Grassland human settlement space ecological safety pattern construction method

Abstract

The invention relates to a grassland human settlement space ecological security pattern construction method comprising the following steps: 1) identifying an ecological source land, including ecological source land preliminary identification and ecological source land screening; 2) based on grassland living space production and life characteristics, ecological resistance surface identification is carried out; and 3) combining an ecological source land evaluation result and an ecological resistance surface identification result, simulating an ecological corridor, an ecological key point and an ecological obstacle point by adopting a circuit theoretical model, and constructing an ecological safety pattern as an identification result of an ecological space in the grassland living space. The grassland human settlement space ecological safety pattern construction method developed by the invention can adapt to the particularity of the grassland pastoral area human settlement space, and provides a thought for grassland pastoral area territorial space layout optimization and management and control partition delimitation.

Description

Technical Field

[0001] The present application belongs to the field of ecological space identification technology, and specifically relates to a method for constructing an ecological security pattern of grassland human settlement space. Background Art

[0002] Most of the existing studies on the construction of ecological security patterns focus on administrative areas such as metropolitan areas, provinces, and urban areas, while there are relatively few studies focusing on regional types, especially grassland human settlements with significant regional characteristics. The ecological environment is sensitive and the construction method is rough. In order to further balance the contradiction between ecological environment protection and human construction and production, it is urgent to scientifically identify ecological space as a base map for spatial layout optimization. CN116227950A discloses a method for constructing an ecological security pattern. According to various types of geographic spatial data, the service capacity index corresponding to the regional ecosystem is obtained, and the classification corresponding to the regional ecosystem is determined; the regional ecosystem classified as extremely important is selected as the ecological source, and the initial resistance surface is obtained; the resistance surface is determined according to natural conditions and socio-economic activities; the ecological security pattern is constructed according to each ecological source and the modified resistance surface after correction; however, the patent does not consider the interference of human activities on the ecosystem, that is, the sensitivity of the ecological environment. In addition, the existing research does not focus on the construction method of the ecological security pattern of grassland pastoral areas. The production and life of grassland human settlements are significantly different from other regions. Specific indicators and calculation methods are required to adapt to the identification and construction of specific grassland human settlement ecological spaces.

[0003] CN11 8014525A is guided by the integration of urban and rural ecology and constructs an ecological security pattern from the perspective of urban and rural integration. However, this patent needs to consider urban and rural driving factors and is not suitable for the identification and construction of ecological space in grassland pastoral areas. The existing technologies have ignored the systematic nature of the ecological environment and the attributes of the landscape space structure, and there is a general lack of discussion on the identification of ecological spaces with complete ecosystems and functional stability.

[0004] In order to solve the above technical problems, this application develops a method for constructing the ecological security pattern of grassland human settlement space, which can adapt to the ecological particularity of grassland human settlement space and provide ideas for optimizing the land space layout and demarcation of management and control zones in grassland pastoral areas. Summary of the invention

[0005] This application constructs an ecological security pattern path, selects evaluation indicators that reflect the ecological and cultural characteristics of grassland human settlements to identify ecological sources; selects characteristic indicators that are suitable for pastoral production and living characteristics to identify ecological resistance surfaces; and selects circuit theory models to improve the accuracy of ecological corridor construction.

[0006] Specifically, the first step is ecological source assessment, which includes preliminary identification of ecological sources and screening of ecological source patches. Preliminary identification of ecological sources: Conduct "ecological sensitivity assessment (soil and water loss sensitivity, land desertification sensitivity) and ecological service function importance assessment (importance of water conservation function, importance of soil and water conservation function, importance of biodiversity maintenance function, importance of windbreak and sand fixation service function)", and superimpose the "high-value ecological sensitivity areas and high-value ecological service function areas" in the above evaluation results as preliminary identification results.

[0007] Then, the ecological source patches were screened: Since the evaluation patches after various superposition analyses were highly fragmented, the morphological spatial pattern analysis (MSPA) method and landscape connectivity analysis were used to evaluate and screen again as the final quantitative evaluation results of the ecological source. "Nature reserves and prohibited construction areas" were used as qualitative evaluation results to supplement the source, and then combined with the quantitative evaluation results to obtain the ecological source identification results.

[0008] Then, based on the production and living characteristics of grassland human settlement space, resistance values ​​were assigned to different land use types in the region to form a basic ecological resistance surface and evaluate the resistance value. Two influencing factors, namely the grazing intensity of herders and the activity intensity of residents, were selected, and the modified resistance index was superimposed on the basic resistance index to obtain an ecological resistance surface suitable for grassland pastoral areas.

[0009] Finally, combining the evaluation results of “ecological source” and the identification results of “ecological resistance surface”, the circuit theory model is used to simulate ecological corridors and ecological key points and ecological barrier points to construct the “ecological security pattern” as the ecological space identification results (such as Figure 1 shown).

[0010] In the first aspect, the present application provides a method for constructing an ecological security pattern of grassland human settlement space, comprising the following steps:

[0011] 1) Identify ecological sources:

[0012] In order to adapt to the characteristics of grassland pastoral areas, the ecological security pattern of grassland human settlement space constructed is more accurate. This application introduces the ecological sensitivity index to form a dual evaluation system of ecological sensitivity and ecological service importance. This is because from the perspective of various land uses in grassland human settlement space, grassland is the main land type. Taking Inner Mongolia as an example, the grassland area in Inner Mongolia accounts for 74% of the total land area of ​​the region. The evaluation results of the main land types have a greater impact on the evaluation results of the overall ecological service importance. The single influencing factor is not conducive to the accuracy of ecological source identification. In recent years, due to human activities and climate change, grassland degradation, desertification, salinization and other problems have become acute, seriously threatening the sustainable development of grassland human settlements. Therefore, it is necessary to introduce ecological sensitivity evaluation (ecological environment sensitivity, used to characterize the sensitivity of the ecosystem to the interference of natural and human activities in the region, that is, the difficulty and possibility of ecological and environmental problems in the regional ecosystem when encountering interference). The higher the ecological sensitivity index, the better the ecological environment, the more it meets the standards of the ecological source, and after superimposing the evaluation results of the importance of ecological services, the ecological source obtained is more suitable for grassland pastoral areas.

[0013] 1.1 Preliminary evaluation of ecological sources: Select ecological sensitivity and ecological service importance as two evaluation dimensions for preliminary evaluation:

[0014] 1.1.1 Ecological sensitivity assessment and analysis, including two assessment dimensions: soil erosion sensitivity and land desertification sensitivity.

