地表臭氧时空分布及其与多尺度景观类型的关系研究

Spatiotemporal distribution of ground-level ozone and its relationship with multi-scale landscape types

地表臭氧是中国许多城市的首要大气污染物,其浓度与城市景观规划密切相关。本文以深圳市为研究区,利用大气监测站点数据和多源地理空间数据,选择广义加性模型(Generalized additive model,GAM),刻画地表臭氧时空分布特征。结合相关分析和多元逐步回归分析方法,研究地表臭氧浓度与多尺度景观类型的关系。结果显示:(1)地表臭氧年均浓度空间差异明显,呈现西高东低,西北靠近内陆的区域浓度较高。秋季浓度最高,年度峰值出现在10月,是地表臭氧污染防治的重点时期。(2)人工地表扩张会显著提高地表臭氧浓度,人工地表斑块优势度和聚合度越高,对地表臭氧浓度的促进越明显;林地占比的增多对地表臭氧浓度有明显的抑制作用,林地斑块优势度和聚合度越高,对地表臭氧浓度的抑制作用越明显。(3)整体景观的异质性降低、优势度和聚合度提高,对地表臭氧浓度的削减作用显著。研究结果可为协同推进地表臭氧污染防治和景观优化设计提供科学依据。

In recent years,ground-level ozone has been the primary atmospheric pollutant in China,especially in the big cities and their surrounding areas.The ground-level ozone concentration in these areas is closely related to local landscape type and configuration.In this paper,Shenzhen was taken as the study area.A generalized additive model was used to characterize the spatial and temporal distribution of ground-level ozone concentrations.The hourly ground-level ozone in situ observations obtained from the air quality monitoring stations and multiple source geospatial datasets were used as the input data to build the generalized additive model.By means of Pearson correlation analysis and significance test,as well as stepwise multiple regression model,the relationship between ground-level ozone concentrations and multi-scale landscape types were deeply analyzed.The research results can be concluded as:(1)The spatial distribution characteristics of the annual average concentration of ground-level ozone had obvious differences.The ground-level ozone concentration in the western region was higher than that in the eastern region.The annual average concentration was high in the northwestern part of the study area near the interior.The seasonal and monthly trends of ground-level ozone concentration were basically the same.The highest seasonal average concentration was observed in autumn,and the monthly average concentration peak in October,which was the key period for ground-level ozone pollution prevention and control.(2)The expansion of artificial surface had an obvious promotion effect on ground-level ozone concentration.The higher the degree of the dominance and aggregation,the more obvious the promotion effect of artificial surface patches on ground-level ozone concentration.In addition,the increase of the proportion of forest land is crucial to the reduction of ground-level ozone concentration.The higher the degree of the dominance and aggregation,the more obvious the inhibition effect of the forest land patches on ground-level ozone concentration.(3)The decrease of heterogeneity and the increase of dominance and aggregation degree of the overall landscape significantly inhibited the ground-level ozone concentration.The research results can provide scientific basis and important consults for promoting the prevention and control of ground-level ozone pollution and landscape optimization design.