Ecological corridor heat island mitigation function monitoring method and system

Abstract

The invention provides an ecological corridor heat island mitigation function monitoring method and system, and the method comprises the steps: obtaining a remote sensing image of a monitoring region which comprises a target ecological corridor and a plurality of buildings in a buffer interface adjacent to the target ecological corridor; the method comprises the following steps: calculating an openness index, a height-width ratio index, an enhanced vegetation index and a building density index; respectively carrying out weighted summation on the openness index, the aspect ratio index, the enhanced vegetation index and the building density index to obtain a heat island mitigation function comprehensive index of the target ecological corridor; and when the heat island mitigation function comprehensive index is smaller than a preset heat island mitigation function comprehensive index threshold value, alarm information is sent out. By acquiring and analyzing the remote sensing image covering the target ecological corridor and the adjacent buffer interface thereof in the monitoring area, the monitoring efficiency and accuracy of the heat island mitigation function of the ecological corridor can be effectively improved.

Description

Technical Field

[0001] This application relates to the field of geographic information technology, and particularly to a method and system for monitoring the heat island mitigation function of ecological corridors. Background Art

[0002] In high-density urbanized areas with a dense population, the urban heat island effect has gradually changed the urban thermal environment and wind environment, and affected regional climate, hydrology, air quality, soil, biological distribution, and many urban ecological processes. For a city, large ecological patches connected by ecological corridors, as important urban cold sources, play an important role in mitigating the urban heat island effect. It can be seen that the construction of ecological corridors is of great significance in mitigating the urban heat island effect and other aspects.

[0003] Currently, the existing methods for monitoring the heat island mitigation function of ecological corridors mainly rely on manual sampling. In areas with a high degree of urbanization and a large population density, ecological corridors are often widely distributed and the environment is complex. Manual sampling needs to cover all key areas to ensure the comprehensiveness and representativeness of the data. However, in actual operation, due to limited human resources, sampling points often only cover part of the monitoring area, resulting in the inability to accurately monitor the heat island mitigation effect of ecological corridors in this area. Moreover, the process of using manual sampling data and the process of processing the sampled data are cumbersome and time-consuming, and there is a problem of low efficiency in monitoring the heat island mitigation function of ecological corridors. Summary of the Invention

[0004] This application aims at the problems in the prior art and provides a method and system for monitoring the heat island mitigation function of ecological corridors, which can effectively improve the monitoring efficiency and accuracy by obtaining and analyzing remote sensing images covering the target ecological corridor and its adjacent buffer interface in the monitoring area.

[0005] A method for monitoring the heat island mitigation function of ecological corridors includes:

[0006] Obtaining a remote sensing image of the monitoring area, where the monitoring area includes a target ecological corridor and several buildings in the buffer interface adjacent to the target ecological corridor;

[0007] Based on the remote sensing image and the length of the target ecological corridor, analyzing the openness impact of the buildings on the target ecological corridor based on a preset openness index model to obtain an openness index;

[0008] Based on the remote sensing image, the width of the target ecological corridor, and the height of the building, calculating the height-width ratio index of the building and the target ecological corridor based on a preset height-width ratio model;

[0009] Based on the remote sensing image and a preset enhanced vegetation index calculation formula, analyze the urban green quantity of the buffer interface to obtain the enhanced vegetation index;

[0010] According to the base areas of the buildings and the area of the buffer interface, calculate the building density index of the buffer interface;

[0011] Respectively perform weighted summation on the openness index, aspect ratio index, enhanced vegetation index, and building density index to obtain the comprehensive heat island mitigation function index of the target ecological corridor;

[0012] When the comprehensive heat island mitigation function index is less than a preset comprehensive heat island mitigation function index threshold, an alarm message is sent.

[0013] This application also provides an ecological corridor heat island mitigation function monitoring system, including:

[0014] Data acquisition module: used to acquire the remote sensing image of the monitoring area, where the monitoring area includes a target ecological corridor and several buildings in the buffer interface adjacent to the target ecological corridor;

[0015] Openness index acquisition module: used to analyze the openness impact of the buildings on the target ecological corridor based on a preset openness index model according to the remote sensing image and the length of the target ecological corridor to obtain the openness index;

[0016] Aspect ratio index acquisition module: used to calculate the aspect ratio index of the buildings and the target ecological corridor based on a preset aspect ratio model according to the remote sensing image, the width of the target ecological corridor, and the height of the buildings;

[0017] Enhanced vegetation index acquisition module: used to analyze the urban green quantity of the buffer interface based on a preset enhanced vegetation index calculation formula according to the remote sensing image to obtain the enhanced vegetation index;

[0018] Building density index acquisition module: used to calculate the building density index of the buffer interface according to the base areas of the buildings and the area of the buffer interface;

[0019] Comprehensive heat island mitigation function index acquisition module: used to respectively perform weighted summation on the openness index, aspect ratio index, enhanced vegetation index, and building density index to obtain the comprehensive heat island mitigation function index of the target ecological corridor;

[0020] Alarm module: used to send an alarm message when the comprehensive heat island mitigation function index is less than a preset comprehensive heat island mitigation function index threshold.

[0021] Compared with the prior art, after natural wind enters the city, elements such as high-density buildings in the city will impede the wind, causing the wind speed to drop sharply inside the city, which has a significant impact on the heat island mitigation function of the ecological corridor. Therefore, in this application, by obtaining remote sensing images covering the target ecological corridor and its adjacent buffer interface in the monitoring area, and calculating the openness index of several buildings in the buffer interface adjacent to the target ecological corridor, the height-width ratio index of the buildings and the target ecological corridor, and calculating the building density of the buffer interface based on the remote sensing images, the degree of obstruction of the ecological corridor by surrounding buildings and the degree of wind penetration between surrounding buildings can be analyzed. At the same time, by combining the calculation of the enhanced vegetation index of the buffer interface and analyzing the cooling effect of the urban green quantity on the heat island mitigation function of the target ecological corridor, the heat island mitigation function of the ecological corridor can be jointly monitored, which can effectively improve the monitoring efficiency and accuracy of the heat island mitigation function of the ecological corridor.

