Next Article in Journal
Monitoring and Mapping a Decade of Regenerative Agricultural Practices Across the Contiguous United States
Previous Article in Journal
Prioritizing Urban River Restoration Management Practices: A Cross-Evaluation Using the Criticality Index for Watershed Restoration (CIWR) and Opportunity Layers
 
 
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Landscape Metrics as Ecological Indicators for PM10 Prediction in European Cities

by
Seyedehmehrmanzar Sohrab
1,*,
Nándor Csikós
2,3 and
Péter Szilassi
1,*
1
Department of Physical and Environmental Geography, University of Szeged, Egyetem u. 2-6, H-6722 Szeged, Hungary
2
HUN-REN Institute of Soil Sciences, Centre for Agricultural Research, Fehérvári út 132-144, H-1116 Budapest, Hungary
3
MTA-SZTE Lendület Applied Ecology Research Group, Közép fasor 52, H-6726 Szeged, Hungary
*
Authors to whom correspondence should be addressed.
Land 2024, 13(12), 2245; https://doi.org/10.3390/land13122245
Submission received: 26 November 2024 / Revised: 16 December 2024 / Accepted: 17 December 2024 / Published: 21 December 2024

Abstract

:
Despite significant progress in recent decades, air pollution remains the leading environmental cause of premature death in Europe. Urban populations are particularly exposed to high concentrations of air pollutants, such as particulate matter smaller than 10 µm (PM10). Understanding the spatiotemporal variations of PM10 is essential for developing effective control strategies. This study aimed to enhance PM10 prediction models by integrating landscape metrics as ecological indicators into our previous models, assessing their significance in monthly average PM10 concentrations, and analyzing their correlations with PM10 air pollution across European urban landscapes during heating (cold) and non-heating (warm) seasons. In our previous research, we only calculated the proportion of land uses (PLANDs), but according to our current research hypothesis, landscape metrics have a significant impact on PM10 air quality. Therefore, we expanded our independent variables by incorporating landscape metrics that capture compositional heterogeneity, including the Shannon diversity index (SHDI), as well as metrics that reflect configurational heterogeneity in urban landscapes, such as the Mean Patch Area (MPA) and Shape Index (SHI). Considering data from 1216 European air quality (AQ) stations, we applied the Random Forest model using cross-validation to discover patterns and complex relationships. Climatological factors, such as monthly average temperature, wind speed, precipitation, and mean sea level air pressure, emerged as key predictors, particularly during the heating season when the impact of temperature on PM10 prediction increased from 5.80% to 22.46% at 3 km. Landscape metrics, including the SHDI, MPA, and SHI, were significantly related to the monthly average PM10 concentration. The SHDI was negatively correlated with PM10 levels, suggesting that heterogeneous landscapes could help mitigate pollution. Our enhanced model achieved an R² of 0.58 in the 1000 m buffer zone and 0.66 in the 3000 m buffer zone, underscoring the utility of these variables in improving PM10 predictions. Our findings suggest that increased urban landscape complexity, smaller patch sizes, and more fragmented land uses associated with PM10 sources such as built-up areas, along with larger and more evenly distributed green spaces, can contribute to the control and reduction of PM10 pollution.

1. Introduction

Air pollution is Europe’s largest environmental health risk, causing cardiovascular and respiratory diseases that impact health, reduce people’s quality of life, and cause preventable deaths. Urban air quality concerning particulate matter (PM) pollution, such as PM2.5 and PM10 (particles with a diameter of ≤10 μm) pollution, presents significant challenges to public health and the sustainability of urban development globally [1,2,3]. Particulate matter is a year-round pollutant and comprises a mixture of suspended solids and liquids in the air that are categorized based on size. The particles are produced from industrial, traffic, and geological sources (dust from roads or via chemical reactions in the atmosphere caused by released chemicals from motor vehicles or industrial sources). PM is not visible. Coarse particles (PM10) are 2.5 to 10 μm in diameter. Their small size allows them to make their way to the air passages deep within the lungs where they may be deposited and result in adverse health effects [4]. PM10 also causes visibility reduction. The European Environment Agency (EEA) plays a crucial role in monitoring and assessing air quality, publishing annual reports summarizing pollution levels including PM10 and their effects [5]. EU directives underscore the importance of air quality modeling in managing and mitigating air pollution in European cities. Directive 2008/50/EC, a cornerstone of European air quality legislation, emphasizes the use of modeling techniques to assess and predict pollutant concentrations, particularly in areas where fixed measurements are limited. The directive recognizes the role of modeling in understanding the spatial distribution of pollutants, identifying pollution hotspots, and developing effective mitigation strategies [6]. Modeling plays a crucial role in informing policy decisions, evaluating the effectiveness of emission reduction measures, and predicting future air quality trends in European cities [7]. Accurate models for predicting PM10 concentrations are essential to improving ecological management and guide urban planning efforts [1,8,9]. To understand the functioning of landscapes, landscape patterns must be considered, and indicators that address the spatial configuration of landscapes are therefore needed [10,11]. Our previous research focused on the effects of geological parameters such as soil texture, land use proportions (PLANDs), transportation network characteristics, and meteorological factors on PM10 levels. We found that climatological parameters, including temperature and wind speed, were significant contributors to PM10 variations [12]. Although the predictive precision of our models, as reflected in the adequate R² values, was promising, our objective was to investigate whether incorporating landscape metrics as additional ecological indicators can further enhance our PM10 prediction models. We hypothesized that these metrics will provide deeper insights into the spatial characteristics of urban environments and how land use patterns influence air pollution.
According to the ’pattern and process’ paradigm (how landscape structure affects ecological processes) [13,14], the pattern of the landscape structure is both a determinant and an indicator of the ecological and environmental processes that occur in a given landscape [15,16,17,18,19,20,21,22,23]. According to [24], the characterization of the landscape structure should assess both the spatial proportion (composition) of the patch types and the spatial arrangement (configuration) of the land use and land cover (LULC) patches (Figure 1).
Different landscape metrics have diverse effects on atmospheric particulate matter concentrations at different scales [25,26]. Metrics such as the SHDI, Shape Index (SHI), and Mean Patch Area (MPA) have been widely used to assess the complexity and heterogeneity of urban landscape structures, factors that can affect the dispersion and concentration of air pollutants [25,26,27,28,29,30,31,32]. The SHDI is a key measure of landscape complexity, which reflects the diversity and abundance of different types of land use within a given area. A more diverse and heterogeneous landscape can influence the movement and accumulation of PM10 by altering airflow patterns and pollutant dispersion [29,33,34,35,36].
Furthermore, the SHI and MPA provide insight into the dominance and scale of land use types and the complexity of the landscape that influence how pollutants are distributed throughout the landscape [29,31]. The contrast indexes, specifically the CI1 metric, reflect the interaction between land use types and air pollutant dispersion, with more extensive edges potentially enhancing pollutant trapping or dispersion in certain zones with different land use metrics.
In our previous findings, we identified correlations between different PLANDs and monthly average PM10 concentrations, categorizing land use types into three groups: those with a positive correlation (Group 1), a negative correlation (Group 2), and changeable correlation (Group 3) with PM10 levels [37]. Building on these results, we chose specific landscape metrics for each group to explore their potential as indicators in our model. For Groups 1 and 2, we selected metrics such as contrast indexes and AREA_MN, given their relevance in areas where certain land use types positively or negatively influence PM10 concentrations. For Group 3, our objective was to investigate whether landscape patterns without strong direct correlations could still play an indirect role in PM10 dispersion through their interactions with adjacent land uses.
Recent advances in machine learning (ML) techniques offer powerful tools for analyzing large and complex datasets, allowing for the capture of complex relationships between ecological landscape indicators and air pollution levels [38,39,40,41,42,43]. The Random Forest (RF) algorithm, in particular, is well-suited for this type of ecological modeling due to its ability to handle high-dimensional data and complex non-linear interactions [44,45,46,47,48]. Our study used RF to analyze a dataset comprising 26 independent variables, including climatological parameters, geological factors, and landscape metrics, based on more than 3000 data pairs. The capacity of RF to assess the importance of variables is crucial to identifying which landscape metrics are key predictors of PM10 concentrations. RF has been shown to be effective in similar environmental studies, demonstrating robustness and high accuracy [49,50,51].
The primary objectives of this study were to improve the accuracy of PM10 concentration prediction models by incorporating landscape metrics as landscape ecological indicators, assess the importance of these metrics in relation to PM10 pollution, and explore the correlations between landscape metrics and PM10 concentrations in different seasonal periods, such as the heating and cooling seasons. By achieving these goals, our aim was to advance the understanding of urban ecology and contribute to sustainable air quality management practices in European cities.

2. Study Area and Methods

2.1. Data Sources

The 2018 monthly average PM10 concentration data (µg/m³) were obtained from the European AQ Portal, which covers 1216 air quality (AQ) monitoring stations (1039 urban and 177 suburban) throughout Europe [52]. The landscape indicators surrounding the PM10 monitoring stations were analyzed using the 2018 Copernicus Land Monitoring Urban Atlas Service of the European Union. This polygon-based LULC dataset, with a minimum mapping unit of 0.25 hectares, was published by the EEA under the Copernicus program on 16 April 2020, and updated on 16 July 2021 [53]. Based on previous studies, the aggregated Urban Atlas land use categories were applied [12,37]. Based on LUCAS topsoil data, the USDA soil texture class dataset was used to assess the physical properties of the European topsoil. It includes soil texture categories such as clay, silty clay, sandy clay loam, and more [54]. This dataset was published in 2015 by the European Soil Data Center (ESDAC) under the European Commission and Joint Research Center. Monthly data for 2018 were sourced from the Climate Data Store (CDS) to analyze meteorological conditions, such as the average monthly 10 m wind speed (m s−1) (the horizontal speed of the wind, or movement of air, at a height of ten meters above the surface of the Earth), MSL (mean sea level) pressure (Pa) (the pressure (force per unit area) of the atmosphere on the surface of the Earth, adjusted to the height of the mean sea level), 2 m average temperature (the temperature of air 2 m above the surface of land, the sea, or inland waters), and total precipitation (mm) (the accumulated liquid and frozen water, comprising rainfall and snowfall, on the Earth’s surface) [55].