[0015] (1) Sensitivity to soil erosion

[0016] Soil and water loss sensitivity is used to evaluate the possibility of water loss and soil erosion. The higher the sensitivity, the more likely it is to have water loss and soil erosion problems. Due to the sensitive ecological environment of grassland pastoral areas, the problems caused by soil and water loss will affect the sustainable development of grassland pastoral areas. Based on the soil and water loss equation (RUSLE), comprehensive consideration is given to factors such as precipitation, topography, vegetation and soil texture, and factors such as rainfall erosivity index, terrain undulation index, soil erodibility coefficient, and vegetation cover index are selected. The soil and water loss sensitivity is calculated using formula (1-1):

[0017] T i =E i ·LS i ·C i ·K i (1-1)

[0018] Where: T i Representative i evaluates the regional soil erosion sensitivity index: E i LS i , C i , K i, respectively represent the level values ​​of the relevant indicators of precipitation erosivity index (Table 3-soil), slope index (Table 3-topography), soil erodibility coefficient (Table 3-soil), and vegetation cover index (Table 3-normalized vegetation index NDVI) of the evaluation area i;

[0019] (2) Sensitivity to land desertification

[0020] This index is used to evaluate the possibility of land desertification and is affected by the climate and ecological environment. Based on the characteristics of dry winter in grassland human settlements, high sand content in the land, high degree of surface exposure, and easy occurrence of sandstorms, four factors are selected: number of days with sandstorms, dryness index, vegetation cover index, and soil texture. The land desertification sensitivity is calculated using formula (1-2):

[0021]

[0022] Where: D i Representative i evaluates the sensitivity index of regional land desertification: G i ,I i , W i , K i , respectively represent the grade values ​​of the related indicators of dryness index (Table 3-climate), number of days with sand-raising wind (Table 3-climate), soil texture (Table 3-soil), and vegetation cover index (Table 3-normalized difference vegetation index NDVI) of the evaluation area i;

[0023] (3) Superposition of ecological sensitivity assessment results: The Arc GIS comprehensive superposition tool was used to superimpose the maximum values ​​of the assessment results of soil erosion sensitivity and land desertification sensitivity to obtain the ecological sensitivity assessment results.

[0024] 1.1.2 Evaluation of the importance of ecological services, including evaluation in several dimensions, including the importance of biological maintenance, water conservation, soil and water conservation, and wind and sand control.

[0025] (1) Importance of biological maintenance:

[0026] Used to evaluate whether an area has sufficient conditions to support a variety of organisms. The human settlement space of grasslands is mainly terrestrial organisms, and the ecological space area accounts for a large proportion. The NPP (annual average gross domestic product) method is used. The higher the NPP index, the stronger the ecosystem service index. The comprehensive service capacity of the ecosystem is characterized by the annual average net productivity of vegetation, and there are three other factors: annual average temperature, annual average precipitation, and altitude. The importance of biological maintenance is calculated using formula (1-3):

[0027] B i =NPP mean ·F pre ·F tem ·(1-F alt) (1-3)

[0028] Where: B i Represents the importance index of biodiversity conservation in the evaluation area i: NPP represents the annual average primary net productivity of the evaluation area i (data source: annual average primary net productivity NPP) F pre is the slope factor; F tem is the average annual temperature (Table 3-Climate); F alt is the elevation (Table 3 - Topography).

[0029] (2) Importance of water conservation:

[0030] The water conservation of grassland human settlements is directly related to the ecological security of the region. Its importance is specifically manifested in the infiltration, accumulation, and interception of precipitation, as well as evaporation, regulation of groundwater flow, and promotion of water circulation based on the structural characteristics of grassland ecosystems (stems, leaves, and roots of low-growing vegetation such as forage grasses). Its specific functions include optimizing water quality, retaining floodwater, and replenishing drought. Due to the influence of data accuracy, the NPP (annual gross domestic product) method is used for correction, and factors such as soil seepage capacity, slope, and slope direction are selected for calculation, which is of great significance for conserving grassland moisture. The importance of water conservation is calculated using formula (1-4):

[0031] WR i =NPP meam ·F sic ·F pre ·F slo (1-4)

[0032] In the formula: WR i represents the water conservation importance index of the evaluation area i: NPP represents the annual average primary net productivity of the evaluation area i (Table 3 - Annual average primary net productivity NPP), F sic 、F pre 、F slo They represent the grade values ​​of the soil seepage factor (Table 3 - soil), slope (Table 3 - terrain), and aspect factor (Table 3 - terrain) related indicators of the evaluation area i.

[0033] (3) Importance of Soil and Water Conservation:

[0034] This indicator is used to evaluate the ability of an ecosystem to withstand rainwater erosion and soil erosion resistance, thereby maintaining the ecological function of the soil (providing water and nutrients for plants; providing material energy and habitats for animals). The importance of soil and water conservation in grassland human settlements should be evaluated by focusing on the structural characteristics of low-lying vegetation such as forage in grassland ecosystems, as well as soil erosion caused by human activities. Based on the water and soil loss equation (RUSLE), five factors, namely vegetation coverage, rainfall erosion, slope length, soil erodibility, and slope, are selected, which are of great significance to maintaining the water conservation function of grassland human settlements and providing a good ecological environment for organisms. The importance of soil and water conservation is calculated using formula (1-5):

[0035] A i =C i ·K i ·L i ·L si ·(1-E i ) (1-5)

[0036] Where: A i Representative i evaluates the importance index of regional soil and water conservation: K i 、E i , L i , C i , Ls i They respectively represent the grade values ​​of the vegetation cover index (Table 3 - Normalized Difference Vegetation Index NDVI), precipitation erosion index (Table 3 - soil), slope length factor (Table 3 - topography), soil erodibility factor (Table 3 - soil), and slope factor (Table 3 - topography) related indicators of the evaluation area i.

[0037] (4) Importance of windbreak and sand fixation:

[0038] Since grassland human settlements are mainly distributed in my country's sandstorm source areas and are an important part of my country's northern sand-control belt, calculating the importance of windbreak and sand fixation in grassland pastoral areas is of great significance to the construction of my country's "northern ecological security barrier". The NPP (annual average gross domestic product) method is used for correction. The higher the NPP index, the stronger the ecosystem service index. The comprehensive service capacity of the ecosystem is characterized by the average annual net productivity of vegetation, as well as factors such as soil erodibility, average annual temperature, and surface roughness. The importance of windbreak and sand fixation is calculated using formula (1-6):

[0039] S i =NPP mean ·C i ·F tem ·H i (1-6)

[0040] Where: S irepresents the importance index of windbreak and sand fixation in the evaluation area i: NPP represents the annual average primary net productivity of the evaluation area i (Table 3 - Annual average primary net productivity NPP), C i 、F tem , H i They represent the grade values ​​of soil erodibility factor (Table 3-soil), average annual temperature factor (Table 3-climate), and surface roughness factor (Table 3-soil) of evaluation area i respectively.

[0041] (5) Overlay of ecosystem service importance evaluation results: Using the Arc GIS comprehensive overlay tool, the maximum values ​​of the evaluation results of the four dimensions of biological maintenance importance, water conservation importance, soil and water conservation importance, and windbreak and sand fixation importance were overlaid to obtain the ecosystem service importance evaluation results.

[0042] 1.1.3 The ecological sensitivity and the ecosystem service importance assessment results are superimposed using ArcGIS software to obtain preliminary identification results of ecological sources.

[0043] Ecological sensitivity assessment is used to identify spaces prone to environmental problems, and ecosystem service importance assessment is used to identify areas with stable ecological and environmental functions. The comprehensive evaluation of the two is helpful to efficiently evaluate the impact of human social and economic activities on the ecological environment. In current research, the comprehensive methods of the two include hierarchical analysis method, spatial distance index method, entropy method, etc. Some scholars have also used their own research experience assignment, equal weight superposition, direct superposition of the optimal area, two-dimensional correlation matrix, etc., but there are few studies on grassland areas and similar research areas, and the weight of indicators that can be used as a reference is not very persuasive.

[0044] To ensure the neutrality, objectivity and comprehensiveness of the evaluation indicators, this application first uses equal weights to calculate the various evaluation factors of ecological sensitivity evaluation and ecosystem service importance evaluation, and then divides the areas into five levels of sensitive areas and five levels of importance areas respectively, and finally overlaps the extremely ecologically sensitive areas and the extremely ecologically important areas to obtain the preliminary identification results of the ecological source.