[0022] To better understand this application, the specific implementation manners of this application will be described below in conjunction with the accompanying drawings. Brief Description of the Drawings

[0023] Figure 1 It is a flowchart of a method for monitoring the heat island mitigation function of an ecological corridor in this application;

[0024] Figure 2 It is a flowchart of a method for calculating the openness index in a method for monitoring the heat island mitigation function of an ecological corridor;

[0025] Figure 3 It is a flowchart of a method for calculating the building width in a method for monitoring the heat island mitigation function of an ecological corridor;

[0026] Figure 4 It is a schematic diagram of extracting the contour points of adjacent buildings in a method for monitoring the heat island mitigation function of an ecological corridor;

[0027] Figure 5 It is a flowchart of a method for obtaining building two-dimensional vector data in a method for monitoring the heat island mitigation function of an ecological corridor;

[0028] Figure 6 It is a flowchart of a method for calculating the height-width ratio index in a method for monitoring the heat island mitigation function of an ecological corridor;

[0029] Figure 7 It is a flowchart of a method for calculating the building density index in a method for monitoring the heat island mitigation function of an ecological corridor;

[0030] Figure 8 It is a flowchart of a method for calculating the comprehensive index of the heat island mitigation function in a method for monitoring the heat island mitigation function of an ecological corridor;

[0031] Figure 9It is a flowchart of a method for calculating weights in a method for monitoring the heat island mitigation function of an ecological corridor;

[0032] Figure 10 This is a schematic diagram of a system for monitoring the heat island mitigation function of an ecological corridor according to the present application. Detailed implementation manners

[0033] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0034] It should be understood that the schematic drawings are not drawn to actual scale. The flowcharts used in the present application illustrate the operations implemented according to some embodiments of the present application. It should be understood that the operations in the flowchart may not be implemented in sequence, and steps without logical context relationships may be reversed or implemented simultaneously. In addition, those skilled in the art can add one or more other operations to the flowchart or remove one or more operations from the flowchart under the guidance of the content of the present application.

[0035] Referring to "embodiments" herein means that the specific features, structures or characteristics described in conjunction with the embodiments may be included in at least one embodiment of the present application. The phrase appears in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0036] Embodiment 1

[0037] Please refer to Figure 1 , Figure 1 This is a flowchart of a method for monitoring the heat island mitigation function of an ecological corridor according to the present application. The present application provides a method for monitoring the heat island mitigation function of an ecological corridor, which specifically includes the following steps:

[0038] S1: Obtain remote sensing images of the monitoring area, where the monitoring area includes a target ecological corridor and several buildings in the buffer interface adjacent to the target ecological corridor;

[0039] S2: Based on the remote sensing images and the length of the target ecological corridor, analyze the openness impact of the buildings on the target ecological corridor based on a preset openness index model to obtain an openness index;

[0040] S3: Calculate the aspect ratio index of the building and the target ecological corridor based on the preset aspect ratio model according to the remote sensing image, the width of the target ecological corridor, and the height of the building;

[0041] S4: Analyze the urban green quantity of the buffer interface based on the preset enhanced vegetation index calculation formula according to the remote sensing image to obtain the enhanced vegetation index;

[0042] S5: Calculate the building density index of the buffer interface according to the base area of each building and the area of the buffer interface;

[0043] S6: Perform weighted summation on the openness index, aspect ratio index, enhanced vegetation index, and building density index respectively to obtain the comprehensive index of the heat island mitigation function of the target ecological corridor;

[0044] S7: When the comprehensive index of the heat island mitigation function is less than the preset threshold of the comprehensive index of the heat island mitigation function, an alarm message is sent.

[0045] Compared with the prior art, after natural wind enters the city, elements such as high-density buildings in the city will impede the wind, causing the wind speed to drop sharply inside the city, which has a significant impact on the heat island mitigation function of the ecological corridor. Therefore, in this solution, by acquiring the remote sensing image covering the target ecological corridor and its adjacent buffer interface in the monitoring area, and calculating the openness index of several buildings in the buffer interface adjacent to the target ecological corridor, the aspect ratio index of the building and the target ecological corridor, and calculating the building density of the buffer interface based on this remote sensing image, the degree of obstruction of the ecological corridor by surrounding buildings and the degree of wind penetration between surrounding buildings are analyzed. At the same time, the enhanced vegetation index of the buffer interface is also calculated to consider the impact of urban green quantity on the heat island mitigation function of the target ecological corridor. That is, by jointly monitoring the heat island mitigation function of the ecological corridor through the openness index, enhanced vegetation index, aspect ratio index, and building density index, the monitoring efficiency and accuracy of the heat island mitigation function of the ecological corridor can be effectively improved.

[0046] The method for monitoring the heat island mitigation function of the ecological corridor of the present invention can be executed by the following computer system, which includes an ecological corridor monitoring database server, a data acquisition server, and an ecological corridor monitoring server. The ecological corridor monitoring database server is used to store information such as the remote sensing image of the monitoring area, the length, width, and area of the target ecological corridor, and the height and base area of each building in the buffer interface, so as to construct the ecological corridor monitoring database.

[0047] The data acquisition server is used to obtain information such as remote sensing images of the monitoring area, the length, width, and area of the target ecological corridor, and the height and base area of each building in the buffer interface from the ecological corridor monitoring database server, and send them to the ecological corridor monitoring server for processing.

