GIS-based steep slope farmland slope subdivision and zoning classification protection and utilization analysis method

Abstract

This invention discloses a GIS-based method for the detailed subdivision and zoning-based protection and utilization analysis of steep slope farmland. The method includes constructing a DEM-based slope calculation model, subdividing dry slope farmland meeting steep slope definition criteria into multiple slope levels, collecting land use data and spatial influencing factor information, and inputting this data into a mountainous staple food farmland calculation model to initially determine the basic attribute characteristics of the steep slope farmland area. This data, along with the subdivided slope data, is then imported again into a classification and extraction model. In-depth comprehensive analysis is performed using the aforementioned spatial influencing factor information to determine an optimized planning zoning scheme for the steep slope farmland. Based on the optimized planning scheme, the steep slope farmland is spatially classified. This invention, by constructing a refined slope calculation model and a multi-dimensional data integration and analysis system, achieves detailed slope grading of steep slope farmland, accurately delineates steep slope farmland utilization areas, and formulates differentiated strategies, thereby improving the scientific rigor and relevance of steep slope farmland protection and utilization schemes.

Description

Technical Field

[0001] This invention relates to the field of farmland protection data analysis, and in particular to a method for analyzing the protection and utilization of steep farmland based on GIS-based subdivision of slope and zoning classification. Background Technology

[0002] Currently, in land spatial planning and farmland protection, relevant technical personnel often rely on land survey results and geographic information tools to conduct basic classification and utilization assessment of farmland resources. For farmland with certain slope characteristics, it is usually only roughly divided according to general slope standards, and then protection and utilization strategies are formulated in combination with basic land use data. This process largely relies on conventional geospatial analysis methods to meet basic farmland management needs.

[0003] However, existing technologies have significant shortcomings in handling farmland with specific slope ranges. On the one hand, farmland that meets the criteria for steep slopes is not further subdivided into slope levels, making it difficult to accurately reflect the actual utilization conditions of different steep slope areas. On the other hand, the analysis process fails to fully integrate various types of land use data and key influencing factors, resulting in farmland protection and utilization schemes that are not highly targeted and cannot provide strong support for precise farmland management and planning. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] In view of the problems existing in the above and / or existing GIS-based methods for analyzing the slope subdivision and zoning of steep farmland for protection and utilization, this invention is proposed.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for analyzing the slope subdivision and zoning classification of steep farmland based on GIS, characterized by comprising the following steps:

[0007] Based on existing land survey results, dry slope farmland within the farmland protection red line that meets the steep slope definition criteria is selected. A DEM-based slope calculation model is constructed, and the geospatial data of the dry slope farmland is imported into the model. Based on the model, the dry slope farmland that meets the steep slope definition criteria is subdivided into multiple slope levels, and a steep slope farmland slope subdivision database is established.

[0008] Based on the established steep slope farmland gradient subdivision database, land use data and spatial influencing factor information are collected. The land use data and spatial influencing factor information are put into the calculation model of planting land for staple food fields in mountainous areas. Through spatial overlay analysis, the basic attribute characteristics of steep slope farmland areas are preliminarily determined.

[0009] After selecting the basic attribute characteristics of the initially determined steep slope farmland area, the basic attribute characteristics and slope subdivision data are imported into the classification extraction model again. Combined with the spatial influencing factor information, a deep comprehensive analysis is conducted to determine the zoning results in the steep slope farmland.

[0010] Based on the zoning results, optimize the planning scheme for the protection and utilization of steep slope farmland. According to the optimized planning scheme, classify the spatial types of steep slope farmland and establish a zoning and classification protection and utilization system for steep slope farmland.

[0011] As a preferred embodiment of the GIS-based steep slope farmland gradient subdivision and zoning classification protection and utilization analysis method described in this invention, the existing land survey results include land change survey data, farmland quality grade survey data and land use status maps for the past three years. Before selecting dry slope farmland that meets the steep slope definition criteria, the existing land survey results need to be cleaned to remove duplicate records and logically contradictory data.

[0012] As a preferred embodiment of the GIS-based steep slope farmland slope subdivision and zoning classification protection and utilization analysis method described in this invention, wherein: during the construction of the DEM-based plot slope calculation model, DEM data needs to be imported and preprocessed to form a slope map;

[0013] The preprocessing includes depression filling, smoothing and noise reduction, and resolution matching. The classification of the multi-level slope grades is based on the regional terrain characteristics and the actual needs of farmland use, and the classification threshold is set accordingly.

[0014] Let the elevation of each pixel in the DEM data be z. j,k Define a set of depressions D. First, find all depression pixels. For each depression pixel (j,k), calculate the average elevation z of its eight neighboring pixels. j,k :

[0015] ,in or The fill factor α ranges from 0.1 to 0.3, and the new fill elevation z fill The calculation formula is:

[0016] Where (m, n) are the eight neighboring pixels of the depression pixel (j, k).

