Method and system for evaluating accessibility of service facilities in urban and rural community life circle

Abstract

The application discloses a method and system for evaluating the accessibility of service facilities in urban and rural community life circles. First, high-precision road networks, residential plots, four types of public service facilities, and population statistics data are obtained. A walking travel impedance map containing traffic obstacles is constructed based on the road network. The single accessibility index is calculated using an improved two-step mobile search method. The facility weight is determined by the analytic hierarchy process, and the comprehensive accessibility index is obtained. The accessibility is spatially superimposed with population density and aging degree to identify the short-board area of facility configuration. The comprehensive accessibility, population size, and aging degree are used to calculate the rectification priority, and a hierarchical rectification priority map is generated. The application fully considers the walking traffic obstacles, facility service capacity, and distance attenuation, and quantitatively evaluates the actual situation. The short board can be accurately identified, and the rectification priority is given. The application provides efficient and reliable data support and intelligent decision-making basis for the layout optimization of public service facilities in urban and rural community life circles.

Description

Technical Field

[0001] This invention relates to the field of urban and rural planning and geographic information system technology, specifically to a method, system and storage medium for assessing the accessibility of service facilities in urban and rural community living circles. Background Technology

[0002] With the continuous advancement of the construction of urban and rural community living circles in my country, the balanced allocation and efficient accessibility of basic public service facilities such as education, medical care, elderly care, culture and sports have become core aspects of improving residents' quality of life and ensuring the equalization of basic public services.

[0003] Existing methods for assessing accessibility to public service facilities generally suffer from the following technical deficiencies: 1) The calculation of walking travel costs is too simplified, only calculating the impedance based on straight-line distance or constant walking speed, without taking into account actual obstacles such as road slope, road surface conditions, and traffic restrictions, resulting in a significant deviation between walking impedance and the actual travel experience; 2) The traditional two-step moving search method does not fully couple facility service capacity constraints and distance attenuation effects, making it difficult to objectively reflect the supply and demand matching relationship of facilities, and the evaluation results tend to be idealized; 3) The weighting of the comprehensive accessibility of various types of facilities relies heavily on subjective experience and lacks a hierarchical and verifiable scientific quantitative method; 4) Accessibility assessments only focus on spatial distribution and do not incorporate key socioeconomic attributes such as population density and aging levels for overlay analysis. This makes it difficult to accurately identify areas with high-pressure, high-demand infrastructure deficiencies and to formulate feasible tiered rectification priorities.

[0004] The aforementioned problems make it difficult for existing assessment methods to meet the actual needs of refined planning and dynamic optimization of urban and rural community living circles. There is an urgent need for a service facility accessibility assessment technology that is more in line with real walking scenarios and takes into account the balance of supply and demand and comprehensive analysis of multiple factors. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention discloses a method and system for assessing the accessibility of service facilities in urban and rural community living circles, in order to solve the problems mentioned in the background.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for assessing the accessibility of service facilities in urban and rural community living circles, comprising the following steps: S1. Obtain high-precision road network data, residential plot vector data, spatial location and service capacity data of four types of basic public service facilities (education, medical care, elderly care, culture and sports) within the study area, as well as demographic data including population size, population density and aging degree. S2. Construct a pedestrian travel impedance map that considers road traffic obstacles based on high-precision road network data. The pedestrian travel impedance map has road network nodes as vertices and road segment walking time as edge weights. S3. Using an improved two-step moving search method, and considering the service capacity constraints of various public service facilities, calculate the individual accessibility index of each residential plot to four types of basic public service facilities: education, medical care, elderly care, and culture and sports. S4. Based on the analytic hierarchy process, determine the weight coefficients of the four types of basic public service facilities, and calculate the comprehensive accessibility index of each residential plot using weighted average. S5. Spatial overlay analysis of the spatial distribution of the comprehensive accessibility index with population density data and aging data is performed to identify spatially deficient areas with serious inadequate infrastructure. S6. Based on the comprehensive accessibility index, population size, and aging degree of the spatially deficient areas, calculate the rectification priority index for each area and generate a hierarchical rectification priority map.

[0007] Preferably, the high-precision road network data includes information on road segment type, slope, road surface condition, and traffic restrictions. The specific method for constructing the pedestrian travel impedance map in step S2 includes: S21: Preprocess the high-precision road network data, extract pedestrian-accessible road sections, and remove dedicated motor vehicle lanes, expressways, and other road sections where pedestrian access is prohibited; S22: Determine the walking speed correction factor for each road segment based on the road segment type, slope, and road surface conditions. Calculate the walking time for each road segment using the following formula, based on the actual length of the road segment, the standard walking speed, and the walking speed correction factor for that road segment: , In the formula, Let be the walking time for road segment ij. Let be the actual length of road segment ij. For standard walking speed, This is the walking speed correction factor for road segment ij; S23: Use Dijkstra's algorithm to calculate the shortest walking path and shortest walking time between any two road network nodes, and construct a walking travel impedance graph with road network nodes as vertices and shortest walking time as edge weights.

