海南岛细颗粒物污染特征、影响因素及潜在源区分析

Characteristics,Impact Factors and Potential Sources of PM_(2.5)Pollution for Hainan Island

基于2015~2021年海南岛环境监测数据和气象观测数据,利用后向轨迹模型、聚类分析、多元线性回归方法、潜在源区贡献因子算法和权重轨迹方法等探讨了海南岛PM_(2.5)污染特征,影响因素及潜在贡献源区.结果表明,海南岛PM_(2.5)浓度具有明显的季节性变化特征,冬季ρ(PM_(2.5))最高(22.6μg·m^(−3)),秋季和春季次之(17.38和16.53μg·m^(−3)),夏季最低(9.79μg·m^(−3)).近7年海南岛共有30 d出现PM_(2.5)浓度超标,且年平均和4季PM_(2.5)浓度均出现显著的下降趋势,其气候倾向率[μg·(m^(3)·a)^(−1)]分别为−0.97(年平均)、−1.09(春季)、−0.61(夏季)、−0.83(秋季)和−1.25(冬季).海南岛PM_(2.5)浓度与气态污染物高度相关,相关系数分别为0.471(SO_(2))、0.633(NO_(2))、0.479(CO)和0.773(O_(3)-8h),均达到了0.01的显著性水平.海南岛PM_(2.5)浓度与平均风速和大气压呈正相关关系,与降水量、相对湿度、日照时数、平均气温和总辐射呈负相关关系,其中平均气温、相对湿度和太阳总辐射是主控气象因子.后向轨迹和潜在贡献源区分析表明,冬季和秋季受来自内陆地区的气流影响时,海南岛平均的PM_(2.5)浓度普遍偏高(≥20μg·m^(−3)),福建、浙江、湖南、江西、广东和广西等省份是海南岛PM_(2.5)主要潜在贡献源区.

Based on the environmental monitoring data and meteorological observational data in Hainan Island from 2015 to 2021,the PM_(2.5)-polluted characteristics,influencing factors,and potential contributing regions were analyzed using the backward trajectory simulation,cluster analysis,potential source analysis function(PSCF),and concentration weight trajectory(CWT)methods.The results showed that PM_(2.5)in Hainan Island had an obvious seasonal variation,with the highest in winter(22.6μg·m^(−3)),followed by that in autumn and spring(17.38 and 16.53μg·m^(−3),respectively),with the lowest in summer(9.79μg·m^(−3)).In the past seven years,there were 30 days in Hainan Island in which PM_(2.5)concentration exceeded the standard.The annual average and four seasons of PM_(2.5)showed a significant downward trend,and the climatic change rates were−0.97(annual mean),−1.09(spring),−0.61(summer),−0.83(autumn),and−1.25(winter)μg·(m^(3)·a)−1.PM_(2.5)in Hainan Island was highly correlated with gaseous pollutants,with correlation coefficients of 0.471(SO_(2)),0.633(NO_(2)),0.479(CO),and 0.773(O_(3)-8h),all passing a significance level of 0.01.PM_(2.5)was positively correlated with average wind speed and atmospheric pressure and negatively correlated with precipitation,relative humidity,sunshine duration,average temperature,and total solar radiation.Among them,average temperature,relative humidity,and total solar radiation were the main dominant meteorological factors on PM_(2.5)in Hainan Island.Backward trajectory and potential source analysis revealed that PM_(2.5)concentration was high(≥20μg·m^(−3))in winter and autumn,which was influenced by airflow from inland regions,and Fujian,Zhejiang,Hunan,Jiangxi,Guangdong,and Guangxi provinces were the main potential sources of PM_(2.5)in Hainan Island.