A method and system for preventing and controlling erosion of slope farmland by arranging forests and grasses

Abstract

The present application relates to the field of slope farmland erosion prevention and control, and discloses a kind of slope farmland erosion prevention and control forest and grass layout method and system, comprising: obtaining slope farmland multidimensional background data, constructing digital elevation model to identify runoff convergence path and sediment transport channel;According to the erosion risk gradient, four types of prevention and control units are delimited and the site conditions are clarified;Matching prevention and control target determines control threshold and forest and grass layout benchmark parameter, completes buffer zone layout, species screening and community configuration;Constructing full-slope layout scheme and setting up reinforced control nodes, after model checking and iterative optimization, the final layout is completed;The present application solves the problem that the prior art cannot simultaneously meet the multiple requirements of slope farmland erosion precision prevention and control, farmland resource protection, scheme quantization controllable, long-term stable adaptation.

Description

Technical Field

[0001] This invention relates to the field of erosion control of sloping farmland, and in particular to a method and system for forest and grassland layout for erosion control of sloping farmland. Background Technology

[0002] Sloping farmland is a core source of soil erosion and an important agricultural production resource in my country, widely distributed in key soil erosion areas such as the Loess Plateau, the Southwest Karst, the Southern Red Soil Hills, and the Northeast Black Soil. Water erosion of sloping farmland not only leads to farmland degradation and decreased productivity, but also causes ecological problems such as river siltation and non-point source pollution, making it a key target for soil and water conservation and ecological protection in my country.

[0003] Forestry and grassland ecological measures are the core technical means for the long-term prevention and control of erosion on sloping farmland due to their long-lasting control effects, significant ecological benefits, low operation and maintenance costs, and compatibility with agricultural production. The rationality of forestry and grassland layout directly determines the quality of control effectiveness. Currently, existing technologies mostly focus on the selection of native soil and water conservation species, optimization of single buffer zone structures, and improvement of vegetation coverage, forming conventional layout patterns such as contour hedges and shrub-grass buffer zones on slopes. However, the following core technical deficiencies still exist:

[0004] Existing models are mostly based on experience and generalization, failing to consider the entire dynamic process of sloping farmland erosion, accurately identify core erosion nodes such as runoff confluence paths and sediment transport channels, and resulting in a disconnect between forest and grassland layout and actual erosion patterns, leading to low efficiency in runoff interception and sediment retention. There is a lack of a linkage and matching mechanism between "control targets - quantitative thresholds - deployment parameters," with core parameters such as buffer zone bandwidth and spacing determined primarily based on engineering experience, easily leading to insufficient control or excessive deployment occupying farmland, and poor scenario adaptability. The overall slope collaborative control capability is insufficient, focusing mainly on deployment in the main cultivated area, failing to construct a full-gradient collaborative control system of "source interception - slope surface control - gully edge erosion prevention - slope toe retention," easily leading to intensified erosion in boundary areas and insufficient overall slope treatment effect. There is a lack of standardized scheme pre-verification and targeted optimization mechanisms, with most designs being static, unable to quantitatively verify control effects in advance, and lacking a graded iterative optimization process, resulting in large deviations between the actual implementation effect and expectations, and insufficient stability.

[0005] In summary, existing forestry and grassland layout technologies for controlling erosion of sloping farmland cannot simultaneously meet the multiple needs of precise control of erosion of sloping farmland, protection of farmland resources, quantitative and controllable schemes, and long-term stable adaptation. There is an urgent need to develop a forestry and grassland layout method based on accurate identification of the dynamic process of erosion of sloping farmland, coordinated control of the entire slope gradient, quantitative matching design, and closed-loop optimization capabilities, in order to solve the core pain points of existing technologies. Summary of the Invention

[0006] The present invention aims to provide a method and system for the layout of forests and grasslands to prevent and control erosion of sloping farmland, so as to solve the problem that the existing technology cannot simultaneously meet the multiple requirements of precise prevention and control of erosion of sloping farmland, protection of farmland resources, quantitative and controllable schemes, and long-term stable adaptation.

[0007] To achieve the above objectives, the present invention provides the following method:

[0008] The present invention provides a method for forest and grassland layout to control erosion on sloping farmland:

[0009] S1: Obtain topographic elevation data, soil physicochemical property data, historical erosion status data, meteorological and hydrological data, and native vegetation baseline data of the target sloping farmland; construct a digital elevation model based on the topographic elevation data; and identify the runoff confluence path and sediment transport channel of the target sloping farmland.

[0010] S2: Based on the runoff confluence path, the sediment transport channel, and the historical erosion status data, along the vertical contour line direction of the target sloping farmland, four types of control units are delineated in sequence according to the erosion risk gradient: slope top interception control unit, slope surface gradient control unit, gully edge blocking control unit, and slope toe holding control unit. Simultaneously, based on the acquired topographic elevation data, soil physicochemical property data, meteorological and hydrological data, and native vegetation background data, the site conditions corresponding to each of the four types of control units are clarified.

[0011] S3: Determine the core erosion control targets for each of the four types of control units, and combine the meteorological and hydrological data with the soil physicochemical property data to obtain two types of control thresholds: runoff velocity control threshold and sediment flux control threshold, which correspond one-to-one with the four types of control units. Determine the benchmark parameters for forest and grassland layout based on the two types of control thresholds.

[0012] S4: For the slope gradient control unit among the four types of control units, based on the forest and grassland layout benchmark parameters, multi-level tree-shrub-grass composite buffer zones are laid out along the contour lines, and the three layout parameters of each tree-shrub-grass composite buffer zone are determined: bandwidth, spacing, and layout direction.

[0013] S5: Based on the site conditions, core targets of erosion control, and two control thresholds of the four types of control units, and in conjunction with the soil physicochemical property data and the native vegetation baseline data, suitable native tree, shrub, and herb species are selected to determine the forest and grass species combination and community configuration mode that have both runoff interception and sediment retention functions for each of the four types of control units.

[0014] S6: Based on the layout parameters of the tree-shrub-grass composite buffer zone of the slope gradient control unit, and the forest and grass species combination and community configuration mode of the four types of control units, construct a forest and grass layout scheme for the entire slope farmland, and set up enhanced blocking nodes to match the runoff confluence path and the sediment transport channel.

[0015] S7: Using a soil erosion forecasting model and combining the meteorological and hydrological data, verify the runoff regulation and erosion control effects of the whole-slope farmland forest and grassland layout scheme, obtain the verification results, and simultaneously determine whether the whole-slope farmland forest and grassland layout scheme meets the two types of control thresholds.

[0016] S8: If the verification result does not meet the two types of control thresholds, then optimize and adjust the benchmark parameters for forest and grassland layout and the combination and community configuration mode of forest and grassland species, and repeat the verification process of step S7 until the forest and grassland layout scheme of the whole slope farmland meets the two types of control thresholds, and complete the final forest and grassland layout for erosion control of slope farmland.

