Cooperative improvement system for dust retention and noise reduction functions of urban ecological corridor

Abstract

The invention relates to the technical field of urban ecological engineering, and discloses an urban ecological corridor dust retention and noise reduction function collaborative improvement system, which comprises a three-dimensional topographic structure, which comprises an ecological core area and a pollution source, and the ecological core area and the pollution source have a height difference; the composite plant layer structure comprises a pollution source interface layer which comprises a wide hedge belt arranged along the boundary of a pollution source; the core filtering layer is arranged by adopting a pure arbor belt and is arranged on one side, far away from the pollution source, of the pollution source interface layer; the ecological protection layer is arranged by adopting a shrub and grass composite belt and is arranged between one side, far away from the pollution source interface layer, of the core filtering layer and the ecological core area. According to the invention, the terrain gradient evolution and the plant hierarchical structure accurately correspond to form a spatial topology coupling system, so that the terrain fluctuation and the plant community generate a synergistic interaction effect, and the dual functions of PM2.5 retardation and noise attenuation are synchronously enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of urban ecological engineering, and in particular to a system for collaboratively improving the dust retention and noise reduction functions of urban ecological corridors. Background Art

[0002] With the acceleration of urbanization, particulate matter pollution and traffic noise generated in linear spaces such as roads and rivers have become prominent urban ecological problems.

[0003] Traditional ecological corridor design has the following technical defects:

[0004] Functional segmentation flaw: Existing technologies often adopt a single-function design approach, with dust-retaining plant belts and noise-reduction structures spatially separated. This results in poor longitudinal continuity of the ecological corridor and an inability to achieve functional synergy. Typical manifestations include: dense shrub areas offering significant noise reduction but poor dust retention, while open areas with trees offer enhanced dust retention but increased noise reflection.

[0005] Improper plant configuration: Traditional methods generally adopt a homogenous plant layout and fail to establish a three-dimensional configuration system that matches the pollution gradient. For example:

[0006] The shrub layer is mostly randomly distributed, and no special noise reduction hedges are set up to target the high pollution features within a certain range on the road side;

[0007] The shrub-grass transition zone lacks a hierarchical filtration structure, resulting in a high secondary dust collection rate for fine particles;

[0008] Inefficient terrain utilization: Existing ecological corridor terrain designs mostly use zero fill or a single gentle slope, failing to form a height difference system that matches the diffusion law of pollutants.

[0009] Therefore, there is an urgent need for an ecological corridor system that can synergistically improve the dust retention and noise reduction efficiency and achieve terrain-plant parameter matching. Summary of the Invention

[0010] The purpose of the present invention is to solve the problems existing in the prior art and to propose a system for collaboratively improving the dust retention and noise reduction functions of urban ecological corridors.

[0011] In order to achieve the above object, the present invention adopts the following technical solutions:

[0012] A system for collaboratively improving the dust retention and noise reduction functions of urban ecological corridors, characterized by comprising:

[0013] Three-dimensional terrain structure, including ecological core areas and pollution sources:

[0014] Among them, there is a height difference between the ecological core area and the pollution source;

[0015] Composite plant layer structure, including:

[0016] Pollution source interface layer, including wide hedge strips set along the pollution source boundary;

[0017] The core filter layer is set up with a pure tree belt and is set up on the side of the pollution source interface layer away from the pollution source;

[0018] The ecological protection layer is set up in the form of a shrub-grass composite belt, which is set between the side of the core filter layer away from the pollution source interface layer and the ecological core area.

[0019] Preferably, the height of the pollution source is higher than that of the ecological core area, and the terrain is arranged in a gradually descending trend.

[0020] Preferably, in the three-dimensional terrain structure, a gradient terrain is set along the direction from the ecological core area to the pollution source, including:

[0021] Initial uplift section: forming a continuously uplifted terrain;

[0022] High-level stable section: maintains the height of the elevated terrain up to the pollution source;

[0023] Composite plant layer structure, including:

[0024] Pollution source interface layer: includes wide hedge strips set along the boundary of the pollution source;

[0025] Core filter layer: It is set up with a pure tree belt and is located on the side of the pollution source interface layer away from the pollution source;

[0026] Ecological protection layer: A composite belt of shrubs and grasses is set up between the side of the core filter layer away from the pollution source interface layer and the ecological core area.

[0027] Preferably, the slope ratio of the elevated terrain is 1:10-1:15, and the elevation rises from H0 to H1=H0+(0.8-1.5) m.

[0028] Preferably, the high-level stable section maintains the terminal height H1 of the elevated terrain fluctuating within ±0.15 m up to the pollution source.

[0029] Preferably, the initial lifting section and the high-position stable section are connected by a broken-line transition, with the turning point being located at 10m±0.5m.