[0008] Preferably, the first step of the improved two-step move search method in step S3 specifically includes: S31: For each public service facility point j, with facility point j as the center, search the pedestrian travel impedance map for walking times less than or equal to a preset threshold. All residential plots i; S32: Calculate the weighted sum of the population of all residential plots within the service area of ​​facility point j, as the potential service population of facility point j; S33: Calculate the supply-demand ratio of facility point j based on its service capacity and potential service population; the formula for calculating the supply-demand ratio of facility point j is: , In the formula, Let the supply and demand ratio be that of facility point j. For the service capacity of facility point j, For the set of residential plots within the service area of ​​facility point j, Let i be the population of residential plot i. The shortest walking time from residential plot i to facility point j. This is a distance decay function used to characterize the decaying effect of walking time on residents' willingness to use facilities.

[0009] Preferably, the distance decay function adopts a Gaussian decay function, specifically in the form of: , In the formula, The maximum walking time threshold is set. When the walking time from the residential area to the facility exceeds this threshold, the residential area is considered to be outside the effective service range of the facility, and the distance decay function value is 0. When the walking time is less than or equal to this threshold, the distance decay function value decreases non-linearly with the increase of walking time.

[0010] Preferably, the second step of the improved two-step move search method in step S3 specifically includes: S34: For each residential plot i, with residential plot i as the center, search the walking impedance map for a walking time less than or equal to a preset threshold. All public service facilities points j; S35: Multiply the supply-demand ratios of all searched facility points j by the corresponding distance decay function values ​​and sum them to obtain the single accessibility index of residential plot i for this type of public service facility; wherein, the formula for calculating the single accessibility index of residential plot i for a certain type of public service facility is: , In the formula, Let be the accessibility index of residential plot i to the k-th type of public service facility. Let i be the set of public service facilities of type k within walking distance of residential plot i. Let be the supply-demand ratio of facility point j in the k-th type of public service facility.

[0011] Preferably, the specific method for determining the weight coefficients of the four types of basic public service facilities based on the analytic hierarchy process in step S4 includes: S41: Construct a hierarchical analysis model, taking comprehensive accessibility as the target layer and four types of facilities—education, healthcare, elderly care, and culture and sports—as the criteria layer. S42: Construct pairwise comparison judgment matrices to quantitatively evaluate the relative importance of the four types of facilities; S43: Calculate the largest eigenvalue and the corresponding eigenvector of the judgment matrix, normalize the eigenvector, and obtain the weight coefficients of the four types of facilities. S44: Perform a consistency check on the judgment matrix. If the consistency ratio is less than a preset threshold, accept the calculated weight coefficients; otherwise, reconstruct the judgment matrix. S45: Based on the calculated weight coefficients of the four types of basic public service facilities, the individual accessibility indices of each residential plot to the four types of facilities are weighted and summed to obtain the comprehensive accessibility index of each residential plot. The specific formula for calculating the comprehensive accessibility index is as follows: , In the formula, The comprehensive accessibility index for residential plot i. Let be the weight coefficient of the k-th type of public service facility, and satisfy . =1.

[0012] Preferably, the specific method for spatial overlay analysis in step S5 includes: S51: Spatial rasterization is performed on the comprehensive accessibility index, population density and aging degree respectively to obtain three raster layers with the same resolution. S52: Spatial overlay operation is used to multiply the three raster layers pixel by pixel to obtain the facility supply and demand pressure index raster layer; the calculation formula for the facility supply and demand pressure index of each raster cell is as follows: , In the formula, The facility supply and demand pressure index for grid cell x. The comprehensive reachability index of raster cell x. The population density of grid cell x. The degree of aging of grid cell x; the facility supply and demand pressure index is negatively correlated with the comprehensive accessibility index, and positively correlated with population density and degree of aging; S53: The natural discontinuity grading method is used to divide the facility supply and demand pressure index into multiple levels, and areas where the facility supply and demand pressure index is higher than the preset threshold are identified as spatial bottleneck areas with serious deficiencies in facility configuration.

