 m, the row spacing is 3-4 m, and the density is ≤110 plants / mu; *Caragana microphylla* is interplanted within the rows, with a density of ≤40 plants / mu; *Leymus chinensis* is broadcast between rows. *Chenopodium album* yields 150-200 kg of hay per mu.

[0052] (3) Semi-fixed sandy land Prunus cerasifera ecological and economic configuration (Prunus cerasifera + Caragana microphylla + Leymus chinensis) Prunus cerasifera should be planted at a spacing of 2 m between plants and 2.5-3 m between rows, with a density of ≤110 plants / mu; Caragana microphylla should be planted on the windward side edge, with a density of ≤30 plants / mu; Leymus chinensis should be sown between rows.

[0053] (4) Fixed sandy land forest and grassland strip configuration (poplar wood + alfalfa + ice grass) Plant *Populus edulis* in double rows with a spacing of 8-10 m and a density of ≤150 plants / mu; broadcast *Saussurea involucrata* between the strips at a seeding rate of 0.8 kg / mu; reseed within the *Cephalotaxus fortunei* strip. *Populus edulis* and *Saussurea involucrata* create a vertical separation of water sources.

[0054] (5) Three-dimensional configuration of trees, shrubs and grasses in lowland areas between hills (Ulmus parvifolia + Salix psammophila + Daylily + Leymus chinensis) Sand dune elm (3 m × 4 m) at a density of ≤45 plants / mu; yellow willow (between rows and perimeter) at a density of ≤80 clumps / mu; daylily (planted in holes under the forest canopy) at a density of 4000–5000 plants / mu; sheepgrass (buckweed) sown under the forest canopy.

[0055] (6) Economic configuration of daylily for water conservation in lowland forest edge between hills (daylily + yellow willow + ice grass) Daylilies are planted in holes along contour lines, 30 cm × 40 cm, at a density of 4000–5000 plants / mu; they are planted on the upper part of the slope of *Salix matsudana*, at a density of ≤50 clumps / mu; and *Isodon japonica* is sown between rows.

[0056] Step S5: Perform water balance simulation on typical schemes.

[0057] Water balance simulations were conducted on three typical configuration patterns: semi-fixed sandy land Prunus serrulata ecological and economic configuration (Prunus serrulata + Caragana microphylla + Leymus chinensis), fixed sandy land forest and grassland strip configuration (Populus spp. + Alternaria alternifolia + Agrocybe aegerita), and inter-dune lowland tree, shrub and grass three-dimensional configuration (Ulmus parvifolia + Salix matsudana + Daylily + Leymus chinensis). The simulation results showed that within the recommended density range, all three configuration patterns maintained a positive soil moisture balance, as shown in Table 2.

[0058] Table 2. Water balance simulation results for three typical configuration modes In summary, the method and system for three-dimensional tree, shrub, and grass configuration in sandy areas based on water resource carrying capacity described in this application have the following advantages compared with the prior art: 1. Determine greening based on water availability for ecological sustainability: Treat water resource carrying capacity as a rigid constraint to prevent soil drying and groundwater level decline caused by over-planting from the source, and ensure the long-term stability of vegetation communities.

[0059] 2. Stratified water use to avoid vicious competition: Functional classification is based on root depth, and vertical water niche differentiation is formed through deep-shallow root species mixing, which significantly improves water use efficiency and avoids interspecific water competition.

[0060] 3. Refined and differentiated configuration: Customized configuration schemes are proposed for different micro-topographic units, with clear technical parameters, strong operability, and can guide front-line production practices.

[0061] 4. Balancing ecology and economy: Shrubs and herbs with economic value (such as European plum, daylily, etc.) can be included in the configuration to provide economic benefits to farmers and herdsmen while preventing wind erosion and fixing sand, and to promote the long-term consolidation of the governance results.

[0062] 5. Includes a simulation verification step: The configuration scheme is pre-verified through water balance simulation, reducing the cost of on-site trial and error and improving the reliability of the technology.

[0063] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents. .