[0017] Preferably, step S1 specifically includes: acquiring topographic elevation data with a spatial resolution of not less than 5 meters using UAV aerial surveying or field measurements; acquiring soil physicochemical property data including soil texture, bulk density, organic matter content, and erosion resistance indicators using field profile sampling and indoor experiments; acquiring historical erosion status data including erosion type, intensity, and gully erosion distribution through remote sensing interpretation and field surveys; acquiring meteorological and hydrological data including rainfall, rainfall intensity, and runoff for more than 10 consecutive years through local meteorological stations; acquiring native vegetation baseline data including native species types and community structure through quadrat surveys; and removing outliers from the topographic elevation data using the 3x standard deviation method. Gaussian filtering was used to smooth and denoise the terrain elevation data to obtain the corrected topographic elevation data. Based on the corrected terrain elevation data, an initial digital elevation model was constructed using inverse distance weighted interpolation. A depression-filling algorithm was used to correct the micro-topography and eliminate false depressions, resulting in a final digital elevation model with the same accuracy as the corrected terrain elevation data. Based on the final digital elevation model, the D8 algorithm was used to calculate the runoff accumulation of each grid. Combined with historical erosion status data, a dynamic runoff threshold was determined. The dynamic runoff threshold was lower in areas with higher erosion intensity. Continuous grid sequences with runoff accumulation greater than the dynamic runoff threshold were identified as runoff confluence paths, and runoff confluence paths that were continuously connected to gully erosion were identified as sediment transport channels.

[0018] Preferably, step S2 specifically includes: along the vertical contour line direction of the target sloping farmland, sequentially delineating the slope top interception control unit from the watershed to the farmland's upper boundary, the slope gradient control unit from the farmland's upper boundary to its lower boundary, the gully edge blocking control unit from the farmland's lower boundary to the gully edge, and the slope toe holding control unit from the gully edge to the gully channel stability boundary; breaking down site conditions into four categories of indicators: topography, soil, hydrology, and vegetation. Topographic indicators include slope, slope length, slope aspect, and slope position; soil indicators include soil texture, bulk density, organic matter content, and erosion resistance; hydrological indicators include multi-year average runoff and soil moisture content; and vegetation indicators include native vegetation coverage and dominant species types. Based on the corrected topographic elevation data, soil physicochemical property data, meteorological and hydrological data, and native vegetation baseline data, extracting various indicators corresponding to the four control units; and using the range standardization method to assign values ​​from 0 to 1 to each indicator, forming a quantitative dataset of site conditions for each control unit, thus clarifying the site conditions.

[0019] Preferably, step S3 specifically includes: determining the core objectives of erosion control for four types of control units: the top interception control unit intercepts source runoff and blocks confluence; the slope gradient control unit slows runoff velocity and impounds sediment; the gully edge blocking control unit blocks runoff into the gully and inhibits gully erosion development; and the slope toe holding control unit holds the gully bank soil to intercept transported sediment. The natural slope runoff velocity of each control unit is calculated using meteorological and hydrological data, and the natural slope sediment flux of each control unit is calculated using soil physicochemical property data and historical erosion status data. Based on the core objectives of erosion control for each control unit, the runoff reduction rate and sediment interception rate of the corresponding unit are determined. Combining the natural slope runoff velocity and natural slope sediment flux, a runoff velocity control threshold corresponding to each control unit is obtained. Two types of control thresholds are used: a value and a sediment flux control threshold. For control units with higher erosion risk levels, the corresponding runoff reduction rate and sediment interception rate are higher, and the corresponding runoff velocity control threshold and sediment flux control threshold are lower. Based on the difference between the runoff velocity control threshold and the runoff velocity on the natural slope, the lower limits of forest and grassland coverage and vegetation canopy closure for each control unit are determined; the larger the difference, the higher the corresponding lower limits of forest and grassland coverage and vegetation canopy closure. Based on the difference between the sediment flux control threshold and the sediment flux on the natural slope, the lower limit of buffer zone density for each control unit is determined; the larger the difference, the higher the corresponding lower limit of buffer zone density. Integrating the lower limits of forest and grassland coverage, vegetation canopy closure, and buffer zone density for each control unit yields the forest and grassland layout baseline parameters.

[0020] Preferably, step S4 specifically includes: determining that the layout direction of the tree-shrub-grass composite buffer zone is parallel to the contour lines of the target sloping farmland, with a deviation angle not exceeding 3°; and dividing the slope gradient control unit into slopes less than 5° and 5°. 15°, 15° The slope is graded into four levels: 25°, greater than 25°, and based on the slope grading and the lower limit of buffer zone density in the forestry and grassland layout reference parameters, the total number of levels of the tree-shrub-grass composite buffer zone is determined. For each increase in slope grading, the total number of layout levels increases by 2. Based on the slope length of the slope gradient control unit and the total number of layout levels, the belt spacing reference value is determined. The belt spacing reference value is adjusted based on the slope grading, with the belt spacing decreasing by 15% for every 5° increase in slope, resulting in the final belt spacing between adjacent levels of the tree-shrub-grass composite buffer zone. Based on the lower limit of forestry and grassland coverage in the forestry and grassland layout reference parameters, the bandwidth reference value is determined. The bandwidth reference value is adjusted based on the erosion intensity level at the corresponding location, with the bandwidth increasing by 20% for each increase in erosion intensity level, resulting in the final bandwidth of each tree-shrub-grass composite buffer zone. Integrating the determined layout direction, final belt spacing, and final bandwidth, the three tree-shrub-grass composite buffer zone layout parameters are obtained, completing the layout of the multi-level tree-shrub-grass composite buffer zone.

[0021] Preferably, step S5 specifically includes: establishing a functional evaluation system for native species that includes runoff interception capacity, sediment retention capacity, site adaptability, growth stability, and local adaptability, with each indicator using a 0.05-0.05 ratio. A 10-point quantitative scoring system is used. Based on the core erosion control objectives of each of the four types of control units, the weights of species evaluation indicators for each control unit are determined using the analytic hierarchy process (AHP). Units with higher runoff interception and sediment retention requirements have higher weights for their runoff interception and sediment retention capacity indicators. Combined with the baseline data of native vegetation, naturally distributed native trees, shrubs, and herbaceous species within the target sloping farmland area are selected. Based on the native species function evaluation system and the corresponding control unit indicator weights, a comprehensive evaluation score for each species is calculated. Species with a comprehensive evaluation score higher than 6 are selected to form a candidate species pool for each control unit. Based on the erosion control objectives of each control unit... The core objective of erosion control is to select suitable tree, shrub, and herbaceous species from the candidate species library to form forest-grass species combinations. Specifically, the species combinations of the slope crest interception control unit and the slope foot holding control unit include trees, shrubs, and herbs; the species combination of the tree-shrub-grass composite buffer zone of the slope gradient control unit includes shrubs and herbs; and the species combination of the gully edge blocking control unit is mainly shrub species with herbaceous species as a supplement. Based on the site conditions of each control unit and the two types of control thresholds, the spacing between rows and plants, the interlayer ratio, and the planting sequence of each species in the forest-grass species combination are determined to form the community configuration pattern of the corresponding control unit.