[0030] Preferably, the wide hedge strip is set along the side boundary of the road at 3.0±0.2m and contains mixed trees and shrubs.

[0031] Preferably, the tree is at least one of weeping willow and Sophora japonica, and the shrub is at least one of boxwood and holly hedge.

[0032] Preferably, the core filter layer is arranged in an area 3-20 m away from the pollution source.

[0033] Preferably, the shrub-grass composite belt is arranged in an area 20-30 m away from the pollution source and contains mixed trees and shrubs.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. This invention forms a spatial topological coupling system by precisely matching the evolution of terrain gradients with the plant hierarchy (pollution interface layer → core filtration layer → ecological protection layer). This creates a synergistic effect between terrain undulations and plant communities, simultaneously enhancing the dual functions of PM2.5 blocking and noise attenuation.

[0036] 2. This invention adopts a three-stage terrain evolution model and a standardized 30m module design, which can quickly match the optimal construction plan for different corridor types such as rivers and roads. The broken line transition of terrain turning points and the regular arrangement of plant matrices significantly improve the construction positioning accuracy and the predictability of ecological functions.

[0037] 3. Based on the modular segmentation of the three-stage terrain evolution model (0m→10m→20m→30m), combined with the hierarchical boundary marking of plant configuration, an intuitively identifiable construction guidance system is formed, which greatly reduces the technical threshold for coordinated construction of complex terrain and heterogeneous plant communities. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of the changes in the position of shrubs;

[0039] Figure 2 This is a schematic diagram comparing the noise reduction rates of various plant configuration patterns in the sample plot;

[0040] Figure 3 Comparison of atmospheric particulate matter reduction rates for various plant configuration models in the sample plot;

[0041] Figure 4 This is a schematic diagram of the planting pattern;

[0042] Figure 5 This is a schematic diagram of terrain change types;

[0043] Figure 6 It is the plane distribution map of PM2.5 concentration;

[0044] Figure 7 It is the plane difference distribution map of PM2.5 concentration;

[0045] Figure 8 This is the plane difference distribution map of PM2.5 concentration in different terrains under planting type B;

[0046] Figure 9 This is the plane distribution diagram of PM2.5 concentration of blank control;

[0047] Figure 10 It is the graph of increase and decrease rate of PM2.5 concentration of blank control and mode 2;

[0048] Figure 11 The PM2.5 concentration increase and decrease rate curves for blank control and mode 2 (Y = 20m);

[0049] Figure 12 Schematic diagram of noise attenuation when passing through the corridor green belt;

[0050] Figure 13 is the noise attenuation change diagram;

[0051] Figure 14 This is the plan and elevation drawing of Tangshan sample plot 1;

[0052] Figure 15 This is the plane distribution map of PM2.5 concentration in Tangshan quadrat 1;

[0053] Figure 16 This is the distribution map of PM2.5 concentration increase and decrease rates before and after the transformation of Tangshan quadrat 1;

[0054] Figure 17 This is the noise attenuation change diagram of Tangshan quadrat 1;

[0055] Figure 18 This is the 6-level elevation drawing of the Nanjing sample plot;

[0056] Figure 19 This is the plane distribution map of 6PM2.5 concentration in Nanjing sample plot;

[0057] Figure 20 This is the distribution map of PM2.5 concentration increase and decrease rates before and after the transformation of Nanjing quadrat 6;

[0058] Figure 21 This is the noise attenuation change diagram of Nanjing sample plot 6. DETAILED DESCRIPTION

[0059] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0060] This example selects Tangshan, Nanjing, and Xining, typical cities in North China, the middle and lower reaches of the Yangtze River, and Northwest China, and investigates three types of urban ecological corridors: composite ecological corridors, road ecological corridors, and river ecological corridors. The survey mainly includes the current status of plants in corridor green belts, height differences, noise reduction, and dust retention effects. It summarizes the classic plant configuration patterns of urban ecological corridors, studies the relationship between plant configuration, terrain changes, and dust retention and noise reduction functions in field monitoring data, and uses ENVI-met and Rhino software to simulate and demonstrate the comprehensive effectiveness of ecological services such as dust retention and noise reduction under the classic plant configuration model. It proposes an optimization plan for the plant configuration model based on the minimum width of urban road corridors to improve the dust retention and noise reduction function.

[0061] The specific process is as follows:

[0062] Sample selection:

[0063] This example selected 8 sample plots in Tangshan, 9 sample plots in Nanjing, and 6 sample plots in Xining, and selected a total of 21 sample plots, all of which are typical sample plots of local urban ecological corridors. According to the three types of urban ecological corridors, namely road ecological corridors, river ecological corridors, and composite ecological corridors, the 21 sample plots were classified and summarized to obtain the following table:

[0064]

[0065] As can be seen from the above table, there are two types of sample plot configuration patterns: trees, shrubs and grasses, and trees and grasses. The tree and grass configuration pattern is rare and not typical. The plant configuration pattern of urban ecological corridor green space is basically dominated by trees, shrubs and grasses.