[0048] The ecological corridor monitoring server executes the ecological corridor heat island mitigation function monitoring method of the present invention. According to information such as remote sensing images, the length, width, and area of the target ecological corridor, and the height and base area of each building in the buffer interface, it calculates the openness index, enhanced vegetation index, aspect ratio index, and building density index, and performs weighted summation to obtain the comprehensive index of the heat island mitigation function of the target ecological corridor. When the comprehensive index of the heat island mitigation function is less than the preset threshold of the comprehensive index of the heat island mitigation function, an alarm message or adjustment instruction is sent to the urban management department or urban planning department. Among them, the adjustment instruction is used to indicate adjusting the building layout of the monitoring area until the comprehensive index of the heat island mitigation function is greater than the threshold of the comprehensive index of the heat island mitigation function.

[0049] For step S1, in this embodiment, in response to the call instruction of the ecological corridor monitoring server to the ecological corridor monitoring database server, the remote sensing image of the monitoring area is obtained from the ecological corridor monitoring database server. Among them, the monitoring area includes the target ecological corridor and several buildings in the buffer interface adjacent to the target ecological corridor. The target ecological corridor is a corridor area with specific ecological functions and service values, such as a passage connecting different ecological areas, a key area for protecting biodiversity, etc. The buffer interface is a transitional zone established around the target ecological corridor to reduce the interference of human activities on the target ecological corridor and protect its ecological functions.

[0050] In this embodiment, a buffer interface with a width of 1 kilometer is established around the target ecological corridor to form a continuous transitional area. The transitional area can be circular or strip-shaped, specifically determined according to the shape of the target ecological corridor. There are several buildings in the buffer interface, and information such as the height and base area of each building can be obtained through the urban planning department or construction management department.

[0051] Of course, in other embodiments, the width of the buffer interface can be adaptively modified according to the actual monitoring requirements of the ecological corridor.

[0052] For step S2, the openness index model is a mathematical model for quantitatively analyzing the openness of a specific area, such as the target ecological corridor. The openness index is used to measure the openness or permeability between the target ecological corridor and the buffer interface, especially the buildings in the buffer interface. The larger the openness index, the smaller the obstruction of the target ecological corridor by the buildings in the buffer interface, and the better the heat island mitigation effect of the target ecological corridor.

[0053] In this embodiment, please refer to Figure 2 , Figure 2 which is a flowchart of a method for calculating the openness index in an ecological corridor heat island mitigation function monitoring method. Based on the remote sensing image and the length of the target ecological corridor, and based on a preset openness index model, analyzing the impact of the buildings on the openness of the target ecological corridor to obtain the openness index, including:

[0054] S21: Screen the neighboring buildings directly adjacent to the target ecological corridor, and based on the remote sensing image, calculate the side length of the side adjacent to the target ecological corridor in each of the neighboring buildings as the building width of each of the neighboring buildings;

[0055] S22: Input the building width of each of the neighboring buildings and the length of the target ecological corridor into the openness model to obtain the openness index:

[0056]

[0057] where F is the openness index, A i is the building width of the i-th neighboring building, and n is the total number of neighboring buildings.

[0058] For step S21, since the building has multiple sides, to analyze the most direct physical obstruction or impact of the building on the target ecological corridor, the side length of the side of each building within 100 meters of the target ecological corridor in the buffer interface that is most directly adjacent to the target ecological corridor is preferentially selected as the building width, specifically the side length of the side with the shortest distance between the building and the target ecological corridor.

[0059] In one embodiment, please refer to Figure 3 and Figure 4 , Figure 3 which is a flowchart of a method for calculating the building width in an ecological corridor heat island mitigation function monitoring method, Figure 4It is a schematic diagram for extracting contour points of adjacent buildings in an ecological corridor heat island mitigation function monitoring method. According to the remote sensing image, calculating the side length of the side adjacent to the target ecological corridor in each of the adjacent buildings as the building width of each of the adjacent buildings further includes:

[0060] S211: Extract the contours of the adjacent buildings and the target ecological corridor on the remote sensing image and convert them into vector data to obtain building two-dimensional vector data;

[0061] S212: According to the building two-dimensional vector data, extract the boundary contour lines of each of the adjacent buildings and the boundary contour line of the target ecological corridor adjacent to the buffer interface;

[0062] S213: Generate a number of contour points on the boundary contour line of the adjacent building based on a preset contour point spacing;

[0063] S214: Screen each of the contour points closest to the boundary contour line of the ecological corridor to determine the boundary contour line of the side of the adjacent building adjacent to the target ecological corridor;

[0064] S215: According to the following formula, multiply the total number of contour points on the boundary contour line of the side of the adjacent building adjacent to the target ecological corridor by the contour point spacing to obtain the building width of each of the adjacent buildings:

[0065] A i =m i ×d

[0066] where A i is the building width of the adjacent building, m i is the total number of contour points on the boundary contour line of the side of the adjacent building adjacent to the target ecological corridor, and d is the contour point spacing.

[0067] For step S211, the remote sensing image is an image of the earth's surface information obtained through remote sensing technology, such as sensors carried on platforms such as satellites and airplanes. The building two-dimensional vector data is vector data describing the building contour, usually including geometric information such as the boundary and vertices of the building.

[0068] Before extracting the contours of the adjacent buildings and the target ecological corridor on the remote sensing image, preprocessing the remote sensing image is also included, specifically geometric and radiometric correction accuracy and contrast enhancement, etc.

[0069] Please also refer to Figure 5 , Figure 5It is a method flow chart for obtaining building two-dimensional vector data in an ecological corridor heat island mitigation function monitoring method. According to the remote sensing image, extracting the outlines of the adjacent buildings and the target ecological corridor on the remote sensing image and converting them into vector data to obtain the building two-dimensional vector data, including:

[0070] S211a: Identifying edge features in the remote sensing image based on an edge detection algorithm;

[0071] S211b: Extracting continuous edge lines from the edge features based on a contour tracking algorithm to form the outlines of the buildings and the target ecological corridor;

[0072] S211c: Converting the outlines of the buildings and the target ecological corridor into a vector data format to obtain the building two-dimensional vector data.