2.2. Spatial Data Analysis

2.2.1. Calculation of Landscape Metrics

Landscape patterns quantified using landscape metrics are useful for predicting and understanding PM10 concentrations. Landscape metrics can provide information on the composition and configuration of the landscape (Figure 1).
Previous studies have shown that landscape metrics can provide a good explanation for PM concentrations, but effectiveness is affected by the spatial scale of the analysis [25,29,56]. Due to our previous studies [12,37,57], we applied different buffer zones with a radius of 1 km and 3 km centered on the 1039 European air quality monitoring stations in urban landscapes. Buffer zones with less than 80% land use coverage were excluded to focus on zones where a predominant land use type is present, improving the reliability of the correlation between land use and PM10 concentrations. In areas with at least 80% coverage, the dominant land use provided a clearer and more consistent influence on air quality, enhancing the predictive precision of PM10 concentration modeling.
In our analysis, to calculate the landscape metrics relevant to PM10 prediction modeling (Table 1), we used two main tools: the V-LATE extension in ArcMap and the ZonalMetrics tools in ArcGIS Pro 3.2.2. The SHDI was calculated for each buffer area to assess the diversity of land cover types surrounding the air quality monitoring stations. For class-level analysis, the MPA and SHI were determined for each of the three groups: barriers, sources, and changeable land uses. Land use polygons with centroids located within designated buffer zones were specifically selected to calculate the SHI. This strategy allowed us to include complete patches representing the landscape structure within each buffer, ensuring a more accurate connection between shape characteristics and PM10 concentrations. By focusing only on polygons with centroids inside the buffer, we minimized issues associated with fragmented patches along the buffer edges. Contrast indices such as the Contrast Class Edge (CCE), CI1, and CI2 were calculated specifically between land uses that are sources or barriers of PM10, allowing us to evaluate differences in PM10 concentrations associated with the respective land use categories. This targeted approach provided information on the interactions between various landscape structures and air quality.
Three types of land cover were formed in the Urban Atlas according to the correlation of their area with PM10 values. Among the LULC types of the Urban Atlas, some increased (sources) and others decreased (barriers) urban air PM10 concentrations during all months of the year. The third so-called ‘temporary changeable’ group of Urban Atlas LULC categories was made up of LULC types that showed opposite relationship with PM10 values during the heating and cooling periods (Table 2) [37].
The configuration of urban landscapes was characterized by averages of landscape metrics describing the MPA and complexity (SHI) of the LULC patches belonging to the three LULC groups above, and the length of their edges divided by the areas of the different buffer zones (CCE, CI1, and CI2). The compositional heterogeneity of urban landscapes (buffer areas around PM10 monitoring stations) was characterized by the spatial PLAND of each Urban Atlas LULC category (PLAND) and the SHDI index of the heterogeneity of the LULC pattern.

2.2.2. Calculation of Soil and Meteorological Factors

Other independent variables such as soil texture, and meteorological variables—including wind speed (m/s), mean sea level pressure (Pa), total precipitation (mm), and mean temperature (°C)—were calculated or extracted from urban landscape 1000 m and 3000 m buffer zones, following prior findings on scale sensitivity [36]. The spatial analysis was performed using Arc Map 10.6.1, QGIS 3.22, and ArcGIS Pro 3.2.2.

2.3. Statistical Analyzes

2.3.1. Random Forest Modeling (RF)

We chose 18.3 °C as the threshold for the monthly average temperature in Europe to distinguish between heating and cooling periods for buildings, following the guidelines of previous studies [58,59,60,61,62]. The urban landscape dataset was divided accordingly. When the monthly mean temperature was below 18.3 °C, it was classified as the heating period and when it exceeded 18.3 °C, it was classified as the cooling period [12].
In this study, we applied a Random Forest regression model using the Databricks platform to predict PM10 concentrations, incorporating a variety of ecological landscape indicators (26 independent variables). Random Forest was selected for its robustness in handling large datasets, its ability to capture complex relationships, and its built-in feature importance mechanism. This algorithm excels in scenarios with complex and nonlinear interactions between variables, which is particularly important in environmental studies where the interdependency between ecological indicators in the landscape can be complex [44]. Furthermore, Random Forest models tend to be less prone to overfitting, making them highly suitable for ecological research that involves diverse and complex datasets [63].
Cross-validation was used to enhance the reliability of the model by tuning the hyperparameters and evaluating the performance of different subsets of the data, ensuring that the model generalized well to unseen samples. This approach helps prevent overfitting while optimizing the predictive power of the model [64]. The Databricks platform, a cloud-based environment optimized for big data analytics, was leveraged for its seamless integration with Apache Spark, which allowed the use of distributed computing to process our large datasets efficiently. Apache Spark is an open-source distributed computing system designed for big data processing. It is known for its speed due to its in-memory data processing, scalability between computer clusters, and support for various tasks such as data streaming and machine learning [65]. This integration significantly reduces the computational time and improves scalability, which is critical in studies that require the analysis of large ecological datasets. Databricks also offers an interactive and collaborative environment that supports Python-based libraries such as Scikit-Learn, making it an ideal choice for iterative model building and hyperparameter tuning [66].

2.3.2. Model Development

We used a 70/30 split of training/test datasets, following a similar approach to that used by [12] to ensure consistency in model development and validation. This split allowed us to evaluate model performance on both the training and test datasets, providing a balanced assessment of the model’s predictive power. The Random Forest model was implemented using the Scikit-Learn library in Python (version 3.9.19), a well-established tool for machine learning due to its flexibility and reliability [66]. Scikit-Learn is used in ecological modeling and environmental studies, providing reliable and efficient solutions for handling large datasets and complex models [67], as well as supporting high-performance machine learning techniques for classification, regression, and clustering tasks [68]. Random Forest is a machine learning technique that is particularly well-suited to handling multicollinearity, a condition where independent variables in a dataset are highly correlated. Unlike linear regression models, which can suffer from inflated standard errors and misleading statistical inferences due to multicollinearity, Random Forests are less affected because of their tree-based structure and random feature selection process during training. Random Forests build multiple decision trees, each using a random subset of features, which reduces the influence of correlated predictors on the model’s performance [44,69]. To optimize the model, we performed 5-fold cross-validation, which is a robust method for tuning hyperparameters like ‘max_depth’ and ‘n_estimators’. Cross-validation ensures that the model avoids overfitting and generalizes well to unseen data [70]. After selecting the best hyperparameters, we evaluated the performance of the model using the coefficient of determination (R²) for both the training and test sets. Strong agreement between the R² scores of these sets indicated minimal overfitting, demonstrating the strong ability of the Random Forest model to generalize to new data [44]. This consistent performance confirmed the robustness of the model in predicting PM10 concentrations.

2.3.3. Model Evaluation

We evaluated the accuracy of all models using key performance metrics, including the coefficient of determination (R²), RMSE (Root Mean Square Error), and MAE (Mean Absolute Error). The high R² values in both the training and the test datasets further validated the precision and reliability of the Random Forest model in predicting PM10 concentrations. Additionally, the inclusion of the RMSE and MAE provided a more comprehensive assessment of model performance, quantifying the average magnitude of the prediction errors and ensuring robustness [71,72,73]. These metrics not only confirmed the model’s predictive accuracy but also facilitated meaningful comparisons with our previous modeling approaches [12], further strengthening the reliability of our findings.

2.3.4. Feature Importance

We assessed the contribution of each variable using the importance attribute of the characteristics of the best-performing model. This method provides a ranking of the predictor variables based on their influence on the model’s predictions. The results were normalized into percentages, highlighting the relative importance of each landscape index, environmental factor, and meteorological factor in explaining the variations of PM10.

2.3.5. Spearman Coefficient Correlation

The Spearman correlation coefficient was applied to explore the relationships between environmental variables and the monthly average PM10 concentrations in different periods and buffer zones. The dataset, initially stored in a Spark DataFrame, was processed in Databricks and converted to a Pandas DataFrame for ease of manipulation. The categorical variables were transformed using one-hot encoding to allow for numerical comparisons. Spearman correlation was chosen for its ability to measure both linear and non-linear monotonic relationships. Correlation coefficients and p-values were calculated to evaluate the strength and significance of each variable’s impact on PM10 concentrations, helping to identify key ecological and environmental drivers of the landscape at the different spatial scales. To address potential multicollinearity among the independent variables identified through Spearman correlation, Variance Inflation Factor (VIF) values were calculated. This step ensures that the predictor variables used in the modeling process are independent and do not exhibit problematic levels of multicollinearity. The VIF analysis was conducted in Python (Version 3.9.19) using the processed Pandas DataFrame. The results, presented in Table A2, show that all the VIF values were below 9, confirming that multicollinearity was not a concern in our analysis. This additional step strengthens the reliability of our modeling approach.

3. Results

3.1. Improvements to the Model’s Performance

The performance of the RF model was evaluated using a combination of landscape metrics, climatological variables, and soil texture categories. The performance of the RF model was improved by incorporating new landscape metrics along with the existing variables. Table 3 summarizes the R2 values of the model for the training and test sets, as well as the hyperparameters that were used to achieve the best performance.
The addition of landscape metrics led to a noticeable improvement in the model’s predictive capability compared to that seen in the previous study [6]. For example, in the 1000 m buffer zone during the cooling period, the R2 for the training set increased from 0.36 (in the previous study) to 0.52, while the R2 for the test set reached 0.58. Similarly, in the 3000 m buffer zone during the cooling period, the R² value improved from 0.41 to 0.48 for the training set and 0.50 for the test set, indicating better model performance. During the heating period, the model also showed a significant improvement. In the 1000 m buffer zone, the R2 of the training set increased from 0.57 to 0.593, with the test set showing an R² of 0.619. The best performance was observed in the 3000 m buffer zone during the heating period, where the R² for the training set improved from 0.61 to 0.652, and the test set achieved an R² of 0.666. To enhance model validation, the RMSE and MAE metrics were calculated, showing clear improvements compared to the previous study. Incorporating landscape metrics significantly reduced prediction errors. For example, in the 1000 m buffer zone during the cooling period, the RMSE decreased from 4.84 to 3.72 and the MAE decreased from 3.58 to 2.74. Similar improvements were observed across all buffer zones and periods. These findings confirm the enhanced predictive accuracy of the RF model. The detailed metrics are presented in Table A1.

3.2. Analysis of Independent Variable Importance and Spearman Correlation Coefficient

3.2.1. Heating Period

During the heating period within the 1000 m buffer zone, the temperature emerged as the most critical variable that influenced the concentration of PM10, with an importance of 20.08%. This was closely followed by total precipitation (11.99%) and wind speed (11.10%). These variables exhibited significant negative correlations with the PM10 concentration, suggesting a reduction in PM10 levels with higher values of these climatic factors. Specifically, temperature showed a Spearman correlation coefficient of −0.197 (p < 0.001), while total precipitation and wind speed had coefficients of −0.273 (p < 0.001) and −0.231 (p < 0.001), respectively. These findings, illustrated in Figure 2, indicate that higher temperatures, increased precipitation, and stronger winds are associated with decreased PM10 concentrations in this buffer zone during the heating period. The SHI for LULC Group 3 which comprises LULC classes that demonstrated varying impacts on the monthly average PM10 concentration in our earlier research [37] shows that it contributed to PM10 predictions by up to 5.23% and exhibited a positive correlation with PM10 levels.
In the 3000 m buffer zone during the heating period, temperature continued to exert the greatest influence on the PM10 concentration, with an increased importance of 22.46%. The second and third most influential variables were wind speed (14.58%) and total precipitation (11.77%). All three variables maintained negative correlations with the PM10 concentration, underscoring their importance in reducing particulate levels during this period. The temperature correlation with the concentration of PM10 was −0.24 (p < 0.001), while the correlations of wind speed and total precipitation were −0.272 (p < 0.001) and −0.299 (p < 0.001), respectively. These negative associations, represented in Figure 3, emphasize the importance of these variables, especially precipitation, in the potential dispersal or mitigation of PM10 levels during the heating period.

