陕西省天然源挥发性有机物排放清单及时空分布特征研究

Inventory and spatiotemporal distribution characteristics of emissions of biogenic volatile organic compounds in Shaanxi Province

基于Guenther提出的天然源性有机化合物(BVOCs)公式计算模型,利用高精度土地利用遥感资料,模拟估算了2000-2020年陕西省107个区县BVOCs的排放量、排放组成及时空分布规律.测算结果显示,陕西省近20年来BVOCs排放量呈上升趋势,总排放量从101.17×10^(4)t·a^(-1)上升至111.43×10^(4)t·a^(-1).近20年陕西省年平均BVOCs排放量为106.01×10^(4)t·a^(-1),其中,异戊二烯排放量为31.65×10^(4)t·a^(-1),占比为29.86%;单萜烯排放量为35.61×10^(4)t·a^(-1),占比为33.60%;其他VOCs排放量为38.75×10^(4)t·a^(-1),占比为36.54%.BVOCs排放总量存在季节性变化,呈夏季高、冬季低的规律,夏、冬两季排放量分别为69.0×104、2.44×10^(4)t·a^(-1),占比分别为65.09%和2.31%.BVOCs排放量高值分布于陕西省南部和中部,主要分布在汉中市(20.6×10^(4)t·a^(-1))、安康市(18.87×10^(4)t·a^(-1))和延安市(18.40×10^(4)t·a^(-1)),榆林市、商洛市的BVOCs排放量较小,平均排放量分别为3.26×104和2.54×10^(4)t·a^(-1);不同土地覆盖类型的BVOCs排放贡献具有显著差异,其中,林地(61.35%)最大,耕地(20.42%)和草地(11.85%)次之.本研究所获取的陕西省BVOCs排放清单和时空分布特性可为后续定量评估BVOCs对大气环境的影响和规划管理提供数据支持.

Based on the formula calculation model of BVOCs proposed by Guenther,the emissions of BVOCs and their temporal and spatial distributions were explored using high-precision remote sensing data for land use in 107 districts and counties of Shaanxi Province from 2000 to 2020.The results showed that the total emission of BVOCs in Shaanxi Province increased from 1011700 t·a^(-1) to 1114300 t·a^(-1) in the last 20 years,with an annual emission of 1060100 t·a^(-1).Average across 20 years,the emissions of isoprene,monoterpene,and other VOCs were 316500,356100 and 387500 t·a^(-1),accounting for 29.86%,33.60%,and 36.54%of total emissions,respectively.Emission of BVOCs was higher in summer but lower in winter.The total emission of BVOCs was 690000 t·a^(-1) in summer and 24400 t·a^(-1) in winter,which accounting for 65.09%and 2.31%of annual emission,respectively.The higher emissions of BVOCs were found in the south and central of Shaanxi Province,namely Hanzhong City(206000 t·a^(-1)),Ankang City(188700 t·a^(-1))and Yan'an City(184000 t·a^(-1)),while lower emissions were found in the north with values of 32600 t·a^(-1) and 25400 t·a^(-1) in Yulin City and Shangluo City,respectively.The emissions of BVOCs varied with land use types.About 61.35%of total emissions of BVOCs were from woodland,followed by cultivated land(20.42%)and grassland(11.85%).The emission inventory and temporal and spatial distribution characteristics of BVOCs in Shaanxi Province obtained in this study can provide a data support for subsequent quantitative assessment of the impact of BVOCs on atmospheric environment and planning management.