[0073] For S211a - S211c, the edge detection algorithm can be edge detection algorithms such as obel and Canny. The vector data format can be Shapefile, GeoJSON, etc. After converting the outlines of the buildings and the target ecological corridor into a vector data format, smoothing processing can also be performed to reduce the jagged edges introduced by the edge detection algorithm; ensuring the topological correctness of the vectorized data, such as checking for overlapping, broken, or discontinuous contour lines; and performing manual inspection on the vectorized results to correct possible errors or omissions, etc.

[0074] For steps S212 - S215, the boundary contour lines of the buildings and the ecological corridor can be extracted through tools such as "Feature to Polygon" or "Feature Outline" in ArcGIS software. Through tools such as "Create Feature" or "Generate Points Along Line" in ArcGIS software, several contour points can be generated on the boundary contour lines. By using the "Nearest Neighbor Analysis" in ArcGIS software to screen the contour points closest to the boundary contour line of the target ecological corridor, the total number of the closest contour points is obtained. Finally, multiplying the total number of contour points on the boundary contour line of the side of the adjacent building adjacent to the target ecological corridor by the contour point spacing, the building widths of the respective adjacent buildings are obtained.

[0075] The contour point spacing can be set to 1 meter, 5 meters, etc. Of course, in other embodiments, the contour point spacing can be adaptively adjusted according to the actual size of the building. Among them, the smaller the contour point spacing, the higher the accuracy of the calculated building width.

[0076] For step S22, for a target ecological corridor in a large-scale area such as across provinces or cities, its extension range is wide and its shape is complex. Directly measuring its length is inefficient. In this regard, the perimeter of the target ecological corridor can be obtained from channels such as the urban planning department, and half of the perimeter of the target ecological corridor is used as the length of the target ecological corridor.

[0077] For a target ecological corridor in a small-scale area such as an urban park or green space, its shape and scale are relatively simple. To calculate the length of the target ecological corridor, the above steps S212 - S215 can be referred to. The difference is that at a preset contour point spacing, several contour points are generated on the boundary contour line of the target ecological corridor, so as to calculate the length of the target ecological corridor, and the details will not be elaborated here.

[0078] In this embodiment, for step S3, the remote sensing image is a MODIS remote sensing image containing the spectral reflectance of specific bands, where the specific bands include the near-infrared band, the red band, and the blue band. The larger the enhanced vegetation index, the denser the vegetation in the buffer interface. On the one hand, the cooling effect of the buffer interface is enhanced through the transpiration of vegetation; on the other hand, through the shading effect of vegetation, the amount of solar radiation received by the ground can be effectively reduced, and the ground temperature can be lowered. Furthermore, the heat island mitigation function of the ecological corridor can be effectively improved.

[0079] Analyzing the urban green quantity of the buffer interface based on a preset enhanced vegetation index calculation formula according to the remote sensing image to obtain the enhanced vegetation index, including:

[0080] According to the spectral reflectances of the near-infrared band, the red band, and the blue band, the enhanced vegetation index is obtained according to the enhanced vegetation index calculation formula. The enhanced vegetation index calculation formula is:

[0081]

[0082] Among them, EVI is the enhanced vegetation index, G is a preset enhancement parameter for enhancing EVI, which can be set to 2.5, NIR is the spectral reflectance of the near-infrared band, R is the spectral reflectance of the red band, B is the spectral reflectance of the blue band, and C1 and C2 are the preset first and second atmospheric resistance coefficients, which can be set to 6.0 and 7.5 respectively. Of course, in other embodiments, the enhancement parameter, the first atmospheric resistance coefficient, and the second atmospheric resistance coefficient can also be adjusted adaptively.

[0083] In one embodiment, for step S4, the openness index model is a mathematical model for quantitatively analyzing the openness of a specific area, such as the target ecological corridor. The buffer interface includes a first buffer interface and a second buffer interface located on both sides of the target ecological corridor. The aspect ratio index refers to the ratio of the height of the building closest to the target ecological corridor in the first buffer interface and the second buffer interface to the width of the target ecological corridor, which is used to reflect the impact degree of the building on the target ecological corridor. Specifically, the smaller the aspect ratio index, the smaller the flow resistance of the wind in the target ecological corridor, and the better the heat island mitigation effect of the target ecological corridor.

[0084] Please refer to Figure 6 , Figure 6 which is a flowchart of a method for calculating the aspect ratio index in a method for monitoring the heat island mitigation function of an ecological corridor. Based on the remote sensing image, the width of the target ecological corridor, and the height of the building, and based on a preset aspect ratio model, calculating the aspect ratio index between the building and the target ecological corridor includes:

[0085] S41: According to the remote sensing image, calculate the distance between each building and the boundary contour line of the target ecological corridor, and respectively determine the first nearest building and the second nearest building in the first buffer interface and the second buffer interface that are closest to the target ecological corridor;

[0086] S42: Based on the width of the target ecological corridor, the building heights of the first nearest building and the second nearest building, and based on the aspect ratio model, obtain the aspect ratio index. The calculation formula of the aspect ratio model is:

[0087]

[0088] where E is the aspect ratio index, H 1 and H 2 are the building heights of the first nearest building and the second nearest building respectively, and D is the width of the ecological corridor.

[0089] For step S41, preferably determine the first nearest building and the second nearest building from among the buildings within a distance of 100 meters from the target ecological corridor in the first buffer interface and the second buffer interface.

[0090] The principle of calculating the distance between each building and the boundary contour line of the target ecological corridor based on the remote sensing image and respectively determining the first nearest building and the second nearest building closest to the target ecological corridor in the first buffer interface and the second buffer interface can refer to the above steps S211 - S214. The difference is that step S41 is to determine the building closest to the target ecological corridor, which will not be elaborated here.

