武汉市黑碳气溶胶在“大气-地表尘-植物群落吸滞尘-表土”系统中沉降规律的观测研究

Abstract:n order to solve the \"urban aerosol mass concentration of black carbon whether all through dry, wet sedimentation to travel to the surface settlement of the problem, find out black carbon aerosol distribution, to find the quantitative plant community sluggish black carbon absorption characteristics and the differences of different plant type dust effect and other issues, this study carried out by wuhan black carbon (aerosol, dust, leaf table, overburden) observation, trying to understand natural dustfall in wuhan region of black carbon content in the space-time change rule and the main influence factors, to find a suitable in wuhan black carbon sedimentation model; Can know black carbon from the Angle of material migration system is of great significance in the quality distribution of each part, to the study of black carbon in the atmosphere - dust - the distribution of the overburden soil characteristics in black carbon aerosol release, delivery and settlement and release rule again, to the understanding of black carbon aerosol on climate and biogeochemical effects have important theoretical significance, at the same time in order to compare different urban green space colony inhibition of black carbon adsorption capacity, lateral comparison of wuhan city center of shrubbery, structure of community, the structure of the halosols deserts, Joe grass structure of community, the structure of the arbor layer, bringing community structure, the lawn, bare land seven types of urban green space unit of black carbon removal ratio and settlement rule, analyzes its adsorption efficiency of black carbon, put forward the best adsorption community types

为了解决“城市气溶胶中一定质量浓度的黑碳是否全部通过干、湿沉降作用到达地表”这一问题、弄清黑碳气溶胶沉降分布规律、弄清植物群落吸滞黑碳的定量特征以及不同植物类型滞尘效应的差异等问题，本研究通过对武汉地区开展的黑碳（气溶胶、尘、叶表、表土）观测，试图了解武汉地区自然降尘中黑碳含量的时空变化规律及其主要影响因素，寻找适合武汉地区的黑碳沉降模型；可以从物质迁移的系统角度认识黑碳在各个环节的质量分布特征具有重要意义，能够研究黑碳在大气-灰尘-表土土壤的分配特征对认识黑碳气溶胶释放、输送和沉降和再释放规律，对深入地认识黑碳气溶胶的气候和生物地球化学效应有重要的理论意义，同时为了比较城市绿地不同群落吸附抑制的黑碳能力，横向对比武汉市中心城区的乔灌结构群落、乔灌草结构群落、乔草结构群落、乔木单层结构群落、灌草结构群落、草坪、裸地七种类型城市绿地单元对黑碳的清除比例和沉降规律，分析其吸附黑碳的效率，提出最佳吸附群落类型

本项目首先进行了室外采样工作和基于WRF-CMAQ模型的室内模拟工作，得到了武汉地区黑碳气溶胶的水平向时空分布规律和垂直向沉降分布规律；其次运用HYSPLIT多受点前向轨迹模型、轨迹聚类分析、潜在源贡献因子分析等方法，对区域水平向和垂向主要污染传输通道进行模拟研究，确定气团移动轨迹，研究BC的输送路径，定性分析了不同气团背景下武汉地区16个高度层积聚黑碳气溶胶浓度的潜在源区；第三，围绕解决“城市气溶胶中一定质量浓度的黑碳是否全部通过干、湿沉降作用到达地表”这一问题，开展了黑碳（气溶胶、尘、叶表、表土）的垂向浓度变化野外采样观测工作，弄清了植物群落吸滞黑碳的定量特征以及不同植物类型滞尘效应的差异等问题，比较城市绿地不同群落吸附抑制的黑碳能力，横向对比武汉市中心城区的乔灌结构群落、乔灌草结构群落、乔草结构群落、乔木单层结构群落、灌草结构群落、草坪、裸地七种类型城市绿地单元对黑碳的清除比例和沉降规律，分析其吸附黑碳的效率，提出最佳吸附群落类型。研究结果可为掌握大气中黑碳气溶胶的垂向分布提供数据依据，同时可为城市群大气复合污染联防联控提供参考数据。