Claims

1. A method for three-dimensional configuration of trees, shrubs, and grasses in sandy land based on water resource carrying capacity, characterized in that, Includes the following steps: Step S1: Site type classification and assessment of available water resources; Based on topography, soil moisture, and wind erosion intensity, the treatment area was divided into multiple site units. The water balance method was used to assess the available water resources (Wava) in each site unit during the vegetation growing season. Where: P—Growing season precipitation (mm), using the local multi-year average; G—Groundwater capillary recharge (mm), estimated based on groundwater level depth and soil capillary water rise height; R—Surface runoff and deep seepage loss (mm). Es—Evaporation rate of bare soil (mm); Step S2: Based on the root water absorption depth of each species, they are divided into three functional types: deep-rooted water-consuming type, medium-deep-rooted water-saving type, and shallow-rooted fast-growing type. Step S3: Calculation of water resource carrying capacity threshold; Based on the available water resources (Wava) obtained in step S1, and combined with the transpiration water consumption coefficient of each plant species, the maximum allowable total vegetation cover and the upper limit of planting density for each life form are calculated for different site units; the calculation follows water balance constraints. Where T i The transpiration water consumption (mm) per plant per unit area of ​​the i-th plant species during the growing season, N. i The number of plants per unit area; through iterative calculation, the maximum canopy and density thresholds are determined under the condition of ensuring a non-negative soil water balance. Step S4: Generate configuration scheme; For each site unit, based on the core principle of water source ecological niche differentiation, species are selected from the functional types in step S2 according to the configuration rules to form a tree-shrub-grass vertical configuration scheme. The configuration rules include: ① The same configuration unit must simultaneously include functional types with different root depths to achieve stratified utilization of soil water in deep, medium and shallow layers; ② Trees should only be planted in low-lying areas between hills or in areas where the groundwater depth is less than 4 meters; ③ The configuration density shall not exceed the upper limit of water resource carrying capacity determined in step S3; ④ Based on the differences in micro-topography, patch or strip mosaic patterns are used; Step S5: Moisture balance simulation verification; For each configuration scheme obtained in step S4, the soil moisture balance model is used to simulate the soil moisture budget for one growing season: Where P is the growing season precipitation (mm), using the local multi-year average; G is the groundwater capillary recharge (mm), estimated based on the groundwater level depth and the soil capillary water rise height; R is the surface runoff and deep seepage loss (mm); ET is the total evapotranspiration of the system, which includes vegetation transpiration and soil evaporation; ΔS is the change in soil moisture; if ΔS≥0, the scheme passes verification; if ΔS<0, the density or species combination is adjusted until water balance is met; Step S6: Output configuration scheme, output a list of tree, shrub and grass configurations that have been verified as feasible in step S5.

2. The method for three-dimensional configuration of trees, shrubs, and grasses in sandy land based on water resource carrying capacity according to claim 1, characterized in that, In step S1, the treatment area is divided into four types of site units: mobile sand dunes, semi-fixed sand dunes, fixed sand dunes, and inter-dune lowlands.

3. The method for three-dimensional tree, shrub, and grass configuration in sandy areas based on water resource carrying capacity according to claim 1, characterized in that, In step S2, the deep-rooted water-consuming type has a taproot depth greater than 150 cm and mainly utilizes deep soil water or groundwater; the medium-deep-rooted water-saving type has a taproot depth of 60–150 cm and mainly utilizes medium-deep soil water; and the shallow-rooted fast-growing type has a taproot depth of 0–60 cm and mainly utilizes shallow soil water formed by rainwater infiltration.

4. The method for three-dimensional tree, shrub, and grass configuration in sandy areas based on water resource carrying capacity according to claim 1, characterized in that, In step S3, the life form includes trees and shrubs.

5. The method for three-dimensional configuration of trees, shrubs, and grasses in sandy land based on water resource carrying capacity according to claim 1, characterized in that, The micro-topographical features include the windward slope, the leeward slope, and the bottom of the slope.

6. The method for three-dimensional configuration of trees, shrubs, and grasses in sandy land based on water resource carrying capacity according to claim 1, characterized in that, The list of tree, shrub, and grass configurations includes the dominant species combination, planting density, row and plant spacing, land preparation method, and sand barrier supporting measures for each site type.

7. A system based on the method for three-dimensional configuration of trees, shrubs, and grasses in sandy land based on water resource carrying capacity as described in any one of claims 1-6, characterized in that, include: The data acquisition module is used to acquire data on the topography, soil moisture, wind erosion intensity, precipitation, and groundwater depth of the treatment area. The site type classification and water resource calculation module is used to divide the treatment area into multiple site units and use the water balance method to calculate the available water resources (Wava) of each site unit during the vegetation growing season. The functional classification module is used to store root water absorption depth data for each plant species and classify the plant species into three functional types: deep-rooted water-consuming type, medium-deep-rooted water-saving type, and shallow-rooted fast-growing type. The water resource carrying capacity calculation module, based on the available water resource quantity Wava and the single plant transpiration water consumption coefficient of each plant species, performs iterative calculations to satisfy the water balance constraint condition ∑(Ti · Ni) ≤ Wava, and determines the maximum allowable vegetation cover and upper limit of planting density for each site unit. The configuration scheme generation module is used to select species from the three functional types to generate a tree-shrub-grass vertical configuration scheme according to preset configuration rules; The simulation verification module is used to simulate the soil moisture balance of the generated configuration scheme. When the change in soil moisture ΔS≥0, the scheme is output; otherwise, the configuration scheme generation module is triggered to make adjustments.

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