[0022] Preferably, step S6 specifically includes: establishing a planar rectangular spatial layout coordinate system for the target sloping farmland, using the final digital elevation model as the spatial base, the northwest corner of the target sloping farmland as the origin, the east direction as the positive X-axis, and the north direction as the positive Y-axis; sequentially importing the spatial boundaries of the four types of control units, the layout parameters of the tree-shrub-grass composite buffer zone, and the forest and grass species combination and community configuration mode into the spatial layout coordinate system to complete the preliminary spatial positioning of the forest and grass layout of each control unit; optimizing the connection of the forest and grass layout of adjacent control units to ensure a gradient transition in the forest and grass coverage and species height of adjacent units, guaranteeing the continuous and uninterrupted runoff interception and sediment retention control functions of adjacent units; integrating the preliminary spatial positioning and the connection optimization results to generate an initial full-scale spatial layout map including a spatial layout map, a species configuration table, and a layout parameter table. A forest and grassland layout scheme for sloping farmland is developed. Based on the spatial distribution of the runoff confluence paths and sediment transport channels, locations with a runoff accumulation greater than twice the average runoff accumulation in the same area are identified as peak runoff accumulation locations. The intersections of two or more runoff confluence paths or sediment transport channels are identified, as well as the boundary connection locations of the four types of control units. These three types of locations are selected as candidate locations for enhanced control nodes. Based on the runoff intensity and sediment transport intensity of each candidate location, the node layout scale and coverage are determined. The top three species with the highest comprehensive evaluation scores in the candidate species library of the control unit to which each enhanced control node belongs are matched, completing the spatial placement of the enhanced control nodes. The spatial placement results, species configuration, and layout parameters of the enhanced control nodes are updated to the initial full-slope farmland forest and grassland layout scheme to obtain the final full-slope farmland forest and grassland layout scheme.

[0023] Preferably, step S7 specifically includes: the soil erosion prediction model adopts a general soil loss equation, and inputs the forest and grassland coverage, vegetation canopy density, tree-shrub-grass composite buffer zone layout parameters, community configuration pattern, and enhanced control node layout parameters from the final full-slope cultivated land forest and grassland layout scheme into the general soil loss equation; combined with the meteorological and hydrological data, sets simulation conditions for three rainfall return periods of 2 years, 5 years, and 10 years, and each condition sets the maximum 30-minute rainfall intensity and 6-hour rainfall duration for the corresponding return period; and simulates the data using the general soil loss equation. The calculation yields the slope runoff, soil erosion modulus, runoff interception rate, and sediment retention rate of the target sloping farmland under three working conditions, along with the four types of control units. The overall runoff interception rate and sediment retention rate of the entire slope are compared with the overall slope compliance requirements of the two types of control thresholds. The runoff interception rate and sediment retention rate at each unit level are compared with the corresponding control unit's two types of control thresholds to obtain comparison results. Based on the comparison results, a verification result is generated, which includes the compliance status of the entire slope and each control unit, non-compliance locations, non-compliance index types, and control threshold gap values.

[0024] Preferably, step S8 specifically includes: locating the non-compliant control units and core non-compliant locations based on the verification results, quantifying the corresponding control threshold gap values, and identifying the core influencing parameters corresponding to the gaps; targeting and optimizing the layout parameters of the tree-shrub-grass composite buffer zone at the non-compliant locations, reducing the spacing between the zones or increasing the bandwidth, with each adjustment not exceeding 20% ​​of the original parameters, and repeating the verification process of step S7 after adjustment; if the optimized layout parameters of the tree-shrub-grass composite buffer zone still do not meet the standards, then optimizing and adjusting the forest and grass species combination and community configuration pattern of the non-compliant control unit, replacing it with species that have a higher comprehensive evaluation score, and gradually increasing the ratio of shrubs to herbs. After adjustment, repeat the verification process of step S7; if the optimization and adjustment to the highest level of the forest and grassland species combination and community configuration mode still does not meet the standards, then optimize and adjust the forest and grassland layout benchmark parameters of the non-compliant control units, increase the lower limit of forest and grassland coverage, the lower limit of vegetation canopy density, or the lower limit of buffer zone layout density, and repeat the verification process of step S7; until the verification results of the entire slope and all control units meet the two types of control thresholds, or the number of iterations reaches 10, the loop is terminated, and the finally compliant forest and grassland layout benchmark parameters and the forest and grassland species combination and community configuration mode are updated to the whole slope farmland forest and grassland layout scheme to complete the final slope farmland erosion control forest and grassland layout.

[0025] The present invention provides a forest and grassland layout system for erosion control on sloping farmland, characterized in that it includes: a data acquisition and processing module, an erosion control zoning and site analysis module, a control target and benchmark parameter determination module, a slope buffer zone layout module, a forest and grassland species and community configuration module, a whole-slope layout scheme construction module, a control effect verification module, and a layout scheme optimization and iteration module.

[0026] The data acquisition and processing module acquires the topographic elevation data, soil physicochemical property data, historical erosion status data, meteorological and hydrological data, and native vegetation baseline data of the target sloping farmland. Based on the topographic elevation data, it constructs a digital elevation model and identifies the runoff confluence path and sediment transport channel of the target sloping farmland.

[0027] The erosion control zoning and site analysis module: Based on the runoff confluence path, the sediment transport channel, and the historical erosion status data, along the vertical contour line direction of the target sloping farmland, it sequentially delineates four types of control units according to the erosion risk gradient: slope top interception control unit, slope surface gradient control unit, gully edge blocking control unit, and slope toe holding control unit. Simultaneously, based on the acquired topographic elevation data, soil physicochemical property data, meteorological and hydrological data, and native vegetation baseline data, it clarifies the site conditions corresponding to each of the four types of control units.

[0028] The module for determining prevention and control targets and benchmark parameters: determines the core erosion prevention and control targets for each of the four types of prevention and control units, and, in combination with the meteorological and hydrological data and the soil physicochemical property data, matches two types of control thresholds, namely, the runoff velocity control threshold and the sediment flux control threshold, which correspond one-to-one with the four types of prevention and control units, and determines the benchmark parameters for forest and grassland layout based on the two types of control thresholds;

[0029] The slope buffer zone layout module: For the slope gradient control unit among the four types of control units, based on the forest and grass layout benchmark parameters, a multi-level tree-shrub-grass composite buffer zone is laid out along the contour line, and the three layout parameters of the tree-shrub-grass composite buffer zone, namely the bandwidth, spacing and direction, are determined.

[0030] The forest and grassland species and community configuration module: based on the site conditions, core targets of erosion control, and two control thresholds of the four types of control units, combined with the soil physicochemical property data and the native vegetation baseline data, it screens suitable native tree, shrub, and herb species, and determines the forest and grassland species combination and community configuration mode that have both runoff interception and sediment retention functions for each of the four types of control units.

[0031] The whole-slope layout scheme construction module: Based on the layout parameters of the tree-shrub-grass composite buffer zone of the slope gradient control unit, and the forest and grass species combination and community configuration mode of the four types of control units, a whole-slope cultivated land forest and grass layout scheme is constructed, and the enhanced control nodes are set up to match the runoff confluence path and the sediment transport channel.

[0032] The control effect verification module uses a soil erosion forecasting model and combines it with the meteorological and hydrological data to verify the runoff regulation and erosion control effect of the whole slope farmland forest and grassland layout scheme, obtain the verification results, and simultaneously determine whether the whole slope farmland forest and grassland layout scheme meets the two types of control thresholds.

[0033] The layout scheme optimization and iteration module: if the verification result does not meet the two types of control thresholds, then optimize and adjust the forest and grassland layout benchmark parameters and the forest and grassland species combination and community configuration mode, repeat the verification process until the whole slope farmland forest and grassland layout scheme meets the two types of control thresholds, and complete the final slope farmland erosion prevention and control forest and grassland layout.