[0013] Preferably, the specific method for calculating the rectification priority index in step S6 includes: S61: Standardize the comprehensive accessibility index, population size and aging degree of each spatially disadvantaged area to eliminate the influence of dimensions; S62: Based on the preset weighting coefficients for comprehensive accessibility, population size, and aging degree, the three standardized indicators are weighted and summed to obtain the rectification priority index for each spatially deficient area; the calculation formula for the rectification priority index is as follows: , In the formula, This represents the priority index for rectification of the m-th spatial bottleneck area. Let m be the standardized comprehensive accessibility index for the m-th spatial bottleneck region. Let m be the standardized population size of the m-th spatial bottleneck region. The standardized aging degree of the m-th spatial bottleneck region. These are the weighting coefficients for comprehensive accessibility, population size, and aging degree, respectively, and they satisfy the following conditions: =1; S63: The rectification priority index is divided into three levels—high, medium, and low—using the natural discontinuity grading method, and a graded rectification priority map is generated.

[0014] This invention also provides a system for assessing the accessibility of service facilities in urban and rural community living circles, comprising: The data acquisition module is used to acquire high-precision road network data, residential plot data, public service facility data, and population statistics within the study area; A pedestrian impedance map construction module, connected to the data acquisition module, is used to construct a pedestrian travel impedance map that considers road traffic obstacles based on high-precision road network data. The pedestrian travel impedance map has road network nodes as vertices and road segment walking time as edge weights. The single accessibility calculation module, connected to the walking impedance map construction module and the data acquisition module, is used to calculate the single accessibility index of each residential plot to four types of basic public service facilities (education, medical care, elderly care, and culture and sports) under the condition of considering the service capacity constraints of various public service facilities, using an improved two-step movement search method. The comprehensive accessibility calculation module, connected to the individual accessibility calculation module, is used to determine the weight coefficients of the four types of basic public service facilities based on the analytic hierarchy process, and to calculate the comprehensive accessibility index of each residential plot using weighted average. The spatial overlay analysis module, connected to the comprehensive accessibility calculation module and the data acquisition module, is used to perform spatial overlay analysis on the spatial distribution of the comprehensive accessibility index with population density data and aging degree data to identify spatially deficient areas with serious inadequate facility configuration. The rectification priority generation module is connected to the spatial overlay analysis module. It is used to calculate the rectification priority index of each shortcoming area based on the comprehensive accessibility index, population size and aging degree of the spatial shortcoming area, and generate a hierarchical rectification priority map. The output module, connected to the rectification priority generation module, is used to output a graded rectification priority map and related evaluation results.

[0015] The present invention also provides a storage medium storing a computer program, which, when executed by a processor, implements a method for assessing the accessibility of service facilities in urban and rural community living circles.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention improves the accuracy of pedestrian impedance calculation and enhances the objectivity of assessment. By introducing real-world obstacles such as road segment type, slope, and road surface conditions to construct a pedestrian travel impedance map, it replaces the traditional straight-line distance or constant speed estimation method, making the cost of walking travel more realistic and significantly improving the accuracy and reliability of accessibility assessment results.

[0017] 2. This invention realizes quantitative analysis of supply and demand matching, enhancing the scientific nature of the assessment; by adopting an improved two-step moving search method, combined with facility service capacity and Gaussian distance decay, it accurately calculates the facility supply-demand ratio and individual accessibility; and by using the analytic hierarchy process to achieve scientific quantification of weights and consistency verification, it avoids subjective assignment bias.

[0018] 3. This invention quantifies the supply and demand pressure of facilities by spatially superimposing comprehensive accessibility with population density and aging degree, and automatically generates a rectification priority map, providing directly implementable data basis and decision support for optimizing the layout of urban and rural public service facilities. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0020] In the attached diagram: Figure 1 This is a flowchart of a method for assessing the accessibility of service facilities in urban and rural community living circles according to the present invention; Figure 2 This is a simplified structural diagram of an urban and rural community living circle service facility accessibility assessment system according to the present invention. Detailed Implementation

[0021] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0022] like Figure 1 As shown, this embodiment provides a method for assessing the accessibility of service facilities in urban and rural community living circles, including the following steps: S1. Data acquisition steps: Acquire high-precision road network data, residential plot vector data, spatial location and service capacity data of four types of basic public service facilities (education, medical care, elderly care, culture and sports) within the study area, as well as demographic data including population size, population density and aging degree. S2. Steps for constructing a pedestrian impedance map: Based on high-precision road network data, a pedestrian travel impedance map considering road traffic obstacles is constructed. The pedestrian travel impedance map uses road network nodes as vertices and the walking time of road segments as edge weights. S3. Steps for calculating individual accessibility: Using an improved two-step move search method, and considering the service capacity constraints of various public service facilities, calculate the individual accessibility index of each residential plot to four types of basic public service facilities: education, medical care, elderly care, and culture and sports. S4. Comprehensive Accessibility Calculation Steps: Determine the weight coefficients of the four types of basic public service facilities based on the analytic hierarchy process, and calculate the comprehensive accessibility index of each residential plot using weighted averages. S5. Spatial Shortcoming Identification Steps: Spatial overlay analysis of the spatial distribution of the comprehensive accessibility index with population density data and aging data is performed to identify spatial shortcoming areas with serious inadequate facility configuration. S6. Steps for generating rectification priorities: Based on the comprehensive accessibility index, population size and aging degree of the spatially deficient areas, calculate the rectification priority index of each area and generate a hierarchical rectification priority map.