[0017] Use zfill Replace the original elevation z of the depression cell (j,k). j,k Repeat this process until there are no more depressions.

[0018] As a preferred embodiment of the GIS-based method for analyzing the slope subdivision and zoning of arable land for protection and utilization described in this invention, the land use data includes rural homestead data, collective construction land data, land use data within the ecological protection red line, and land use data in areas prone to geological disasters. After collecting the land use data, the land use data is converted into a unified geographic coordinate system.

[0019] The spatial influencing factors information includes food security guarantee demand indicators, ecological function maintenance requirements, geological disaster risk level assessment results, and spatial replacement feasibility assessment data. Before importing the spatial influencing factors information into the calculation model of planting land for staple food fields in mountainous areas, it is necessary to quantify and assign values ​​to each influencing factor and establish an influencing factor weight system.

[0020] As a preferred embodiment of the GIS-based method for slope subdivision and zoning-based protection and utilization analysis of steep farmland described in this invention, the slope subdivision involves constructing a DEM-based slope calculation model to subdivide steep farmland with a slope greater than 25 degrees into nine levels: 25-30 degrees, 30-35 degrees, 35-40 degrees, 40-45 degrees, 45-50 degrees, 50-55 degrees, 55-60 degrees, 60-65 degrees, and above 65 degrees.

[0021] In the slope subdivision, each pixel within a pixel is considered a unit. Pixels with a slope value less than 25 are treated as null values ​​and excluded from the calculation. Pixels with a slope value greater than 25 are calculated based on their actual slope. The average slope of all pixels within the pixel is taken as the final slope value of the pixel. The calculation formula is as follows:

[0022]

[0023] Where Pb is the slope value of the plot, P i It is the slope value of a single pixel within the patch, and N is the total number of slope pixels within the patch.

[0024] As a preferred embodiment of the GIS-based steep slope farmland slope subdivision and zoning classification protection and utilization analysis method described in this invention, the spatial overlay analysis process adopts a multi-level overlay strategy, performs basic overlay on land use data and slope subdivision data to obtain a basic layer of spatial distribution of steep slope farmland, and then overlays a layer of spatial influencing factor information. Through spatial intersection operation and attribute association, a basic attribute feature layer of steep slope farmland area is generated.

[0025] As a preferred embodiment of the GIS-based steep slope farmland slope subdivision and zoning classification protection and utilization analysis method described in this invention, wherein: in the process of conducting in-depth comprehensive analysis to determine the zoning results of steep slope farmland, a multi-criteria decision algorithm is adopted, which uses the quantitative indicators in the spatial influencing factor information as decision criteria, sets the criteria priority, and optimizes the zoning boundaries of steep slope farmland by weighted summation and threshold judgment.

[0026] The zoning results determine four categories of zoning results in steep slope farmland: areas for the preservation of staple food planting land, areas applicable for spatial replacement, areas for returning farmland to forest, and ecological protection areas. The results also generate zoning vector graphics and attribute statistics tables.

[0027] As a preferred embodiment of the GIS-based steep slope farmland slope subdivision and zoning classification protection and utilization analysis method described in this invention, the steep slope farmland zoning classification protection and utilization system includes a data management module, a zoning display module, a planning optimization module, and a strategy push module.

[0028] The data management module is used to store slope breakdown data, land use data, and zoning result data.

[0029] The planning optimization module is used to dynamically adjust the protection and utilization planning scheme according to the regional development goals.

[0030] The strategy push module is used to push differentiated management and control measures to steep slope farmland with different spatial types.

[0031] In a second aspect, some embodiments of the present invention provide an electronic device, including: one or more processors; and a storage device having one or more programs stored thereon, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the method described in any of the implementations of the first aspect above.

[0032] Thirdly, some embodiments of the present invention provide a computer-readable medium having a computer program stored thereon, wherein the program, when executed by a processor, implements the method described in any of the implementations of the first aspect above.

[0033] This invention effectively addresses the shortcomings of existing technologies by constructing a refined slope calculation model and a multi-dimensional data integration and analysis system. It not only enables detailed slope classification of steep arable land and the establishment of a comprehensive, segmented database, but also allows for in-depth analysis combining various land use data and core influencing factors. This precise delineation of steep arable land utilization areas and the formulation of differentiated strategies significantly enhances the scientific rigor and relevance of steep arable land protection and utilization plans, providing more reliable technical support for strengthening the red line of arable land protection and ensuring food security. Attached Figure Description

[0034] Figure 1 This is a flowchart of the GIS-based method for analyzing the slope subdivision and zoning of cultivated land for protection and utilization in Example 1.

[0035] Figure 2 This is a 3×3 local moving window image of DEM based on the GIS-based method for subdividing steep slope farmland and classifying and protecting its utilization in Example 1.

[0036] Figure 3 This is the X and Y direction slope map calculation window for the GIS-based steep slope farmland slope subdivision and zoning classification protection and utilization analysis method in Example 1.