[0091] For step S42, the width of the target ecological corridor is the average width, which can be directly obtained from channels such as the urban planning department. It can also be obtained by obtaining the area and length of the target ecological corridor from channels such as the urban planning department and dividing the area of the target ecological corridor by the length to get the average width.

[0092] For step S5, the building density index refers to the ratio of the base area of the buildings within the buffer interface to the total area of the buffer interface, and it is also used to represent the degree of influence of the buildings on the target ecological corridor. Specifically, the smaller the building density index, the higher the air ventilation efficiency of the target ecological corridor, and the better the heat island mitigation effect of the target ecological corridor.

[0093] In this embodiment, please refer to Figure 7 , Figure 7 is a flowchart of a method for calculating the building density index in an ecological corridor heat island mitigation function monitoring method. Calculating the building density index of the buffer interface according to the base area of each building and the area of the buffer interface includes:

[0094] S51: Divide the buffer interface into several buffer cells, where the sum of the areas of all the buffer cells is equal to the area of the buffer interface;

[0095] S52: Accumulate the base areas of the buildings in the buffer cells to obtain the total base area of the buffer cells;

[0096] S53: Divide the total base area by the area of the buffer cell to obtain the building density index of the buffer cell;

[0097] S54: Perform an arithmetic mean calculation on the building density indices of all the buffer cells to obtain the building density index of the buffer interface.

[0098] For steps S51 - S54, geographic information system software such as ArcGIS can be used to divide the buffer interface into rectangular or square cells with equal areas, or perform irregular division according to the terrain.

[0099] In this embodiment, for the buffer interface with a width of 1 km, in combination with the length of the target ecological corridor, the area of the buffer interface can be obtained and preferentially divided into several square buffer cells each with a size of 100 * 100 m. The base areas of the buildings in each of the square buffer cells are accumulated to obtain the total base area of the square buffer cell, and then divided by the area of the square buffer cell to obtain the building density index of the square buffer cell. Finally, the building density indices of all the square buffer cells are averaged arithmetically to obtain the building density index of the buffer interface.

[0100] Of course, in other embodiments, the area setting of the buffer cells can be adjusted adaptively according to the actual area of the buffer interface.

[0101] For step S6, the comprehensive heat island mitigation function index is a comprehensive index obtained by weighted summation of multiple related indices (such as the enhanced vegetation index, openness index, aspect ratio index, and building density index), and is used to quantitatively analyze the overall effectiveness of the target ecological corridor in mitigating the urban heat island effect.

[0102] In one embodiment, please refer to Figure 8 , Figure 8 which is a flowchart of a method for calculating the comprehensive heat island mitigation function index in an ecological corridor heat island mitigation function monitoring method. The weighted summation of the openness index, aspect ratio index, enhanced vegetation index, and building density index respectively to obtain the comprehensive heat island mitigation function index of the target ecological corridor includes:

[0103] S61: Based on the preset assignment mapping relationships of the openness index, aspect ratio index, enhanced vegetation index, and building density index, the openness index, aspect ratio index, enhanced vegetation index, and building density index are respectively assigned to obtain the openness index assignment, aspect ratio index assignment, enhanced vegetation index assignment, and building density index assignment;

[0104] S62: According to the following formula, the openness index assignment, aspect ratio index assignment, enhanced vegetation index assignment, and building density index assignment are weighted and summed to obtain the comprehensive heat island mitigation function index:

[0105]

[0106] where R is the comprehensive heat island mitigation function index of the target ecological corridor, Yi is the assignment of the i-th index, and the index assignment includes: the openness index assignment, aspect ratio index assignment, enhanced vegetation index assignment, and building density index assignment, and K iis the weight of the i-th index. The index weights include: the weight of the openness index, the weight of the aspect ratio index, the weight of the enhanced vegetation index, and the weight of the building density index. n is the number of the index assignments or index weights.

[0107] For step S61, the assignment mapping relationships of the enhanced vegetation index, the openness index, the aspect ratio index, and the building density index can be as shown in Table 1.

[0108] Table 1:

[0109]

[0110]

[0111] In other embodiments, according to actual requirements, the assignment mapping relationships of the enhanced vegetation index, the openness index, the aspect ratio index, and the building density index can also be adaptively adjusted, specifically by adjusting the value grading and the corresponding assignments.

[0112] For step S62, the greater the comprehensive index of the heat island mitigation function, the better the heat island mitigation function effect of the target ecological corridor.

[0113] In another embodiment, please refer to Figure 9 , Figure 9 is a flowchart of a method for calculating weights in an ecological corridor heat island mitigation function monitoring method. Calculating the weights of the openness index, the aspect ratio index, the enhanced vegetation index, and the building density index includes the following steps:

[0114] S621: Obtain a number of sample assignment sets, where each sample assignment set includes an openness index sample assignment, an aspect ratio index sample assignment, an enhanced vegetation index sample assignment, and a building density index sample assignment;

[0115] S622: According to the following formula, calculate the assignment probability values of the openness index sample assignment, the aspect ratio index sample assignment, the enhanced vegetation index sample assignment, and the building density index sample assignment under each sample assignment set respectively:

[0116]

[0117] where p ij is the assignment probability value of the j-th index under the i-th sample assignment set. The probability values of the index include: the openness index sample assignment probability value, the aspect ratio index sample assignment probability value, the enhanced vegetation index sample assignment probability value, and the building density index sample assignment probability value. X ijAssign the value of the j-th indicator under the i-th sample assignment set. The assignments of the indicators include: the assignment of the openness index sample, the assignment of the aspect ratio index sample, the assignment of the enhanced vegetation index sample, and the assignment of the building density index sample; m is the number of the sample assignment sets.