[0023] The specific implementation steps include: S1: Data Acquisition Steps: In this step, the specific methods and content for acquiring various types of data are as follows: High-precision road network data: It is preferred to use 1:5000 scale road network data provided by OpenStreetMap (OSM) or local surveying departments. The data should include attribute information such as road segment ID, road segment length, road segment type (pedestrian walkway, non-motorized vehicle lane, mixed lane, etc.), slope, road surface condition (good, fair, poor), and traffic restrictions (whether walking is allowed, whether there are steps, etc.).

[0024] Residential land parcel vector data: Obtain the latest land use status map from the local natural resources department, extract residential land parcels, and each parcel should include attribute information such as parcel ID, parcel area, and building volume ratio.

[0025] Public service facility data: obtained through a combination of on-site surveys, publicly available government data, and POI data, including: 1) Educational facilities: kindergartens, primary schools, and secondary schools; service capacity is expressed in terms of the number of classes or student places. 2) Medical facilities: community health service centers and community health service stations, with service capacity expressed in terms of the number of beds or the number of outpatients per day; 3) Elderly care facilities: nursing homes and day care centers; service capacity is expressed in terms of the number of beds. 4) Cultural and sports facilities: cultural stations, libraries, sports venues, and fitness plazas. Service capacity is expressed in terms of building area or the number of people that can be accommodated at the same time.

[0026] Population statistics: Obtain data from the Seventh National Population Census or the latest population sampling survey from the local statistics department, including the population size, population density (people / square kilometer), and aging degree (percentage of the population aged 60 and above) of each residential area.

[0027] S2: Steps for constructing an impedance map for pedestrian travel This step involves constructing a pedestrian travel impedance map that considers road access barriers based on high-precision road network data. Specifically, it includes the following sub-steps: S21: Road network data preprocessing, which involves cleaning and preprocessing the acquired high-precision road network data. Specific operations include: 1) Remove sections of road where pedestrian access is prohibited, such as dedicated motor vehicle lanes, highways, and railways; 2) Repair road network topology errors, such as hanging nodes, duplicate road segments, and road segment breaks; 3) Merge adjacent road segments with the same attributes to simplify the road network structure.

[0028] S22: Calculation of walking time for road segments. The walking speed correction coefficient for each road segment is determined based on the road segment type, slope and road surface conditions, and then the walking time for each road segment is calculated.

[0029] The standard walking speed v0 is preferably set to 1.2 m / s (i.e. 4.32 km / h), which is consistent with the average walking speed of a healthy adult on a flat and good surface.

[0030] Walking speed correction factor The method for determining it is as follows: 1) Road segment type correction factor: 1.0 for pedestrian walkways, 0.9 for mixed lanes, and 0.7 for road segments with steps; 2) Slope correction factor: 1.0 for slope ≤ 5%, 0.8 for 5% < slope ≤ 10%, 0.6 for 10% < slope ≤ 15%, and 0.4 for slope > 15%; 3) Road surface condition correction factor: 1.0 for good, 0.8 for average, and 0.6 for poor.

[0031] The overall walking speed correction factor for road segment ij is the product of the three correction factors mentioned above, that is: , Then, the walking time for road segment ij is calculated using the following formula: , In the formula, The walking time (in seconds) for road segment ij. This represents the actual length of road segment ij (in meters).

[0032] S23: Shortest Path Calculation and Impedance Map Construction Dijkstra's algorithm is used to calculate the shortest walking path and shortest walking time between any two road network nodes. Specifically, the networkx library in Python or the network analysis module in ArcGIS can be used for implementation. A directed weighted graph, i.e., a walking impedance graph, is constructed with road network nodes as vertices and shortest walking time as edge weights. This graph accurately reflects the actual walking cost between any two points within the study area.

[0033] S3: Steps for calculating the single accessibility index This step employs an improved two-step move-search method to calculate the individual accessibility index of each residential plot to four types of basic public service facilities, specifically including the following two steps: Step 1: Calculate the supply-demand ratio of the facility sites S31: For each public service facility point j, with facility point j as the center, search the pedestrian travel impedance map for walking times less than or equal to a preset threshold. All residential plots i.

[0034] Maximum walking time threshold The optimal values ​​should be set according to the service radius requirements of different types of facilities, as follows: 1) Educational facilities (primary school): 15 minutes (900 seconds); 2) Medical facilities (community health service centers): 10 minutes (600 seconds); 3) Elderly care facilities (day care center): 10 minutes (600 seconds); 4) Cultural and sports facilities: 15 minutes (900 seconds).