[0037] Figure 4 This is a map showing the distribution of steep slope farmland in a certain city, based on the GIS-based method for subdividing steep slope farmland into subdivisions and classifying and protecting and utilizing it, as described in Example 2.

[0038] Figure 5 This is a schematic diagram of the spatial overlap between steep slope farmland and land converted from farmland to forest in a certain city, based on the GIS-based method for slope subdivision and zoning classification protection and utilization analysis of steep slope farmland in Example 2.

[0039] Figure 6 This is a schematic diagram of the electronic structure of the steep slope farmland slope subdivision and zoning classification protection and utilization analysis method based on GIS in Example 4. Detailed Implementation

[0040] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0041] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0042] Example 1

[0043] Reference Figures 1 to 3 This is the first embodiment of the present invention, which provides a method for analyzing the slope subdivision and zoning of steep farmland for protection and utilization based on GIS, comprising:

[0044] The method for analyzing the slope subdivision and zoning classification of steep farmland based on GIS is characterized by the following steps:

[0045] Based on existing land survey results, dry slope farmland within the farmland protection red line that meets the steep slope definition criteria is selected. A DEM-based slope calculation model is constructed, and the geospatial data of the dry slope farmland is imported into the model. Based on the model, the dry slope farmland that meets the steep slope definition criteria is subdivided into multiple slope levels, and a steep slope farmland slope subdivision database is established.

[0046] The existing land survey results include land change survey data, cultivated land quality grade survey data and land use status maps from the past three years. Before selecting dry slope cultivated land that meets the steep slope definition criteria, the existing land survey results need to be cleaned to remove duplicate records and logically contradictory data.

[0047] Based on the established steep slope farmland gradient subdivision database, land use data and spatial influencing factor information are collected. The land use data and spatial influencing factor information are put into the calculation model of planting land for staple food fields in mountainous areas. Through spatial overlay analysis, the basic attribute characteristics of steep slope farmland areas are preliminarily determined.

[0048] In the process of constructing a slope calculation model for map patches based on DEM, it is necessary to import DEM data and preprocess it to generate a slope map.

[0049] The preprocessing includes depression filling, smoothing and noise reduction, and resolution matching. The classification of the multi-level slope grades is based on the regional terrain characteristics and the actual needs of farmland use, and the classification threshold is set accordingly.

[0050] A smoothing and denoising formula based on weighted average is adopted;

[0051] Let z be the elevation of the pixels in the n×n (n is an odd number, e.g., n=3) neighborhood surrounding the depression pixel (j,k). p,q , ; Define the weight matrix W. p,q The weight is inversely proportional to the distance from the neighboring pixel to the center pixel (j,k). For example, for a 3×3 neighborhood:

[0052]

[0053] Smoothed elevation The calculation formula is:

[0054] ;

[0055] Calculate the slope classification in the x-direction and the slope components in the y-direction, respectively. and ;

[0056] Terrain correction factor k tThis coefficient is determined based on the complexity of the regional terrain, ranging from 0.8 to 1.2. The more complex the terrain, the larger the value. (The last part, "arable land use efficiency coefficient k," appears to be an unrelated fragment and is omitted from the translation.) u The coefficient is determined by the actual utilization of cultivated land, with a value ranging from 0.7 to 1.1. The higher the utilization efficiency, the larger the value. Therefore, the slope calculation model S... modified for

[0057]

[0058] A slope map, created by importing and preprocessing DEM data, is a raster data map. In this map, each raster cell represents a small area on the ground, and the cell value indicates the slope of that area. The slope map visually displays the spatial distribution of slopes throughout the study area. Colors are typically used to classify slopes according to their magnitude; for example, light colors represent areas with gentler slopes, and dark colors represent areas with steeper slopes. The slope map clearly shows which areas have slopes greater than 25 degrees and which have slopes less than 25 degrees, providing fundamental data for subsequent analysis of steep-slope farmland.

[0059] Based on regional topographic features and actual farmland use needs, a multi-level slope grade threshold system was established. Assuming there are n grades, the threshold values ​​are T1, T2, ..., T... n−1 (0) <T1<T2<…<T n−1 The rules for classifying slope grades are as follows:

[0060] When 0 modified When the slope is less than or equal to T1, the slope grade is L1;

[0061] When T1 modified When T2 is less than or equal to T2, the slope grade is L2.

[0062] …

[0063] When T n−1 modified At that time, the slope grade was L. n .

[0064] Land use data includes rural homestead data, collective construction land data, land use data within the ecological protection red line area, and land use data in areas prone to geological disasters. After collecting the land use data, the land use data is converted into a unified geographic coordinate system.