[0045] 1.2 Screening of important ecological sources

[0046] The preliminary identification results of ecological source areas are optimized: through morphological spatial pattern analysis (MSPA) and landscape connectivity analysis, the core area patches with important ecological significance and ecological source patches with high landscape connectivity are evaluated from the aspects of the size, shape, area, perimeter, and connectivity between patches of ecological source areas. In addition, in order to improve the comprehensiveness and integrity of ecological source areas, qualitative evaluation indicators can also be selected to supplement the quantitative evaluation results.

[0047] 1.2.1 Using morphological spatial pattern analysis (MSPA) to evaluate and select core area blocks

[0048] The morphological spatial pattern analysis method uses the erosion calculation method based on the domain connectivity rules to obtain the core area ecological patches, and expands and reconstructs them. The skeleton extraction algorithm is used to determine whether they belong to the same core area. The binary raster image is divided into seven landscape types (core area, island, bridge area, ring area, pore area, edge area, and branch line), which can be used to analyze the spatial position and connectivity of each ecological patch.

[0049] Specifically, this application adopts the eight-field analysis method of Guidos Toolbox analysis software, takes the preliminary identification results of the ecological source in step 1) as the foreground land class (1), and other spaces as the background land class (0), saves them in TIFF format and imports them, and takes the "ecological core area (Core)" with higher ecological value and higher priority as the key ecological source.

[0050] 1.2.2 Landscape connectivity assessment

[0051] Landscape connectivity is used to evaluate the circulation and interactivity of organisms and information in the above-mentioned landscape types, and to characterize biodiversity conservation and ecosystem integrity. There are two main evaluation indicators: the overall connectivity index (IIC) and the possible connectivity index (PC).

[0052] ① Overall connectivity index (IIC): When the interval between two patches is lower than a certain threshold, they are not connected; when it is close to the threshold, they are connected; if the value is larger, it means that the overall connectivity of the region is good. The overall connectivity index (IIC) is calculated using formula (1-7):

[0053]

[0054] In the formula, n represents the total number of patches in the study area, and parameter a represents the patch area; nl ij represents the number of shortest path connections between patch i and patch j; A L Represents a landscape attribute value.

[0055] ②Possible connectivity index (PC): It indicates the weighted probability of connectivity between two patches, and pays more attention to the connectivity possibility between patches. The source patches with higher landscape connectivity have stronger ecological functions, more frequent internal material and energy exchanges, and higher degree of connection with the outside world. They can also be determined as important ecological source patches. The possible connectivity index (PC) is calculated using formula (1-8):

[0056]

[0057] In the above formula, n represents the total number of patches in the study area, parameter a represents the patch area; p ij * represents the maximum possibility of the biological circulation path between patch i and patch j; A L Represents a landscape attribute value.

[0058] Patches with overall connectivity index (IIC)>1 and possible connectivity index (PC)>1 were selected as the final ecological source areas.

[0059] 2) Identification of ecological resistance surface

[0060] The ecological resistance surface identification method of the present application fully takes into account the particularity of grassland human settlement space. As a key element in the ecological security pattern, the current identification method of ecological resistance surface is relatively simple, and the resistance value is usually directly defined by the land use type. Among them, the "grassland" land type is usually defined as land with good ecological environment and small ecological resistance value. However, grassland in grassland pastoral areas also has pastoral production functions, and there is overgrazing by herders in some grassland human settlement spaces, which has a negative impact on ecological environmental protection and biological circulation. The ecological resistance value increases accordingly, which is contrary to the ecological resistance surface identification principles in other regions. Therefore, the ecological resistance surfaces used in other regions are not applicable to grassland pastoral areas. This application proposes a corresponding ecological resistance surface identification method based on the production and living characteristics of pastoral areas.

[0061] The identification of ecological resistance surface includes: evaluating the basic ecological resistance surface of land cover according to the characteristics of grassland human settlement space, and then revising the above resistance surface by evaluating herders' grazing and residents' activities.

[0062] 2.1 Basic ecological resistance surface coefficient R o :The resistance surface reflects the spatial distribution characteristics of resistance in different ecological processes and characterizes the impact of landscape heterogeneity on ecological flow. This application assigns resistance values ​​to different land use types in the study area, constructs a basic ecological resistance surface, and obtains resistance factors;

[0063] 2.2 Correction of the ecological resistance surface of grassland human settlement space: As the key to the accurate identification of ecological corridors, the construction of ecological resistance surface to simulate the difficulty of the flow and transmission of ecological elements is crucial for the construction of ecological security pattern. In order to weaken the influence of subjective assignment, this application selects two factors with greater influence, namely the grazing intensity of herders and the intensity of residents' activities, based on the characteristics that grasslands in grassland human settlement space have ecological functions but grazing will have a negative impact on ecology, and the contradictory characteristics of residents' activities and sensitive ecological environmental protection, to characterize human interference in the flow and transmission of ecological elements, and correct the comprehensive ecological resistance surface; then superimpose the corrected resistance index with the basic resistance index to obtain the ecological resistance surface suitable for grassland human settlement space, which is calculated specifically using formula (1-9).

[0064]

[0065]

[0066]

[0067]

[0068]

[0069] Where: HGS i 、HAS i Respectively represent the grazing intensity value and the resident activity intensity value, R HGSi represents the normalized grazing intensity index, R HASi represents the normalized resident activity intensity index, R i represents the modified ecological resistance index, R o It is the basic ecological resistance index.

[0070] D i is the animal husbandry production density value in region i; M i is the probability deviation of animal husbandry production in region i, k is the number of livestock species, r a , L a are the conversion coefficient of the standard unit of a type of livestock, the number of livestock (data source: government documents), S g is the unit grassland area; u is the livestock production utilization rate of grassland, which is 0.45 (according to the Guiding Opinions on Determining the Suitable Carrying Capacity of Grassland in Xilin Gol League [S]. (Xishubanfa

[2021] No. 15)); t is the number of factors affecting the probability of livestock production; v ic is the value of the influencing factor of grazing intensity in item c in region i (factor level = factor value), see Table 1. The number of influencing factors of pastoral production probability includes grassland resources, herders' grazing area selection intention and herders' grazing conditions and convenience; the conversion coefficient of residents' activity intensity of the land is determined by the land use / cover type. The influencing factors of grazing intensity.

[0071] Table 1 Calculation table of factors affecting grazing intensity (v ic )

[0072]

[0073]

[0074] S CLE is the equivalent area of ​​construction land; SL i is the area of ​​the i-th land use / cover type (data source: land use - see Table 3 for details): CL i is the conversion coefficient of residents’ activity intensity for the i-th type of land, see Table 2 for details.

[0075] Table 2 Conversion coefficients of construction land equivalent for various land use / cover types (CL i )

[0076]

[0077] 3. Ecological corridor evaluation

[0078] Since the space for population migration and exchange also has important ecological value, in order to ensure the systematicness and integrity of the ecological space, it is also necessary to integrate the ecological corridors and key nodes of biological circulation.

[0079] 3.1 Identification of ecological corridors

[0080] The Linkage Mapper tool in Arc GIS was used to identify ecological corridors, and the circuit theory was used to simulate the random walk paths and population diffusion probabilities of biological individuals in space. The entire study area was regarded as a conductive surface, and the "ecological source" was regarded as a "zero resistance energy surface". Each energy surface had a current density difference, and the cumulative current density value was used as the consumption path. The cumulative current density value was proportional to the utilization rate of the ecological corridor. The current density value was relatively low, which was a potential ecological corridor. The "ecological resistance surface" was regarded as a "resistance surface". The area with low resistance value had high permeability, frequent species migration and diffusion or gene exchange, and the area with high resistance value was the opposite.

