基于空间尺度效应的山东省PM_(2.5)浓度时空变化及空间分异地理探测

Spatial-temporal Variation and Spatial Differentiation Geographic Detection of PM_(2.5) Concentration in the Shandong Province Based on Spatial Scale Effect

基于PM_(2.5)遥感数据,采用Theil-Sen Median趋势分析和Mann-Kendall显著性检验,分析2000~2021年山东省PM_(2.5)浓度时空变化特征,结合地理探测器,在省-市-县三级空间尺度上探测影响山东省PM_(2.5)浓度空间分异的影响因子影响力.结果表明:①时间上,2000~2021年山东省ρ(PM_(2.5))均值在38.15~88.63μg·m^(−3)之间,略微高于《环境空气质量标准》中可吸入颗粒物的二级标准限值(35μg·m^(−3)).在年际尺度上,2013年是ρ(PM_(2.5))变化的峰值年,其值为83.36μg·m^(−3),据此将山东省PM_(2.5)浓度变化趋势分为两个阶段:持续上升和快速下降阶段.在季节尺度上,PM_(2.5)浓度呈现“夏低冬高,春秋居中”分布特征和先降后升的“U”型变化规律.②空间上,山东省PM_(2.5)浓度呈现出“西高东低”的空间分布格局,PM_(2.5)浓度高值区分布山东省西部地区,低值区则分布在东部半岛地区.PM_(2.5)浓度空间变化趋势呈现显著的空间异质性,极显著下降的区域主要分布在东部半岛地区.③因子探测结果表明,气候因子是影响山东省PM_(2.5)浓度空间分异的重要影响因素,平均气温对山东省PM_(2.5)浓度空间分异的影响最高,q值为0.512.省-市-县多尺度探测结果显示,影响PM_(2.5)浓度空间分异的影响因子及其影响力在不同空间尺度上具有差异性.省级尺度上,平均气温、日照时数和坡度是影响PM_(2.5)浓度空间分异的主要影响因子;市级尺度上,降水、高程和相对湿度是影响PM_(2.5)空间分异的主要影响因子;县级尺度上,降水、平均气温和日照时数是影响PM_(2.5)浓度空间分异的主要影响因子.

PM_(2.5) remote sensing data was applied in this study,and Theil-Sen Median trend analysis and the Mann-Kendall significance test were utilized to analyze the temporal and spatial variation in PM_(2.5) in the Shandong Province from 2000 to 2021.The influencing power of the influencing factors on the spatial differentiation of PM_(2.5) concentration in the Shandong Province was detected at the provincial-city-county levels based on Geo-detector data.The results showed that:①on the temporal scale,the meanρ(PM_(2.5))in the Shandong Province ranged from 38.15 to 88.63μg·m^(−3) from 2000 to 2021,which was slightly higher than the secondary limit of inhalable particulate matter(35μg·m^(−3))in the Ambient Air Quality Standards.On the interannual scale,2013 was the peak year for the variation inρ(PM_(2.5))with a value of 83.36μg·m^(−3),according to which the trend of PM_(2.5) concentrations in the Shandong Province was divided into two phases:a continuous increase and a rapid decrease.On the seasonal scale,PM_(2.5) concentration presented the distribution characteristics of“low in summer and high in winter and moderate in spring and autumn”and the U-shaped change rule of first decreasing and then increasing.②On the spatial scale,the PM_(2.5) concentration in the Shandong Province presented a spatial distribution pattern of“high in the west and low in the east.”The areas with high PM_(2.5) concentration were distributed in the western area of the Shandong Province,whereas the areas with low PM_(2.5) concentration were distributed in the eastern peninsula region.The spatial variation in the changing trend of PM_(2.5) concentration showed significant spatial heterogeneity,and the extremely significant decrease was mainly distributed in the eastern peninsula region.③The results of factor detection showed that climate factor was an important factor affecting the spatial differentiation of PM_(2.5) concentration in the Shandong Province.Mean temperature had the highest influence on the spatial differentiation of PM_(2.5) concentration in the Shandong Province,with a q value of 0.512.Provincial-city-county multi-scale detection results showed that the influencing factors affecting the spatial differentiation of PM_(2.5) concentration and their influencing power differed at different spatial scales.At the provincial scale,mean temperature,sunshine duration,and slope were the main factors affecting the spatial differentiation of PM_(2.5) concentration.At the city level,precipitation,elevation,and relative humidity were the main factors affecting the spatial differentiation of PM_(2.5).At the county level,precipitation,mean temperature,and sunshine duration were the main factors affecting the spatial variation in PM_(2.5) concentration.