[0065] ​​​The spatial influencing factors information includes indicators of food security needs, requirements for ecological function maintenance, geological disaster risk level assessment results, and spatial replacement feasibility assessment data. Before importing the spatial influencing factors information into the calculation model for planting land in mountainous areas, each influencing factor needs to be quantified and assigned a weight system. Slope subdivision involves constructing a map-based slope calculation model based on DEM, subdividing steep slopes above 25 degrees into nine levels: 25-30 degrees, 30-35 degrees, 35-40 degrees, 40-45 degrees, 45-50 degrees, 50-55 degrees, 55-60 degrees, 60-65 degrees, and above 65 degrees.

[0066] In the slope subdivision, each pixel within a pixel is considered a unit. Pixels with a slope value less than 25 are treated as null values ​​and excluded from the calculation. Pixels with a slope value greater than 25 are calculated based on their actual slope. The average slope of all pixels within the pixel is taken as the final slope value of the pixel. The calculation formula is as follows:

[0067]

[0068] Where Pb is the slope value of the plot, P i It is the slope value of a single pixel within the patch, and N is the total number of slope pixels within the patch.

[0069] Spatial overlay analysis and processing adopts a multi-level overlay strategy. Basic overlay is performed on land use data and slope subdivision data to obtain a basic layer of spatial distribution of steep slope farmland. Then, a layer of spatial influencing factors information is overlaid. Through spatial intersection operation and attribute association, a basic attribute feature layer of steep slope farmland area is generated.

[0070] After selecting the basic attribute characteristics of the initially determined steep slope farmland area, the basic attribute characteristics and slope subdivision data are imported into the classification and extraction model. Combined with the spatial influencing factor information, a deep comprehensive analysis is performed to determine the zoning results of the steep slope farmland. In the process of conducting deep comprehensive analysis to determine the zoning results of the steep slope farmland, a multi-criteria decision algorithm is adopted. The quantitative indicators in the spatial influencing factor information are used as decision criteria, the criteria priority is set, and the zoning boundary of the steep slope farmland is optimized by weighted summation and threshold judgment.

[0071] In the in-depth comprehensive analysis process, a multi-criteria decision-making and spatial interaction model is used to optimize the partition boundaries. The model calculates the comprehensive suitability index of each evaluation unit using the following formula:

[0072]

[0073] Where L is the comprehensive suitability index of the evaluation unit, and v l f is the normalized weight coefficient for the l-th criterion. lLet f be the standardized quantitative value of the l-th criterion, m be the total number of criteria involved in the decision-making process, λ be the spatial interaction moderating coefficient, and f be the standard quantitative value of the l-th criterion. a and f b Let δ be the standardized quantization value of any two different criteria. ab It is the correlation decay factor between a certain criterion a and a certain criterion b.

[0074] This formula, by introducing multiple criteria (m criteria) and summing the standardized quantitative value (fl) of each criterion with the normalized weight coefficient (vl), can comprehensively consider the impact of these different factors on the suitability of steep slope farmland, and helps to more accurately classify steep slope farmland of different suitability levels.

[0075] The second term in the formula Spatial interactions between different criteria were considered. In the spatial distribution of arable land on steep slopes, various influencing factors do not exist in isolation; soil type and distance from water sources interact and affect the actual use of arable land. This factor captures the impact of the interactions between these factors on overall suitability, thus making the classification results more reflective of the actual situation. Spatial interaction moderating coefficient λ and correlation attenuation factor δ are also considered. ab To describe the interaction between different criteria. Based on the subdivision of steep slope farmland slope, λ depends on the spatial interaction between the steep slope topography and the farmland topography, δ ab To identify regional differences in cultivated land with varying slopes through correlation analysis.

[0076] The weight of spatial interactions in the overall suitability assessment is adjusted, while δ ab This takes into account the differences in the degree of correlation between different criteria.

[0077] The zoning results determine four categories of zoning results in steep slope farmland: areas for the preservation of staple food planting land, areas applicable for spatial replacement, areas for returning farmland to forest, and ecological protection areas. The results also generate zoning vector graphics and attribute statistics tables.

[0078] The system for the zoning, classification, protection, and utilization of steep slope farmland includes a data management module, a zoning display module, a planning optimization module, and a strategy push module.

[0079] The data management module is used to store slope breakdown data, land use data, and zoning result data.

[0080] The planning optimization module is used to dynamically adjust the protection and utilization planning scheme according to the regional development goals.

[0081] The strategy push module is used to push differentiated management and control measures to steep slope farmland with different spatial types.

[0082] Based on the zoning results, optimize the planning scheme for the protection and utilization of steep slope farmland. According to the optimized planning scheme, classify the spatial types of steep slope farmland and establish a zoning and classification protection and utilization system for steep slope farmland.

[0083] Example 2

[0084] Reference Figures 4 to 5 This is a second embodiment of the present invention, which differs from the first embodiment in that it further includes:

[0085] Table 1. Detailed Statistical Table of Slope Gradients for Cultivated Land with Steep Slopes Above 25 Degrees

[0086] Unit: 10,000 mu

[0087]

[0088] As shown in the table above, the current status of arable land in a certain city is as follows:

[0089] 1. Slope classification is mainly based on 30-35 degrees. In accordance with the technical regulations for farmland slope classification using the Third National Land Survey's Digital Earth Scale (DEM), for the first time, the slope of 3.7716 million mu of steep-slope farmland within the farmland protection red line was subdivided. The results show that farmland with slopes of 25-30 degrees covers 772,300 mu.