[0081] Based on the identification results of ecological sources and ecological resistance surfaces, the optimal path between ecological sources and the shortest straight-line distance between the center points of ecological sources are calculated to construct ecological corridors. Channels with relatively low resistance values ​​for ecological flow and energy flow are potential ecological corridors.

[0082] 3.2 Identification of ecological key points

[0083] Ecological key points are areas with high current density and voltage values ​​between ecological sources. They are also areas where species in ecological corridors are very likely to pass through. Some ecological key points may become ecological stepping stones and should be protected to avoid degradation or destruction. The ecological key points in grassland pastoral areas are mainly composed of high and medium coverage grasslands and concentrated woodland patches. This application uses the Pinchpoint Mapper tool in Arc GIS to identify ecological key points. Based on circuit theory, the resistance value is used to characterize the resistance of the species migration and diffusion process, and the current and voltage values ​​are used to characterize the degree of connectivity between ecological sources. The better the ecological environment quality of the ecological source, the more conducive it is to species migration and diffusion, and the greater the current value of the corresponding ecological key point.

[0084] 3.3 Identification of ecological obstacles

[0085] Ecological barrier points mainly refer to areas where species encounter resistance and obstacles when migrating between different ecological sources. After the ecological function is improved or the ecological barrier points are restored, the ecological connectivity will be significantly improved. The ecological barrier points in grassland human settlements are mostly ecologically fragile areas such as construction land and cultivated land. This application uses the Barrier Mapper tool in Linkage Mapper in Arc GIS to identify ecological barrier points. Removing ecological barrier points can improve the connectivity between ecological sources and lay the foundation for subsequent ecological space optimization.

[0086] Based on the above analysis and identification results, an ecological security pattern of grassland human settlement space is constructed.

[0087] In one embodiment of the present application, the grassland area refers to Xinghuang Banner, Xilin Gol League, Inner Mongolia Autonomous Region, my country.

[0088] In the second aspect, the present application provides the application of the method for constructing an ecological security pattern of grassland human settlement space described in the first aspect in constructing an ecological security pattern and identifying ecological space.

[0089] Beneficial effects of the present application: For the first time, the present application targets the characteristics of grassland human settlements, and based on the path of ecological security pattern "ecological source assessment-ecological resistance surface identification-ecological corridor identification" as the framework for constructing the ecological security pattern of grassland human settlements, uses ecological sensitivity evaluation and ecological service importance evaluation to conduct a dual evaluation system, superimposes extremely important areas as preliminary evaluation results of ecological sources, and uses morphological pattern analysis to screen out more accurate and comprehensive core block areas, and then further combines landscape connectivity evaluation to obtain identification results of ecological sources; at the same time, creatively corrects and identifies ecological resistance surfaces, thereby optimizing the identification results of ecological resistance surfaces, and obtaining resistance surface coefficients that are more suitable for grassland human settlements, and finally uses the ecological source identification results and ecological resistance surface identification results to identify ecological corridors, forming an ecological security pattern of grassland human settlements, and based on the above-mentioned ecological security pattern, analyzes its ecological sources, ecological corridors, and ecological key points, identifies ecological spaces, and provides practical guidance for the construction of high-quality urban and rural development of grassland human settlements (such as Xianghuang Banner). BRIEF DESCRIPTION OF THE DRAWINGS

[0090] Figure 1 A flow chart of the method for constructing the ecological security pattern of grassland human settlement space for this application;

[0091] Figure 2 This is the distribution map of the ecologically extremely sensitive areas in Xinghuang Banner;

[0092] Figure 3 This is the distribution map of the ecologically important areas in Xinghuang Banner;

[0093] Figure 4This is the result of the Morphological Spatial Pattern Analysis (MSPA) of Xinghuang Banner;

[0094] Figure 5 This is the distribution map of the important ecological sources of Xinghuang Banner;

[0095] Figure 6 This is the distribution map of comprehensive ecological resistance in Xinghuang Banner;

[0096] Figure 7 This is the identification map of the Xinghuang Banner ecological corridor;

[0097] Figure 8 This is the distribution map of ecological key points in Xinghuang Banner;

[0098] Fig. 9 This is the distribution map of ecological obstacles in Xinghuang Banner;

[0099] Fig.10 It is the ecological security pattern of Xinghuang Banner. DETAILED DESCRIPTION

[0100] Example 1

[0101] This embodiment uses grassland pastoral areas to develop a method for constructing an ecological security pattern of grassland human settlement space. The specific process is as follows: Figure 1 As shown, an empirical study was conducted on Xinghuang Banner to promote the sustainable development of urban and rural areas in Xinghuang Banner.

[0102] Xianghuang Banner is located in the west of central Inner Mongolia and south of Xilinhot City, spanning 113°22′~114°45′ east longitude and 41°56′~42°45′ north latitude. It is a town located in the Xilin Gol grassland. Xianghuang Banner is adjacent to Zhengxiangbai Banner and Zhenglan Banner in the east, and Sonid Left Banner, Sonid Right Banner and Abaga Banner in the north. It is connected by national highways such as G5516, G1013 and G5511, forming a group of pastoral banners and counties. The area of ​​Xianghuang Banner is 5137.26km 2 It has two towns (Xinbaolag Town, an administrative center with comprehensive services, and Bayintala Town, which is dominated by industry and mining); two sumus (Wenggongwula Sumu and Baogedayingaoler Sumu, which are dominated by animal husbandry); and 60 purely pastoral gachas.

[0103] For the relevant factors of each indicator, data sources and data processing methods in this embodiment, please refer to Table 3.

[0104] Table 3 Summary of data sources recommended for this application

[0105]

[0106] 1.1 Preliminary evaluation of ecological source areas

[0107] 1.1.1 Ecological sensitivity assessment

[0108] Based on the characteristics of Xinghuang Banner, two indicators, land desertification sensitivity and soil and water loss sensitivity, were selected. Factors such as precipitation erosion, terrain undulation, soil erodibility, vegetation coverage, number of days with sandstorms and soil dryness were used to evaluate the ecological sensitivity of Xinghuang Banner.

[0109] (1) Soil and water loss sensitivity: Formula (1-1) is used to evaluate the soil and water loss sensitivity of Xinghuang Banner:

[0110] T i =E i ·LS i ·C i ·K i (1-1)

[0111] Where: T i Representative i evaluates the regional soil erosion sensitivity index: E i LS i , C i , K i , respectively represent the level values ​​of the relevant indicators of precipitation erosivity index (Table 3-soil), slope index (Table 3-topography), soil erodibility coefficient (Table 3-soil), and vegetation cover index (Table 3-normalized vegetation index NDVI) of the evaluation area i;

[0112] The reclassification function of Arc GIS is used to divide the data into five levels, and the specific distribution is shown in Table 4 below.

[0113] Table 4 Soil and water loss sensitivity of Xinghuang Banner

[0114] Level Value importance <![CDATA[Area (km 2 )]]> Proportion 5 Extremely sensitive 312.8823 6.2％ 4 More sensitive 71.1108 1.4％ 3 sensitive 239.6043 4.7％ 2 Subsensitive 1066.3128 21.0％ 1 Insensitive 3388.1535 66.7％

[0115] (2) Assessment of land desertification sensitivity

[0116] Formula (1-2) was used to evaluate the desertification sensitivity of Xinghuang Banner land, and the land was divided into five levels using the Arc GIS reclassification function. The specific distribution is shown in Table 5.