[0034] The beneficial effects of this invention are reflected in the following aspects: This invention accurately matches the dynamic process of erosion on sloping farmland, and locks down core erosion nodes by precisely identifying runoff confluence paths and sediment transport channels, breaking through the limitations of traditional experience-based generalized deployment and significantly improving runoff interception and sediment retention efficiency. By constructing a quantitative linkage system of "control targets - control thresholds - deployment parameters," core forestry and grassland deployment parameters are precisely designed based on erosion risk gradients, balancing erosion control effectiveness with farmland protection needs, achieving a balance between ecological protection and agricultural production. By forming a comprehensive slope gradient collaborative control system, a closed-loop governance model of "source interception - slope surface control - gully edge erosion prevention - slope toe retention" is constructed, setting up enhanced control nodes in high-erosion areas, filling the gaps in traditional control technologies. The establishment of a standardized effect pre-verification and hierarchical targeted optimization mechanism allows for the quantitative verification of the control effect of the scheme in advance, significantly reducing the deviation in implementation effects, improving the scenario adaptability and long-term stability of the scheme, and broadening its applicability. Attached Figure Description

[0035] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0036] Figure 1 A flowchart illustrating a method for forest and grassland layout to control erosion on sloping farmland, provided in an embodiment of the present invention;

[0037] Figure 2This is a flowchart illustrating a forest and grassland layout system for preventing erosion of sloping farmland, provided in an embodiment of the present invention. Detailed Implementation

[0038] To enable those skilled in the art to better understand the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0039] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, apparatus, product, or end that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or ends.

[0040] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0041] Forestry and grassland ecological measures are the core technical means for the long-term prevention and control of erosion on sloping farmland due to their long-lasting control effects, significant ecological benefits, low operation and maintenance costs, and compatibility with agricultural production. The rationality of forestry and grassland layout directly determines the quality of control effectiveness. Currently, existing technologies mostly focus on the selection of native soil and water conservation species, optimization of single buffer zone structures, and improvement of vegetation coverage, forming conventional layout patterns such as contour hedges and shrub-grass buffer zones on slopes. However, the following core technical deficiencies still exist:

[0042] Existing models are mostly based on experience and generalization, failing to consider the entire dynamic process of sloping farmland erosion, accurately identify core erosion nodes such as runoff confluence paths and sediment transport channels, and resulting in a disconnect between forest and grassland layout and actual erosion patterns, leading to low efficiency in runoff interception and sediment retention. There is a lack of a linkage and matching mechanism between "control targets - quantitative thresholds - deployment parameters," with core parameters such as buffer zone bandwidth and spacing determined primarily based on engineering experience, easily leading to insufficient control or excessive deployment occupying farmland, and poor scenario adaptability. The overall slope collaborative control capability is insufficient, focusing mainly on deployment in the main cultivated area, failing to construct a full-gradient collaborative control system of "source interception - slope surface control - gully edge erosion prevention - slope toe retention," easily leading to intensified erosion in boundary areas and insufficient overall slope treatment effect. There is a lack of standardized scheme pre-verification and targeted optimization mechanisms, with most designs being static, unable to quantitatively verify control effects in advance, and lacking a graded iterative optimization process, resulting in large deviations between the actual implementation effect and expectations, and insufficient stability.

[0043] In summary, existing forestry and grassland layout technologies for controlling erosion of sloping farmland cannot simultaneously meet the multiple needs of precise control of erosion of sloping farmland, protection of farmland resources, quantitative and controllable schemes, and long-term stable adaptation. There is an urgent need to develop a forestry and grassland layout method based on accurate identification of the dynamic process of erosion of sloping farmland, coordinated control of the entire slope gradient, quantitative matching design, and closed-loop optimization capabilities, in order to solve the core pain points of existing technologies.

[0044] The present invention aims to provide a method and system for the layout of forests and grasslands to prevent and control erosion of sloping farmland, so as to solve the problem that the existing technology cannot simultaneously meet the multiple requirements of precise prevention and control of erosion of sloping farmland, protection of farmland resources, quantitative and controllable schemes, and long-term stable adaptation.

[0045] Example 1

[0046] This embodiment uses a typical sloping farmland in the hilly and gully region of the Loess Plateau as the implementation object. The sloping farmland has a slope of 12°, a slope length of 80m, and the soil type is loess loess. The average annual rainfall is 450mm, and the historical erosion intensity is moderate. The main erosion types are sheet erosion and gully erosion. It is a typical dryland sloping farmland in this region. The specific implementation steps of the forest and grassland layout method for erosion control on sloping farmland provided in this embodiment are as follows:

[0047] like Figure 1 As shown in the figure, a specific embodiment of the present invention provides a method for forest and grassland layout to control erosion of sloping farmland, including the following steps:

[0048] Step S1: Baseline data acquisition and identification of erosion core channels

[0049] Baseline data acquisition: Topographic elevation data with a spatial resolution of 2m was obtained using UAV aerial surveys; soil physicochemical properties data such as soil texture, bulk density, organic matter content, and soil erosion resistance index were obtained through field profile sampling and indoor experiments; historical erosion status data such as erosion type, erosion intensity, and gully distribution location were obtained through high-resolution remote sensing image interpretation combined with detailed field surveys; meteorological and hydrological data such as annual rainfall, maximum 30-minute rainfall intensity, rainfall duration, and slope runoff for the past 20 years were obtained through local national meteorological stations; and baseline data of native vegetation such as native species types, community structure, and growth status were obtained through 1m×1m quadrat surveys.

[0050] Data preprocessing and DEM construction: Outliers in the terrain elevation data were removed using the 3x standard deviation method, and Gaussian filtering was used for smoothing and denoising to obtain corrected terrain elevation data. Based on the corrected terrain elevation data, an initial digital elevation model was constructed using the inverse distance weighted interpolation method. A depression filling algorithm was used to correct micro-topography and eliminate pseudo-depressions to obtain a final digital elevation model with a horizontal accuracy of 2m.

[0051] Identification of core erosion channels: Based on the final digital elevation model, the D8 algorithm is used to calculate the cumulative runoff volume of each grid. Combined with historical erosion status data, a dynamic runoff threshold is determined. The runoff threshold for moderately eroded areas is set to 800, and the runoff threshold for lightly eroded areas is set to 1200. Continuous grid sequences with a cumulative runoff volume greater than the corresponding threshold are identified as runoff confluence paths, and runoff confluence paths that are continuously connected to gullies are identified as sediment transport channels.

[0052] Step S2: Delineation of prevention and control units and clarification of site conditions

[0053] Four types of control units are defined as follows: along the vertical contour lines of the sloping farmland, the following units are defined in sequence: the section from the watershed to the upper boundary of the farmland (slope length 0-5m) is the top interception control unit; the section from the upper boundary of the farmland to the lower boundary of the farmland (slope length 5-70m) is the slope gradient control unit; the section from the lower boundary of the farmland to the edge of the erosion gully (slope length 70-75m) is the gully edge blocking control unit; and the section from the gully edge to the stable boundary of the gully channel (slope length 75-80m) is the slope toe holding control unit.

