Study of the PM2.5 Concentration Variation and its Influencing Factors in the Beijing-Tianjin-Hebei Urban Agglomeration Using Geo-Detector
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摘要: 研究京津冀城市群PM2.5浓度时空格局变化和影响因素,对区域大气环境保护和经济可持续发展具有十分重要的意义. 基于PM2.5遥感数据、地面站点气象数据、DEM数据、MODIS NDVI数据、夜间灯光数据、人口密度数据、土地利用类型数据和路网数据,利用Theil-Sen Median趋势分析、Mann-Kendall显著性检验和Getis-Ord Gi*分析,运用地理探测器分析京津冀城市群PM2.5浓度时空变化和空间聚集特征,并探究影响其空间分异的影响因素. 结果表明:①2000—2021年京津冀城市群PM2.5污染严重,全年平均PM2.5浓度为59.94 μg/m3,冬季是京津冀城市群PM2.5污染的高发季,但京津冀城市群PM2.5浓度总体呈下降趋势,变化斜率为–0.85 μg/(m3·a). ②PM2.5浓度在空间上呈东南高、西北低的分布格局,且PM2.5浓度呈显著下降的区域占比为9.92%,主要集中在张家口市. ③PM2.5浓度变化的聚集性呈西北高、东南低的空间分布格局,PM2.5浓度变化热点区域占比为50.95%. ④因子探测结果表明,气温、高程和路网密度是影响京津冀城市群PM2.5浓度空间分异最主要的因子,研究时段内降水对京津冀城市群PM2.5空间分异的影响力呈上升趋势,相对湿度、日照时数、夜间灯光和路网密度对京津冀城市群PM2.5空间分异的影响力均呈下降趋势. 交互探测结果表明,气温在因子交互中发挥十分重要的作用,气温与降水、高程和路网密度的交互作用均是影响京津冀城市群PM2.5空间分异的主要因子组合. 研究显示,2000—2021年京津冀城市群PM2.5浓度整体呈下降趋势,气温、高程和路网密度对京津冀城市群PM2.5浓度的空间分异有显著影响.
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关键词:
- 京津冀城市群 /
- PM2.5浓度 /
- 空间自相关分析 /
- Getis-Ord Gi*分析 /
- 地理探测器
Abstract: Studying the spatial and temporal pattern changes and influencing factors of PM2.5 concentration in the Beijing-Tianjin-Hebei Urban Agglomeration is of great significance to regional atmospheric environmental protection and sustainable economic development. Based on PM2.5 remote sensing data, ground station meteorological data, DEM data, MODIS NDVI data, night light data, population density data, land use type data and road network data, Theil-Sen Median trend analysis, Mann-Kendall significance test and Getis-Ord Gi* analysis were used to analyze the spatial and temporal changes and spatial aggregation characteristics of PM2.5 concentration in the Beijing-Tianjin-Hebei Urban Agglomeration, and Geo-detector was used to explore the influencing factors of its spatial differentiation. The results showed that: (1) From 2000 to 2021, PM2.5 pollution in Beijing-Tianjin-Hebei Urban Agglomeration was serious, the annual average PM2.5 concentration was 59.94 μg/m3, winter was the high incidence season of PM2.5 pollution, but the PM2.5 concentration generally showed a downward trend, with a change slope of −0.85 μg/(m3·a). (2) The spatial distribution pattern of PM2.5 concentration was high in the southeast and low in the northwest, and the area where PM2.5 concentration decreased significantly accounted for 9.92%, mainly concentrated in Zhangjiakou City. (3) The aggregation of PM2.5 concentration changes was high in the northwest and low in the southeast. The hot spot area of PM2.5 concentration changes accounted for 50.95%. (4) The factor detection results showed that temperature, elevation and road network density were the main factors affecting the spatial differentiation of PM2.5 concentration in the Beijing-Tianjin-Hebei Urban Agglomeration. During the study period, the influence of precipitation on the spatial differentiation of PM2.5 in the Beijing-Tianjin-Hebei Urban Agglomeration showed an increasing trend, while the influence of humidity, sunshine hours, night light and road network density on the spatial differentiation of PM2.5 showed a downward trend. The interactive detection results showed that temperature played a very important role in the factor interaction, and the interaction between temperature and precipitation, elevation and road network density was the main factor combination affecting the spatial differentiation of PM2.5 in Beijing-Tianjin-Hebei Urban Agglomeration. The research results showed that the PM2.5 concentration in the Beijing-Tianjin-Hebei Urban Agglomeration showed a downward trend from 2000 to 2021, and temperature, elevation, and road network density played a significant role in the spatial differentiation of PM2.5 concentration in the Beijing-Tianjin-Hebei Urban Agglomeration. -
表 1 京津冀城市群PM2.5浓度变化显著性统计
Table 1. Statistics result of the significance test of PM2.5 concentrtion in the Beijing-Tianjin-Hebei Urban Agglomeration
时间尺度 面积占比/% PM2.5浓度不显著下降 PM2.5浓度显著下降 春季 75.34 24.66 夏季 48.81 51.19 秋季 92.87 7.13 冬季 71.28 28.72 全年 90.08 9.92 表 2 京津冀城市群PM2.5浓度变化冷热点区域统计
Table 2. Statistics result of the cold and hot spots of PM2.5 concentration variation in the Beijing-Tianjin-Hebei Urban Agglomeration
时间尺度 占比/% 冷点区 次冷点区 不显著区 次热点区 热点区 春季 42.97 0.25 4.24 0.86 51.69 夏季 44.77 0.22 3.85 0.64 50.53 秋季 43.97 0.25 4.54 1.02 50.23 冬季 43.49 0.42 6.63 1.56 47.91 全年 44.04 0.26 4.10 0.65 50.95 表 3 2000年、2010年和2021年京津冀城市群因子探测q值统计
Table 3. Detection Statistics of q value in the Beijing-Tianjin-Hebei Urban Agglomeration factors in 2000, 2010 and 2021
影响因子 q值 2000年 2010年 2021年 平均值 X1 0.83 0.84 0.76 0.81 X2 0.03 0.02 0.02 0.02 X3 0.50 0.47 0.41 0.46 X4 0.92 0.91 0.90 0.91 X5 0.17 0.34 0.41 0.31 X6 0.62 0.43 0.30 0.45 X7 0.67 0.23 0.00 0.30 X8 0.06 0.04 0.05 0.05 X9 0.67 0.66 0.57 0.63 X10 0.03 0.09 0.12 0.08 X11 0.54 0.52 0.43 0.50 X12 0.35 0.34 0.29 0.33 表 4 2000—2021年影响因子交互作用的q平均值
Table 4. Statistic result of the mean q value of interaction detection from 2000 to 2021
项目 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X1 0.81 X2 0.82 0.02 X3 0.83 0.48 0.46 X4 0.93 0.91 0.93 0.91 X5 0.87 0.33 0.62 0.93 0.31 X6 0.87 0.46 0.77 0.92 0.69 0.45 X7 0.83 0.31 0.55 0.92 0.55 0.60 0.30 X8 0.83 0.08 0.51 0.91 0.40 0.49 0.36 0.05 X9 0.85 0.64 0.70 0.93 0.75 0.81 0.74 0.66 0.63 X10 0.81 0.10 0.47 0.91 0.35 0.50 0.37 0.13 0.64 0.08 X11 0.82 0.51 0.61 0.92 0.64 0.70 0.64 0.53 0.69 0.51 0.50 X12 0.83 0.36 0.53 0.92 0.53 0.68 0.49 0.40 0.68 0.35 0.57 0.33 -
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