[0118] S623: According to the assignment probability values of the openness index sample, the aspect ratio index sample, the enhanced vegetation index sample, and the building density index sample under each sample assignment set, calculate the assignment entropy value of the openness index sample, the assignment entropy value of the aspect ratio index sample, the assignment entropy value of the enhanced vegetation index sample, and the assignment entropy value of the building density index sample according to the following formula:

[0119]

[0120] where, e j is the entropy value of the j-th indicator. The entropy values of the indicators include the assignment entropy value of the openness index sample, the assignment entropy value of the aspect ratio index sample, the assignment entropy value of the enhanced vegetation index sample, and the assignment entropy value of the building density index sample. p ij is the probability value of the j-th indicator under the i-th sample assignment set. The probability values of the indicators include: the assignment probability value of the openness index sample, the assignment probability value of the aspect ratio index sample, the assignment probability value of the enhanced vegetation index sample, and the assignment probability value of the building density index sample; m is the number of the sample assignment sets.

[0121] S624: According to the assignment entropy value of the openness index sample, the assignment entropy value of the aspect ratio index sample, the assignment entropy value of the enhanced vegetation index sample, and the assignment entropy value of the building density index sample, calculate the weight of the openness index, the weight of the aspect ratio index, the weight of the enhanced vegetation index, and the weight of the building density index according to the following formula:

[0122]

[0123] where, K j is the weight of the j-th indicator. The weights of the indicators include the weight of the openness index, the weight of the aspect ratio index, the weight of the enhanced vegetation index, and the weight of the building density index. e j is the entropy value of the j-th indicator. The entropy values of the indicators include the assignment entropy value of the openness index sample, the assignment entropy value of the aspect ratio index sample, the assignment entropy value of the enhanced vegetation index sample, and the assignment entropy value of the building density index sample.

[0124] For step S621, by selecting different ecological corridors, the corresponding enhanced vegetation index, openness index, aspect ratio index, and building density index can be calculated, and according to the above-mentioned assignment mapping relationships of the enhanced vegetation index, openness index, aspect ratio index, and building density index, the weights of the openness index, aspect ratio index, enhanced vegetation index, and building density index can be obtained, so as to obtain the above-mentioned several sample assignment sets.

[0125] For step S7, the comprehensive heat island mitigation function index threshold can be set to 1. When the comprehensive heat island mitigation function index is less than the preset comprehensive heat island mitigation function index threshold, an alarm message is sent to the urban management department or urban planning department, etc. Of course, in other embodiments, the comprehensive heat island mitigation function index threshold can also be adaptively modified.

[0126] In this embodiment, the alarm message is specifically an adjustment instruction, where the adjustment instruction is used to indicate adjusting the building layout of the monitored area until the comprehensive heat island mitigation function index is greater than the comprehensive heat island mitigation function index threshold. For example, by demolishing some unnecessary buildings in the buffer interface or increasing the distance between buildings during reconstruction, and restricting the height of buildings, the air flow can be increased, which is beneficial to heat dissipation, thereby improving the openness index, building density index, and aspect ratio index; adding green vegetation such as trees, shrubs, and lawns at the open spaces between buildings, building roofs, and walls in the buffer interface to increase the vegetation coverage area, thereby enhancing the enhanced vegetation index. Through the above adjustments, the comprehensive heat island mitigation function index can be effectively improved, which helps to alleviate the urban heat island effect.

[0127] Embodiment 2

[0128] Please refer to Figure 10 , Figure 10 which is a schematic diagram of an ecological corridor heat island mitigation function monitoring system of the present application.

[0129] The present application also provides an ecological corridor heat island mitigation function monitoring system, including:

[0130] Data acquisition module 1: used to acquire remote sensing images of the monitored area, where the monitored area includes a target ecological corridor and several buildings in a buffer interface adjacent to the target ecological corridor;

[0131] Openness index acquisition module 2: used to analyze the openness impact of the buildings on the target ecological corridor based on a preset openness index model according to the remote sensing images and the length of the target ecological corridor, so as to obtain the openness index.

[0132] Aspect ratio index acquisition module 3: configured to calculate the aspect ratio index of the building and the target ecological corridor based on a preset aspect ratio model according to the remote sensing image, the width of the target ecological corridor, and the height of the building;

[0133] Enhanced vegetation index acquisition module 4: configured to analyze the urban green quantity of the buffer interface based on a preset enhanced vegetation index calculation formula according to the remote sensing image to obtain an enhanced vegetation index;

[0134] Building density index acquisition module 5: configured to calculate the building density index of the buffer interface according to the base area of each building and the area of the buffer interface;

[0135] Comprehensive heat island mitigation function index acquisition module 6: configured to perform weighted summation on the openness index, the aspect ratio index, the enhanced vegetation index, and the building density index respectively to obtain the comprehensive heat island mitigation function index of the target ecological corridor;

[0136] Alarm module 7: configured to send an alarm message when the comprehensive heat island mitigation function index is less than a preset comprehensive heat island mitigation function index threshold.

[0137] It should be noted that the data obtained when an ecological corridor heat island mitigation function monitoring system provided by the present application implements an ecological corridor heat island mitigation function monitoring method are stored in the storage of this system in a one-to-one correspondence. When relevant calculations are required, the data required for the calculation can be directly obtained from the storage correspondingly.

[0138] It should also be noted that when an ecological corridor heat island mitigation function monitoring system provided by the above embodiment implements an ecological corridor heat island mitigation function monitoring method, only the above-mentioned division of each functional module is used for illustration. In actual application, the above functions can be allocated to different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, an ecological corridor heat island mitigation function monitoring system provided by the above embodiment and an ecological corridor heat island mitigation function monitoring method of Embodiment 1 belong to the same concept. The implementation process thereof is detailed in the method embodiment and will not be elaborated here.