[0090] 2. Steep slope farmland is mainly concentrated in the Three Gorges Reservoir area in Northeast China and the Wuling Mountains in Southeast China. Analysis shows that steep slope farmland in these two areas accounts for as much as 72.2% of the total steep slope farmland in the city. Among them, 11 districts and counties, including Chengkou, Wuxi, Wushan, and Fengjie, have steep slope farmland accounting for more than 25% of their total farmland, with Chengkou County having the highest proportion at 61%. A map showing the distribution of steep slope farmland in the city is shown below. Figure 4 As shown.

[0091] Table 2023: Distribution and Proportion of Steep Slope Farmland in Various Regions of a Certain City

[0092]

[0093] 3. 353,500 mu overlap with the ecological protection red line (the “three zones and three lines” delineation rules do not explicitly state that the farmland protection red line cannot intersect with the ecological protection red line), and 906,800 mu are located in areas prone to geological disasters.

[0094] 4. 64% of steep slope farmland is located at an altitude of over 500 meters. Among them, 571,900 mu (approximately 38,667 hectares) are located at an altitude of over 1,000 meters. With the advancement of the relocation work in high-altitude areas, steep slope farmland in high-altitude areas will face the situation of being uncultivated.

[0095] 5. 680,600 mu (approximately 45,333 hectares) overlap with the areas already covered in the second round of the "Grain for Green" program. Of this, 306,900 mu (approximately 20,467 hectares) are about to become forests or orchards. The remaining steep-slope farmland will gradually become forests or orchards in the future, posing a significant risk of land exodus. A schematic diagram illustrating the overlap between steep-slope farmland and the "Grain for Green" program in a certain city is shown below. Figure 5 As shown.

[0096] Based on the existing farmland situation in the aforementioned city, four key factors are considered: food security for the people, ecological protection needs, disaster prevention needs, and the feasibility of spatial replacement.

[0097] Taking into account the factors affecting the classification and management of steep slope farmland, it is proposed to first divide the 3.77 million mu of steep slope farmland within the farmland protection red line into four categories, based on the influence of slope size and the bottom-line control requirements for ecological protection and geological disaster prevention: steep slope farmland above 35 degrees, steep slope farmland within the ecological protection red line of 25-35 degrees, steep slope farmland within the geological disaster high-incidence area of ​​25-35 degrees, and steep slope farmland outside the ecological protection red line and non-geological disaster high-incidence area of ​​25-35 degrees.

[0098] By overlaying slope classification data, a disaster-prone area layer, and an ecological protection red line layer, the area of ​​cultivated land on steep slopes above 35 degrees is calculated to be 430,000 mu, the area of ​​cultivated land on steep slopes within the ecological protection red line range of 25-35 degrees is 290,000 mu, the area of ​​cultivated land on steep slopes within the disaster-prone area range of 25-35 degrees is 730,000 mu, and the area of ​​cultivated land on steep slopes outside the ecological protection red line and disaster-prone area range of 25-35 degrees is 2.32 million mu.

[0099] Table 3. Detailed Zoning Results of Steep Slope Farmland

[0100] Unit: 10,000 mu

[0101]

[0102] Note: Farmland located within both the ecological protection red line and the high-risk area for geological disasters is included in the statistics of the ecological protection red line area.

[0103] Example 3

[0104] This is the third embodiment of the present invention, which differs from the first two embodiments in that:

[0105] This experiment selected a mountainous county in southern China as the study area. Over 70% of this area is mountainous or hilly, with scattered steep-slope farmland facing the dual challenges of food security and ecological protection, making it a valuable research subject. In the preparation phase, existing land survey data for the region were collected, including land use vector data from the past two years, farmland quality grade survey reports, and 0.5-meter resolution satellite remote sensing images.

[0106] Meanwhile, high-precision DEM data covering the entire study area was obtained through drone-based regional aerial surveys for subsequent slope analysis. Geospatial data processing was performed using ArcGIS 10.8 software, and the hardware consisted of workstations equipped with high-performance processors and 32GB of memory to ensure efficient computation of large volumes of data and stable model operation.

[0107] The experiment was conducted strictly in accordance with the invention's content, proceeding step by step:

[0108] The first step involved extracting the vector boundary file of the farmland protection red line from the national land survey results. Using the "Spatial Overlay Analysis" tool in ArcGIS software, the red line boundary was overlaid with the current land use data to identify dry slope farmland patches within the red line area that met the steep slope definition criteria. A total of 126 valid patches were selected. Subsequently, the DEM data was imported into the software's "Slope Analysis" module. Slope calculations were performed on each selected dry slope farmland patch. Based on the calculation results and combined with the region's topographic features and actual farmland use needs, the steep slope farmland was subdivided into multiple slope levels. Information such as the patch's number, slope level, actual area, and center coordinates was recorded, constructing a complete database of steep slope farmland slope subdivisions. The data for each patch in the database underwent three repeated calculations and verifications to ensure accuracy and reliability.