[0054] Site condition index extraction and quantification: Site conditions are divided into four categories of indicators: topography, soil, hydrology, and vegetation. Based on the baseline data obtained from S1, indicators such as slope, slope length, soil bulk density, organic matter content, multi-year average runoff, and native vegetation coverage are extracted for each of the four control units. The range standardization method is used to standardize the values ​​of each type of indicator in the 0-1 range to form a quantitative dataset of site conditions for each control unit, thus clarifying the site conditions.

[0055] Step S3: Determining Prevention and Control Targets and Quantifying Benchmark Parameters

[0056] The core objectives for erosion control were determined as follows: The core objectives for four types of control units were defined as follows: The top interception control unit aims to intercept source runoff and block confluence, with a runoff reduction rate target of no less than 60%; the slope gradient control unit aims to slow runoff velocity and retain slope sediment, with a sediment interception rate target of no less than 70%; the gully edge control unit aims to block runoff into gullies and inhibit gully development, with a runoff reduction rate target of no less than 75%; and the slope toe stabilization control unit aims to stabilize gully bank soil and intercept transported sediment, with a sediment interception rate target of no less than 80%.

[0057] Two types of control threshold matching: The natural slope runoff velocity of each control unit is calculated by combining meteorological and hydrological data, and the natural slope sediment flux is calculated by combining soil physicochemical property data and historical erosion status data; Based on the runoff reduction rate and sediment interception rate targets of each unit, the corresponding runoff velocity control threshold and sediment flux control threshold are matched one by one. The unit with higher erosion risk has a lower control threshold.

[0058] The baseline parameters for forest and grassland layout were determined as follows: Based on the difference between the runoff velocity control threshold and the natural runoff velocity, the lower limits of forest and grassland coverage and vegetation canopy density for each unit were determined; based on the difference between the sediment flux control threshold and the natural sediment flux, the lower limit of buffer zone layout density was determined; the baseline parameters for forest and grassland layout were integrated to obtain the following: the lower limit of forest and grassland coverage for the slope gradient control unit is 25%, and the lower limit of buffer zone layout density is 3 levels / 100m slope length.

[0059] Step S4: Layout of composite buffer zone of trees, shrubs and grass on slope

[0060] Determining the layout direction: Ensure that the layout direction of the tree-shrub-grass composite buffer zone is completely parallel to the contour lines of the sloping farmland, with the deviation angle controlled within 2°.

[0061] Determination of the number of buffer zone levels and the spacing between the buffer zones: In this embodiment, the slope is 12°, which belongs to the 5°-15° grade. Based on the lower limit of the buffer zone density, the total number of buffer zone levels is determined to be 3. Based on the slope length of 65m and the total number of buffer zone levels, the baseline value of the spacing between the buffer zones is determined to be 21.7m. After adjusting the slope, the final spacing between the buffer zones is set to 20m.

[0062] Bandwidth determination: Based on the lower limit of forest and grassland coverage, the baseline value of bandwidth is determined to be 1.5m. Combined with the moderate erosion level of the slope, the bandwidth is increased by 20%, and the final bandwidth is set to 1.8m.

[0063] By integrating the three parameters of layout direction, belt spacing, and belt width, the three-level tree-shrub-grass composite buffer zone was laid out along the contour lines.

[0064] Step S5: Screening of native species and determination of community configuration patterns

[0065] Species evaluation system construction: Establish a functional evaluation system for native species that includes runoff interception capacity, sediment retention capacity, site adaptability, growth stability, and local adaptability. Each indicator is scored quantitatively from 0 to 10. Based on the core objectives of each control unit, the weight of the indicators is determined by the analytic hierarchy process. The combined weight of runoff interception capacity and sediment retention capacity of the slope gradient control unit is 60%.

[0066] Construction of candidate species pool: Based on the baseline data of native vegetation, native species naturally distributed in this region are screened. Based on the evaluation system, a comprehensive score is calculated, and species with a score higher than 6 are selected to form candidate species pools for each unit: candidate tree species are Platycladus orientalis and Prunus armeniaca; candidate shrub species are Caragana korshinskii, Hippophae rhamnoides and Rhizoma Cyathea rubra; candidate herb species are Alfalfa, Agrostis chinensis and Osmanthus fragrans.

[0067] The species combination and community configuration were determined as follows: the slope top interception and slope foot fixation control unit adopted a mixed tree, shrub and grass pattern of "Chinese arborvitae + sea buckthorn + ice grass"; the slope gradient control unit buffer zone adopted a shrub and grass combination pattern of "Caragana korshinskii + alfalfa"; the gully edge blocking control unit adopted a shrub-dominant and herb-supplemented pattern of "wolf's tooth thorn + sweet clover"; at the same time, the plant spacing, interlayer ratio and autumn planting sequence of each species were determined to form the final community configuration pattern.

[0068] Step S6: Construction of the whole-slope forest and grassland layout scheme

[0069] Establishment of spatial coordinate system: Using the final digital elevation model as the spatial basis, with the northwest corner of the sloping farmland as the origin of the coordinate system, east as the positive direction of the X-axis and north as the positive direction of the Y-axis, a plane rectangular spatial layout coordinate system is established.

[0070] Preliminary spatial positioning and connection optimization: Import the boundaries of four types of prevention and control units, buffer zone layout parameters, species combinations and community configuration patterns into the coordinate system to complete the preliminary spatial positioning; optimize the connection of forest and grassland layout of adjacent units to make the forest and grassland coverage and species height transition in a gradient, ensure the continuity of prevention and control functions without breaks, and generate an initial full-slope forest and grassland layout scheme.

[0071] Strengthening the setting of control nodes: Based on the runoff confluence path and sediment transport channel, the peak location of the cumulative runoff volume, the intersection of the confluence channels, and the boundary location of the control unit were identified, and a total of 5 enhanced control nodes were determined; the node coverage range was determined based on the runoff intensity, the top 3 species in the candidate species library of the corresponding unit were matched, the shrub and grass ratio was increased to complete the node layout, the node parameters were updated to the initial scheme, and the final forest and grassland layout scheme of the entire slope of cultivated land was obtained.

[0072] Step S7: Verification of Prevention and Control Effectiveness

[0073] Model and operational condition settings: The Chinese Soil Loss Equation (CSLE) is adopted as the soil erosion prediction model. The forest and grassland coverage, buffer zone layout parameters, community configuration patterns, and enhanced control node parameters of the scheme are input into the model, and the corresponding biological measure factor B and engineering measure factor E are substituted. Combined with meteorological and hydrological data, three rainfall return periods of 2 years, 5 years, and 10 years are set to simulate operational conditions.

[0074] Simulation calculation and result comparison: Through model simulation calculation, the slope runoff, soil erosion modulus, runoff interception rate and sediment retention rate of the whole slope and each unit under three working conditions are obtained; the calculation results are compared with two types of control thresholds. Under the 5-year return period working condition in this embodiment, the whole slope runoff interception rate is 68% and the sediment retention rate is 76%, which meets the preset control threshold requirements, and the compliance verification result is generated.

[0075] Step S8: Iterative optimization of the solution

[0076] The verification results of this embodiment meet the preset control threshold, so no optimization or adjustment is required. The final forest and grassland layout scheme for the entire sloping farmland is directly used as the final scheme to complete the forest and grassland layout for erosion control of sloping farmland.