[0035] S32: Calculate the weighted sum of the population of all residential plots within the service area of ​​facility point j, as the potential service population of facility point j.

[0036] S33: Based on the service capacity and potential service population of facility point j, calculate the supply-demand ratio of facility point j. The calculation formula is as follows: .

[0037] The distance decay function uses a Gaussian decay function, specifically in the form of: , This function can accurately characterize the nonlinear decay effect of walking time on residents' willingness to use facilities. When walking time exceeds a threshold... When the walking time from the residential area to the facility exceeds the threshold, the residential area is considered to be outside the effective service range of the facility, and the distance decay function value is 0; when the walking time is less than or equal to the threshold, the distance decay function value decreases non-linearly with the increase of walking time.

[0038] Step 2: Calculate the individual accessibility index of residential plots. S34: For each residential plot i, with residential plot i as the center, search the walking impedance map for a walking time less than or equal to a preset threshold. All public service facilities point j.

[0039] S35: Multiply the supply-demand ratios of all searched facility points j by their corresponding distance decay function values ​​and sum them to obtain the single accessibility index of residential plot i for this type of public service facility. The calculation formula is as follows: The higher the single accessibility index, the better the accessibility of the residential area to that type of public service facility.

[0040] S4: Steps for calculating the comprehensive accessibility index This step determines the weight coefficients of the four types of basic public service facilities based on the analytic hierarchy process (AHP), and then calculates the weighted comprehensive accessibility index for each residential plot. Specifically, it includes the following sub-steps: S41: Construct a hierarchical analysis structure model, specifically a three-level hierarchical analysis structure model. 1) Target layer: Comprehensive accessibility of public service facilities in urban and rural community living circles; 2) Standards Layer: Educational facilities, medical facilities, elderly care facilities, and cultural and sports facilities; 4) Scheme layer: Each residential plot.

[0041] S42: Construct pairwise comparison judgment matrices The relative importance of the four types of facilities was quantitatively evaluated using the 1-9 scale method, and a pairwise comparison judgment matrix was constructed. ,in This indicates the degree of importance of facility type i relative to facility type j.

[0042] An example judgment matrix is ​​as follows: S43: Calculate the weighting coefficients Calculate the largest eigenvalue of the judgment matrix The corresponding feature vectors are then normalized to obtain the weight coefficients for the four types of facilities. For the above exemplary judgment matrix, the calculated weight coefficients are approximately: Education 0.27, Healthcare 0.47, Elderly Care 0.17, and Culture & Sports 0.09.

[0043] S44: Consistency Check Perform a consistency check on the judgment matrix and calculate the consistency index CI and the consistency ratio CR: ; In the formula, n is the order of the judgment matrix (n=4 in this embodiment), and RI is the average random consistency index. When n=4, RI=0.90. If the consistency ratio CR<0.1, the judgment matrix is ​​considered to have satisfactory consistency, and the calculated weight coefficients are accepted; otherwise, the judgment matrix is ​​reconstructed.

[0044] S45: Calculate the overall accessibility index Based on the calculated weight coefficients of the four types of basic public service facilities, the individual accessibility indices of each residential plot to the four types of facilities are weighted and summed to obtain the comprehensive accessibility index of each residential plot. The calculation formula is as follows: In the formula, Let be the comprehensive accessibility index of residential plot i, and satisfy . =1.

[0045] S5: Steps for identifying spatial bottleneck areas This step involves spatial overlay analysis of the spatial distribution of the accessibility index with population density and aging data to identify areas with severe infrastructure deficiencies. This includes the following sub-steps: S51: Spatial Rasterization Processing The comprehensive accessibility index, population density, and aging level are each spatially rasterized to obtain three raster layers with the same resolution. Preferably, the raster resolution is set to 30m × 30m, which balances computational accuracy and efficiency.

[0046] S52: Calculation of Facility Supply and Demand Pressure Index Spatial overlay is used to multiply the three raster layers pixel by pixel to obtain the facility supply and demand pressure index raster layer. The formula for calculating the facility supply and demand pressure index for each raster cell is as follows: The infrastructure supply and demand pressure index is negatively correlated with the comprehensive accessibility index and positively correlated with population density and aging degree; the higher the index, the more prominent the infrastructure supply and demand contradiction in the region.

[0047] S53: Spatial Shortcoming Area Identification The natural discontinuity grading method is used to divide the facility supply and demand pressure index into 5 levels (extremely high, high, medium, low, and extremely low). Areas with facility supply and demand pressure indices higher than a preset threshold (such as the top 20%) are identified as spatially deficient areas with serious facility configuration deficiencies.