[0109] The second step involves collecting various land use data from the experimental area, including vector data of rural homesteads, ecological protection red lines, and areas prone to geological disasters. Simultaneously, in conjunction with the county's rural revitalization and ecological protection plans, spatial influencing factors are identified, specifically including food security needs, ecological protection needs, geological disaster mitigation needs, and spatial replacement feasibility. This land use data is then uniformly converted to the CGCS2000 coordinate system, spatially matched with plot data in the slope subdivision database, and imported into the calculation model for agricultural land use in mountainous areas.

[0110] In the model, the land use data layer and the slope subdivision layer are superimposed layer by layer using the "spatial overlay analysis" tool. Based on the attribute association results of the superimposed patches, the basic attribute characteristics of each steep slope farmland area are preliminarily determined, such as "highly suitable for grain production", "suitable for spatial replacement", and "need to be converted from farmland to forest".

[0111] The third step involves associating the preliminary identified basic attribute feature data of steep slope farmland areas with the slope level data in the slope subdivision database through map patch numbers to form a "slope-attribute" associated dataset, which is then imported into the classification and extraction model.

[0112] In the classification extraction model, classification rules are set based on spatial influencing factors. For example, plots with low slope and close proximity to homesteads with low geological disaster risk are classified as areas for the preservation of farmland for food production; plots with medium slope and adjacent to idle homesteads with high feasibility for spatial replacement are classified as areas suitable for spatial replacement; plots with high slope and strong ecological sensitivity are classified as areas for returning farmland to forest; and plots with extremely high slope and located in the core area of ​​the ecological red line or areas prone to geological disasters are classified as ecological protection areas.

[0113] By using the model's "attribute filtering" and "spatial clipping" functions, the associated dataset is processed to ultimately determine the specific range and included polygons of the four types of partitions, generating partition vector maps and attribute statistics tables.

[0114] The fourth step involves optimizing the planning scheme for the protection and utilization of steep slope farmland based on the results of the four zoning categories and in conjunction with the county's planning goal of "not reducing the amount of arable land and increasing the proportion of ecological land".

[0115] For example, within the scope of land reserved for staple food crops, maintain its utilization status, improve basic infrastructure, and guide the development of agriculture, culture, and tourism; in areas suitable for spatial replacement, based on the requirements for economic crop planting and local natural conditions, establish a list of suitable "mountain" locations for fruit trees and formulate a spatial replacement plan of "mountain for fruit trees and land for farmland"; in areas of returning farmland to forest and ecological protection areas, match suitable tree and shrub varieties to local conditions and formulate a plan for returning farmland to forest and ecological conservation.

[0116] According to the optimized planning scheme, 126 steep slope farmland plots were divided into three spatial types: preservation and utilization, spatial replacement, and conversion of farmland to forest. A zoning and classification protection and utilization system for steep slope farmland was built. The system has functions such as data query, zoning display, and strategy generation to complete the entire experimental process.

[0117] Table 4. Results of detailed slope breakdown for steep farmland

[0118]

[0119] Table 5 Spatial Overlay Results of Land Use Data

[0120]

[0121] Table 6. Results of Spatial Influencing Factors Analysis

[0122]

[0123] Table 7. Zoning Results of Steep Slope Cultivated Land

[0124]

[0125] Table 8. Classification Results of Spatial Types of Steep Slope Cultivated Land

[0126]

[0127] Table 9 Comparison of the effects of the inventive method and the prior art

[0128]

[0129] The basic data in Tables 4-8 clearly verify the technical logic and data reliability of the experiment. In Table 4, the results of the slope subdivision of steep farmland were verified three times, and the data reliability was higher than 95%. Moreover, the deviation between the area of ​​the map patch and the actual field survey data was less than 0.02 hm², which proves that the slope analysis and classification process based on DEM is rigorous and the results truly reflect the slope differences of different map patches.

[0130] The spatial overlay results of the land use data in Table 5 show that the overlay matching degree is over 96%, the data integrity is close to 100%, and only a very small number of map patches have 1-3 spatial conflicts. This indicates that the coordinate system of the land use data is standardized and the layer overlay operation is standardized, ensuring the validity of the basic data.

[0131] In Table 6, the spatial influencing factors analysis results show that each patch has a preliminary attribute determination based on four influencing factors. The determination is based on sufficient evidence and the results are highly consistent with the actual conditions of the patch, further verifying the rationality of the experimental process.

