基于遥感资料的中国东部地区植被VOCs排放强度研究

本研究充分基于遥感资料获取中国东部地区叶面积指数和叶生物量的最新信息,并广泛调研了植被VOCs排放因子的最新研究进展,以2008—2010年的植被和气象的平均状态为背景,基于MEGAN排放模型,研究了中国东部地区植被VOCs(BVOCs)排放的时空分布特征.结果表明,我国东部地区BVOCs年排放总量为11.3×106t(以C计,下同),其中异戊二烯(ISOP)、单萜烯(MON)和其它VOC(OVOC)质量分数(下同),分别为44.9%、31.5%、23.6%.BVOCs排放呈现明显的季节变化特征,春、夏、秋、冬4个季节分别占全年的11.2%、71.8%、14.1%和3.0%.空间分布上,排放高值区主要分布于大小兴安岭、长白山脉、秦岭大巴山脉、东南丘陵、海南等植被茂密的区域,年均排放强度一般在1500～6000kg·km-·2a-1之间,福建、广东、江西、浙江、湖南、湖北等省份BVOCs的排放总量与平均排放强度均较高.本研究所得到的高时空分辨率的BVOCs排放清单,可以为区域环境与气候的数值模拟研究提供基础.

Estimation of biogenic VOCs emissions in Eastern China based on remote sensing data

In order to study emission features of biogenic VOCs(BVOCs) in Eastern China,the widely-used model of emissions of gases and aerosols from nature(MEGAN) was adopted.Recent information on leaf area index(LAI) and leaf biomass density of vegetations were based on the remote sensing data.Up-to-date observations on emission factors were investigated from literature.Based on average conditions of vegetation and meteorology between the year 2008 and 2010,hourly biogenic emissions of BVOCs in eastern China were calculated,with spatial grid resolution of 10 km.The results showed that the total amount BVOCs emissions was 11.3×106 t(C),with isoprene(ISOP),monoterpene(MON) and other VOC(OVOC) accounting for 44.9%、31.5%,and 23.6%,respectively.Seasonal variations were significant,and contributions of spring,summer,autumn and winter to the yearly total were 11.2%,71.8%,14.1% and 3.0%,respectively.High emission intensities were usually found in Xing’an Mountain,Changbai Mountain,Qinling-Daba Mountain and southern hilly areas,generally between 1500 and 6500 kg · km-2 · a-1.Both total amount and intensities of emissions from provinces of Fujian,Guangdong,Jiangxi,Zhejiang,Hunan and Hubei are relatively high.Attentions should be paid on the interactions between BVOCs and anthropogenic pollutants(e.g.,nitrogen oxides) in these areas.The inventory of BVOCs emissions achieved in this study is an important groundwork for environmental and climate modeling.