[0117]

[0118] Where: D i Representative i evaluates the sensitivity index of regional land desertification: G i ,I i , W i , K i , respectively represent the grade values ​​of the related indicators of dryness index (Table 3-climate), number of days with sand-raising wind (Table 3-climate), soil texture (Table 3-soil), and vegetation cover index (Table 3-normalized difference vegetation index NDVI) of the evaluation area i;

[0119] Table 5: Sensitivity of land desertification in Xinghuang Banner

[0120]

[0121]

[0122] The analysis results show that the sensitive patches of land desertification in Xinghuang Banner present a distribution pattern of "high in the southwest and low in the northeast", and the patch connectivity is relatively high. The insensitive area accounts for the largest proportion of 34.2%, which is concentrated in Alabori Gacha and Chagannaoer Gacha in the northwest. The sensitive area is about 30.9% of the area of ​​Xinghuang Banner. The relatively sensitive area and sensitive area are interlaced around the extremely sensitive area. Most of the urban construction land is covered by these two types of areas. The remaining patches are concentrated in Xinsumo Gacha and Desigetu Gacha. The extremely sensitive area accounts for 13.4% of the area, with an area of ​​677.74km 2 It is distributed in Bogedayingaoler Sumu and the western part of Wenggongwula Sumu, Hadengsumo Gacha, Bogedayingaoler Gacha, Ulannur Gacha and other places. The main land type is grassland with a high average slope and great construction difficulty. The classified area also includes two polymetallic mines. During development and construction, attention should be paid to the prevention and control of land desertification, and monitoring and information management should be strengthened. Native grasses should be selected according to local conditions for planting, and prevention and control should be given equal importance.

[0123] (3) Superposition of ecological sensitivity assessment results

[0124] Combined with the above ecological sensitivity assessment results, according to the maximum value superposition calculation method of ecological sensitivity assessment results, ArcGIS GIS was used to obtain the comprehensive superposition assessment results, with a total area of ​​1177.27km 2 , accounting for 22.91%. The high ecological sensitivity area is mainly distributed in the southeast of Xinghuang Banner, contiguous to Hadensumo Gacha and Haoniqinhaxiatu Gacha of Bogeda Yingaoler Sumu; the central and northern parts are distributed in blocks, such as Xinsumo Gacha and Baorihujier Gacha; the southeast part is more fragmented, mainly Yintu Gacha, Gusigui Gacha and Kundulun Gacha, such as Figure 2 shown.

[0125] 1.1.2 Results of the evaluation of ecological service importance

[0126] (1) Importance of biological conservation: Refer to formula (1-3) to evaluate the importance of species diversity in Xianghuang Banner:

[0127] B i =NPP mean ·F pre ·F tem ·(1-F alt ) (1-3)

[0128] Where: NPP represents the annual average primary net productivity of the evaluation area i (Table 3 - Annual average primary net productivity NPP), F pre is the slope factor; Ftem is the average annual temperature (Table 3-Climate); F alt is the elevation (Table 3 - Topography).

[0129] The natural breakpoint method and reclassification function of Arc GIS were used to divide the land into five levels. The specific distribution is shown in Table 6.

[0130] Table 6: Importance of species diversity in Xinghuang Banner

[0131]

[0132] The analysis results show that the layout of the five important areas of species diversity importance in Xianghuang Banner is clear. The area of ​​the extremely important area is 643.03 km 2 , accounting for 12.61% of the total area of ​​Xianghuang Banner, and distributed in the northern end of Haoyierhudugacha, Aribaolaggacha, and Arishutgacha. The land here is mainly woodland and shrub woodland, with a good ecological base. A small part is the Achnatherum splendens meadow grassland located in the southeastern end of Haotinggaolegacha. The two areas of more important and important have a high degree of mixing and are distributed around the extremely sensitive area. The area of ​​more sensitive areas accounts for 6.75%. The sensitive area accounts for 25.38%. The unimportant area has a strong integrity and is mainly divided into four parts. It is located in the southwest and southeast of Baogedayinggaole Sumu and the south of Bayantala Town. It is also connected to Altanmaodugacha. These gachas have a large proportion of sandy land, a large population, and a high economic index. They can be targeted to restore and transform land and optimize the type of sumu industry.

[0133] (2) Importance of water conservation: Refer to formula (1-4) to evaluate the importance of water conservation in the study area of ​​Xianghuang Banner. Based on the classification standard of water conservation importance, the Arc GIS natural breakpoint method and reclassification function are used to divide it into five levels.

[0134] WR i =NPP mean ·F sic ·F pre ·F slo (1-4)

[0135] In the formula: WR i represents the water conservation importance index of the evaluation area i: NPP represents the annual average primary net productivity of the evaluation area i (Table 3 - Annual average primary net productivity NPP), F sic 、F pre 、F slo They represent the grade values ​​of the soil seepage factor (Table 3 - soil), slope (Table 3 - terrain), and aspect factor (Table 3 - terrain) related indicators of the evaluation area i.

[0136] The natural breakpoint method and reclassification function of Arc GIS were used to divide the land into five levels. The specific distribution is shown in Table 7.

[0137] Table 7 Importance of water conservation in Xinghuang Banner

[0138]

[0139]

[0140] According to the analysis results, the water conservation importance of Xinghuang Banner is distributed in a pattern of "high in the north and low in the south", and the overall importance of the east is higher than that of the west. Among them, the area of ​​extremely important water conservation areas is about 643km 2 , accounting for 20.47% of the total area, distributed in Arishut Gacha, Chagan Nur Gacha, and Aribaola Gacha of Wenggong Ula Sumu in the north. This includes the third water source of Xianghuang Banner, which is a concentrated area of ​​arbor and shrub forests. It is a planned desert tourism area. In the future, attention should be paid to water source protection and regular soil pollution testing in development and construction; the area of ​​relatively important water conservation accounts for the largest proportion of 36.35%, which is ring-shaped around the eastern part of Xianghuang Banner and is mixed with important areas and relatively important areas in Bayintala Town. It is greatly affected by the elevation, and the village types of Gacha are rich in the comprehensive evaluation results, and its ecological conservation function can be explored; the unimportant water conservation area is concentrated in Hannur Gacha and Yihe Ula Gacha of Bogeda Yingao Le Sumu in the southwest of Xianghuang Banner. These two Gachas have the largest proportion of cultivated land / village area in the whole banner and high integrity. These areas are semi-arid and require attention to the causes and trends of groundwater loss, as well as the short-term reduction in dry runoff caused by large-scale vegetation restoration measures.

[0141] (3) Importance of Soil and Water Conservation:

[0142] The importance of soil and water conservation in Xianghuang Banner of the study area was evaluated by referring to formula (1-5), and the natural breakpoint method and reclassification function of Arc GIS were used to divide it into five levels, as shown in Table 8.

[0143] A i =C i ·K i ·L i ·L si ·(1-E i ) (1-5)

[0144] Where: A i Representative i evaluates the importance index of regional soil and water conservation: K i 、E i , L i , C i , L siThey respectively represent the grade values ​​of the vegetation cover index (Table 3 - Normalized Difference Vegetation Index NDVI), precipitation erosion index (Table 3 - soil), slope length factor (Table 3 - topography), soil erodibility factor (Table 3 - soil), and slope factor (Table 3 - topography) related indicators of the evaluation area i.