[0048] S6: Steps for Generating Rectification Priorities This step calculates the rectification priority index for each area with spatial shortcomings based on its comprehensive accessibility index, population size, and aging level, and generates a tiered rectification priority map. Specifically, it includes the following sub-steps: S61: Standardization of indicators. The comprehensive accessibility index, population size, and aging degree of each spatially disadvantaged area are respectively subjected to min-max standardization to eliminate the influence of dimensions. The standardization formula is: In the formula, Here, x represents the standardized indicator value, and x represents the original indicator value. This is the minimum value of the indicator. This represents the maximum value of the indicator.

[0049] For the comprehensive accessibility index, since a lower value indicates poorer accessibility and a higher priority for rectification, it is inverted after standardization, i.e.: .

[0050] S62: Calculation of Rectification Priority Index Based on the pre-set weighting coefficients for comprehensive accessibility, population size, and aging degree, the three standardized indicators are weighted and summed to obtain the rectification priority index for each spatially deficient area. The calculation formula is as follows: ;in, These are the weighting coefficients for comprehensive accessibility, population size, and aging degree, respectively, and they satisfy α+β+γ=1.

[0051] Preferably, the weighting coefficients are set as follows: α=0.4, β=0.3, γ=0.3. This weighting setting takes into account both the accessibility of facilities itself and the size of the affected population and the needs of special groups (the elderly).

[0052] S63: Generation of a Priority Map for Hierarchical Rectification The natural discontinuity grading method is used to divide the rectification priority index into three levels: high, medium, and low, generating a graded rectification priority map. High-priority areas should be prioritized for facility construction or renovation, medium-priority areas next, and low-priority areas can be gradually improved according to the actual situation.

[0053] This embodiment provides a system for assessing the accessibility of service facilities in urban and rural community living circles, used to perform any of the assessment methods described above, such as... Figure 2 As shown, the system includes: Data Acquisition Module: This module is used to acquire high-precision road network data, residential plot data, public service facility data, and population statistics within the study area. It supports importing various data formats, including Shapefile, GeoJSON, and CSV.

[0054] Pedestrian Impedance Map Construction Module: Connected to the data acquisition module, this module constructs a pedestrian travel impedance map that considers road obstacles based on high-precision road network data. It incorporates road network preprocessing, walking time calculation, and Dijkstra's shortest path algorithm.

[0055] Individual Accessibility Calculation Module: Connected to the walking impedance map construction module and the data acquisition module, it is used to calculate the individual accessibility index of each residential plot to four types of basic public service facilities by adopting an improved two-step movement search method, under the condition of considering the service capacity constraints of various public service facilities.

[0056] The comprehensive accessibility calculation module, connected to the individual accessibility calculation module, is used to determine the weight coefficients of the four types of basic public service facilities based on the analytic hierarchy process (AHP) and to calculate the comprehensive accessibility index of each residential plot using weighted averages. This module provides a visual interface for constructing the judgment matrix and a consistency check function.

[0057] Spatial overlay analysis module: connected to the comprehensive accessibility calculation module and the data acquisition module, used to perform spatial overlay analysis on the spatial distribution of the comprehensive accessibility index with population density data and aging degree data to identify spatially deficient areas with serious inadequate facility configuration.

[0058] Rectification Priority Generation Module: Connected to the spatial overlay analysis module, it is used to calculate the rectification priority index of each area with spatial shortcomings based on the comprehensive accessibility index, population size, and aging degree of the area with spatial shortcomings, and generate a hierarchical rectification priority map.

[0059] Output module: Connected to the rectification priority generation module, it is used to output a tiered rectification priority map and related evaluation results. It supports exporting the results in formats such as images, PDFs, and Shapefiles.

[0060] In another preferred embodiment, the walking speed correction coefficient was further optimized to take into account the differences in walking ability among people of different age groups.

[0061] Specifically, the population is divided into three age groups: Children (6-12 years old): The standard walking speed is set at 0.9 m / s; Adults (18-60 years old): The standard walking speed is set at 1.2 m / s; For seniors (60 years and older): the standard walking speed is set at 0.8 m / s.

[0062] Meanwhile, considering that older adults are more sensitive to slope and road surface conditions, the correction coefficients for slope and road surface conditions have been adjusted: Slope correction factor for the elderly: 1.0 for slope ≤ 3%, 0.7 for 3% < slope ≤ 7%, 0.5 for 7% < slope ≤ 12%, and 0.3 for slope > 12%. Road condition correction factor for elderly people: 1.0 for good, 0.7 for average, and 0.5 for poor.

[0063] By calculating the walking impedance maps and accessibility indices for different age groups, the service level of public service facilities for different groups can be assessed more accurately, especially to better identify the shortcomings in facility needs for vulnerable groups such as the elderly and children. This preferred embodiment can further improve the relevance and practicality of the assessment results, providing a more scientific basis for differentiated facility configuration.

[0064] This embodiment provides a storage medium storing a computer program. When the computer program is executed by a processor, it implements the accessibility assessment method for urban and rural community living circle service facilities described above.

[0065] The storage medium can be any medium capable of storing computer programs, such as read-only memory (ROM), random access memory (RAM), hard disk, optical disk, or USB flash drive. When the computer program is executed by a processor, it can implement all the steps of the method of this invention, thereby completing the automated assessment of the accessibility of service facilities in urban and rural community living circles.

[0066] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for assessing the accessibility of service facilities in urban and rural community living circles, characterized in that, Includes the following steps: S1. Obtain high-precision road network data, residential plot vector data, spatial location and service capacity data of public service facilities, and population statistics within the study area; S2. Construct a pedestrian travel impedance map that considers road traffic obstacles based on high-precision road network data. The pedestrian travel impedance map has road network nodes as vertices and walking time of road segments as edge weights. S3. Using an improved two-step moving search method, under the condition of considering the service capacity constraints of various public service facilities, calculate the individual accessibility index of each residential plot to four types of basic public service facilities: education, medical care, elderly care, and culture and sports. S4. Based on the analytic hierarchy process, determine the weight coefficients of the four types of basic public service facilities, and calculate the comprehensive accessibility index of each residential plot using weighted average. S5. Spatial overlay analysis of the spatial distribution of the comprehensive accessibility index with population density data and aging data is performed to identify spatially deficient areas with serious inadequate infrastructure. S6. Based on the comprehensive accessibility index, population size, and aging degree of the spatially deficient areas, calculate the rectification priority index for each area and generate a hierarchical rectification priority map.

2. The method for assessing the accessibility of service facilities in urban and rural community living circles according to claim 1, characterized in that: The high-precision road network data includes information on road segment type, slope, road surface condition, and traffic restrictions. Specifically, the method for constructing the pedestrian travel impedance map in step S2 includes: S21: Preprocess the high-precision road network data, extract pedestrian-accessible road sections, and remove dedicated motor vehicle lanes, expressways, and other road sections where pedestrian access is prohibited; S22: Determine the walking speed correction factor for each road segment based on the road segment type, slope, and road surface conditions. Calculate the walking time for each road segment using the following formula, based on the actual length of the road segment, the standard walking speed, and the walking speed correction factor for that road segment: ， In the formula, Let be the walking time for road segment ij. Let be the actual length of road segment ij. For standard walking speed, This is the walking speed correction factor for road segment ij; S23: Calculate the shortest walking path and shortest walking time between any two road network nodes, and construct a walking travel impedance graph with road network nodes as vertices and shortest walking time as edge weights.

3. The method for assessing the accessibility of service facilities in urban and rural community living circles according to claim 1, characterized in that: The first step of the improved two-step move search method in step S3 specifically includes: S31: For each public service facility point j, with facility point j as the center, search the pedestrian travel impedance map for walking times less than or equal to a preset threshold. All residential plots i; S32: Calculate the weighted sum of the population of all residential plots within the service area of ​​facility point j, as the potential service population of facility point j; S33: Calculate the supply-demand ratio of facility point j based on its service capacity and potential service population; the formula for calculating the supply-demand ratio of facility point j is: ， In the formula, Let the supply and demand ratio be that of facility point j. For the service capacity of facility point j, For the set of residential plots within the service area of ​​facility point j, Let i be the population of residential plot i. The shortest walking time from residential plot i to facility point j. This is a distance decay function used to characterize the decaying effect of walking time on residents' willingness to use facilities.

4. The method for assessing the accessibility of service facilities in urban and rural community living circles according to claim 3, characterized in that: The distance decay function uses a Gaussian decay function, specifically in the form of: ， In the formula, This is the preset maximum walking time threshold.

5. The method for assessing the accessibility of service facilities in urban and rural community living circles according to claim 3, characterized in that: The second step of the improved two-step move search method in step S3 specifically includes: S34: For each residential plot i, with residential plot i as the center, search the walking impedance map for a walking time less than or equal to a preset threshold. All public service facility points j; S35: Multiply the supply-demand ratios of all searched facility points j by the corresponding distance decay function values ​​and sum them to obtain the single accessibility index of residential plot i for this type of public service facility; wherein, the formula for calculating the single accessibility index of residential plot i for a certain type of public service facility is: ， In the formula, Let be the accessibility index of residential plot i to the k-th type of public service facility. Let i be the set of public service facilities of type k within walking distance of residential plot i. Let be the supply-demand ratio of facility point j in the k-th type of public service facility.