[0139] Based on the same inventive concept, the present application further provides an electronic device, which can be a server, a desktop computing device, or a mobile computing device (for example, a laptop computing device, a handheld computing device, a tablet computer, a netbook, etc.). The device includes one or more processors and a memory. The processor is configured to execute a program to implement the above-mentioned ecological corridor heat island mitigation function monitoring method; the memory is configured to store a computer program executable by the processor.

[0140] This application is not limited to the above embodiments. If various modifications or variations of this application do not depart from the spirit and scope of this application, and if these modifications and variations are within the scope of the claims of this application and equivalent technical scope, then this application also intends to include these modifications and variations.

Claims

1. A method for monitoring the heat island mitigation function of an ecological corridor, characterized in that: The following steps are involved: Acquire a remote sensing image of a monitoring area, wherein the monitoring area includes a target ecological corridor and a plurality of buildings in a buffer interface adjacent to the target ecological corridor; According to the remote sensing image and the length of the target ecological corridor, based on a preset openness index model, analyzing the impact of the building on the openness of the target ecological corridor to obtain an openness index; Calculate the aspect ratio index between the building and the target ecological corridor based on the remote sensing image, the width of the target ecological corridor and the height of the building and on the basis of a preset aspect ratio model; According to the remote sensing image, based on a preset enhanced vegetation index calculation formula, the urban green volume of the buffer interface is analyzed to obtain an enhanced vegetation index; Calculating the building density index of the buffer interface according to the base area of ​​each of the buildings and the area of ​​the buffer interface; The openness index, aspect ratio index, enhanced vegetation index and building density index are weighted and summed respectively to obtain a comprehensive index of the heat island mitigation function of the target ecological corridor; When the heat island mitigation function comprehensive index is less than a preset heat island mitigation function comprehensive index threshold, an alarm message is issued.

2. The method for monitoring the heat island mitigation function of an ecological corridor according to claim 1, characterized in that: The weighted sum of the openness index, aspect ratio index, enhanced vegetation index and building density index is performed respectively to obtain the comprehensive index of the heat island mitigation function of the target ecological corridor, including: Based on the preset openness index assignment mapping relationship, aspect ratio index assignment mapping relationship, enhanced vegetation index assignment mapping relationship and building density index assignment mapping relationship, the openness index, aspect ratio index, enhanced vegetation index and building density index are assigned respectively to obtain the openness index assignment, aspect ratio index assignment, enhanced vegetation index assignment and building density index assignment; According to the following formula, the openness index value, the aspect ratio index value, the enhanced vegetation index value and the building density index value are weighted and summed to obtain the comprehensive index of the heat island mitigation function: Among them, R is the comprehensive index of the heat island mitigation function, Y i Assign a value to the i-th index, wherein the index assignment includes: the openness index assignment, the aspect ratio index assignment, the enhanced vegetation index assignment and the building density index assignment, K i is the ith indicator weight, and the indicator weights include: the weight of the openness index, the weight of the aspect ratio index, the weight of the enhanced vegetation index and the weight of the building density index, and n is the number of indicator values ​​or indicator weights.

3. The method for monitoring the heat island mitigation function of an ecological corridor according to claim 2, characterized in that: Calculating the weight of the openness index, the weight of the aspect ratio index, the weight of the enhanced vegetation index and the weight of the building density index comprises the following steps: Acquire a plurality of sample value sets, wherein each of the sample value sets includes an openness index sample value, an aspect ratio index sample value, an enhanced vegetation index sample value, and a building density index sample value; According to the following formulas, the openness index sample assignment probability value, the aspect ratio index sample assignment probability value, the enhanced vegetation index sample assignment probability value and the building density index sample assignment probability value under each sample assignment set are calculated respectively: Among them, p ij is the probability value of the jth indicator under the i-th sample assignment set, and the probability values ​​of the indicators include: the probability value of the openness index sample assignment, the probability value of the aspect ratio index sample assignment, the probability value of the enhanced vegetation index sample assignment, and the probability value of the building density index sample assignment, X ij is the value assignment of the jth indicator under the i-th sample value assignment set, the value assignment of the indicator includes: the sample value assignment of the openness index, the sample value assignment of the aspect ratio index, the sample value assignment of the enhanced vegetation index and the sample value assignment of the building density index; m is the number of the sample value assignment sets; According to the openness index sample assignment probability value, aspect ratio index sample assignment probability value, enhanced vegetation index sample assignment probability value and building density index sample assignment probability value under each of the sample assignment sets, the openness index sample assignment entropy value, aspect ratio index sample assignment entropy value, enhanced vegetation index sample assignment entropy value and building density index sample assignment entropy value are calculated according to the following formula: Among them, e j is the entropy value of the jth index, the entropy value of the index includes the sample assignment entropy value of the openness index, the sample assignment entropy value of the aspect ratio index, the sample assignment entropy value of the enhanced vegetation index and the sample assignment entropy value of the building density index, p ij is the probability value of the jth indicator under the ith sample assignment set, the probability values ​​of the indicators include: the sample assignment probability value of the openness index, the sample assignment probability value of the aspect ratio index, the sample assignment probability value of the enhanced vegetation index and the sample assignment probability value of the building density index, and m is the number of the sample assignment sets; According to the sample assignment entropy value of the openness index, the sample assignment entropy value of the aspect ratio index, the sample assignment entropy value of the enhanced vegetation index and the sample assignment entropy value of the building density index, the weight of the openness index, the weight of the aspect ratio index, the weight of the enhanced vegetation index and the weight of the building density index are calculated according to the following formula: Among them, K j is the weight of the jth index, which includes the weight of the openness index, the weight of the aspect ratio index, the weight of the enhanced vegetation index and the weight of the building density index, e j is the entropy value of the j-th indicator, and the entropy value of the indicator includes the sample assignment entropy value of the openness index, the sample assignment entropy value of the aspect ratio index, the sample assignment entropy value of the enhanced vegetation index and the sample assignment entropy value of the building density index.