[0145] Table 8 Importance of soil and water conservation in Xinghuang Banner

[0146]

[0147]

[0148] The analysis shows that the importance of soil and water conservation in Xianghuang Banner presents a spatial pattern of "high in the north and low in the south", which is similar to the results of water conservation importance, but the specific area proportions of each evaluation level are different. The unimportant area accounts for 16.29%, which is concentrated in Alaboriga Gacha and Chagannaoer Gacha in the northwest. The secondary important area has the largest area of ​​1721.13km 2 , accounting for 33.74% of the total area of ​​Xianghuang Banner. The unimportant areas are concentrated in the southern part of Xianghuang Banner, covering an area of ​​830.67 km 2 , accounting for 16.29%.

[0149] (4) Importance of windbreak and sand fixation: The importance of windbreak and sand fixation in Xianghuang Banner was evaluated with reference to formula (1-6). The natural breakpoint method and reclassification function of Arc GIS were used to divide it into five levels. The results are shown in Table 9.

[0150] S i =NPP mean ·C i ·F tem ·H i (1-6)

[0151] Where: S i represents the importance index of windbreak and sand fixation in the evaluation area i: NPP represents the annual average primary net productivity of the evaluation area i (Table 3 - Annual average primary net productivity NPP), C i 、F tem , H i They represent the grade values ​​of soil erodibility factor (Table 3-soil), average annual temperature factor (Table 3-climate), and surface roughness factor (Table 3-soil) of evaluation area i respectively.

[0152] Table 9 Importance of windbreak and sand fixation in Xinghuang Banner

[0153] Level Value importance Area (km2) Proportion 5 Extremely important 458.0523 9.03％ 4 More important 877.6917 17.30％ 3 important 608.2227 11.99％ 2 Secondary 2188.3041 43.13％ 1 unimportant 941.778 18.56％

[0154] According to the analysis results, the important patches of windbreak and sand fixation in Xinghuang Banner are distributed in the form of "high in the southwest and low in the northeast", and the graded patches are highly connected. The unimportant area accounts for 18.56%, which is concentrated in Alabori Gacha and Chagannur Gacha in the northwest. The important area is about 11.99% of the area of ​​Xinghuang Banner. The more sensitive areas and sensitive areas are interlaced around the extremely sensitive areas. Most of the urban construction land is covered by these two types of areas. The remaining patches are concentrated in Xinsumo Gacha and Desigetu Gacha. The most important areas for windbreak and sand fixation should be paid special attention to, accounting for 9.03% and covering an area of ​​458.05km 2 , distributed in Bogedayingaoler Sumu and the western part of Wenggongwula Sumu, Hadeng Sumogacha, Bogedayingaoler Gacha, and Ulannur Gacha. The main land type is grassland with a high average slope and great construction difficulty. The classified area also includes two polymetallic mines. During development and construction, attention should be paid to the prevention and control of land desertification, and monitoring and information management should be strengthened. For grasslands and shrub woodlands with signs of degradation, light nurturing, replanting and nurturing should be used to promote their rejuvenation; native grasses should be selected according to local conditions, and grass planting and prevention and control should be given equal importance.

[0155] Evaluation result superposition: Combined with the above ecological service importance evaluation results, the maximum value superposition method of comprehensive evaluation indicators in the "double evaluation" was adopted to obtain the comprehensive superposition evaluation results through Arc GIS software, with a total area of ​​1173.83km 2 , accounting for 22.84%. Figure 3 It can be seen that the main important patches are distributed in the northwest of Xinghuang Banner, and are connected to Aribolag Gacha, Haoyihudu Gacha and Arishut Gacha of Wenggongwula Sumu; this place is mainly ecologically important areas, among which Dabusengaoler Gacha is a Gacha with a high degree of grassland cultural inheritance. In the later stage, it can be considered to carry out industrial optimization design based on its extremely important ecological attributes.

[0156] 1.1.3 According to the evaluation results of comprehensive superposition of ecological sensitivity and ecological service importance, there are 7139 ecological source areas in total. They are mainly distributed in the north-west of Xianghuang Banner, and are contiguous to the north of Wenggongwula Sumu and Baogeda Yingaoer Sumu. Most of them are located north of Provincial Road 313; a small number are distributed in the south, and the patch area is small and the connectivity is low.

[0157] 1.2 Screening of important ecological sources

[0158] 1.2.1 Morphological spatial pattern analysis (MSPA): The various evaluation factors of ecological sensitivity evaluation and ecosystem service importance evaluation were calculated using equal weights, and then five levels of sensitive areas and five levels of important areas were divided respectively. Finally, the extremely sensitive ecological areas and extremely important ecological areas were superimposed to form the preliminary identification results of the ecological source. The extreme value superposition results were divided into 30m×30m grid units through Arc GIS software. Then, the preliminary identification results of the ecological source were set as the foreground value (1) and other areas as the background value (0) through MSPA analysis. The binary map was generated using Guidos Toolbox software, and the neighborhood values ​​were set to 1, 2, and 3 respectively. The distribution of the seven types of landscape patterns under different neighborhood values ​​was observed. It was found that when the neighborhood value was 2, the pores were more moderate and the patches of the ecological source were more closely linked. Then, the core area and the bridge area when the domain value was 2 were extracted, and the "ecological core area (Core)" with higher ecological value was used as the ecological source. The results are as follows: Figure 4 shown.

[0159] 1.2.2 Landscape connectivity evaluation: The overall connectivity index (IIC) was calculated using Conefor2.6 software and formula (1-7); the possible connectivity index (PC) was calculated using formula (1-8).

[0160]

[0161] In the formula, n represents the total number of patches in the study area, a represents the size of the patch; nl ij represents the number of shortest path connections between patch i and patch j; A L Represents a landscape attribute value.

[0162]

[0163] In the formula, n and a represent the same as formula (1-7); p ij * represents the maximum possibility of the biological circulation path between patch i and patch j; A L Represents the landscape attribute value, and obtains the landscape connectivity evaluation result of the ecological source area.

[0164] Based on the above evaluation results, patches with larger indices such as possible connectivity, intra-patch connectivity, irreplaceability and overall connectivity were selected, and 30 ecological source patches were obtained as the final identification results. They were divided into three levels according to the coreness of the ecological source patches (such as Figure 5 shown).

[0165] 2. Identification of ecological resistance surface

[0166] 2.1 Basic ecological resistance surface: The resistance surface reflects the spatial distribution characteristics of resistance in different ecological processes and characterizes the impact of landscape heterogeneity on ecological flow. This application assigns resistance values ​​to different land use types in the region to form a basic ecological resistance surface index. The classification of resistance factors and index weights are shown in Table 10. References (Gong Jiali et al., Identification and classification of ecological restoration areas in the national space of Wuhan urban circle from the perspective of ecological security pattern and ecological vulnerability. Geographical Science, 1-9 [2024-10-21], Feng Yanwei et al., Optimization of national space protection and restoration based on ecological security pattern - A case study of Hubao-Ezhou region in Inner Mongolia [J]. Journal of Natural Resources, 2022, 37(11): 2915-2929, Fang Ying et al., Diagnosis and identification of key areas of national space ecological protection and restoration based on ecological security pattern - A case study of Yantai City [J]. Journal of Natural Resources, 2020, 35(01): 190-203).

[0167] Table 10 Basic ecological resistance surface of Xinghuang Banner

[0168]

[0169]

[0170] 2.2 Correction of the ecological resistance surface of grassland human settlement space: Since the resistance index, resistance level and weight are determined by referring to relevant papers and expert scores, they are highly subjective and therefore need to be appropriately corrected to reduce subjective factors.