[0066] Surveys of 21 plots revealed that each plot was 30m x 30m in size. Besides hard paving, the green areas were primarily planted with trees, with shrubs and ground cover understory. Corridors rarely had large open green spaces. This was attributed to the limited width of corridors, while also aiming to achieve sufficient green space for both isolation and ecological benefits. Therefore, corridors were mostly fully planted with trees, forming large arbor forests.

[0067] In the case of fully planted tree plots, the shrub planting sites showed a certain regularity, and the shrubs were basically planted in strips along the road or along the side of the river. The specific changes in shrub location can be classified into 7 forms ( Figure 1 shown)

[0068] Among them, there is a change in the position of one type of shrub along the road ecological corridor:

[0069] The overall pattern of the plot is a combination of trees, shrubs and grasses. On one side of the road, shrubs and roadside trees form a hedge to separate the road space. The interior of the green space is mainly composed of trees.

[0070] There is a change in the location of one type of shrub along the river ecological corridor:

[0071] The overall configuration of the sample plot is a tree, shrub and grass pattern. Shrubs are planted within 15m on the river side, forming a tree, shrub and grass configuration pattern. Outside 15m, tree forests are mainly used, forming a tree and grass configuration pattern.

[0072] There are three types of shrub position changes in the composite ecological corridor, namely:

[0073] (1) Shrub position 1: Within 15 m on the river side, a tree, shrub, and grass configuration pattern is used; beyond 15 m, that is, on the road side, a tree and grass configuration pattern is used.

[0074] (2) Shrub location 2: On the road side, hedges are planted along the road, while trees are mainly planted inside the green space and along the river.

[0075] (3) Shrub location 3: A tree, shrub, and grass configuration pattern is used within 15 m on the river side, and hedges are planted along the road on the road side.

[0076] (4) There are only three plots with tree-grass configuration patterns, that is, the entire area within 30 m is in the tree-grass configuration pattern, and no shrubs are planted.

[0077] Noise reduction function plant configuration optimization:

[0078] This example takes the main noise source as the starting point, collects noise data from sample plots at intervals of 10m, and analyzes noise change trends and reduction rates. In addition to considering different plant configurations, the effects of factors such as the proportion of hard pavement and height difference on noise reduction are also considered. Figure 2 As shown, except for the road ecological corridor sample plot which is mainly composed of zero-fill roads, that is, there is no elevation change, the river ecological corridor and the composite ecological corridor both have elevation changes, ranging from 1.5m to 5m.

[0079] By comparison, it was found that the noise reduction in plots with a high proportion of hard pavement did not show a linear attenuation trend. This is probably because there are many activity venues on the site, including large-scale forest activity squares such as tree array squares, which leads to an increase in noise sources on the site.

[0080] The height difference is between 1.5m and 3m, and the noise reduction effect is better.

[0081] For green spaces with roads as the noise source, noise levels in both road ecological corridor plots and composite ecological corridor plots showed no discernible pattern in the first 20 meters. At sampling points of 10 and 20 meters, noise levels fluctuated, but by 30 meters, a clear attenuation trend was evident. Comparing plots with higher noise reduction rates, it was found that planting large trees along roads, combined with hedges approximately 3 meters wide, and with trees and grasses within the green belts, provided the best noise reduction results. Planting shrubs along rivers had little impact on noise reduction.

[0082] The river ecological corridor sample plot has no nearby roads, the site is relatively quiet, and the initial noise is low, so the overall noise reduction rate is relatively low.

[0083] Dust retention function is improved and plant configuration is optimized:

[0084] The PM2.5 concentrations at 0m, 15m, and 30m of the sample plot were collected to analyze the dust retention trend and reduction rate level (e.g. Figure 3 By comparison, it is found that the height difference with the best dust retention effect is between 1.5m and 4m.

[0085] The size of the hard pavement area has little effect on the dust retention effect and no relevant pattern is shown, which shows that the herb has a small adsorption effect on dust.

[0086] Generally speaking, green belts near roads have higher concentrations of pollutants due to road pollution, such as vehicle exhaust and dust, and are the primary source of pollutants in urban ecological corridors. River ecological corridors, without nearby roads, are relatively quiet and have fewer sources of pollutants, resulting in lower dust retention reduction rates overall.