3.2.2. Cooling Period

During the cooling period in the 1000 m buffer zone, total precipitation became the main factor influencing the PM10 levels, with an importance of 9.40%. Three landscape metrics emerged as notable factors, with 7.55%, 7.51%, and 6.68% importance, respectively. The MPS of LULC categories with a changeable effect on PM10 levels and the SHI of LULC categories with a changeable effect on PM10 levels exhibited significant positive correlations with the PM10 concentration, with coefficients of 0.3 (p < 0.001) and 0.337 (p < 0.001), respectively. In contrast, total precipitation showed a negative correlation with PM10 levels (−0.098, p < 0.001), suggesting a mitigating effect. Furthermore, a greater diversity in LULC categories was associated with a reduction in monthly average PM10 pollution within the 1000 m buffer zones. These findings are illustrated in Figure 4.
In the 3000 m buffer zone during the cooling period, air pressure emerged as the most significant variable associated with the PM10 concentration, accounting for 12.76% of the importance. This was followed by total precipitation (9.55%) and the SHI of the PM10 source LULC categories (6.04%). The air pressure exhibited a negative correlation with PM10 (−0.104, p < 0.001), suggesting that a higher air pressure could help disperse PM10. However, the SHI of the PM10 source LULC categories showed a negative correlation coefficient of −0.212 (p < 0.001), indicating that a higher SHI for these types of LULC categories can contribute to higher levels of PM10 under certain conditions. Figure 5 provides a visual representation of these associations, highlighting the important effects of air pressure and landscape metric variables on PM10 pollution levels during cooling periods.

3.2.3. Effect of Different Soil Texture Categories

The findings revealed that the texture of the soil exerted a stronger influence during the heating period and in areas closer to the AQ stations. The Spearman correlation coefficients indicated similar significance within the 1000 m and 3000 m buffer zones around the stations. During the cooling period, soil textures, such as silty clay, were positively correlated with PM10 concentrations, suggesting that these soil types contribute to higher PM10 levels. On the contrary, loam, sandy loam, and silt loam showed negative correlations, which implies that these soil textures were associated with lower PM10 concentrations. During the heating period, the correlation patterns changed. The sandy clay and loam showed significant negative correlations with PM10 concentrations, indicating a reduction in PM10 levels. However, loamy sand, silt loam, and silty clay loam were positively correlated with PM10 levels, suggesting that they exacerbated pollution levels.

4. Discussion

4.1. Model Improvement

The improvement in model performance can be attributed to the inclusion of new landscape metrics, which served as important ecological landscape indicators. Metrics such as shape indices, patch sizes, and diversity indices offered a more detailed view of LULC patterns and their relationship with PM10 concentrations. By incorporating these ecological indicators of the landscape, the model was able to capture more complex spatial relationships, leading to better predictions of levels of air pollution. Compared to the previous approach, the current model provided a more accurate representation of the ecological landscape and its influence on air quality. The analysis of feature importance for both the cooling and heating periods highlighted significant changes in the key variables influencing PM10 concentrations in urban landscapes, and compared the results of the previous study [12] with those of the current study that incorporates landscape metrics as landscape ecological indicators. Furthermore, the spatial scale of the analysis, represented by the buffer zones, significantly affected the relationship between the landscape metrics and PM10 concentration, which is comparable to that of [25]. Table 4 shows the main variables with more than 5% importance in both studies, categorized by buffer zones (1000 m and 3000 m) during the cooling and heating periods.
In the cooling period in the 1000 m buffer zone, the previous study identified soil texture (20.75%) and roads (11.77%) as the most important variables, while in the current study, total precipitation (9.39%) and the MPS of LULC categories with a changeable effect on PM10 (7.55%) ranked the highest. Temperature appeared in both studies but was more important in the previous study (10.26%) compared to the current study (6.36%). Forests were important in the previous study (7.94%), but not in the current one. In the 3000 m buffer zone, the previous study highlighted forests (15.44%) and soil texture (12.83%) as the main variables, while the current study showed that MSL air pressure (12.76%) and total precipitation (9.55%) were the most significant. Temperature and wind speed were present in both studies but with slight differences in their degrees of importance.
In the heating period in the 1000 m buffer zone, the temperature had the highest importance in both studies, with 26.33% in the previous study and 20.08% in the current study. Wind speed and total precipitation were also key variables, and both studies showed similar importance levels. The current study added MSL air pressure (8.38%) and the SHI of LULC categories with a changeable effect on PM10 (5.23%) to the main variables, which were not present in the previous study. In the 3000 m buffer zone, total precipitation and wind speed were important in both studies, although the current study assigned lower percentages (11.77% and 14.58%, respectively) compared to the previous study. The temperature also remained significant, with a slight reduction from 12.79% in the previous study to 22.46% in the current one. The MSL air pressure was identified as a significant variable only in the current study (7.82%).

4.2. Effects of Climatological Variables

Our study confirmed the significant influence of temperature, wind speed, total precipitation, and air pressure on PM10 concentrations, highlighting their importance in predicting and managing PM10 levels, especially during the heating season. In particular, temperature exerted a particularly pronounced effect on PM10 levels during the heating period, with its predictive influence nearly quadrupling compared to the cooling period (ranging from 5.80% in the cooling period within a 3000 m radius to 22.46% during the heating period within the same distance). This substantial increase indicates that temperature fluctuations during the heating season may enhance the retention of pollutants, likely due to limited atmospheric mixing and reduced dispersal. In contrast, during the cooling period, total precipitation emerged as the dominant predictor, suggesting that precipitation plays a more active role in mitigating PM10 concentrations through washout effects when heating sources are minimal.
Additionally, we identified distinct seasonal correlation patterns: a negative correlation between temperature and PM10 concentration during the heating season, likely due to heightened emissions from heating sources in colder conditions, and a positive correlation during the cooling season due to enhanced evaporation and the formation of secondary particles [74,75]. For example, a study in Switzerland found a positive correlation between high afternoon temperatures and PM10 concentrations, particularly in summer [74]. This suggests that as temperatures increase, the evaporation of volatile compounds increases, contributing to the formation of secondary aerosols that can increase PM10 levels. On the contrary, low temperatures, particularly during winter, can also lead to increased PM10 concentrations. This is attributed to the condensation of volatile compounds and the increase in residential heating emissions, particularly from wood burning [76,77,78]. The Swiss study also found a positive correlation between low temperatures in winter and high PM10 concentrations [74]. This finding highlights the need to consider seasonal variations when examining the impact of temperature on PM10 levels [79]
Our findings also revealed a consistent negative correlation between the monthly average total precipitation and monthly average wind speed with monthly average PM10 concentrations in both seasonal periods in 2018. These results suggest that higher wind speeds and precipitation rates are effective in reducing PM10 levels throughout the year, either by dispersing particulate matter or by facilitating its removal from the atmosphere. Higher wind speeds promote PM10 dispersion and dilution, leading to lower concentrations. This is supported by previous studies such as [12,77,78,79,80,81,82,83,84]. Precipitation, especially rainfall, is widely recognized as a significant factor in reducing PM10 concentrations [12,77,80,85,86,87]. Rainfall effectively removes PM10 from the atmosphere through wet deposition, leading to lower PM10 levels.
According to our findings, there was a significant negative correlation between the monthly average air pressure at sea level and the monthly average PM10 concentration, especially during the cooling period. In contrast, several studies have indicated a positive correlation between air pressure and PM10 concentrations [75,79,81,88] because traditionally, high atmospheric pressure is often associated with stable atmospheric conditions, which can trap pollutants near the surface, leading to higher PM10 concentrations. The observed negative correlation during the cooling period suggests that other factors may be at work, potentially overriding the traditional influence of high pressure. Cooling periods are generally characterized by transitional weather patterns, which can significantly influence atmospheric dynamics, such as wind pattern mixing and precipitation effects. Cooling periods often experience changes in wind patterns, which can enhance the vertical mixing and dispersion of pollutants, even under high pressure conditions. The increase in wind speed during these periods could counteract the trapping effect of high pressure, leading to lower concentrations of PM10. For example, Ref. The importance of wind patterns and their influence on the transport and dispersion of pollutants, particularly during seasonal transitions [81]. Furthermore, cooling periods, depending on the specific geographic location, could also be associated with increased precipitation, which can further contribute to the removal of PM10 from the atmosphere through wet deposition. Analyzing long-term meteorological data and PM10 measurements for the study area could provide a comprehensive understanding of the seasonal and temporal variations in this relationship. Understanding these relationships is crucial to developing effective strategies to manage and mitigate PM10 pollution, ultimately improving air quality and protecting public health.