[0171] As the key to accurately identify ecological corridors, constructing an ecological resistance surface to simulate the difficulty of the flow and transmission of ecological elements is crucial for the construction of an ecological security pattern. In order to weaken the impact of subjective assignment, this study selected two factors with greater influence, namely, the grazing intensity of herders and the intensity of residents' activities, based on the characteristics that grasslands in grassland human settlement space have ecological functions and will have a negative impact on the ecology, as well as the contradictory characteristics of residents' activities and sensitive ecological environmental protection, to characterize human interference in the flow and transmission of ecological elements, and to correct the ecological comprehensive resistance surface. The modified resistance index is then superimposed on the basic resistance index to obtain an ecological resistance surface suitable for grassland pastoral areas, which is calculated using formula (1-9).

[0172]

[0173]

[0174]

[0175]

[0176]

[0177] Where: HGS i 、HAS i Respectively represent the grazing intensity value and the resident activity intensity value, R HGSi represents the normalized grazing intensity index, R HASi represents the normalized resident activity intensity index, R i represents the modified ecological resistance index, R o It is the basic ecological resistance index.

[0178] D i is the animal husbandry production density value in region i; M i is the probability deviation of livestock production in region i, k is the number of livestock species (Table 3 - Livestock), r a , L a are the conversion coefficient of the standard unit of a type of livestock, the number of livestock (Table 3-Livestock), S g is the unit grassland area (Table 3-Land Use); u is the livestock production utilization rate of grassland, which is 0.45 (refer to the Guiding Opinions on Determining the Suitable Carrying Capacity of Grassland in Xilin Gol League [S]. (Xishubanfa

[2021] No. 15)); t is the number of factors affecting the probability of livestock production; v ic is the value of the factor influencing grazing intensity in area i (factor level = factor value).

[0179] S CLE is the equivalent area of ​​construction land; SL i is the area of ​​the i-th land use / cover type (Table 3-Land Use); CL i is the conversion coefficient of residents’ activity intensity for the i-th type of land.

[0180] Among them, the calculation of factors affecting grazing intensity is shown in Table 1 above; the construction land equivalent conversion coefficients of various land use / cover types are shown in Table 2 above, and the data sources and processing methods of relevant factors are shown in Table 3 above.

[0181] According to the analysis (such as Figure 6 ), with the overall distribution pattern showing low in the central and northern parts and high in the southern parts. The areas with high comprehensive resistance values ​​are mainly Xinbaolag Town, Elesutai Gacha, Chaganderisu Gacha, and Zabilahu Gacha.

[0182] 3. Ecological corridor evaluation

[0183] 3.1 Identification of ecological corridors

[0184] With the help of the circuit theory model, the ecological corridors are identified through the ecological source and ecological resistance surface. The ecological corridor is an important channel for biological information and species exchange, and is an area with a higher value of bioelectric current in the simulation results. The main organisms in the grassland pastoral area are small and medium-sized mammals such as cattle, sheep, and hares, and the activity range is set to 2km. 74 ecological corridors with a total length of 60.691km and 7 potential ecological corridors with a total length of 15.74km were extracted, which are mainly distributed in the central and northern parts of Xianghuang Banner. Due to the large number of ecological sources in Hana Ula Gacha and the strong connectivity between patches, there are relatively many ecological corridors. The shortest ecological corridor is located in the northern ecological source, in Aribaolag Gacha. The longest ecological corridor is located in the south, with a length of 4.64km, connecting Hadeng Sumo Gacha-Baoridabusu Gacha-Hashatu Gacha. Potential ecological corridors are mainly located in the southeast of Xianghuang Banner, and stepping stones can be added to improve circulation capacity (such as Figure 7 shown).

[0185] 3.2 Identification of ecological key points

[0186] Using the Linkage Mapper tool in Arc GIS and the circuit theory model, the ecological corridors were identified through the ecological source and ecological resistance surface. 30km, 20km, and 15km were selected as the corridor cost weighted distances, and after field investigation, 20km was finally set as the final result (such as Figure 8 A total of 17 ecological key points were screened, and many important pinch points were distributed in groups, mainly in Jiribanhudugacha and Hadenghushugacha in Bayantala Town, and Yihederishugacha and Yihewulagacha in Wenggongwula Sumu. Most of the ecological key points are located at the junction of the ecological corridor and the ecological source. The land use types include grassland and natural reserve. The optimization strategy can be targeted at the main land types of the ecological key points.

[0187] 3.3 Identification of ecological obstacles

[0188] The Pinchpoint Mapper tool in Arc GIS was used to calculate the current resistance value of the Xianghuang Banner ecological corridor. The larger the value, the greater the obstruction to the flow of species, information and energy in the ecological corridor. 24 ecological corridor obstacle points were selected based on the calculated values, and then combined with high-definition satellite images and analysis of the survey results (such as Fig. 9 Most of the ecological barrier points are located in Bayintala Town, where grassland is the main land type. Some are also located in Yarigai Gacha around Xinbaolag Town, the seat of the Xianghuang Banner government, as well as Aoenqige Gacha and Sujiyingal Gacha in the southeast, and Hadenhushu Gacha and Yintu Gacha in the east.

[0189] In summary, based on the method for constructing the ecological security pattern of grassland human settlement space in this application, the ecological security pattern construction results of Xinghuang Banner are obtained (such as Fig.10It includes 30 ecological source areas with a total area of ​​918.21km 2 : accounting for 16.11%, among which the source area of ​​the forest and shrub forest concentrated area in the northeast of Aribaolaggacha, Xianghuang Banner has the largest area and the largest proportion, playing an important ecological function. Based on the comprehensive evaluation results of ecological source and ecological resistance surface, the minimum cumulative resistance path was obtained through the circuit theory model, and a total of 74 ecological corridors in Xianghuang Banner were identified, with a total length of 606.9km. On the whole, it showed a pattern of dense in the north and sparse in the south, more in the east and less in the west. The main trend can be abstracted as two horizontal and four vertical; 7 potential ecological corridors, with a total length of 157.4km, are concentrated at the southeastern border of Xianghuang. Ecological key points play a key role in ecological corridors. A total of 18 ecological key points were identified, mainly distributed at the intersection of ecological corridors and ecological sources, dense in the southeast and sparse in the northwest, and targeted protection can be strengthened in the later stage; ecological barrier points affect the overall ecological connectivity of the region and are key spatial elements that urgently need to be repaired first. A total of 20 ecological barrier points were identified, distributed in clusters in the southeast of Xianghuang Banner. Taking the ecological source and the ecological corridor as the ecological space, and setting the width of the ecological corridor to 100m, the total ecological space area is 978.90km 2 , accounting for 19.1% of the total area of ​​Xianghuang Banner. It is conducive to the subsequent exploration of ecological space optimization ideas suitable for the characteristics of grassland pastoral areas, the classification and zoning of ecological sources, the classification and dredging of ecological corridors, the coordinated development of ecological space and towns, and the targeted ecological space optimization strategies.

[0190] The above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solution of the present application rather than to limit it. The protection scope of the present application is not limited thereto, and the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for constructing an ecological security pattern of grassland human settlement space, characterized in that: include: 1) Identify ecological sources, including preliminary identification and screening of ecological sources; 2) Based on the production and living characteristics of grassland pastoral areas, preliminary identification and correction of ecological resistance surfaces were carried out; 3) Combining the results of ecological source screening with the results of ecological resistance surface identification, the circuit theory model was used to simulate and identify ecological corridors, ecological key points and ecological barrier points, and an ecological security pattern was constructed as the result of ecological space identification; The preliminary identification of ecological sources includes the evaluation of ecological sensitivity and ecological service importance; The ecological source screening adopts morphological spatial pattern (MSPA) evaluation and landscape connectivity evaluation for further screening as the final quantitative evaluation result of the ecological source.