6. The method for assessing the accessibility of service facilities in urban and rural community living circles according to claim 1, characterized in that: The specific methods for determining the weight coefficients of the four types of basic public service facilities based on the analytic hierarchy process in step S4 include: S41: Construct a hierarchical analysis model, taking comprehensive accessibility as the target layer and four types of facilities—education, healthcare, elderly care, and culture and sports—as the criteria layer. S42: Construct pairwise comparison judgment matrices to quantitatively evaluate the relative importance of the four types of facilities; S43: Calculate the largest eigenvalue and the corresponding eigenvector of the judgment matrix, normalize the eigenvector, and obtain the weight coefficients of the four types of facilities. S44: Perform a consistency check on the judgment matrix. If the consistency ratio is less than a preset threshold, accept the calculated weight coefficients; otherwise, reconstruct the judgment matrix. S45: Based on the calculated weight coefficients of the four types of basic public service facilities, the individual accessibility indices of each residential plot to the four types of facilities are weighted and summed to obtain the comprehensive accessibility index of each residential plot. The specific formula for calculating the comprehensive accessibility index is as follows: ， In the formula, The comprehensive accessibility index for residential plot i. is the weighting coefficient for the k-th type of public service facility.

7. The method for assessing the accessibility of service facilities in urban and rural community living circles according to claim 1, characterized in that: The specific methods for spatial overlay analysis in step S5 include: S51: Spatial rasterization is performed on the comprehensive accessibility index, population density and aging degree respectively to obtain three raster layers with the same resolution; S52: Spatial overlay operation is used to multiply the three raster layers pixel by pixel to obtain the facility supply and demand pressure index raster layer; the calculation formula for the facility supply and demand pressure index of each raster cell is as follows: ， In the formula, The facility supply and demand pressure index for grid cell x. For grid cells The comprehensive accessibility index, For grid cells population density For grid cells The degree of aging; the supply and demand pressure index of the facilities is negatively correlated with the comprehensive accessibility index, and positively correlated with population density and the degree of aging; S53: The natural discontinuity grading method is used to divide the facility supply and demand pressure index into multiple levels, and areas where the facility supply and demand pressure index is higher than the preset threshold are identified as spatial bottleneck areas with serious deficiencies in facility configuration.

8. The method for assessing the accessibility of service facilities in urban and rural community living circles according to claim 1, characterized in that: The specific method for calculating the rectification priority index in step S6 includes: S61: Standardize the comprehensive accessibility index, population size and aging degree of each spatially disadvantaged area to eliminate the influence of dimensions; S62: Based on the preset weighting coefficients for comprehensive accessibility, population size, and aging degree, the three standardized indicators are weighted and summed to obtain the rectification priority index for each spatially deficient area; the calculation formula for the rectification priority index is as follows: ， In the formula, This represents the priority index for rectification of the m-th spatial bottleneck area. Let m be the standardized comprehensive accessibility index for the m-th spatial bottleneck region. Let m be the standardized population size of the m-th spatial bottleneck region. The standardized aging degree of the m-th spatial bottleneck region. These are the weighting coefficients for overall accessibility, population size, and degree of aging, respectively. S63: The rectification priority index is divided into three levels—high, medium, and low—using the natural discontinuity grading method, and a graded rectification priority map is generated.

9. A system for assessing the accessibility of service facilities in urban and rural community living circles, characterized in that, A method for assessing the accessibility of urban and rural community living circle service facilities according to any one of claims 1-8 includes: The data acquisition module is used to acquire high-precision road network data, residential plot data, public service facility data, and population statistics within the study area; The pedestrian impedance map construction module is used to construct a pedestrian travel impedance map that considers road traffic obstacles based on high-precision road network data. The pedestrian travel impedance map uses road network nodes as vertices and road segment walking time as edge weights. The single accessibility calculation module is used to calculate the single accessibility index of each residential plot to four types of basic public service facilities: education, medical care, elderly care, and culture and sports, under the condition of considering the service capacity constraints of various public service facilities, using an improved two-step movement search method. The comprehensive accessibility calculation module is used to determine the weight coefficients of four types of basic public service facilities based on the analytic hierarchy process, and to calculate the comprehensive accessibility index of each residential plot using weighted average. The spatial overlay analysis module is used to perform spatial overlay analysis on the spatial distribution of the comprehensive accessibility index with population density data and aging data to identify spatially deficient areas with serious inadequate facilities. The rectification priority generation module is used to calculate the rectification priority index of each area based on the comprehensive accessibility index, population size and aging degree of the spatially deficient areas, and generate a hierarchical rectification priority map. The output module is used to output a priority map of rectification levels and related evaluation results.

10. A storage medium, characterized in that, The storage medium stores a computer program, which, when executed by a processor, implements a method for assessing the accessibility of urban and rural community living circle service facilities as described in any one of claims 1 to 8.

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