[0087] For green spaces with roads as a source of atmospheric particulate matter pollution, the composite ecological corridor plots showed a greater average reduction rate than the road ecological corridor plots. Comparing these plots, planting street trees and shrubs near the road had a moderate dust retention effect. However, planting shrubs farther from the road, between 20 and 30 meters, showed the greatest dust retention, regardless of whether shrubs were present near the road.

[0088] Plant configuration optimization simulation:

[0089] Since this example analyzes the functional effectiveness of urban ecological corridors by focusing on structures such as rivers, roads, and greenbelts, roads are the primary source of atmospheric particulate matter pollution, primarily PM2.5, and are also a major source of noise. Rivers, on the other hand, primarily provide ecological services such as water conservation, biological habitat, and climate regulation, making them an indispensable component of the corridor module. Roads, rivers, and greenbelt systems are indispensable spatial carriers of urban ecological corridors and together form the foundation of the urban ecological network. Therefore, the site elements of the plant configuration optimization module in this study are composed of three elements: rivers, roads, and green spaces. Specifically, this example, targeting a composite ecological corridor, sets a 30m*30m green space module based on the 30m minimum width of the survey plot. The study examines how to achieve an optimal solution for synergistically improving dust retention and noise reduction functions by adjusting the tree, shrub, and grass configuration pattern. Considering that the corridor green space is primarily planted with trees based on the survey plots, the green space module is set to be fully planted with trees. At the same time, according to the above mentioned shrub position changes: ① Planting 3m wide hedges along the road has the best noise reduction effect; ② Planting shrubs away from the side of the road, that is, between 20m and 30m, has the best dust retention effect. Based on these two shrub position conditions and combined with the tree planting conditions, three plant configuration optimization modules are finally summarized ( Figure 8 Planting Patterns A, B, and C significantly improve the overall effectiveness of noise reduction and dust retention. Divide the 30-meter plot into 10-meter intervals. Within 10 meters of the river, a tree-shrub-grass or tree-grass pattern is used; within 10 meters of the center of the plot, a tree-grass pattern is used. Near the road, large trees and 3-meter-wide hedges are planted along the roadside, or only trees and grass are used.

[0090] The topographic changes in the road ecological corridor are mostly zero-fill sections, that is, the elevation difference is 0m. However, the topographic changes in the river ecological corridor and the composite ecological corridor are all the lowest at the river. According to the survey results of the sample plots, the topography can be summarized into three types: topographic change I, topographic change II, and topographic change III (such as Figure 5 As shown in the figure, the 30m sample plot is divided into 10m intervals. The side close to the river or the road has a significant height difference, followed by a gentle slope of 20m. Or the terrain gradually decreases within 30m along the road towards the river.

[0091] For the three planting pattern modules and three types of terrain variation described above, we selected the 3-meter elevation difference with the largest number of samples for simulation, and established a total of nine site models using ENVI-met software. Plant species with the highest frequency of occurrence in the survey plots were selected, with weeping willow and Sophora japonica selected as trees, and boxwood as shrub.

[0092] The two variable factors in this experiment are planting type and terrain change. One of them is selected as the only variable to simulate the quantitative change of green space. Through different combinations of planting type and terrain change, a total of 9 models are obtained, as shown in the following table:

[0093] Site Model Mode 1 Mode 2 Mode 3 Mode 4 Mode 5 Mode 6 Mode 7 Mode 8 Mode 9 Planting form A B C A B C A B C Terrain changes I I I II II II III III III

[0094] ENVI-met numerical simulation:

[0095] ENVI-met software consists of sub-models for the atmosphere, soil, buildings, and plants. Operations are performed through the collaborative interaction of these sub-models, simulating the interactions between building surfaces, urban subsurfaces, individual plants or communities, and the atmosphere. The Albero plant database stores default tree species, but due to regional and climatic factors, the model can be adjusted or restructured based on site plant conditions.

[0096] Using the ENVI-met model simulation method, nine models were simulated and analyzed to analyze the attenuation trend of atmospheric particulate matter concentration. The impact of urban ecological corridors on its reduction in terms of height difference and plant configuration patterns was explored, and an optimization technology for dust retention configuration within the minimum width of urban ecological corridors was proposed.