4.3. Effects of Landscape Metrics

Our results proved that landscape metrics significantly affect PM10 concentrations; these effects varied across the heating and non-heating periods and different buffer zones. For instance, forests and urban parks played an essential role in reducing PM10 levels. Specifically, we observed a strong negative correlation between the PLAND metric for forests (in both buffer zones) and urban parks (within the 3000 m buffer zone only) during both the heating and cooling periods. This indicates that expanding vegetated areascould effectively reduce PM10 concentrations, which is in agreement with the results reported in [89]. The effectiveness of green spaces as PM filters is influenced by their shape, size, and configuration. Green areas with large surface areas (high AREA_MN) and complex shapes (high Shape Index) are more effective at capturing particulates [29]. This aligns with our current findings, which demonstrated a significant negative correlation between the SHI of LULC types acting as barriers to PM10 pollution and distances of 1000 m from air quality monitoring stations during both the cooling and heating periods.
Increasing the area of grassland patches (measured by AREA_MN) was beneficial for PM10 reduction in both buffer zones during the cooling period, because grassland acts as effective natural filters for air pollutants. The vegetation in grassland areas captures particulate matter, including PM10, through processes such as sedimentation and deposition [90].
The analysis of land use metrics, particularly the SHI and MPA, across different groups of LULC categories (G1, G2, and G3) revealed distinct patterns in their correlation with monthly average PM10 concentrations. Our findings demonstrated that for Group 3 (LULC categories with changeable effects on PM10 concentrations), both the SHI and MPA had substantial impacts on PM10 concentrations, particularly during the cooling (non-heating) period within a 1000 m buffer zone from the air quality (AQ) stations.
The positive correlation between PM10 levels and the SHI of LULC categories with a changeable effect on PM10 suggests that a more complex and fragmented urban structure leads to higher PM10 pollution and is supported by several studies that highlight the impact of landscape configuration on PM concentrations. For instance, a study on green space buffers (GBSs) in Shanghai discovered that a higher landscape SHI was correlated with a longer diffusion distance for atmospheric particles such as PM2.5 and PM10. This indicates that more complex shapes were less effective in reducing PM pollution, potentially allowing for a wider spread of pollutants [91]. Studies have emphasized that a fragmented landscape can hinder the effectiveness of green spaces in mitigating air pollution, allowing pollutants to accumulate in urban areas. Research in Shenzhen [26] indicated that increasing the percentage of land and edge density in built-up areas contributes to higher PM10 concentrations. Furthermore, a study in Seoul [92] found that areas with densely built-up areas and high traffic volumes, often characteristic of fragmented landscapes, experienced prolonged periods of high levels of PM2.5. These findings support the idea that a more complex and fragmented urban structure, represented by a higher SHI in our analysis, can lead to higher PM10 pollution. Additionally, during heating months (when temperatures drop below 18.3 °C), the demand for heating increases emissions and complex urban patches tend to trap pollutants due to reduced air circulation. In non-heating months (above 18.3 °C), when emissions are lower, the complex shapes still hinder pollutant dispersion. This means that irregular LULC patterns in urban areas can restrict airflow, causing pollutants such as PM10 to accumulate, especially when heating demands add to pollution. More information using data on air circulation patterns and pollutant dispersion would improve our understanding of these mechanisms. Factors such as building height and compactness, wind direction, and temperature inversions, which are discussed in the cited references, can significantly influence air circulation and pollutant dispersion [26,34,93,94].
The findings indicate that there is a positive correlation between PM10 levels and the MPA for Groups 1 and 3. Group 1, identified as sources of PM10, likely includes areas with high emissions. Larger patches in these high-emission areas appeared to concentrate PM10 pollution, particularly during the heating season, when emissions were high due to heating demands. This is consistent with the understanding that emission sources and urban morphology can interact to influence air quality. A study in Poland [29] found that the highest concentrations of PM10 occurred in autumn and winter, suggesting the importance of residential and traffic sources. PM concentration was observed to be higher inside urban landscapes than outside, particularly for PM10, highlighting the role of urban emissions in pollution levels. The increased concentration of PM10 in larger patches within the LULC categories that are sources of PM10 pollution during the heating season is consistent with the understanding that heating demands contribute significantly to PM emissions. A study in Weifang, China [95], found that PM2.5 pollution was exacerbated in winter due to increased emissions from coal burning for heating. Research in Poland [29] also highlighted the influence of household heating using solid fuels on PM10 levels, particularly during the colder months.
For LULC categories with a changeable effect on PM10, larger patches were associated with an increase in PM10 during the heating period within a radius of 1000 m to 3000 m, and within 1000 m during the cooling period. This pattern suggests that the relationship between the MPA and PM10 concentration is complex and is influenced by factors beyond emissions alone. One of the possible reasons could be that compact urban patterns in Group 3 contributed to pollutant accumulation, even in periods of lower emissions, due to limited air dispersion in dense environments. Research in Nanchang, China [96], found that PM2.5 concentrations were higher in compact urban areas compared to open areas, indicating that the density of buildings can influence air quality. Our results highlight the importance of considering scale when analyzing the relationship between urban form and air quality.
On the contrary, Group 2 (railways and forests within 1000 m and industrial units, urban parks, grasslands, and water bodies in the 3000 m buffer zone), as barriers to PM10 pollution, demonstrated a negative correlation between PM10 concentrations and the MPS, with larger patches acting as barriers to PM10 pollution within 1000 m of the AQ stations in both the heating and cooling seasons. These areas probably consist of green spaces or low-emission zones that buffer pollutants and promote cleaner air. Larger patches in the LULC PM10 barrier may have provided a dispersive effect, allowing PM10 to dissipate more easily and decreasing pollutant levels near the AQ stations. This suggests that integrating larger green or low-emission areas around urban centers can be effective in managing air quality, particularly near emission sources. Forests play a vital role in PM10 mitigation and their effectiveness increases with greater coverage and connectivity [25,97]. The presence of forests within both 1000 m and 3000 m radii could contribute significantly to reducing PM10 concentrations. According to [94], the negative regression coefficient of the building agglomeration index within 1000 m in winter suggested that increased building density, which might indirectly indicate reduced forest coverage, was associated with higher PM10 concentrations. Moreover, the combined presence of forests, urban parks, and grasslands can create a synergistic effect, maximizing PM10 mitigation potential [94,95]. Larger and more connected patches of these green spaces within both radii could effectively act as barriers to PM10 pollution.
Among landscape metrics, the Shannon diversity index (SHDI) plays an important role in PM10 prediction within 1000 m buffer zones during the cooling period. SHDI reflects landscape complexity and balance in the distribution of various LULC patch types in the landscape [31,98]. Although some references discuss the relationship between landscape metrics such as the SHDI and PM2.5 concentrations [31,34,89,93], Other authors have not investigated the relationship between the Shannon diversity index and PM10 in the literature.. According to our results, the Shannon diversity index, a measure of landscape complexity, was negatively correlated with the monthly average PM10 concentration in all buffer zones in both the heating and non-heating periods. This suggests that a more diverse landscape with a mix of LULC classes can contribute to lower PM10 levels. These findings are consistent with previous studies, such as [94]. Diverse landscapes often include more green spaces. Green spaces act as sinks for air pollutants such as PM10 [29,37,93]. These findings support the idea that a mixed land use strategy can reduce the risk of exposure to a high concentration of PM by dispersing PM in urban areas [99]. They also recommend securing sufficient open space in urban areas to minimize PM concentration and variability. Some authors confirmed our finding that a higher landscape complexity (LULC heterogeneity) can contribute to the reduction of PM pollution levels [89].
In our study, the contrast index (CI1) measured the edge length of LULC categories that are sources of PM10 pollution. This index was particularly relevant during the cooling period, where it showed a significant positive correlation with monthly average PM10 concentrations. In other words, a longer edge length for LULC categories that contribute to PM10 pollution is associated with higher PM10 levels in the surrounding area. Several studies have investigated the connection between the edge length of specific LULC types, often represented by the landscape metric edge density (ED), and PM concentration [89,94]. Ref. [94] found a positive correlation between the edge density (ED) of architectural landscapes and PM10 concentrations. This indicates that as the length of the edge and fragmentation of the built-up areas increase, PM concentrations also tend to rise. Our findings contribute to a growing body of research highlighting the importance of landscape configuration, specifically the edge length of PM source areas, in understanding and mitigating PM pollution.

4.4. Effect of Different Soil Textures

The influence of soil texture on PM10 emissions, especially during the heating seasons, was significant due to factors such as reduced vegetation cover, intensified wind erosion, and increased particulate matter from human activities such as residential heating. Fine-textured soils—particularly those rich in clay and silt—play a crucial role in PM10 emissions because these fine particles are more readily retained by the soil and subsequently resuspended in the air, leading to elevated PM10 levels. During the colder months, when the vegetative cover is sparse, silty clay soils tend to trap more particles that can easily be lifted into the atmosphere. Ref. [100] highlighted that fine-textured soils, such as silty clay, significantly contribute to dust resuspension, especially in dry and windy conditions, a finding consistent with our study, which noted higher PM10 emissions in areas with fine soils during heating periods.
The size of soil particles has been shown to affect PM10 emission levels, with finer particles, such as clay, being more susceptible to resuspension. Ref. [101] reported that finer particles, such as clay, resulted in higher concentrations of PM10 as they are more readily transported by wind. In contrast, coarser soils, such as loam and sandy loam, exhibited reduced susceptibility to resuspension, resulting in lower PM10 emissions. Ref. [102] observed that coarser soils resist wind erosion more effectively, leading to a negative correlation between coarse soil textures and PM10 concentrations, findings that align with our observations that coarser soils inherently contributed less to PM10 pollution.
Ref. [103] reinforced the role of soil texture in particulate emissions, noting that PM10 emissions were higher in soils with a higher silt and clay content but lower in sandy soils. This relationship emphasizes that soil composition plays a key role in PM10 emissions and resuspension, especially during seasons with increased particulate release due to heating and wind. Other studies further support that finer soils containing more clay and silt have a higher PM10 emission potential than coarser soils with a predominance of sand [101,104,105]. For example, studies using a dust resuspension chamber in the San Joaquin Valley of California Valley demonstrated a strong correlation between PM10 emissions and clay content, with clay-rich soils showing a higher propensity for PM10 emissions [104]. Wind tunnel experiments confirmed these findings, indicating that PM10 emissions increase with silt content and decrease with sand content [101].
The distinct characteristics of clay and silt particles make them particularly influential in PM10 pollution. Clay particles, due to their small size, are easily airborne, directly contributing to PM10 emissions. Silt, although larger than clay, also falls within the PM10 range and can be easily transported by wind [102,106]. In contrast, sandy soils, though vulnerable to wind erosion, may emit less PM10 if they have already lost fine particles through previous erosion events. Research in the free state region of South Africa supports this, demonstrating that erodible, loose soils with clay and silt significantly increase PM10 emissions [107].
In summary, soil texture—specifically clay and silt content—emerged as a key factor influencing PM10 emissions, with fine-textured soils showing a higher susceptibility to resuspension and particulate release than coarser soils. As our findings contribute to the growing evidence on the subject, it becomes increasingly clear that soil texture should be considered in PM10 pollution mitigation strategies, particularly in regions with seasonal climatic changes that amplify particulate emissions.
According to our findings, the effect of climate change has opposite effects during cooling and heating periods: when the temperature increases, then PM10 from heating is reduced, which could count as a benefit of climate change; however, during cooling periods (summer), the monthly average temperature can increase the monthly average PM10 concentration because the top soil will be dryer, and therefore, it can be a source of PM10 pollution. To mitigate the impact of fine-textured soils on PM10 emissions, especially during heating seasons, shelterbelts can be planted to reduce wind erosion and the soil can be covered during the winter months with crops such as cabbage to limit soil exposure. Leaves of plant residues from previous harvests can also act as a natural barrier against wind erosion. These strategies not only reduce particulate pollution but also improve soil health and agricultural sustainability, offering practical solutions for regions prone to high PM10 levels.

5. Conclusions

In conclusion, this study demonstrated that incorporating landscape metrics such as the SI, MPS, and SHDI significantly improves PM10 prediction models, providing a more accurate understanding of how LULC influences air quality. Meteorological factors, such as monthly average temperature, wind speed, precipitation, and air pressure, had a strong impact on PM10 concentrations. Notably, the temperature’s effect was amplified during the heating season, with its impact nearly quadrupling, which indicates increased pollutant retention during this time. Landscape composition, especially the presence of green spaces, is vital to reducing monthly average PM10 levels. Larger patches in high-emission areas (LULC Groups 1 and 3) tended to increase PM10, particularly during the heating periods due to concentrated emissions. In contrast, larger patches in barrier zones (LULC Group 2) helped mitigate PM10 levels by acting as buffers or facilitating pollutant dispersion. This study highlights that the specific landscape configurations, such as the size, shape, and connectivity of green spaces, significantly impact the diffusion and distribution of PM10. For instance, larger, contiguous patches of forests and urban parks are more effective in mitigating PM10, while fragmented and complex built-up areas tend to exacerbate pollution levels. Soil texture, especially fine-textured soils rich in clay and silt, also contributes to PM10 levels by resuspending particles, particularly in the colder months when vegetation cover is limited. These findings underscore the importance of adapting PM10 management strategies to account for landscape structure, seasonal variations, and climate trends to enhance urban air quality and public health. Our research provides valuable information for landscape planners looking to create sustainable urban environments. Although we cannot fully control climate-related factors, modifying LULC and landscape configurations presents an effective tool for reducing PM10 pollution and improving urban planning results. Climate change is likely to further influence PM10 levels through altered temperature and precipitation patterns. Warmer temperatures could reduce heating-related emissions in winter but could increase dust generation due to the dryness of the soil in summer [108]. Changes in precipitation could also affect wet deposition processes, altering the removal of PM10 from the atmosphere. Given the complex interplay of these factors, a comprehensive approach to mitigation is essential. This includes integrating urban planning strategies, emission control measures, and public health considerations. Promoting green infrastructure and optimizing urban forms to enhance ventilation are key interventions that can help address PM10 pollution and improve urban air quality [96]. Cities can adopt design guidelines to enhance air circulation, such as lower aspect ratios for street canyons, strategic building orientations aligned with wind patterns, and ground-level porosity through features like arcades or elevated structures [109,110,111]. Zoning regulations can restrict building heights and densities in ventilation corridors or near sensitive areas like schools and hospitals [110]. Mixed-use development, reduced vehicle reliance, and green infrastructure, such as green roofs and strategically placed trees, could further improve air quality when carefully planned [109,112,113]. This study was limited by the thematic accuracy (≥80%) of the Urban Atlas LULC dataset, which may have introduced uncertainties in the spatial modeling. While landscape metrics such as the PLANDs, SHDI, SHI, and MPA were effectively used, future research could improve predictions by integrating urban form indexes (e.g., connectivity, compactness, and 3D structural metrics) to better capture spatial configurations. Additionally, using daily PM10 concentrations instead of monthly averages could enhance temporal precision and provide deeper insights into short-term variations in air quality.