[0132] Table 7 comprehensively displays the key parameters of the four categories of zoning: the retention area of ​​staple food farmland, the applicable area for spatial replacement, the area of ​​returning farmland to forest, and the ecological protection area. This demonstrates the precise control of the zoning results by the invented method. In terms of the number and area of ​​included map patches, the four categories of zoning cover all 126 map patches without omission or duplication. Among them, the retention area of ​​staple food farmland and the applicable area for spatial replacement account for a relatively high proportion, which is in line with the basic positioning of the region as "ensuring food security and meeting the needs of rural construction."

[0133] In terms of average slope, the four types of zones show a gradient change from "lower steep slope → medium steep slope → higher steep slope → extremely steep slope", which is perfectly matched with the functional positioning of the zones. Grain production requires lower slopes to ensure ease of cultivation, while ecological protection can support the ecological functions of areas with extremely high slopes. In terms of the proportion of low-risk geological disasters and the soil fertility compliance rate, the proportion of low-risk geological disasters and the soil fertility compliance rate are the highest in the area where staple food planting land is reserved, ensuring the safety and stability of grain production. The two indicators are the lowest in the ecological protection area, which is in line with its positioning of "prioritizing ecological functions and weakening production functions".

[0134] Furthermore, the accuracy of the zoning boundary is controlled within 1 meter, providing precise spatial basis for subsequent planning and implementation, fully demonstrating that the invented method can effectively realize the division and implementation of the four types of zoning.

[0135] The comparative data in Table 9 clearly demonstrates the technological breakthrough of the method of this invention, effectively making up for the shortcomings of existing technologies. In terms of core technology accuracy, the slope classification accuracy of this invention reaches 97.6%, which is more than 30% higher than that of existing technologies. This solves the defect of existing technologies that "only classify steep slope farmland into a single category and cannot reflect the differences in subdivision"—existing technologies usually classify farmland that meets the steep slope standard uniformly as "steep slope farmland", ignoring the impact of different slope levels on utilization methods. In contrast, this invention lays the foundation for subsequent accurate zoning through multi-level slope subdivision, demonstrating the creativity of the slope analysis process.

[0136] The zoning results have an accuracy rate of 95.2%, which is 25%-30% higher than existing technologies. The key reason is that this invention integrates land use data with multiple spatial influencing factors to form a complete chain of "data-analysis-judgment". Existing technologies mostly rely on slope or land use data alone, which leads to the zoning results being out of touch with actual needs. This approach of multi-factor comprehensive analysis has significant novelty.

[0137] In terms of practical application, the food security guarantee rate and ecological protection compliance rate of this invention are significantly higher than those of existing technologies and the industry average. It solves the industry pain point of existing technologies that "it is difficult to balance food security and ecological protection"—through precise zoning, it not only ensures the grain production function of high-quality steep slope farmland, but also enhances the regional ecological function through returning farmland to forest and protection zoning.

[0138] The data processing efficiency reaches 45 plots / hour, an improvement of over 60% compared to existing technologies. This is due to the automated model process constructed by this invention, which overcomes the problems of "manual data processing, cumbersome operation, and low efficiency" in existing technologies. Furthermore, this invention ultimately forms a complete application system of "zoning-classification-system," not only completing the zoning but also realizing the technology's implementation through spatial type classification and protection and utilization systems. Existing technologies often remain at a single stage of data processing or zoning, lacking systematic application design. This end-to-end innovation "from technical analysis to practical application" further demonstrates the inventiveness and novelty of this invention, providing a feasible and highly efficient technical solution for the protection and utilization of steep slope farmland.

[0139] Example 4

[0140] Reference Figure 6 This is the fourth embodiment of the present invention, which differs from the previous three embodiments in that:

[0141] The following is for reference. Figure 6The diagram illustrates a structural schematic of an electronic device 300 suitable for implementing some embodiments of the present invention. The electronic devices in some embodiments of the present invention may include, but are not limited to, mobile terminals such as mobile phones, laptops, digital broadcast receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), in-vehicle terminals (e.g., in-vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. Figure 6 The terminal device shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments of the present invention.

[0142] like Figure 6 As shown, the electronic device 300 may include a processing unit (e.g., a central processing unit, a graphics processing unit, etc.) 301, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 302 or a program loaded from a storage device 308 into a random access memory (RAM) 303. The RAM 303 also stores various programs and data required for the operation of the electronic device 300. The processing unit 301, ROM 302, and RAM 303 are interconnected via a bus 304. An input / output (I / O) interface 305 is also connected to the bus 304.

[0143] Typically, the following devices can be connected to I / O interface 305: input devices 306 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 307 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 308 including, for example, magnetic tapes, hard disks, etc.; and communication devices 309. Communication device 309 allows electronic device 300 to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 6 An electronic device 300 with various devices is shown; however, it should be understood that it is not required to implement or possess all of the devices shown. More or fewer devices may be implemented or possessed alternatively. Figure 6 Each box shown can represent a device or multiple devices as needed.