2. The construction method according to claim 1, characterized in that: 1) Identify ecological sources, including the following steps: 1.1 Preliminary evaluation of ecological source areas: preliminary evaluation based on ecological sensitivity and ecological service importance: 1.1.1 Ecological sensitivity assessment and analysis, including two assessment dimensions: soil erosion sensitivity and land desertification sensitivity; 1.1.2 Evaluation of the importance of ecological services: including the importance of biological maintenance, water conservation, soil and water conservation, and windbreak and sand fixation; 1.1.3 Superimpose the ecological sensitivity and ecosystem service importance assessment results to obtain preliminary identification results of ecological sources; 1.2 Screening of important ecological sources: 1.2.1 Use the morphological spatial pattern (MSPA) evaluation to screen out the core area blocks; 1.2.2 Landscape connectivity evaluation: Screen patches with overall connectivity index (IIC)>1 and possible connectivity index (PC)>1 as the final ecological source.

3. The construction method according to claim 2, characterized in that: 2) Identification of ecological resistance surface includes assigning resistance index according to land cover type to obtain basic ecological resistance surface, and then modifying the basic resistance surface by evaluating herdsmen’s grazing and residents’ activities.

4. The construction method according to claim 3, characterized in that: 3) Ecological corridor evaluation includes: ecological corridor identification, ecological key point identification and ecological barrier point identification.

5. The construction method according to claim 2, characterized in that: In step 1.1.1, the soil erosion sensitivity is calculated using formula (1-1): T i =E i ·LS i ·C i ·K i (1-1) Where: T i Representative i evaluates the regional soil erosion sensitivity index: E i LS i , C i , K i , respectively represent the level values ​​of the precipitation erosivity index, slope index, soil erodibility coefficient, and vegetation coverage index of the evaluation area i; The land desertification sensitivity is calculated using formula (1-2): Where: D i Representative i evaluates the sensitivity index of regional land desertification: G i ,I i , W i , K i , respectively represent the level values ​​of the dryness index, number of days with sand-raising winds, soil texture, and vegetation coverage index related indicators of the evaluation area i; Superposition of ecological sensitivity assessment results: Superimpose the maximum values ​​of the assessment results of soil and water loss sensitivity and land desertification sensitivity to obtain the ecological sensitivity assessment results.

6. The construction method according to claim 2, characterized in that: In step 1.1.2, the biological maintenance importance is calculated using formula (1-3): B i =NPP mean ·F pre ·F tem ·(1-F alt ) (1-3) Where: B i Represents the importance index of regional biodiversity conservation in evaluation area i: NPP represents the annual average primary net productivity of evaluation area i, F pre is the slope factor; F tem is the average annual temperature; F alt is the elevation; The importance of water conservation is calculated using formula (1-4): WR i =NPP mean ·F sic ·F pre .F slo (1-4) In the formula: WR i Represents the water conservation importance index of the evaluation area i: NPP represents the annual average primary net productivity of the evaluation area i, F sic 、F pre 、F slo They represent the grade values ​​of the soil seepage factor, slope, and aspect factor related indicators of the evaluation area i respectively; The importance of soil and water conservation is calculated using formula (1-5): A i =C i ·K i ·L i ·L si ·(1-E i ) (1-5) Where: A i Representative i evaluates the importance index of regional soil and water conservation: K i 、E i , L i , C i , L si They represent the grade values ​​of the vegetation coverage index, precipitation erosion index, slope length factor, soil erodibility factor, and slope factor related indicators of the evaluation area i respectively; The importance of windbreak and sand fixation is calculated using formula (1-6): S i =NPP mean ·C i ·F tem ·H i (1-6) Where: S i represents the importance index of windbreak and sand fixation in the evaluation area i: NPP represents the annual average primary net productivity of the evaluation area i, C i 、F tem , H i They represent the grade values ​​of soil erodibility factor, annual average temperature factor and surface roughness factor of evaluation area i respectively.

7. The construction method according to claim 2, characterized in that: In step 1.2.1, the various evaluation factors of ecological sensitivity assessment and ecosystem service importance assessment were calculated using equal weights, and then five levels of sensitive areas and five levels of importance areas were divided respectively. Finally, the extremely sensitive ecological areas and the extremely important ecological areas were superimposed to form the preliminary identification results of the ecological source area, and the core area blocks were screened out; In step 1.2.2, the overall connectivity index (IIC) is calculated using formula (1-7): In the formula, n represents the total number of patches in the study area, and parameter a represents the patch area; nl ij represents the number of shortest path connections between patch i and patch j; A L represents the landscape attribute value; The possible connectivity index (PC) is calculated using formula (1-8): In the above formula, n represents the total number of patches in the study area, parameter a represents the patch area; p ij * represents the maximum possibility of the biological circulation path between patch i and patch j; A L Represents a landscape attribute value.

8. The construction method according to claim 2, characterized in that: Step 2) Identification of ecological resistance surface includes the following steps: 2.1 Determine the basic ecological resistance index R o : Assign resistance values ​​to different land use types in the region, form a basic ecological resistance surface, and make resistance value evaluation; 2.2 Correction of ecological resistance surface of grassland human settlement space: Two influencing factors, namely, grazing intensity of herders and activity intensity of residents, were selected and calculated using formula (1-9). The corrected ecological resistance index was superimposed on the basic ecological resistance index to obtain the ecological resistance surface suitable for grassland pastoral areas: Where: HGS i 、HAS i Respectively represent the grazing intensity value and the resident activity intensity value, R HGSi represents the normalized grazing intensity index, R HASi represents the normalized resident activity intensity index, R i represents the modified ecological resistance index, R o is the basic ecological resistance index; D i is the animal husbandry production density value in region i; M i is the probability deviation of animal husbandry production in region i, k is the number of livestock species, r a , L a are the conversion coefficient of the standard unit of a type of livestock, the number of livestock, S g is the unit grassland area; u is the livestock production utilization rate of grassland, which is 0.45; t is the number of factors affecting the probability of livestock production; v ic is the value of the factor affecting grazing intensity in area i; S CLE is the equivalent area of ​​construction land; SL i is the area of ​​the i-th land use / cover type: CL i is the conversion coefficient of residents' activity intensity of the i-th type of land; The number of factors affecting the probability of animal husbandry production includes pasture resources, herders’ grazing area selection intentions, and herders’ grazing conditions and convenience; The conversion coefficient of residents' activity intensity of the land is determined by the land use / cover type.

9. The construction method according to claim 4, characterized in that: Step 3) includes: 3.1 Identification of ecological corridors: Use the Linkage Mapper tool in Arc GIS to identify ecological corridors, and use circuit theory to simulate the random walk paths of biological individuals in space and the probability of population diffusion; 3.2 Identification of ecological key points: Pinchpoint Mapper tool in Arc GIS was used to identify ecological key points. Based on circuit theory, resistance value was used to represent the resistance of species migration and diffusion process, and current and voltage values ​​were used to represent the degree of connectivity between ecological sources. 3.3 Identification of ecological barriers: Use the Barrier Mapper tool in Linkage Mapper in Arc GIS to identify ecological barriers.

10. Application of the method for constructing an ecological security pattern of grassland human settlement space according to any one of claims 1 to 9 in constructing an ecological security pattern and identifying ecological space.

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