Author Contributions

Conceptualization, P.S.; methodology, S.S. and N.C.; validation, S.S. and N.C.; formal analysis, S.S.; investigation, S.S.; resources, S.S.; data curation, S.S.; writing—original draft, S.S.; writing—review and editing, N.C. and P.S.; Visualization, S.S. and N.C.; supervision, P.S.; project administration, P.S. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Data Availability Statement

No new data were created or analyzed in this study. Data sharing is not applicable to this article.

Conflicts of Interest

The authors declare no conflict of interest.

Appendix A

Table A1. Random Forest PM10 Prediction Modeling Performance Validation Metrics, Incorporating Landscape Metrics Across Cooling and Heating Periods in Urban Landscapes.
Table A1. Random Forest PM10 Prediction Modeling Performance Validation Metrics, Incorporating Landscape Metrics Across Cooling and Heating Periods in Urban Landscapes.
Buffer ZonePeriodRMSE
Test Set (30%)
Previous Study
CRF Modeling
MAE
Test Set (30%)
Previous Study
CRF Modeling
RMSE
Test Set (30%)
RF Modeling
MAE
Test Set (30%)
RF Modeling
1000 mCooling4.843.583.722.74
3000 mCooling4.633.354.022.95
1000 mHeating6.834.925.974.29
3000 mHeating6.644.705.964.18
Table A2. Variance Inflation Factor (VIF) of Independent Variables Investigated for Correlation with PM10 Concentration Using Spearman Correlation Across Cooling and Heating Periods at 1000 m and 3000 m Scales in Urban Landscapes.
Table A2. Variance Inflation Factor (VIF) of Independent Variables Investigated for Correlation with PM10 Concentration Using Spearman Correlation Across Cooling and Heating Periods at 1000 m and 3000 m Scales in Urban Landscapes.
Independent VariableVIF
Cooling PeriodHeating Period
1000 m3000 m1000 m3000 m
MPS of PM10 Source LULC Categories1.9118853.0286661.9628843.302535
MPS of PM10 Barriers4.4802912.5973564.2506563.024115
MPS of LULC Categories with Changeable Effect on PM102.3932201.2346642.1808161.229374
SHI of PM10 Source LULC Categories1.2508772.5869771.1970912.005047
SHI of PM10 Barriers1.6625931.3856101.6005991.365938
SHI of LULC with Changeable Effect on PM101.8673001.2150571.8284401.243012
SHDI1.9911321.7541371.9904791.598674
CI14.9586733.8189495.1244834.751261
CI27.3276208.2159718.1874918.902750
CCE8.3445738.3604507.4459028.745668
Air Pressure1.2640551.2812031.0702241.095389
Total Precipitation1.3708481.5006501.1741971.181026
Temperature1.4171261.4165421.1232521.149163
Wind Speed1.2100101.4306291.1012491.259422
PLAND of Built-Up Area8.3806245.5204518.3613146.866883
PLAND of Industrial Unit7.3015252.8200408.2303683.356350
PLAND of Roads4.8155263.2810173.9577303.625052
PLAND of Railways2.7019121.5114172.3555321.600790
PLAND of Mine, Dump, and Construction Sites1.1391291.3319241.1742591.340900
PLAND of Vacant Lands1.4730161.2549671.3357421.277378
PLAND of Urban Parks8.8086992.8365966.2191593.207821
PLAND of Arable Lands8.3757656.9107814.6918727.744227
PLAND of Grasslands6.6329183.7127664.3802734.683871
PLAND of Forests6.9451853.4600856.0283924.489963
PLAND of Water2.8480262.0020942.4812362.822331