[0077] Field verification showed that the forest and grassland layout scheme implemented in this embodiment reduced the annual soil erosion modulus by 45% and achieved a 92% retention rate of cultivated land area compared to the local conventional contour hedge pattern, thus achieving the dual goals of erosion control and agricultural production.

[0078] Example 2

[0079] like Figure 2 As shown, a specific embodiment of the present invention provides a forest and grassland layout system for preventing erosion of sloping farmland, comprising the following steps:

[0080] This embodiment provides a forest and grassland layout system for erosion control of sloping farmland, which is used to implement the forest and grassland layout method for erosion control of sloping farmland in Embodiment 1. The system includes a data acquisition and processing module, an erosion control zoning and site analysis module, a control target and benchmark parameter determination module, a slope buffer zone layout module, a forest and grassland species and community configuration module, a whole slope layout scheme construction module, a control effect verification module, and a layout scheme optimization and iteration module, which are connected in sequence.

[0081] In this embodiment, the data acquisition and processing module interfaces with the UAV aerial survey system, field monitoring equipment, and GIS data processing platform to achieve automatic acquisition, preprocessing, DEM construction, and erosion channel identification of baseline data; the erosion control zoning and site analysis module automatically delineates control units and extracts and quantifies site condition indicators based on the GIS platform; the control target and benchmark parameter determination module has a built-in quantitative calculation model to achieve automatic matching calculation of control thresholds and layout benchmark parameters; the whole slope layout scheme construction module can automatically generate spatial distribution maps, species configuration tables, and layout parameter tables of the layout scheme; the control effect verification module has a built-in Chinese soil loss equation and can automatically complete multi-condition simulation and compliance verification; the layout scheme optimization and iteration module can automatically generate targeted optimization schemes based on the verification results and complete iterative cycles.

[0082] The beneficial effects of this invention are reflected in the following aspects: This invention accurately matches the dynamic process of erosion on sloping farmland, and locks down core erosion nodes by precisely identifying runoff confluence paths and sediment transport channels, breaking through the limitations of traditional experience-based generalized deployment and significantly improving runoff interception and sediment retention efficiency. By constructing a quantitative linkage system of "control targets - control thresholds - deployment parameters," core forestry and grassland deployment parameters are precisely designed based on erosion risk gradients, balancing erosion control effectiveness with farmland protection needs, achieving a balance between ecological protection and agricultural production. By forming a comprehensive slope gradient collaborative control system, a closed-loop governance model of "source interception - slope surface control - gully edge erosion prevention - slope toe retention" is constructed, setting up enhanced control nodes in high-erosion areas, filling the gaps in traditional control technologies. The establishment of a standardized effect pre-verification and hierarchical targeted optimization mechanism allows for the quantitative verification of the control effect of the scheme in advance, significantly reducing the deviation in implementation effects, improving the scenario adaptability and long-term stability of the scheme, and broadening its applicability.

[0083] The above descriptions are merely embodiments of the present invention. Commonly known technical solutions or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for forest and grassland layout to control erosion on sloping farmland, characterized in that, The method includes: S1: Obtain topographic elevation data, soil physicochemical property data, historical erosion status data, meteorological and hydrological data, and native vegetation baseline data of the target sloping farmland; construct a digital elevation model based on the topographic elevation data; and identify the runoff confluence path and sediment transport channel of the target sloping farmland. S2: Based on the runoff confluence path, the sediment transport channel, and the historical erosion status data, along the vertical contour line direction of the target sloping farmland, four types of control units are delineated in sequence according to the erosion risk gradient: slope top interception control unit, slope surface gradient control unit, gully edge blocking control unit, and slope toe holding control unit. Simultaneously, based on the acquired topographic elevation data, soil physicochemical property data, meteorological and hydrological data, and native vegetation background data, the site conditions corresponding to each of the four types of control units are clarified. S3: Determine the core erosion control targets for each of the four types of control units, and combine the meteorological and hydrological data with the soil physicochemical property data to obtain two types of control thresholds: runoff velocity control threshold and sediment flux control threshold, which correspond one-to-one with the four types of control units. Determine the benchmark parameters for forest and grassland layout based on the two types of control thresholds. S4: For the slope gradient control unit among the four types of control units, based on the forest and grassland layout benchmark parameters, multi-level tree-shrub-grass composite buffer zones are laid out along the contour lines, and the three layout parameters of each tree-shrub-grass composite buffer zone are determined: bandwidth, spacing, and layout direction. S5: Based on the site conditions, core targets of erosion control, and two control thresholds of the four types of control units, and in conjunction with the soil physicochemical property data and the native vegetation baseline data, suitable native tree, shrub, and herb species are selected to determine the forest and grass species combination and community configuration mode that have both runoff interception and sediment retention functions for each of the four types of control units. S6: Based on the layout parameters of the tree-shrub-grass composite buffer zone of the slope gradient control unit, and the forest and grass species combination and community configuration mode of the four types of control units, construct a forest and grass layout scheme for the entire slope farmland, and set up enhanced blocking nodes to match the runoff confluence path and the sediment transport channel. S7: Using a soil erosion forecasting model and combining the meteorological and hydrological data, verify the runoff regulation and erosion control effects of the whole-slope farmland forest and grassland layout scheme, obtain the verification results, and simultaneously determine whether the whole-slope farmland forest and grassland layout scheme meets the two types of control thresholds. S8: If the verification result does not meet the two types of control thresholds, then optimize and adjust the benchmark parameters for forest and grassland layout and the combination and community configuration mode of forest and grassland species, and repeat the verification process of step S7 until the forest and grassland layout scheme of the whole slope farmland meets the two types of control thresholds, and complete the final forest and grassland layout for erosion control of slope farmland.

2. The method for forest and grassland layout for erosion control on sloping farmland according to claim 1, characterized in that, Step S1 specifically includes: Topographic elevation data with a spatial resolution of no less than 5 meters was obtained by using UAV aerial surveys or field measurements. Soil physicochemical property data, including soil texture, bulk density, organic matter content, and erosion resistance indicators, were obtained by using field profile sampling and indoor experiments. Historical erosion status data, including erosion type, intensity, and gully erosion distribution, were obtained through remote sensing interpretation and field surveys. Meteorological and hydrological data, including rainfall, rainfall intensity, and runoff, for more than 10 consecutive years were obtained from local meteorological stations. Native vegetation baseline data, including native species types and community structure, were obtained through quadrat surveys. Outliers in the terrain elevation data were removed by using the 3x standard deviation method, and the corrected terrain elevation data were obtained by smoothing and denoising the data using Gaussian filtering. Based on the corrected terrain elevation data, an initial digital elevation model was constructed using the inverse distance weighted interpolation method. A depression-filling algorithm was then used to correct the micro-topography and eliminate false depressions, resulting in a final digital elevation model with the same accuracy as the corrected terrain elevation data. Based on the final digital elevation model, the D8 algorithm is used to calculate the cumulative runoff of each grid, and the dynamic runoff threshold is determined by combining historical erosion status data. The dynamic runoff threshold is lower in areas with higher erosion intensity. Continuous raster sequences with a cumulative runoff volume greater than the dynamic runoff threshold are identified as runoff confluence paths, and runoff confluence paths that are continuously connected to gully erosion are identified as sediment transport channels.