[0097] The software version is ENVI-met 5.6.1. June 1, 2025, which is sunny and windless, with no precipitation for 24 hours and little cloud cover, is selected as the simulation date. The simulation starts at 7:00 and takes 12 hours, with an interval of 30 minutes between each simulation. The initial wind speed is the average value of the measured data converted to a height of 10 meters. Since the main source of air pollution in the corridor is the road, the study selected a 90° wind direction as the simulation parameter. The lanes are all two-way lanes, and the pollution source is set as two line sources. Referring to Wu's emission source rate setting, the emission rate of each line source is 5.6μg / (s*m) 1 Specific parameters are shown in the table below:

[0098]

[0099] The model simulation analysis was carried out according to the reconstructed road section. The X-axis 11-20m is the river water, 21-50m is the corridor green space (30m wide), and 51-60m is the road. All the following ENVI-met software outputs are applicable. The Y-axis 6m to 36m is the north-south model boundary. The wind direction is from east to west. During the peak traffic period of residents' activities, 16:00 when the PM2.5 concentration is more prominent was selected as the simulation result output time. The PM2.5 concentration values ​​at a height of 1.5m were extracted from all scenes to obtain the PM2.5 concentration plane distribution diagrams under 9 modes (such as Figure 6(As shown). PM2.5 concentrations gradually increase from blue to purple, with peak concentrations occurring within 10 meters of the road. The concentrations fan out with wind direction. Road particulate matter concentrations are substantially reduced within 30 meters of the end of the green belt, essentially returning to their initial ambient values. Overall, PM2.5 levels begin to increase and then decrease, starting from the road. This suggests that the green belt has a role in adsorbing, aggregating, and settling particulate matter.

[0100] In order to further understand the effect of green belts on PM2.5 reduction and to more intuitively show the reduction differences between different modes, the PM2.5 concentration differences of different greening forms under the same terrain were compared to obtain the PM2.5 concentration plane difference distribution map at a height of 1.5m (see Figure 2). Figure 7 (as shown), we can know the reduction effect of different planting forms. For example, mode 2-1 is the difference in PM2.5 concentration between mode 2 and mode 1, and the plane difference distribution map of PM2.5 concentration of mode 2-1 is obtained. The blue part of the legend is a negative value, which means that when comparing the two modes, the former has a low concentration and the latter has a high concentration. The brown part of the legend is a positive value, which means that the former has a high concentration and the latter has a low concentration. Under the conditions of terrain I, the PM2.5 reduction effect mode 2>mode 1>mode 3; under the conditions of terrain II, mode 5>mode 4>mode 6; under the conditions of terrain III, mode 8>mode 7>mode 9. Generally speaking, under all types of terrain conditions, planting form B has the best dust retention effect, followed by planting form A, and planting form C is the worst.

[0101] Therefore, under the condition of planting form B, the dust retention effects of three different terrains, namely pattern 2, pattern 5 and pattern 8, were compared ( Figure 8 As shown in the figure, Pattern 2 has the best reduction effect, Pattern 8 is second, and Pattern 5 is the worst. This indicates that under the conditions of planting pattern B, Terrain I > Terrain III > Terrain II.

[0102] In summary, Model 2 has the best dust retention effect among the 9 models. To further understand the effect of green belts on PM2.5 reduction, Model 2 was compared with a blank without green belts (e.g. Figure 9 The data comparison panel of ENVI-met software was used to compare the concentration increase and decrease rate, that is, the relative difference value of PM2.5 concentration between blank control and mode 2, expressed as a percentage. Finally, the relative difference value diagram of blank control and mode 2 was obtained (as shown in the figure). Figure 10 shown).

[0103]

[0104] The relative difference value graph shows that the PM2.5 concentration increase / decrease rate shifts significantly to positive values ​​between 10m and 20m on the X-axis. Within the X-axis range of 20m to 60m, the values ​​are mostly negative. The Y-axis, 20m, represents the model's centerline. The PM2.5 concentration increase / decrease rates from the road to the green belt to the river are summarized in the center of the site, yielding a summary table of the PM2.5 concentration increase / decrease rates for the blank control and Model 2 (as shown in the table below).

[0105] X(m) Concentration increase or decrease rate X(m) Concentration increase or decrease rate X(m) Concentration increase or decrease rate 11 12.13％ 28 -11.70％ 45 -26.32％ 12 10.62％ 29 -13.34％ 46 -27.03％ 13 9.39％ 30 -14.58％ 47 -27.74％ 14 8.04％ 31 -15.41％ 48 -28.53％ 15 7.28％ 32 -16.30％ 49 -29.51％ 16 5.58％ 33 -16.96％ 50 -31.11％ 17 4.98％ 34 -17.59％ 51 -33.14％ 18 3.89％ 35 -18.15％ 52 -35.21％ 19 2.98％ 36 -18.76％ 53 -37.21％ 20 1.45％ 37 -19.48％ 54 -38.77％ 21 -1.30％ 38 -20.34％ 55 -39.74％ 22 -5.87％ 39 -21.32％ 56 -40.21％ 23 -1.17％ 40 -22.28％ 57 -40.38％ 24 -7.29％ 41 -23.23％ 58 -40.45％ 25 -7.34％ 42 -24.13％ 59 -40.60％ 26 -9.70％ 43 -24.96％ 60 -40.89％ 27 -11.82％ 44 -25.70％

[0106] As can be seen from the table above, the X-axis is positive from 11m to 20m, and then negative. From this analysis, starting from 30m in the corridor, the concentration increase and decrease rate gradually exceeds 1.45%, indicating that compared with the blank control, the dust retention effect of the green belt in the first 30m of mode 2 is obvious. In the blank control, due to the lack of plants to block the particles, the particles gradually spread to the distance. Figure 11 It can be seen that there are large changes in the X-axis ranges of 21-27m and 47-51m, indicating that on the basis of planting large trees, hedges have obvious dust retention and adsorption effects on particulate matter.