References

  1. Kuerban, M.; Waili, Y.; Fan, F.; Liu, Y.; Qin, W.; Dore, A.J.; Peng, J.; Xu, W.; Zhang, F. Spatio-Temporal Patterns of Air Pollution in China from 2015 to 2018 and Implications for Health Risks. Environ. Pollut. 2020, 258, 113659. [Google Scholar] [CrossRef] [PubMed]
  2. Zhang, Z.; Wu, L.; Chen, Y. Forecasting PM2.5 and PM10 Concentrations Using GMCN(1,N) Model with the Similar Meteorological Condition: Case of Shijiazhuang in China. Ecol. Indic. 2020, 119, 106871. [Google Scholar] [CrossRef]
  3. Žibert, J.; Cedilnik, J.; Pražnikar, J. Particulate Matter (PM10) Patterns in Europe: An Exploratory Data Analysis Using Non-Negative Matrix Factorization. Atmos. Environ. 2016, 132, 217–228. [Google Scholar] [CrossRef]
  4. Subramanian, A.; Khatri, S.B. The Exposome and Asthma. Clin. Chest Med. 2019, 40, 107–123. [Google Scholar] [CrossRef] [PubMed]
  5. Beloconi, A.; Vounatsou, P. Revised EU and WHO Air Quality Thresholds: Where Does Europe Stand? Atmos. Environ. 2023, 314, 120110. [Google Scholar] [CrossRef]
  6. European Parliament and Council of the European Union. Directive 2008/50/EC of the European Parliament and of the Council. Off. J. Eur. Union 2008, 133, 19–40. [Google Scholar]
  7. European Parliament. Council of the European Union DIRECTIVE (EU) 2024/2881 on Ambient Air Quality and Cleaner Air for Europe. Off. J. Eur. Union 2024, 2881, 1–70. [Google Scholar]
  8. Guerreiro, C.B.B.; Foltescu, V.; de Leeuw, F. Air Quality Status and Trends in Europe. Atmos. Environ. 2014, 98, 376–384. [Google Scholar] [CrossRef]
  9. Vardoulakis, S.; Kassomenos, P. Sources and Factors Affecting PM 10 Levels in Two European Cities: Implications for Local Air Quality Management. Atmos. Environ. 2008, 42, 3949–3963. [Google Scholar] [CrossRef]
  10. Uuemaa, E.; Mander, Ü.; Marja, R. Trends in the Use of Landscape Spatial Metrics as Landscape Indicators: A Review. Ecol. Indic. 2013, 28, 100–106. [Google Scholar] [CrossRef]
  11. Uuemaa, E.; Antrop, M.; Roosaare, J.; Marja, R.; Mander, Ü. Landscape Metrics and Indices: An Overview of Their Use in Landscape Research. Living Rev. Landsc. Res. 2009, 3, 1–28. [Google Scholar] [CrossRef]
  12. Sohrab, S.; Csikós, N.; Szilassi, P. Effect of Geographical Parameters on PM10 Pollution in European Landscapes: A Machine Learning Algorithm-Based Analysis. Environ. Sci. Eur. 2024, 36, 152. [Google Scholar] [CrossRef]
  13. Robinson, H.S.; Weckworth, B. Landscape Ecology: Linking Landscape Metrics to Ecological Processes. In Snow Leopards: Biodiversity of the World: Conservation from Genes to Landscapes; Academic Press: Cambridge, MA, USA, 2016; pp. 395–405. [Google Scholar] [CrossRef]
  14. Forman, R.T.T. Some General Principles of Landscape and Regional Ecology. Landsc. Ecol. 1995, 10, 133–142. [Google Scholar] [CrossRef]
  15. Herzog, H.; Caldeira, K.; Reilly, J. An Issue of Permanence: Assessing the Effectiveness of Temporary Carbon Storage. Clim. Chang. 2003, 59, 293–310. [Google Scholar] [CrossRef]
  16. Haberl, H.; Wackernagel, M.; Wrbka, T. Land Use and Sustainability Indicators. An Introduction. Land Use Policy 2004, 21, 193–198. [Google Scholar] [CrossRef]
  17. Tasser, E.; Sternbach, E.; Tappeiner, U. Biodiversity Indicators for Sustainability Monitoring at Municipality Level: An Example of Implementation in an Alpine Region. Ecol. Indic. 2008, 8, 204–223. [Google Scholar] [CrossRef]
  18. Renetzeder, C.; Schindler, S.; Peterseil, J.; Prinz, M.A.; Mücher, S.; Wrbka, T. Can We Measure Ecological Sustainability? Landscape Pattern as an Indicator for Naturalness and Land Use Intensity at Regional, National and European Level. Ecol. Indic. 2010, 10, 39–48. [Google Scholar] [CrossRef]
  19. Schindler, S.; Sebesvari, Z.; Damm, C.; Euller, K.; Mauerhofer, V.; Schneidergruber, A.; Biró, M.; Essl, F.; Kanka, R.; Lauwaars, S.G.; et al. Multifunctionality of Floodplain Landscapes: Relating Management Options to Ecosystem Services. Landsc. Ecol. 2014, 29, 229–244. [Google Scholar] [CrossRef]
  20. Lausch, A.; Blaschke, T.; Haase, D.; Herzog, F.; Syrbe, R.U.; Tischendorf, L.; Walz, U. Understanding and Quantifying Landscape Structure—A Review on Relevant Process Characteristics, Data Models and Landscape Metrics. Ecol. Model. 2015, 295, 31–41. [Google Scholar] [CrossRef]
  21. Szilassi, P.; Bata, T.; Szabó, S.; Czúcz, B.; Molnár, Z.; Mezősi, G. The Link between Landscape Pattern and Vegetation Naturalness on a Regional Scale. Ecol. Indic. 2017, 81, 252–259. [Google Scholar] [CrossRef]
  22. Gál, T.; Skarbit, N.; Unger, J. Urban Heat Island Patterns and Their Dynamics Based on an Urban Climate Measurement Network. Hung. Geogr. Bull. 2016, 65, 105–116. [Google Scholar] [CrossRef]
  23. Gallé, R.; Happe, A.K.; Baillod, A.B.; Tscharntke, T.; Batáry, P. Landscape Configuration, Organic Management, and within-Field Position Drive Functional Diversity of Spiders and Carabids. J. Appl. Ecol. 2019, 56, 63–72. [Google Scholar] [CrossRef]
  24. Jeanneret, P.; Aviron, S.; Alignier, A.; Lavigne, C.; Helfenstein, J.; Herzog, F.; Kay, S.; Petit, S. Agroecology Landscapes. Landsc. Ecol. 2021, 36, 2235–2257. [Google Scholar] [CrossRef]
  25. Lin, F.; Chen, X. Effects of Landscape Patterns on Atmospheric Particulate Matter Concentrations in Fujian Province, China. Atmosphere 2023, 14, 787. [Google Scholar] [CrossRef]
  26. Ku, C.A. Exploring the Spatial and Temporal Relationship between Air Quality and Urban Land-Use Patterns Based on an Integrated Method. Sustainability 2020, 12, 2964. [Google Scholar] [CrossRef]
  27. Zhang, J.; Wang, X.; Xie, Y. Implication of Buffer Zones Delineation Considering the Landscape Connectivity and Influencing Patch Structural Factors in Nature Reserves. Sustainability 2021, 13, 10833. [Google Scholar] [CrossRef]
  28. Jaafari, S.; Shabani, A.A.; Moeinaddini, M.; Danehkar, A.; Sakieh, Y. Applying Landscape Metrics and Structural Equation Modeling to Predict the Effect of Urban Green Space on Air Pollution and Respiratory Mortality in Tehran. Environ. Monit. Assess. 2020, 192, 412. [Google Scholar] [CrossRef] [PubMed]
  29. Łowicki, D. Landscape Pattern as an Indicator of Urban Air Pollution of Particulate Matter in Poland. Ecol. Indic. 2019, 97, 17–24. [Google Scholar] [CrossRef]
  30. Li, F.; Zhou, T.; Lan, F. Relationships between Urban Form and Air Quality at Different Spatial Scales: A Case Study from Northern China. Ecol. Indic. 2021, 121, 107029. [Google Scholar] [CrossRef]
  31. Xu, W.; Jin, X.; Liu, M.; Ma, Z.; Wang, Q.; Zhou, Y. Analysis of Spatiotemporal Variation of PM2.5 and Its Relationship to Land Use in China. Atmos. Pollut. Res. 2021, 12, 101151. [Google Scholar] [CrossRef]
  32. Park, Y.; Shin, J.; Lee, J.Y. Spatial Association of Urban Form and Particulate Matter. Int. J. Environ. Res. Public Health 2021, 18, 9428. [Google Scholar] [CrossRef] [PubMed]
  33. McGarigal, K.; Marks, B.J. FRAGSTATS: Spatial Pattern Analysis Program for Quantifying Landscape Structure; US Department of Agriculture, Forest Service, Pacific Northwest Research Station: Dolores, CO, USA, 1995; 122p. [CrossRef]
  34. Hu, H.; Zeng, S.; Han, X. Effects of Urban Landscapes on Pollutant Concentrations in Chengdu Plain Urban Agglomeration. Atmosphere 2022, 13, 1492. [Google Scholar] [CrossRef]
  35. Zeng, C.; Song, Y.; He, Q.; Liu, Y. Urban–Rural Income Change: Influences of Landscape Pattern and Administrative Spatial Spillover Effect. Appl. Geogr. 2018, 97, 248–262. [Google Scholar] [CrossRef]
  36. Sterzyńska, M.; Nicia, P.; Zadrożny, P.; Fiera, C.; Shrubovych, J.; Ulrich, W. Urban Springtail Species Richness Decreases with Increasing Air Pollution. Ecol. Indic. 2018, 94, 328–335. [Google Scholar] [CrossRef]
  37. Sohrab, S.; Csikos, N.; Szilassi, P. Effects of Land Use Patterns on PM10 Concentrations in Urban and Suburban Areas. A European Scale Analysis. Atmos. Pollut. Res. 2023, 14, 101942. [Google Scholar] [CrossRef]
  38. Lublin, P.M.; Kujawska, J.; Kulisz, M.; Oleszczuk, P.; Cel, W. Machine Learning Methods to Forecast the Concentration of PM10 in Lublin, Poland. Energies 2022, 15, 6428. [Google Scholar] [CrossRef]
  39. Guo, Q.; He, Z.; Wang, Z. Prediction of Hourly PM2.5 and PM10 Concentrations in Chongqing City in China Based on Artificial Neural Network. Aerosol. Air Qual. Res. 2023, 23, 220448. [Google Scholar] [CrossRef]
  40. Shaziayani, W.N.; Ul-Saufie, A.Z.; Mutalib, S.; Mohamad Noor, N.; Zainordin, N.S. Classification Prediction of PM10 Concentration Using a Tree-Based Machine Learning Approach. Atmosphere 2022, 13, 538. [Google Scholar] [CrossRef]
  41. Mampitiya, L.; Rathnayake, N.; Hoshino, Y.; Rathnayake, U. Performance of Machine Learning Models to Forecast PM10 Levels. MethodsX 2024, 12, 102557. [Google Scholar] [CrossRef]
  42. Jemeļjanova, M.; Kmoch, A.; Uuemaa, E. Adapting Machine Learning for Environmental Spatial Data—A Review. Ecol. Inform. 2024, 81, 102634. [Google Scholar] [CrossRef]
  43. Farmonov, N.; Amankulova, K.; Khan, S.N.; Abdurakhimova, M.; Szatmári, J.; Khabiba, T.; Makhliyo, R.; Khodicha, M.; Mucsi, L. Effectiveness of Machine Learning and Deep Learning Models at County-Level Soybean Yield Forecasting. Hung. Geogr. Bull. 2023, 72, 383–398. [Google Scholar] [CrossRef]
  44. Breiman, L. Random Forests. Mach. Learn. 2001, 45, 5–32. [Google Scholar] [CrossRef]
  45. Hartmann, P.; Urso, L.; Petermann, E.; Gn, F. Use of Random Forest Algorithm for Predictive Modelling of Transfer Factor Soil-Plant for Radiocaesium: A Feasibility Study. J. Environ. Radioact. 2023, 270, 107309. [Google Scholar] [CrossRef]
  46. Simon, S.M.; Glaum, P.; Valdovinos, F.S. Interpreting Random Forest Analysis of Ecological Models to Move from Prediction to Explanation. Sci. Rep. 2023, 13, 3881. [Google Scholar] [CrossRef]
  47. Brugere, L.; Kwon, Y.; Frazier, A.E.; Kedron, P. Forest Ecology and Management Improved Prediction of Tree Species Richness and Interpretability of Environmental Drivers Using a Machine Learning Approach. For. Ecol. Manag. 2023, 539, 120972. [Google Scholar] [CrossRef]
  48. Cappelli, F.; Castronuovo, G.; Grimaldi, S. Random Forest and Feature Importance Measures for Discriminating the Most Influential Environmental Factors in Predicting Cardiovascular and Respiratory Diseases. Int. J. Environ. Res. Public Health 2024, 21, 867. [Google Scholar] [CrossRef]
  49. Czernecki, B.; Marosz, M.; Jędruszkiewicz, J. Assessment of Machine Learning Algorithms in Short-Term Forecasting of PM10 and PM2.5 Concentrations in Selected Polish Agglomerations. Aerosol Air Qual. Res. 2016, 21, 1–18. [Google Scholar] [CrossRef]
  50. Ricardo, A.; Valencia, Z.; Alfonso, A.; Rosales, R. Application of Random Forest in a Predictive Model of PM10 Particles in Mexico City. Nat. Environ. Pollut. Technol. 2024, 23, 711–724. [Google Scholar] [CrossRef]
  51. Mamić, L.; Gašparović, M. Developing PM2.5 and PM10 Prediction Models on a National and Regional Scale Using Open-Source Remote Sensing Data. Environ. Monit. Assess. 2023, 195, 644. [Google Scholar] [CrossRef]
  52. European Environment Agency (EEA). The European Air Quality (AQ) Portal. Available online: https://www.eea.europa.eu/en/analysis/maps-and-charts/ (accessed on 12 October 2022).
  53. EEA Urban Atlas 2018. Available online: https://land.copernicus.eu/local/urban-atlas/urban-atlas-2018 (accessed on 26 January 2023).
  54. Panagos, P.; Van Liedekerke, M.; Borrelli, P.; Köninger, J.; Ballabio, C.; Orgiazzi, A.; Lugato, E.; Liakos, L.; Hervas, J.; Jones, A.; et al. European Soil Data Centre 2.0: Soil Data and Knowledge in Support of the EU Policies. Eur. J. Soil Sci. 2022, 73, e13315. [Google Scholar] [CrossRef]