3. The method for forest and grassland layout for erosion control on sloping farmland according to claim 2, characterized in that, Step S2 specifically includes: Along the vertical contour line of the target sloping farmland, the following units are delineated in sequence: the top interception control unit from the watershed to the upper boundary of the farmland, the slope gradient control unit from the upper boundary of the farmland to the lower boundary, the gully edge blocking control unit from the lower boundary of the farmland to the edge of the erosion gully, and the slope toe holding control unit from the edge of the gully to the stable boundary of the gully. Site conditions are broken down into four categories of indicators: topography, soil, hydrology, and vegetation. Topography indicators include slope, slope length, slope aspect, and slope position; soil indicators include soil texture, bulk density, organic matter content, and erosion resistance; hydrological indicators include multi-year average runoff and soil moisture content; and vegetation indicators include native vegetation coverage and dominant species types. Based on the corrected topographic elevation data, soil physicochemical property data, meteorological and hydrological data, and native vegetation baseline data, various indicators corresponding to the four types of prevention and control units were extracted respectively. The range standardization method was used to assign values ​​to various indicators in the range of 0 to 1, forming a quantitative dataset of site conditions for each prevention and control unit, thus clarifying the site conditions.

4. The method for forest and grassland layout for erosion control on sloping farmland according to claim 3, characterized in that, Step S3 specifically includes: The core objectives of erosion control for the four types of control units were determined as follows: the top slope interception control unit is to intercept the source runoff and block the confluence; the slope gradient control unit is to slow down the runoff velocity and retain sediment; the gully edge blocking control unit is to block the runoff into the gully and inhibit the development of gully erosion; and the slope toe holding control unit is to hold the gully bank soil and intercept the transport of sediment. The natural slope runoff velocity of each control unit was calculated by combining meteorological and hydrological data, and the natural slope sediment flux of each control unit was calculated by combining soil physicochemical property data and historical erosion status data. Based on the core objectives of erosion control for each control unit, the runoff reduction rate and sediment interception rate of the corresponding unit are determined. Combined with the runoff velocity and sediment flux on the natural slope, two types of control thresholds are obtained, one-to-one with each control unit: the runoff velocity control threshold and the sediment flux control threshold. The higher the erosion risk level of the control unit, the higher the corresponding runoff reduction rate and sediment interception rate, and the lower the corresponding runoff velocity control threshold and sediment flux control threshold. Based on the difference between the runoff velocity control threshold and the runoff velocity on the natural slope, the lower limits of forest and grassland coverage and vegetation canopy closure for each control unit are determined. The larger the difference, the higher the corresponding lower limits of forest and grassland coverage and vegetation canopy closure. Based on the difference between the sediment flux control threshold and the sediment flux on the natural slope, the lower limit of buffer zone layout density for each control unit is determined. The larger the difference, the higher the corresponding lower limit of buffer zone layout density. By integrating the lower limits of forest and grassland coverage, vegetation canopy density, and buffer zone layout density of each of the aforementioned prevention and control units, the baseline parameters for forest and grassland layout are obtained.

5. A method for forest and grassland layout to control erosion on sloping farmland according to claim 4, characterized in that, Step S4 specifically includes: The layout direction of the tree-shrub-grass composite buffer zone is determined to be parallel to the contour line of the target sloping farmland, with a deviation angle not exceeding 3°; The slope gradient control unit is divided into slopes less than 5° and 5°. 15°, 15° The slope is divided into four levels: 25°, greater than 25°, and the total number of levels of the composite buffer zone is determined based on the slope classification and the lower limit of the buffer zone layout density in the forest and grass layout benchmark parameters. For each increase of one level in the slope classification, the total number of layout levels increases by 2 levels. Based on the slope length and total number of levels of the slope gradient control unit, the reference value of the belt spacing is determined. The reference value of the belt spacing is adjusted based on the slope grading. For every 5° increase in slope, the belt spacing is reduced by 15% to obtain the final belt spacing between two adjacent levels of the tree-shrub-grass composite buffer belt. Based on the lower limit of forest and grass coverage in the forest and grass layout benchmark parameters, the bandwidth benchmark value is determined. The bandwidth benchmark value is adjusted based on the erosion intensity level of the corresponding location. For each increase in erosion intensity level, the bandwidth increases by 20% to obtain the final bandwidth of each of the tree, shrub and grass composite buffer zones. By integrating the determined layout direction, final belt spacing, and final bandwidth, the three layout parameters of the tree-shrub-grass composite buffer zone are obtained, and the layout of the multi-level tree-shrub-grass composite buffer zone is completed.

6. A method for forest and grassland layout to control erosion on sloping farmland according to claim 4, characterized in that, Step S5 specifically includes: Establish a functional evaluation system for native species that includes runoff interception capacity, sediment retention capacity, site adaptability, growth stability, and local adaptability. Each indicator adopts a 0.05-0.05 ratio. A quantitative score of 10 points; Based on the core erosion control objectives of the four types of control units, the weights of species evaluation indicators for each control unit are determined by the analytic hierarchy process. The unit with higher runoff interception and sediment retention requirements has higher weights of runoff interception and sediment retention capacity indicators. Based on the baseline data of native vegetation, native tree, shrub and herb species naturally distributed within the target sloping farmland are screened. Based on the functional evaluation system of native species and the index weights of the corresponding prevention and control units, the comprehensive evaluation score of each species is calculated, and species with a comprehensive evaluation score higher than 6 are screened to form a candidate species library for each prevention and control unit. Based on the core objectives of erosion control of each control unit, suitable tree, shrub, and herbaceous species are selected from the candidate species library to form forest and grassland species combinations; wherein the species combination of the slope top interception control unit and the slope foot retention control unit includes three types of species: tree, shrub, and herbaceous species; the species combination of the tree-shrub-grass composite buffer zone of the slope gradient control unit includes two types of species: shrub and herbaceous species; and the species combination of the gully edge barrier control unit is mainly composed of shrub species and supplemented by herbaceous species. Based on the site conditions and the two types of control thresholds of each control unit, the spacing between plants and rows, the interlayer ratio and the planting sequence of each species in the forest and grassland species combination are determined to form the community configuration pattern of the corresponding control unit.

7. A method for forest and grassland layout to control erosion on sloping farmland according to claim 4, characterized in that, Step S6 specifically includes: Using the final digital elevation model as the spatial basis, with the northwest corner of the target sloping farmland as the origin of the coordinate system, the east direction as the positive X-axis direction, and the north direction as the positive Y-axis direction, a planar rectangular spatial layout coordinate system for the target sloping farmland is established. In the spatial layout coordinate system, the spatial boundaries of the four types of prevention and control units, the layout parameters of the tree-shrub-grass composite buffer zone, and the forest and grass species combination and community configuration mode are sequentially imported to complete the preliminary spatial positioning of the forest and grass layout of each prevention and control unit. The forest and grassland layout of adjacent control units is optimized to ensure that the forest and grassland coverage and species height of adjacent units are in a gradient transition, so as to ensure the continuous and uninterrupted runoff interception and sediment retention control functions of adjacent units. By integrating the preliminary spatial location and the connection optimization results, an initial full-slope farmland forest and grassland layout scheme is generated, which includes a spatial layout map, a species configuration table, and a layout parameter table. Based on the spatial distribution of the runoff confluence paths and sediment transport channels, the location where the cumulative runoff volume is greater than twice the average cumulative runoff volume in the same area is identified as the peak location of the cumulative runoff volume. The intersection of two or more runoff confluence paths or sediment transport channels is identified, and the boundary connection location of the four types of control units is identified. The three types of locations are used as candidate locations for strengthening the control nodes. Based on the confluence intensity and sediment transport intensity of each of the candidate deployment locations, the scale and coverage of the node deployment are determined. The top three species with the highest comprehensive evaluation scores in the candidate species library of the control unit to which the corresponding deployment location belongs are matched for each of the enhanced control nodes, and the spatial placement of the enhanced control nodes is completed. The spatial location results, species configuration and deployment parameters of the enhanced control nodes are updated to the initial full-slope cultivated land forest and grassland layout scheme to obtain the final full-slope cultivated land forest and grassland layout scheme.

8. A method for forest and grassland layout to control erosion on sloping farmland according to claim 7, characterized in that, Step S7 specifically includes: The soil erosion prediction model adopts a general soil loss equation, and inputs the forest and grass coverage, vegetation canopy density, tree-shrub-grass composite buffer zone layout parameters, community configuration mode, and enhanced barrier control node layout parameters from the final full-slope farmland forest and grass layout scheme into the general soil loss equation. Based on the meteorological and hydrological data, simulation conditions with three rainfall return periods of 2 years, 5 years, and 10 years were set. For each condition, the maximum 30-minute rainfall intensity and 6-hour rainfall duration for the corresponding return period were set. Through simulation calculations using the general soil loss equation, the slope runoff, soil erosion modulus, runoff interception rate, and sediment retention rate of the target sloping farmland under three working conditions and the four types of prevention and control units were obtained. The overall runoff interception rate and sediment retention rate of the entire slope are compared with the overall slope compliance requirements of the two types of control thresholds. The runoff interception rate and sediment retention rate of each unit level are compared with the two types of control thresholds of the corresponding control unit to obtain the comparison results. Verification results are generated based on the comparison results. The verification results include the compliance status of the entire slope and each prevention and control unit, the non-compliant locations, the types of non-compliant indicators, and the control threshold gap values.

9. A method for forest and grassland layout to control erosion on sloping farmland according to claim 8, characterized in that, Step S8 specifically includes: Based on the verification results, the non-compliant prevention and control units and the core non-compliant locations are located, the corresponding control threshold gap values ​​are quantified, and the core impact parameters corresponding to the gaps are identified. For the substandard locations, the layout parameters of the composite buffer zone of trees, shrubs and grasses are optimized and adjusted in a targeted manner, reducing the spacing between the zones or increasing the width of the zone. The adjustment range in a single instance shall not exceed 20% of the original parameters. After the adjustment, the verification process of step S7 is repeated. If the optimized and adjusted parameters of the tree-shrub-grass composite buffer zone still do not meet the standards, the combination of forest and grass species and the community configuration mode of the substandard control unit shall be optimized and adjusted, and the species with a higher comprehensive evaluation score shall be replaced. The ratio of shrubs and herbs shall be gradually increased. After adjustment, the verification process of step S7 shall be repeated. If the optimization and adjustment to the highest level of the forest and grassland species combination and community configuration mode still fails to meet the standards, then the forest and grassland layout benchmark parameters of the substandard prevention and control unit shall be optimized and adjusted to increase the lower limit of forest and grassland coverage, the lower limit of vegetation canopy density or the lower limit of buffer zone layout density. After adjustment, the verification process of step S7 shall be repeated. The loop continues until the verification results of the entire slope and all control units meet the two types of control thresholds, or the number of iterations reaches 10. The final forest and grassland layout benchmark parameters and the forest and grassland species combination and community configuration mode are then updated to the whole slope farmland forest and grassland layout scheme to complete the final slope farmland erosion control forest and grassland layout.

10. A forestry and grassland layout system for controlling erosion on sloping farmland, characterized in that, include: The module includes: data acquisition and processing module, erosion control zoning and site analysis module, control target and benchmark parameter determination module, slope buffer zone layout module, forest and grassland species and community configuration module, whole slope layout scheme construction module, control effect verification module, and layout scheme optimization and iteration module. The data acquisition and processing module acquires the topographic elevation data, soil physicochemical property data, historical erosion status data, meteorological and hydrological data, and native vegetation baseline data of the target sloping farmland. Based on the topographic elevation data, it constructs a digital elevation model and identifies the runoff confluence path and sediment transport channel of the target sloping farmland. The erosion control zoning and site analysis module: Based on the runoff confluence path, the sediment transport channel, and the historical erosion status data, along the vertical contour line direction of the target sloping farmland, it sequentially delineates four types of control units according to the erosion risk gradient: slope top interception control unit, slope surface gradient control unit, gully edge blocking control unit, and slope toe holding control unit. Simultaneously, based on the acquired topographic elevation data, soil physicochemical property data, meteorological and hydrological data, and native vegetation baseline data, it clarifies the site conditions corresponding to each of the four types of control units. The module for determining prevention and control targets and benchmark parameters: determines the core erosion prevention and control targets for each of the four types of prevention and control units, and, in combination with the meteorological and hydrological data and the soil physicochemical property data, matches two types of control thresholds, namely, the runoff velocity control threshold and the sediment flux control threshold, which correspond one-to-one with the four types of prevention and control units, and determines the benchmark parameters for forest and grassland layout based on the two types of control thresholds; The slope buffer zone layout module: For the slope gradient control unit among the four types of control units, based on the forest and grass layout benchmark parameters, a multi-level tree-shrub-grass composite buffer zone is laid out along the contour line, and the three layout parameters of the tree-shrub-grass composite buffer zone, namely the bandwidth, spacing and direction, are determined. The forest and grassland species and community configuration module: based on the site conditions, core targets of erosion control, and two control thresholds of the four types of control units, combined with the soil physicochemical property data and the native vegetation baseline data, it screens suitable native tree, shrub, and herb species, and determines the forest and grassland species combination and community configuration mode that have both runoff interception and sediment retention functions for each of the four types of control units. The whole-slope layout scheme construction module: Based on the layout parameters of the tree-shrub-grass composite buffer zone of the slope gradient control unit, and the forest and grass species combination and community configuration mode of the four types of control units, a whole-slope cultivated land forest and grass layout scheme is constructed, and the enhanced control nodes are set up to match the runoff confluence path and the sediment transport channel. The control effect verification module uses a soil erosion forecasting model and combines it with the meteorological and hydrological data to verify the runoff regulation and erosion control effect of the whole slope farmland forest and grassland layout scheme, obtain the verification results, and simultaneously determine whether the whole slope farmland forest and grassland layout scheme meets the two types of control thresholds. The layout scheme optimization and iteration module: if the verification result does not meet the two types of control thresholds, then optimize and adjust the forest and grassland layout benchmark parameters and the forest and grassland species combination and community configuration mode, repeat the verification process until the whole slope farmland forest and grassland layout scheme meets the two types of control thresholds, and complete the final slope farmland erosion prevention and control forest and grassland layout.

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