[0107] Numerical simulation of noise:

[0108] Based on the outdoor sound propagation attenuation formulas outlined in the "Technical Guidelines for Environmental Impact Assessment of Acoustic Environments" (HJ 2.4-2021) issued by the Ministry of Ecology and Environment, and taking into account the site's actual conditions, the attenuation terms for A.3.4.2 double diffraction calculations and A.3.5.1 attenuation due to greenbelts (Afo1) were calculated to derive noise attenuation variations applicable to corridor greenbelts. To simplify the calculation results and simulation process, only the inter-plot variables—the acoustic path difference δ and the greenbelt attenuation Afol—were calculated. Rhino software was then used to calculate the values ​​for each point, ultimately yielding a visualization of the noise attenuation variation.

[0109] The acoustic path difference δ and green belt attenuation A of this corridor study fol The calculation formula is as follows, and the numerical diagram of each formula is shown in Figure 12 .

[0110] The acoustic path difference δ between the diffracted sound and the direct sound:

[0111]

[0112] Where: δ is the sound path difference, m; a is the projected length of the distance between the sound source and the receiving point parallel to the upper boundary of the barrier, m; d is ss ——Distance from the sound source to the first diffraction edge, m; d sr ——the distance from the second diffraction edge to the receiving point, in m; d——the straight-line distance from the sound source to the receiving point, in m.

[0113] Receiving point noise value AR :

[0114] A R =A S -A fol

[0115] Where: A R ——Noise value at the receiving point, dB; A S ——Noise value of sound source, dB; A fol The attenuation of octave band noise when it propagates through a forest belt, dB. fol The attenuation value is calculated by calculating the total length of d1+d2, that is, the propagation distance, and substituting it into Table A.3 of HJ 2.4-2021. The radius of the curved path is 5 km.

[0116] From the noise attenuation change diagram from mode 1 to mode 9, we can see that ( Figure 13 ), noise showed a significant downward trend after passing through the 30m green belt. Across all terrain conditions, planting pattern B had the best noise reduction effect, followed by planting pattern C, and planting pattern A had the worst. Across all planting patterns, terrain I had the best noise reduction effect, followed by terrain II, and terrain III had the worst.

[0117] Simulation verification of optimization scheme:

[0118] The model validation results above show that planting pattern B has the best dust retention and noise reduction effects. To verify the dust retention and noise reduction effects of planting pattern B, two plots, Tangshan plot 1 and Nanjing plot 6, which performed poorly in the field survey, were selected to optimize the green space planting pattern and conduct model simulation verification.

[0119] Tangshan plot 1 has densely planted trees and neatly arranged trees, but the vegetation structure is simple and the number of shrubs is small, which cannot be closely matched with the trees. Therefore, the transformation plan is to plant 3m wide holly hedges along one side of the road and plant 10m wide shrubs within 30m behind the green belt. Figure 14 ).

[0120] The plane distribution of PM2.5 concentration before and after the transformation is as follows Figure 15 As shown. The PM2.5 concentration increase and decrease rate before and after the transformation is calculated to obtain the relative difference value diagram ( Figure 16 The X-axis (10m to 20m) represents the road, while the green belt (21m to 50m) is marked. The table below clearly shows that the modified plots exhibited significant dust retention within the first 25m of the plot, with PM2.5 concentrations at the end of the green belt decreasing by 7.26%. This modification scheme can, to a certain extent, reduce PM2.5 concentrations in the green belt overall.

[0121] X(m) Concentration increase or decrease rate X(m) Concentration increase or decrease rate X(m) Concentration increase or decrease rate 11 -7.08％ 28 -4.21％ 45 0.82％ 12 -5.97％ 29 -4.11％ 46 1.37％ 13 -4.80％ 30 -3.92％ 47 2.24％ 14 -3.70％ 31 -3.84％ 48 3.20％ 15 -3.29％ 32 -3.80％ 49 4.41％ 16 -3.46％ 33 -3.75％ 50 5.85％ 17 -4.06％ 34 -3.62％ 51 7.26％ 18 -4.48％ 35 -3.36％ 52 8.50％ 19 -4.80％ 36 -2.97％ 53 9.52％ 20 -5.38％ 37 -2.49％ 54 10.36％ 21 -6.27％ 38 -1.97％ 55 11.06％ 22 -6.77％ 39 -1.49％ 56 11.59％ 23 -6.84％ 40 -1.15％ 57 11.92％ 24 -6.54％ 41 -0.93％ 58 11.96％ 25 -5.73％ 42 -0.71％ 59 11.75％ 26 -4.91％ 43 -0.32％ 60 11.43％ 27 -4.36％ 44 0.31％

[0122] According to the noise attenuation change diagram within the 30m square plot ( Figure 17 ) As can be seen, the noise attenuation is greater after the renovation than before. The noise attenuation rate within the green space increased from 13.48% to 22.51%.

[0123] The trees in Nanjing plot 6 are relatively scattered and mostly small in size. The shade provided by the trees is insufficient and the enclosure formed by the trees is not enough. Therefore, the renovation plan is to plant 10m wide shrubs on the side of the green belt close to the river, form an enclosure along the existing weeping willow forest, plant a row of larger weeping willows on the bank, and increase the planting of street trees on both sides of the garden path ( Figure 18 ).

[0124] The plane distribution of PM2.5 concentration before and after the transformation is as follows Figure 19 As shown. The PM2.5 concentration increase and decrease rate before and after the transformation is calculated to obtain the relative difference value diagram ( Figure 20 The x-axis (10m to 20m) represents the river, the 21m to 50m represents the green belt, and the 51m to 60m represents the road. The table below clearly shows that PM2.5 concentrations at the end of the green belt decreased by 2.65% after the renovation compared to before. The renovation plan can reduce PM2.5 concentrations in the green belt to a certain extent.

[0125] X(m) Concentration increase or decrease rate X(m) Concentration increase or decrease rate X(m) Concentration increase or decrease rate 11 6.01％ 28 -4.48％ 45 -0.79％ 12 5.77％ 29 -4.08％ 46 -0.73％ 13 5.67％ 30 -3.55％ 47 -0.67％ 14 5.51％ 31 -3.00％ 48 -0.59％ 15 5.27％ 32 -2.51％ 49 -0.52％ 16 4.95％ 33 -2.15％ 50 0.44％ 17 4.53％ 34 -1.90％ 51 -0.36％ 18 4.00％ 35 -1.72％ 52 -0.10％ 19 3.38％ 36 -1.59％ 53 -0.03％ 20 2.65％ 37 -1.46％ 54 0.05％ 21 0.89％ 38 -1.33％ 55 0.14％ 22 -3.57％ 39 -1.21％ 56 0.23％ 23 -4.00％ 40 -1.11％ 57 0.32％ 24 -4.37％ 41 -1.02％ 58 0.43％ 25 -4.63％ 42 -0.93％ 59 0.56％ 26 -4.76％ 43 -0.86％ 60 0.73％ 27 -4.71％ 44 -0.79％

[0126] According to the noise attenuation change diagram within the 30m square plot ( Figure 21 ) As can be seen, the noise attenuation is greater after the renovation than before. The noise attenuation rate within the green space increased from 22.51% to 35.99%.

[0127] in conclusion:

[0128] This example uses ENVI-met and Rhino simulation software to quantitatively analyze the distribution characteristics of PM2.5 concentration and noise in the site under different greening parameters, and formulates corresponding improvement and transformation strategies based on this. According to the results of multiple comparative analysis, under the premise of improving dust retention and noise reduction effects, for the case where the minimum width of urban road corridors is 30m, the optimal plant configuration pattern for improving dust retention and noise reduction functions is to plant 3m wide shrubs along the road, plant 10m wide shrubs along the end of the green belt, and increase the number and volume of large trees. Since this study only proposes a modular optimal planting configuration pattern, the width setting of shrubs or the arrangement of tree planting points can be adjusted according to the division of pavement or the functional requirements of space, so as to achieve efficient use of space and optimization of landscape effects within a limited space.

[0129] The impact of plants on PM2.5 diffusion on a site is primarily related to their morphological characteristics and planting spacing. The larger the tree canopy and LAD, the smaller the plant spacing, and the lower the air exchange rate, which weakens the ventilation effect and traps PM2.5 concentrations. As a result, PM2.5 concentrations within the site will initially increase and then decrease. Therefore, to improve dust retention and noise reduction, in addition to optimizing plant configuration patterns and terrain variations, dust retention can also be improved by increasing plant size, increasing planting spacing, and selecting plants with large LADs. At the same time, as the contact area increases, the noise reduction effect also improves.

[0130] When selecting plants, considering the differences in plant types between the north and south, plants with larger LADs are more effective at trapping dust. Generally speaking, the size and distribution of LADs are not entirely determined by whether a plant is evergreen or deciduous, but rather by plant species, growing environment, and functional adaptability. Therefore, when selecting appropriate corridor plant species based on regional characteristics, whether evergreen or deciduous, broadleaf or coniferous, plants with large LADs should be chosen.

[0131] Because hard pavement has a minimal impact on dust retention and noise reduction, pedestrian comfort should be considered while maximizing the location of paths and recreational areas away from pollution and noise sources. Based on the results of this example, both particulate matter and noise exhibit a fan-shaped diffusion pattern. Therefore, installing hard pavement at the end of the green belt will minimize air pollutants and noise pollution.

[0132] Compared with existing technologies:

[0133] 1. This invention forms a spatial topological coupling system by precisely matching the evolution of terrain gradients with the plant hierarchy (pollution interface layer → core filtration layer → ecological protection layer). This creates a synergistic effect between terrain undulations and plant communities, simultaneously enhancing the dual functions of PM2.5 blocking and noise attenuation.

[0134] 2. This invention adopts a three-stage terrain evolution model and a standardized 30m module design, which can quickly match the optimal construction plan for different corridor types such as rivers and roads. The broken line transition of terrain turning points and the regular arrangement of plant matrices significantly improve the construction positioning accuracy and the predictability of ecological functions.

[0135] 3. Based on the modular segmentation of the three-stage terrain evolution model (0m→10m→20m→30m), combined with the hierarchical boundary marking of plant configuration, an intuitively identifiable construction guidance system is formed, which greatly reduces the technical threshold for coordinated construction of complex terrain and heterogeneous plant communities.

[0136] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A system for collaboratively improving the dust retention and noise reduction functions of urban ecological corridors, characterized by: include: Three-dimensional terrain structure, including ecological core areas and pollution sources: Among them, there is a height difference between the ecological core area and the pollution source; Composite plant layer structure, including: Pollution source interface layer, including wide hedge strips set along the pollution source boundary; The core filter layer is set up with a pure tree belt and is set up on the side of the pollution source interface layer away from the pollution source; The ecological protection layer is set up in the form of a shrub-grass composite belt, which is set between the side of the core filter layer away from the pollution source interface layer and the ecological core area.

2. The system for collaboratively improving the dust retention and noise reduction functions of urban ecological corridors according to claim 1 is characterized by: The height of the pollution source is higher than that of the ecological core area, and the terrain is arranged in a gradually descending trend.

3. The system for collaboratively improving the dust retention and noise reduction functions of urban ecological corridors according to claim 2 is characterized by: In the three-dimensional terrain structure, a gradient terrain is set along the direction from the ecological core area to the pollution source, including: Initial uplift section: forming a continuously uplifted terrain; High-level stable section: maintains the height of the elevated terrain up to the pollution source; Composite plant layer structure, including: Pollution source interface layer: includes wide hedge strips set along the boundary of the pollution source; Core filter layer: It is set up with a pure tree belt and is located on the side of the pollution source interface layer away from the pollution source; Ecological protection layer: A shrub-grass composite belt is set up between the side of the core filter layer away from the pollution source interface layer and the ecological core area.

4. The system for collaboratively improving the dust retention and noise reduction functions of urban ecological corridors according to claim 3 is characterized by: The slope ratio of the elevated terrain is 1:10-1:15, and the elevation rises from H0 to H1=H0+(0.8-1.5)m.

5. The system for collaboratively improving the dust retention and noise reduction functions of urban ecological corridors according to claim 4 is characterized by: The high-level stable section maintains the terminal height H1 of the elevated terrain fluctuating within ±0.15m up to the pollution source.

6. The system for collaboratively improving the dust retention and noise reduction functions of urban ecological corridors according to claim 5 is characterized by: The initial lifting section and the high-position stable section are connected by a broken-line transition, and the turning point is located at 10m±0.5m.

7. The system for collaboratively improving the dust retention and noise reduction functions of urban ecological corridors according to claim 6 is characterized by: The wide hedge belt is set along the side boundary of the road at 3.0±0.2m and contains mixed trees and shrubs.

8. The system for collaboratively improving the dust retention and noise reduction functions of urban ecological corridors according to claim 7 is characterized by: The tree is at least one of weeping willow and Sophora japonica, and the shrub is at least one of boxwood and holly hedge.

9. The system for collaboratively improving the dust retention and noise reduction functions of urban ecological corridors according to claim 8 is characterized by: The core filter layer is arranged in an area 3-20 m away from the pollution source.

10. The system for collaboratively improving the dust retention and noise reduction functions of urban ecological corridors according to claim 9, characterized in that: The shrub-grass composite belt is set up in an area 20-30 m away from the pollution source and includes mixed trees and shrubs.

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