  55. Hersbach, H.; Bell, B.; Berrisford, P.; Biavati, G.; Horányi, A.; Muñoz Sabater, J.; Nicolas, J.; Peubey, C.; Radu, R.; Rozum, I.; et al. ERA5 Monthly Averaged Data on Single Levels from 1940 to Present. Available online: https://cds.climate.copernicus.eu/cdsapp?fbclid=IwAR1BDSE0WQUyGWYaB2wsTw2DsRLRlsQz4dnuNy0wcS1tmM65sQP_EkeKPWk#!/dataset/reanalysis-era5-single-levels-monthly-means?tab=form (accessed on 30 November 2023).
  56. Liu, Y.; Wu, J.; Yu, D. Characterizing Spatiotemporal Patterns of Air Pollution in China: A Multiscale Landscape Approach. Ecol. Indic. 2017, 76, 344–356. [Google Scholar] [CrossRef]
  57. Sohrab, S.; Csikós, N.; Szilassi, P. Connection between the Spatial Characteristics of the Road and Railway Networks and the Air Pollution (PM10) in Urban–Rural Fringe Zones. Sustainability 2022, 14, 10103. [Google Scholar] [CrossRef]
  58. World Health Organization. WHO Housing and Health Guidelines; WHO: Geneva, Switzerland, 2018; ISBN 9789241550376. [Google Scholar]
  59. Moreci, E.; Ciulla, G.; Lo Brano, V. Annual Heating Energy Requirements of Office Buildings in a European Climate. Sustain. Cities Soc. 2016, 20, 81–95. [Google Scholar] [CrossRef]
  60. Jin, Z.; Zheng, Y.; Zhang, Y. A Novel Method for Building Air Conditioning Energy Saving Potential Pre-Estimation Based on Thermodynamic Perfection Index for Space Cooling. J. Asian Archit. Build. Eng. 2023, 22, 2348–2364. [Google Scholar] [CrossRef]
  61. Xiong, J.; Chen, L.; Zhang, Y. Building Energy Saving for Indoor Cooling and Heating: Mechanism and Comparison on Temperature Difference. Sustainability 2023, 15, 11241. [Google Scholar] [CrossRef]
  62. Moustris, K.P.; Zacharia, P.T.; Larissi, I.K.; Nastos, P.T.; Paliatsos, A.G. Cooling and Heating Degree-Days Calculation for Representative Locations Within the Greater Athens Area, Greece. In Proceedings of the 12th International Conference on Environmental Science and Technology, Rhodes, Greece, 8–10 October 2011; pp. 8–10. [Google Scholar]
  63. Cutler, D.R.; Edwards, T.C.; Beard, K.H.; Cutler, A.; Hess, K.T.; Gibson, J.; Lawler, J.J. Random Forests for Classification in Ecology. Ecology 2007, 88, 2783–2792. [Google Scholar] [CrossRef]
  64. Kohavi, R. A Study of Cross-Validation and Bootstrap for Accuracy Estimation and Model Selection. IJCAI Int. Jt. Conf. Artif. Intell. 1995, 2, 1137–1143. [Google Scholar]
  65. Zaharia, M.; Xin, R.S.; Wendell, P.; Das, T.; Armbrust, M.; Dave, A.; Meng, X.; Rosen, J.; Venkataraman, S.; Franklin, M.J.; et al. Apache Spark: A Unified Engine for Big Data Processing. Commun. ACM 2016, 59, 56–65. [Google Scholar] [CrossRef]
  66. Pedregosa, F.; Varoquaux, G.; Gramfort, A.; Michel, V.; Thirion, B.; Grisel, O.; Blondel, M.; Prettenhofer, P.; Weiss, R.; Dubourg, V.; et al. Scikit-Learn: Machine Learning in Python. J. Mach. Learn. Res. 2011, 12, 2825–2830. [Google Scholar]
  67. Buitinck, L.; Louppe, G.; Blondel, M.; Pedregosa, F.; Mueller, A.; Grisel, O.; Niculae, V.; Prettenhofer, P.; Gramfort, A.; Grobler, J.; et al. API Design for Machine Learning Software: Experiences from the Scikit-Learn Project. arXiv 2013, arXiv:1309.0238. [Google Scholar]
  68. Varoquaux, G.; Buitinck, L.; Louppe, G.; Grisel, O.; Pedregosa, F.; Mueller, A. Scikit-Learn. GetMobile Mob. Comput. Commun. 2015, 19, 29–33. [Google Scholar] [CrossRef]
  69. Evans, J.S.; Murphy, M.A.; Holden, Z.A. Modeling Species Distribution and Change Using Random Forest. In Predictive Species and Habitat Modeling in Landscape Ecology; Springer: New York, NY, USA, 2011; Chapter 8. [Google Scholar] [CrossRef]
  70. Hastie, T.; Tibshirani, R.; Friedman, J. The Elements of Statistical Learning Data Mining, Inference, and Prediction, 2nd ed.; Springer: Berlin/Heidelberg, Germany, 2009; ISBN 9781479932115. [Google Scholar]
  71. Res, C.; Willmott, C.J.; Matsuura, K. Advantages of the Mean Absolute Error (MAE) over the Root Mean Square Error (RMSE) in Assessing Average Model Performance. Clim. Res. 2005, 30, 79–82. [Google Scholar]
  72. Chai, T.; Draxler, R.R. Root Mean Square Error (RMSE) or Mean Absolute Error (MAE)? -Arguments against Avoiding RMSE in the Literature. Geosci. Model. Dev. 2014, 7, 1247–1250. [Google Scholar] [CrossRef]
  73. Karunasingha, D.S.K. Root Mean Square Error or Mean Absolute Error? Use Their Ratio as Well. Inf. Sci. 2022, 585, 609–629. [Google Scholar] [CrossRef]
  74. Barmpadimos, I.; Hueglin, C.; Keller, J.; Henne, S.; Prévôt, A.S.H. Influence of Meteorology on PM10 Trends and Variability in Switzerland from 1991 to 2008. Atmos. Chem. Phys. 2011, 11, 1813–1835. [Google Scholar] [CrossRef]
  75. Peng, L.; Zhao, X.; Tao, Y.; Mi, S.; Huang, J.; Zhang, Q. The Effects of Air Pollution and Meteorological Factors on Measles Cases in Lanzhou, China. Environ. Sci. Pollut. Res. 2020, 27, 13524–13533. [Google Scholar] [CrossRef] [PubMed]
  76. Birinci, E.; Deniz, A.; Özdemir, E.T. The Relationship between PM10 and Meteorological Variables in the Mega City Istanbul. Environ. Monit. Assess. 2023, 195, 304. [Google Scholar] [CrossRef]
  77. Galindo, N.; Varea, M.; Gil-Moltó, J.; Yubero, E.; Nicolás, J. The Influence of Meteorology on Particulate Matter Concentrations at an Urban Mediterranean Location. Water. Air. Soil Pollut. 2011, 215, 365–372. [Google Scholar] [CrossRef]
  78. Li, Y.; Chen, Q.; Zhao, H.; Wang, L.; Tao, R. Variations in Pm10, Pm2.5 and Pm1.0 in an Urban Area of the Sichuan Basin and Their Relation to Meteorological Factors. Atmosphere 2015, 6, 150–163. [Google Scholar] [CrossRef]
  79. Birim, N.G.; Turhan, C.; Atalay, A.S.; Gokcen Akkurt, G. The Influence of Meteorological Parameters on PM10: A Statistical Analysis of an Urban and Rural Environment in Izmir/Türkiye. Atmosphere 2023, 14, 421. [Google Scholar] [CrossRef]
  80. Dung, N.A.; Son, D.H.; Hanh, N.T.D.; Tri, D.Q. Effect of Meteorological Factors on PM10 Concentration in Hanoi, Vietnam. J. Geosci. Environ. Prot. 2019, 7, 138–150. [Google Scholar] [CrossRef]
  81. Giri, D.; Krishna Murthy, V.; Adhikary, P.R. The influence of meteorological conditions on PM10 concentrations in Kathmandu Valley. Int. J. Environ. Res. 2008, 2, 49–60. [Google Scholar]
  82. Özdemir, U.; Taner, S. Impacts of Meteorological Factors on PM10: Artificial Neural Networks (ANN) and Multiple Linear Regression (MLR) Approaches. Environ. Forensics 2014, 15, 329–336. [Google Scholar] [CrossRef]
  83. Talepour, N.; Birgani, Y.T.; Kelly, F.J.; Jaafarzadeh, N.; Goudarzi, G. Analyzing Meteorological Factors for Forecasting PM10 and PM2.5 Levels: A Comparison between MLR and MLP Models. Earth Sci. Inform. 2024, 17, 5603–5623. [Google Scholar] [CrossRef]
  84. Tian, Y.; Yao, X. Urban Form, Traffic Volume, and Air Quality: A Spatiotemporal Stratified Approach. Environ. Plan. B Urban Anal. City Sci. 2021, 49, 92–113. [Google Scholar] [CrossRef]
  85. Zeb, B.; Ditta, A.; Alam, K.; Sorooshian, A.; Din, B.U.; Iqbal, R.; Habib ur Rahman, M.; Raza, A.; Alwahibi, M.S.; Elshikh, M.S. Wintertime Investigation of PM10 Concentrations, Sources, and Relationship with Different Meteorological Parameters. Sci. Rep. 2024, 14, 154. [Google Scholar] [CrossRef] [PubMed]
  86. Volná, V.; Hladkỳ, D. Detailed Assessment of the Effects of Meteorological Conditions on PM10 Concentrations in the Northeastern Part of the Czech Republic. Atmosphere 2020, 11, 497. [Google Scholar] [CrossRef]
  87. Mok, K.M.; Hoi, K.I. Effects of Meteorological Conditions on PM10 Concentrations—A Study in Macau. Environ. Monit. Assess. 2005, 102, 201–223. [Google Scholar] [CrossRef]
  88. Tian, G.; Qiao, Z.; Xu, X. Characteristics of Particulate Matter (PM10) and Its Relationship with Meteorological Factors during 2001–2012 in Beijing. Environ. Pollut. 2014, 192, 266–274. [Google Scholar] [CrossRef] [PubMed]
  89. Wu, J.; Xie, W.; Li, W.; Li, J. Effects of Urban Landscape Pattern on PM2.5 Pollution-A Beijing Case Study. PLoS ONE 2015, 10, e0142449. [Google Scholar] [CrossRef] [PubMed]
  90. Ai, H.; Zhang, X.; Zhou, Z. The Impact of Greenspace on Air Pollution: Empirical Evidence from China. Ecol. Indic. 2023, 146, 109881. [Google Scholar] [CrossRef]
  91. Jiang, R.; Xie, C.; Man, Z.; Zhou, R.; Che, S. Effects of Urban Green and Blue Space on the Diffusion Range of PM2.5 and PM10 Based on LCZ. Land 2023, 12, 964. [Google Scholar] [CrossRef]
  92. Yoon, S.; Heo, Y.; Park, C.; Kang, W. Effects of Landscape Patterns on the Concentration and Recovery Time of PM2.5 in South Korea. Land 2022, 11, 2176. [Google Scholar] [CrossRef]
  93. Yang, D.; Meng, F.; Liu, Y.; Dong, G.; Lu, D. Scale Effects and Regional Disparities of Land Use in Influencing PM2.5 Concentrations: A Case Study in the Zhengzhou Metropolitan Area, China. Land 2022, 11, 1538. [Google Scholar] [CrossRef]
  94. Ren, W.; Zhao, J.; Ma, X. Analysis of the Spatial Characteristics of Inhalable Particulate Matter Concentrations under the Influence of a Three-Dimensional Landscape Pattern in Xi’an, China. Sustain. Cities Soc. 2022, 81, 103841. [Google Scholar] [CrossRef]
  95. Li, C.; Zhang, K.; Dai, Z.; Ma, Z.; Liu, X. Investigation of the Impact of Land-Use Distribution on Pm2.5 in Weifang: Seasonal Variations. Int. J. Environ. Res. Public Health 2020, 17, 5135. [Google Scholar] [CrossRef]
  96. Yang, H.; Leng, Q.; Xiao, Y.; Chen, W. Investigating the Impact of Urban Landscape Composition and Configuration on PM2.5 Concentration under the LCZ Scheme: A Case Study in Nanchang, China. Sustain. Cities Soc. 2022, 84, 104006. [Google Scholar] [CrossRef]
  97. Huang, D.; He, B.; Wei, L.; Sun, L.; Li, Y.; Yan, Z.; Wang, X.; Chen, Y.; Li, Q.; Feng, S. Impact of Land Cover on Air Pollution at Different Spatial Scales in the Vicinity of Metropolitan Areas. Ecol. Indic. 2021, 132, 108313. [Google Scholar] [CrossRef]
  98. Gkyer, E. Understanding Landscape Structure Using Landscape Metrics. In Advances in Landscape Architecture; IntechOpen: London, UK, 2013. [Google Scholar] [CrossRef]
  99. Kim, H.; Hong, S. Relationship between Land-Use Type and Daily Concentration and Variability of PM10 in Metropolitan Cities: Evidence from South Korea. Land 2022, 11, 23. [Google Scholar] [CrossRef]
  100. Yu, Y.; Cao, J. Chemical Fingerprints and Source Profiles of PM10 and PM2.5 from Agricultural Soil in a Typical Polluted Region of Northwest China. Aerosol Air Qual. Res. 2023, 23, 220419. [Google Scholar] [CrossRef]
  101. Aimar, S.B.; Mendez, M.J.; Funk, R.; Buschiazzo, D.E. Soil Properties Related to Potential Particulate Matter Emissions (PM10) of Sandy Soils. Aeolian Res. 2012, 3, 437–443. [Google Scholar] [CrossRef]
  102. Zobeck, T.M.; Amante-Orozco, A. Effect of Dust Source Clay and Carbonate Content on Fugitive Dust Emissions. In Proceedings of the 10th International Emission Inventory Conference—“One Atmosphere, One Inventory, Many Challenges”, Denver, CO, USA, 1–3 May 2001; pp. 1–13. [Google Scholar]
  103. Carvacho, O.F.; Ashbaugh, L.L.; Brown, M.S.; Flocchini, R.G. Measurement of PM2.5 Emission Potential from Soil Using the UC Davis Resuspension Test Chamber. Geomorphology 2004, 59, 75–80. [Google Scholar] [CrossRef]
  104. Carvacho, O.F.; Ashbaugh, L.L.; Brown, M.S.; Flocchini, R.G. Relationship between San Joaquin Valley Soil Texture and PM10 Emission Potential Using the UC Davis Dust Resuspension Test Chamber. Trans. Am. Soc. Agric. Eng. 2001, 44, 1603–1608. [Google Scholar] [CrossRef]
