景观格局对大气污染的影响以福建省为例

Impact of landscape pattern on air pollution: a case study of Fujian Province

  • 摘要: 以福建省为研究对象,利用37个国家环境空气自动监测站点的监测数据和土地利用/覆盖数据,首先分析了土地利用/覆盖对SO2、NO2、O3、CO浓度年变化和季节变化的影响;其次建立国控点不同半径的缓冲区并计算景观格局指数,探讨不同尺度下土地利用/覆盖的景观格局对SO2、NO2、O3、CO浓度的影响。结果表明:土地利用/覆盖对大气污染物浓度变化的影响显著,建设用地的SO2、NO2、CO浓度均为最高,耕地的O3浓度为最高。不同大气污染物浓度在不同土地利用/覆盖下的季节变化存在差异,耕地的SO2浓度呈春冬季低,夏秋季高,其余污染物呈春冬季高,夏秋季低;NO2浓度均呈春冬季高,夏秋季低;耕地与林地的O3浓度为春秋季高,夏冬季低,建设用地与草地则从春季到冬季依次递减;CO浓度均为夏秋季低,春冬季高。不同景观指数对不同大气污染物浓度的影响存在差异及尺度效应,其中,春冬季3 000 m和夏秋季4 000 m半径范围内草地的斑块密度(PD)对SO2浓度的影响较为显著且呈负相关,说明草地的PD越大,SO2浓度越低;春冬季4 000 m半径范围内林地的斑块数量(NP)与NO2浓度呈正相关,说明林地越破碎,NO2浓度越高,而3 000 m半径范围内建设用地的NP与NO2浓度呈负相关,说明建设用地越破碎,NO2浓度越低;5 000 m半径范围内耕地的景观所占比例(PLAND)与O3浓度呈正相关,说明耕地的PLAND越大,O3浓度越高,1 000 m半径范围内林地的PLAND与O3浓度呈正相关,说明林地PLAND的增加对O3浓度的增加有一定的影响;除秋季外,1 000 m半径范围内林地的PLAND与CO浓度呈负相关,说明林地的PLAND越大,CO浓度越低。同时,通过对不同尺度下景观指数的分析发现,SO2的最佳研究尺度为3 000 m;NO2的最佳研究尺度为4 000 m;O3的最佳研究尺度为5 000 m;CO的较佳研究尺度为3 000 m。

     

    Abstract: Taking Fujian Province as the research object, based on the data from 37 national air monitoring stations and land use/cover data in Fujian Province, the effects of land use/cover on the annual and seasonal variations of SO2, NO2, O3 and CO pollution concentrations were analyzed. Then, buffer zones of different radii of the national monitoring stations were established, the landscape pattern indexes were calculated, and the effects of the landscape pattern of land use/cover on SO2, NO2, O3 and CO concentrations at different scales were discussed. The results showed that: Land use/cover had a significant effect on the change of atmospheric pollutant concentration. SO2, NO2 and CO concentrations all showed the highest values in construction land, and O3 concentrations showed the highest values in cultivated land. The seasonal variation of the concentration of air pollutants under different land uses/covers was different. The concentration of SO2 in cultivated land was low in spring and winter, high in summer and autumn, and others were high in spring and winter, low in summer and autumn. The concentration of NO2 was high in spring and winter, but low in summer and autumn. The concentration of O3 in cultivated land and forest land was high in spring and autumn, and low in summer and winter, while the concentration of O3 in construction land and grassland decreased from spring to winter successively. The CO concentration was low in summer and autumn, but high in spring and winter. The effects of different landscape pattern indexes on the concentration of air pollutants were different with the scale effect. Among them, the patch density (PD) in the grassland within the radius of 3 000 m in spring and winter and 4 000 m in summer and autumn had the most significant and negative correlation on SO2 concentration, indicating that the higher the density of grassland patches was, the lower the SO2 concentration would be. There was a positive correlation between the number of patches (NP) and NO2 concentration in the 4 000 m radius of forest land in spring and winter, indicating that the more broken forest land was, the higher the NO2 concentration would be. NP of construction land within 3 000 m radius was negatively correlated with NO2 concentration, indicating that the more broken the construction land was, the lower the NO2 concentration would be. There was a positive correlation between the concentration of O3 and the proportion of landscape (PLAND) of cultivated land in the radius of 5 000 m, indicating that the greater the PLAND of cultivated land was, the higher the concentration of O3 would be. There was a positive correlation between the concentration of O3 and the PLAND of forest land in the radius of 1 000 m, indicating that the increase of PLAND of forest land had certain influence on the increase of O3 concentration. Except for autumn, the PLAND of forest land was related to the CO concentration in the radius of 1 000 m, showing that the greater the PLAND of forest land was, the lower the concentration of CO would be. At the same time, through the analysis of different scales of landscape indexes, it was found that the best study scale of SO2 was 3 000 m, and that for NO2 and O3 was 4 000 and 5 000 m, respectively, while a better study scale for CO was 3 000 m.

     

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