[0144] Furthermore, the storage medium in the embodiments of this application stores program instructions capable of implementing all the above methods. These program instructions can be stored in the storage medium in the form of a software product, including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks, or terminal devices such as computers, servers, mobile phones, and tablets.

[0145] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0146] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A GIS-based method for analyzing the subdivision and zoning of steep farmland slopes for protection and utilization, characterized in that... Includes the following steps: Based on existing land survey results, dry slope farmland within the farmland protection red line that meets the steep slope definition criteria is selected. A DEM-based slope calculation model is constructed, and the geospatial data of the dry slope farmland is imported into the model. Based on the model, the dry slope farmland that meets the steep slope definition criteria is subdivided into multiple slope levels, and a steep slope farmland slope subdivision database is established. The existing land survey results include land change survey data, cultivated land quality grade survey data, and land use status maps for the past three years; Based on the established steep slope farmland gradient subdivision database, land use data and spatial influencing factor information are collected. The land use data and spatial influencing factor information are put into the calculation model of planting land for staple food fields in mountainous areas. Through spatial overlay analysis, the basic attribute characteristics of steep slope farmland areas are preliminarily determined. The spatial overlay analysis and processing adopts a multi-level overlay strategy, which performs basic overlay on land use data and slope subdivision data to obtain a basic layer of spatial distribution of steep slope farmland, and then overlays a layer of spatial influencing factor information. Through spatial intersection operation and attribute association, the basic attribute features of steep slope farmland area are generated. After selecting the basic attribute characteristics of the initially determined steep slope farmland area, the basic attribute characteristics and slope subdivision data are imported into the classification and extraction model. Combined with the spatial influencing factor information, in-depth comprehensive analysis is performed to determine the zoning results in the steep slope farmland. In the slope subdivision, each pixel within a pixel is considered a unit. Pixels with a slope value less than 25 are treated as null values ​​and excluded from the calculation. Pixels with a slope value greater than 25 are calculated based on their actual slope. The average slope of all pixels within the pixel is taken as the final slope value of the pixel. The calculation formula is as follows: ； Where Pb is the slope value of the map patch, Pi is the slope value of a single pixel within the map patch, and N is the total number of slope pixels within the map patch. In the process of conducting in-depth comprehensive analysis to determine the zoning results of steep slope farmland, a multi-criteria decision algorithm is adopted. The quantitative indicators in the spatial influencing factor information are used as decision criteria, the criteria priority is set, and the zoning boundary of steep slope farmland is optimized by weighted summation and threshold judgment. Based on the zoning results, optimize the planning scheme for the protection and utilization of steep slope farmland. According to the optimized planning scheme, classify the spatial types of steep slope farmland and establish a zoning and classification protection and utilization system for steep slope farmland.

2. The method for analyzing the slope subdivision and zoning of steep farmland based on GIS for protection and utilization according to claim 1, characterized in that, Before selecting dry slope farmland that meets the criteria for steep slopes, the existing land survey results need to be cleaned to remove duplicate records and logically contradictory data.

3. The method for analyzing the slope subdivision and zoning of steep farmland based on GIS for protection and utilization according to claim 1, characterized in that, In the process of constructing the DEM-based slope calculation model, DEM data needs to be imported and preprocessed to form a slope map. The preprocessing includes depression filling, smoothing and noise reduction, and resolution matching. The classification of the multi-level slope grades is based on the regional terrain characteristics and the actual needs of farmland use, with the grading thresholds set accordingly.

4. The method for analyzing the slope subdivision and zoning of steep farmland based on GIS for protection and utilization according to claim 1, characterized in that, The land use data includes rural homestead data, land use data within the ecological protection red line area, and land use data in areas prone to geological disasters. After collecting the land use data, the land use data is converted into a unified geographic coordinate system. The spatial influencing factors information includes food security guarantee demand indicators, ecological function maintenance requirements, geological disaster risk level assessment results, and spatial replacement feasibility assessment data. Before importing the spatial influencing factors information into the calculation model of planting land for staple food fields in mountainous areas, it is necessary to quantify and assign values ​​to each influencing factor and establish an influencing factor weight system.

5. The method for analyzing the slope subdivision and zoning of steep farmland based on GIS for protection and utilization according to claim 1, characterized in that, The slope subdivision involves constructing a slope calculation model based on DEM (Digital Equation Model), which subdivides steep farmland with a slope greater than 25 degrees into nine levels: 25-30 degrees, 30-35 degrees, 35-40 degrees, 40-45 degrees, 45-50 degrees, 50-55 degrees, 55-60 degrees, 60-65 degrees, and above 65 degrees.

6. The method for analyzing the slope subdivision and zoning of steep farmland based on GIS according to claim 1, characterized in that, The zoning results determine four categories of zoning results in steep slope farmland: areas for the preservation of staple food planting land, areas applicable for spatial replacement, areas for returning farmland to forest, and ecological protection areas. The results also generate zoning vector graphics and attribute statistics tables.

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