4. The method for monitoring the heat island mitigation function of an ecological corridor according to claim 1, characterized in that: The method of analyzing the influence of the building on the openness of the target ecological corridor based on the remote sensing image and the length of the target ecological corridor and based on a preset openness index model to obtain an openness index includes: Screening adjacent buildings directly adjacent to the target ecological corridor, and calculating the side length of each adjacent building adjacent to the target ecological corridor according to the remote sensing image as the building width of each adjacent building; The width of each adjacent building and the length of the target ecological corridor are input into the openness model to obtain the openness index: Wherein, F is the openness index, A i is the building width of the ith adjacent building, and n is the total number of the adjacent buildings.

5. The method for monitoring the heat island mitigation function of an ecological corridor according to claim 4, characterized in that: The step of calculating the side length of each adjacent building adjacent to the target ecological corridor according to the remote sensing image as the building width of each adjacent building includes: Extracting the contours of the adjacent buildings and the target ecological corridor on the remote sensing image according to the remote sensing image, and converting them into vector data to obtain two-dimensional building vector data; Extracting the boundary contour lines of each of the adjacent buildings and the boundary contour lines of the target ecological corridor adjacent to the buffer interface according to the two-dimensional building vector data; Based on a preset contour point spacing, generating a plurality of contour points on the boundary contour line of the adjacent building; Screening the contour points closest to the boundary contour line of the ecological corridor to determine the boundary contour line of the side of the adjacent building adjacent to the target ecological corridor; The building width of each of the adjacent buildings is obtained by multiplying the total number of contour points on the boundary contour line on the side of the adjacent building adjacent to the target ecological corridor by the contour point spacing.

6. The method for monitoring the heat island mitigation function of an ecological corridor according to claim 5, characterized in that: The buffer interface includes a first buffer interface and a second buffer interface located on both sides of the target ecological corridor; The calculating the aspect ratio index between the building and the target ecological corridor based on the remote sensing image, the width of the target ecological corridor and the height of the building and based on a preset aspect ratio model includes: According to the remote sensing image, the distance between each of the buildings and the boundary contour line of the target ecological corridor is calculated, and the first nearest building and the second nearest building closest to the target ecological corridor in the first buffer interface and the second buffer interface are determined respectively; According to the width of the target ecological corridor, the building heights of the first nearest building and the second nearest building, and based on the aspect ratio model, the aspect ratio index is obtained. The calculation formula of the aspect ratio model is: Wherein, E is the height-to-width ratio index, H1 and H2 are the building heights of the first nearest building and the second nearest building respectively, and D is the width of the ecological corridor.

7. The method for monitoring the heat island mitigation function of an ecological corridor according to claim 1, characterized in that: The step of calculating the building density index of the buffer interface according to the base area of ​​each building and the area of ​​the buffer interface comprises: Dividing the buffer interface into a plurality of buffer cells, wherein the sum of the areas of the buffer cells is equal to the area of ​​the buffer interface; Accumulating the base areas of the buildings in the buffer cells to obtain the sum of the base areas of the buffer cells; Dividing the sum of the base areas by the area of ​​the buffer cells to obtain a building density index of the buffer cells; The building density index of each buffer cell is calculated by arithmetic average to obtain the building density index of the buffer interface.

8. The method for monitoring the heat island mitigation function of an ecological corridor according to claim 1, characterized in that: The remote sensing image is a MODIS remote sensing image containing spectral reflectance of specific bands, and the specific bands include near infrared band, red light band and blue light band; The step of analyzing the urban green volume of the buffer interface based on the remote sensing image and a preset enhanced vegetation index calculation formula to obtain an enhanced vegetation index includes: According to the spectral reflectance of the near-infrared band, the red light band and the blue light band, the enhanced vegetation index is obtained according to the enhanced vegetation index calculation formula. The enhanced vegetation index calculation formula is: Among them, EVI is the enhanced vegetation index, G is a preset enhancement parameter for enhancing EVI, NIR is the spectral reflectivity of the near-infrared band, R is the spectral reflectivity of the red light band, B is the spectral reflectivity of the blue light band, and C1 and C2 are the preset first atmospheric drag coefficient and second atmospheric drag coefficient.

9. The method for monitoring the heat island mitigation function of an ecological corridor according to claim 1, characterized in that: The alarm information is specifically an adjustment instruction, wherein the adjustment instruction is used to instruct to adjust the building layout of the monitored area until the heat island mitigation function comprehensive index is greater than the heat island mitigation function comprehensive index threshold.

10. An ecological corridor heat island mitigation function monitoring system, characterized in that: include: Data acquisition module: used to acquire remote sensing images of a monitoring area, wherein the monitoring area includes a target ecological corridor and several buildings in a buffer interface adjacent to the target ecological corridor; An openness index acquisition module is used to analyze the impact of the building on the openness of the target ecological corridor based on the remote sensing image and the length of the target ecological corridor and based on a preset openness index model to obtain an openness index; A height-to-width ratio index acquisition module: used to calculate the height-to-width ratio index of the building and the target ecological corridor based on the remote sensing image, the width of the target ecological corridor and the height of the building, based on a preset height-to-width ratio model; Enhanced vegetation index acquisition module: used to analyze the urban green volume of the buffer interface according to the remote sensing image and based on a preset enhanced vegetation index calculation formula to obtain an enhanced vegetation index; A building density index acquisition module: used to calculate the building density index of the buffer interface according to the base area of ​​each building and the area of ​​the buffer interface; A heat island mitigation function comprehensive index acquisition module is used to perform weighted summation on the openness index, aspect ratio index, enhanced vegetation index and building density index respectively to obtain a heat island mitigation function comprehensive index of the target ecological corridor; Alarm module: used to issue an alarm message when the comprehensive index of heat island mitigation function is less than a preset comprehensive index threshold of heat island mitigation function.

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