  105. Péterfalvi, N.; Keller, B.; Magyar, M. PM10 Emission from Crop Production and Agricultural Soils. Agrokem. Talajt. 2018, 67, 143–159. [Google Scholar] [CrossRef]
  106. Gherboudj, I.; Beegum, S.N.; Marticorena, B.; Ghedira, H. Journal of Geophysical Research. Nature 1955, 175, 238. [Google Scholar] [CrossRef]
  107. Vos, H.C.; Fister, W.; von Holdt, J.R.; Eckardt, F.D.; Palmer, A.R.; Kuhn, N.J. Assessing the PM10 Emission Potential of Sandy, Dryland Soils in South Africa Using the PI-SWERL. Aeolian Res. 2021, 53, 100747. [Google Scholar] [CrossRef]
  108. Kim, H. Land Use Impacts on Particulate Matter Levels in Seoul, South Korea: Comparing High and Low Seasons. Land 2020, 9, 142. [Google Scholar] [CrossRef]
  109. Huang, Y.; Lei, C.; Liu, C.H.; Perez, P.; Forehead, H.; Kong, S.; Zhou, J.L. A Review of Strategies for Mitigating Roadside Air Pollution in Urban Street Canyons. Environ. Pollut. 2021, 280, 116971. [Google Scholar] [CrossRef] [PubMed]
  110. Li, S.; Zou, B.; Ma, X.; Liu, N.; Zhang, Z.; Xie, M.; Zhi, L. Improving Air Quality through Urban Form Optimization: A Review Study. Build. Environ. 2023, 243, 110685. [Google Scholar] [CrossRef]
  111. Choi, W.; Ranasinghe, D.; Bunavage, K.; DeShazo, J.R.; Wu, L.; Seguel, R.; Winer, A.M.; Paulson, S.E. The Effects of the Built Environment, Traffic Patterns, and Micrometeorology on Street Level Ultrafine Particle Concentrations at a Block Scale: Results from Multiple Urban Sites. Sci. Total Environ. 2016, 553, 474–485. [Google Scholar] [CrossRef] [PubMed]
  112. Vitaliano, S.; Cascone, S.; D’Urso, P.R. Mitigating Built Environment Air Pollution by Green Systems: An In-Depth Review. Appl. Sci. 2024, 14, 6487. [Google Scholar] [CrossRef]
  113. Hassan, A.M.; ELMokadem, A.A.; Megahed, N.A.; Abo Eleinen, O.M. Urban Morphology as a Passive Strategy in Promoting Outdoor Air Quality. J. Build. Eng. 2020, 29, 101204. [Google Scholar] [CrossRef]
Figure 1. Illustration of the two components of landscape structure: composition (horizontal axis), and configuration heterogeneity (vertical axis) (according to [24]).
Figure 1. Illustration of the two components of landscape structure: composition (horizontal axis), and configuration heterogeneity (vertical axis) (according to [24]).
Land 13 02245 g001
Figure 2. Importance of the variables in the Random Forest model (%) and Spearman correlation coefficients for urban landscapes within 1000 m buffer zones during the heating period. Climatological variables Land 13 02245 i001, landscape metrics Land 13 02245 i002, land use proportions Land 13 02245 i003, and soil texture Land 13 02245 i004. * Significant at the 0.05 level. ** Significant at the 0.01 level. *** Significant at the 0.001 level.
Figure 2. Importance of the variables in the Random Forest model (%) and Spearman correlation coefficients for urban landscapes within 1000 m buffer zones during the heating period. Climatological variables Land 13 02245 i001, landscape metrics Land 13 02245 i002, land use proportions Land 13 02245 i003, and soil texture Land 13 02245 i004. * Significant at the 0.05 level. ** Significant at the 0.01 level. *** Significant at the 0.001 level.
Land 13 02245 g002
Figure 3. Importance of the variables in the Random Forest model (%) and Spearman correlation coefficients for urban landscapes within 3000 m buffer zones during the heating period. Climatological variables Land 13 02245 i005, landscape metrics Land 13 02245 i006, land use proportions Land 13 02245 i007, and soil texture Land 13 02245 i008. ** Significant at the 0.01 level. *** Significant at the 0.001 level.
Figure 3. Importance of the variables in the Random Forest model (%) and Spearman correlation coefficients for urban landscapes within 3000 m buffer zones during the heating period. Climatological variables Land 13 02245 i005, landscape metrics Land 13 02245 i006, land use proportions Land 13 02245 i007, and soil texture Land 13 02245 i008. ** Significant at the 0.01 level. *** Significant at the 0.001 level.
Land 13 02245 g003
Figure 4. Importance of the variables in the Random Forest model (%) and Spearman correlation coefficients for urban landscapes within 1000 m buffer zones during the cooling period. Climatological variables Land 13 02245 i009, landscape metrics Land 13 02245 i010, land use proportions Land 13 02245 i011, and soil texture Land 13 02245 i012.* Significant at the 0.05 level. ** Significant at the 0.01 level. *** Significant at the 0.001 level.
Figure 4. Importance of the variables in the Random Forest model (%) and Spearman correlation coefficients for urban landscapes within 1000 m buffer zones during the cooling period. Climatological variables Land 13 02245 i009, landscape metrics Land 13 02245 i010, land use proportions Land 13 02245 i011, and soil texture Land 13 02245 i012.* Significant at the 0.05 level. ** Significant at the 0.01 level. *** Significant at the 0.001 level.
Land 13 02245 g004
Figure 5. Importance of the variables in the Random Forest model (%) and Spearman correlation coefficients for urban landscapes within 3000 m buffer zones during the cooling period. Climatological variables Land 13 02245 i013, landscape metrics Land 13 02245 i014, land use proportions Land 13 02245 i015, and soil texture Land 13 02245 i016. * Significant at the 0.05 level. ** Significant at the 0.01 level. *** Significant at the 0.001 level.
Figure 5. Importance of the variables in the Random Forest model (%) and Spearman correlation coefficients for urban landscapes within 3000 m buffer zones during the cooling period. Climatological variables Land 13 02245 i013, landscape metrics Land 13 02245 i014, land use proportions Land 13 02245 i015, and soil texture Land 13 02245 i016. * Significant at the 0.05 level. ** Significant at the 0.01 level. *** Significant at the 0.001 level.
Land 13 02245 g005
Table 1. Brief description of the landscape metric indicators used for the analysis of urban landscape structure.
Table 1. Brief description of the landscape metric indicators used for the analysis of urban landscape structure.
Landscape IndexDefinition
Shannon Diversity Index
(SHDI)
An index based on the relative area of each landscape type and the total number of LULC types. It is more sensitive to rare patch types than Simpson’s diversity index.
Proportion of LULC
Categories
(PLANDs)
This index reflects the percentage of the total area of a certain type of LULC patch in the entire landscape area, determining the basis for judging dominant landscape elements.
Mean Patch Area
(MPA)
The average area of patches in the landscape of each type. Calculated for each LULC group (PM10 sources, barriers, and changeable).
Shape Index
(SHI)
Describes the complexity of the shape of LULC patches within a landscape. It compares the perimeter of a patch with the perimeter of a standard shape (usually a square or circle) with the same area, thus giving insight into how irregular or fragmented a patch is. Calculated for each LULC group (PM10 sources, barriers, and changeable).
Contrast Class Edge (CCE)Calculated as a percentage of the edge length of “PM10 source” LULC polygons shared with “PM10 barrier” LULC polygons.
Contrast Index 1 (CI1)The edge length of the LULC polygons’ PM10 source showed a positive correlation with the concentration of PM10 in each buffer zone.
Contrast Index 2 (CI2)The edge length of the LULC polygons of the ’PM10 barrier’ showed a negative correlation with the PM10 concentration divided by the area of each buffer zone.
Table 2. Land use groups categorized by their impact on monthly average PM10 concentrations, as identified in our previous study [37].
Table 2. Land use groups categorized by their impact on monthly average PM10 concentrations, as identified in our previous study [37].
Effect on PM10 ConcentrationUrban Atlas LULC Categories Within the 1000 m Buffer ZoneUrban Atlas LULC Categories Within the 3000 m Buffer Zone
Source of PM10 PollutionVacant Lands
Urban Parks
Arable Lands
Built-Up Areas
Railways
Mine, Dump, and Construction Sites
Vacant Lands
Arable Lands
Developing Areas
Barrier to PM10 PollutionRailways
Forests
Industrial Units
Urban Parks
Grasslands
Forests
Water
Changeable Effect on PM10
Pollution
Industrial Units
Roads
Grasslands
Water
Roads
Table 3. Random forest modeling performance after adding the landscape metrics and considering all variables on the Databricks platform using Python 3.9.19.
Table 3. Random forest modeling performance after adding the landscape metrics and considering all variables on the Databricks platform using Python 3.9.19.
Buffer ZonePeriodR2
Training Set (70%)
Previous Study
CRF Modeling
R2
Training Set
(70%)
R2
Test Set (30%)
Best Hyperparameters
Max_DepthN_Estimators
1000 mCooling0.360.5240.58530140
3000 mCooling0.410.4810.5085070
1000 mHeating0.570.5930.61920140
3000 mHeating0.610.6520.66645140
Table 4. Comparing the current study (improved Random Forest regression PM10 prediction modeling by adding landscape metrics) to the previous study (conditional inference regression Random Forest (CRF) PM10 prediction model), showing variables with more than 5% importance in urban landscapes.
Table 4. Comparing the current study (improved Random Forest regression PM10 prediction modeling by adding landscape metrics) to the previous study (conditional inference regression Random Forest (CRF) PM10 prediction model), showing variables with more than 5% importance in urban landscapes.
Cooling PeriodHeating Period
1000 m3000 m1000 m3000 m
Previous study
Soil texture (20.75%)
Roads (11.77%)
Temperature (10.26%)
Forest (7.94%)
Total precipitation (6.62%)
Forests (15.44%)
Soil texture (12.83%)
Vacant land (8.25%)
Wind speed (7.49%)
Temperature (7.04%)
Total precipitation (6.43%)
Roads (5.47%)
Temperature (26.33%)
Wind speed (20.43%)
Total precipitation (12.76%)
Soil texture (8.64%)
Total precipitation (24.02%)
Wind speed (21.28%)
Temperature (12.79%)
Soil texture (6.45%)
Current study
Total precipitation (9.39%)
MPS of LULC categories with changeable effect on PM10 (7.55%)
SHI of LULC categories with changeable effect on PM10 (7.51%)
SHDI (6.67%)
MSL air pressure (6.48%)
Temperature (6.36%)
Wind speed (5.76%)
Urban parks (5.02%)
MSL air pressure (12.76%)
Total precipitation (9.55%)
SHI of LULC with changeable
effect on PM10 (6.04%)
Temperature (5.80%)
Wind speed (5.75%)
Temperature (20.08%)
Total precipitation (11.99%)
Wind speed (11.0%)
MSL air pressure (8.38%)
SHI of LULC with changeable effect on PM10 (5.23%)
Temperature (22.46%)
Wind speed (14.58%)
Total precipitation (11.77%)
MSL air pressure (7.82%)
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Sohrab, S.; Csikós, N.; Szilassi, P. Landscape Metrics as Ecological Indicators for PM10 Prediction in European Cities. Land 2024, 13, 2245. https://doi.org/10.3390/land13122245

AMA Style

Sohrab S, Csikós N, Szilassi P. Landscape Metrics as Ecological Indicators for PM10 Prediction in European Cities. Land. 2024; 13(12):2245. https://doi.org/10.3390/land13122245

Chicago/Turabian Style

Sohrab, Seyedehmehrmanzar, Nándor Csikós, and Péter Szilassi. 2024. "Landscape Metrics as Ecological Indicators for PM10 Prediction in European Cities" Land 13, no. 12: 2245. https://doi.org/10.3390/land13122245

APA Style

Sohrab, S., Csikós, N., & Szilassi, P. (2024). Landscape Metrics as Ecological Indicators for PM10 Prediction in European Cities. Land, 13(12), 2245. https://doi.org/10.3390/land13122245

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop