四川地区气溶胶光学厚度时空分布及其与气象因子的相关性分析

应用MODIS资料和中国地面累年值月值数据集探讨了四川地区2008~2017年气溶胶光学厚度(AOD)时空分布和变化趋势,并分析了2008~2016年AOD与气象因子的相关性。结果表明:四川地区AOD在10a间整体呈先增加后减少的趋势,其中2010年为高值年,2017年为低值年,分别为0.46和0.21。月均值AOD呈双峰型分布,在2月和8月达到峰值,分别为0.44和0.32。空间分布上,东部为高值区,西部为低值区。东部地区AOD下降趋势显著,西部AOD上升趋势不显著;四川盆地AOD与温度显著正相关,与相对湿度和气压显著负相关,与风速、降水相关性较低。     

瓦里关地区气溶胶光学厚度的观测研究

文章利用中国大气本底基准观象台(CGAWBO)瓦里关基地2009年9月至2010年8月的CE-318全自动跟踪太阳光度计观测资料,分析了该地区气溶胶光学厚度(AOD)的变化特征和Angstrom指数分布规律。瓦里关AOD具有早晚出现双峰值的日变化规律,季节变化中春季出现最大值,夏天受降水等影响波动较大但平均值最低。春季黑碳气溶胶浓度也出现最高值,表明瓦里关春季受人为排放的影响最明显,瓦里关地区的AOD日变化与能见度的变化相关性较好。     

基于激光雷达组网的沈阳地区气溶胶光学厚度分布特征及影响因素研究

为研究沈阳地区大气气溶胶光学特性及分布特征,分析了2019年沈阳地区激光雷达组网监测的气溶胶光学厚度(AOD)季节变化特点,探讨了不同空气质量下AOD分布特征及与颗粒物浓度、气象因素间的关系.结果表明,沈阳地区各雷达点位AOD季节特征存在差异性,从空间分布看,市区中心AOD相对较高.在冬季重度及以上污染天中,AOD大于...     

基于MODIS的济南市气溶胶反演及影响机制研究

选取2015年3月6日济南市MODIS卫星遥感影像数据,以ENVI5.3为平台,利用改进的暗像元算法,进行气溶胶光学厚度(AOD)反演,并分析其空间分布特征和影响机制,得到以下结论:济南市平均AOD为0.454,南部山区处于低浓度梯度,西部地区处于高浓度梯度,东部地区介于二者之间;济南市AOD与其地势(DEM)、归一化植被指数(NDVI)呈负相关,与人类活动呈正相关。依据分析结果,提出了分区分层治理、建立生态廊道、转移污染企业、提高植被覆盖的治理策略。     

基于环境一号卫星的四川盆地气溶胶光学厚度精细化反演

四川盆地为中国灰霾形势较为严重的区域之一,对四川盆地大气灰霾的监测具有十分重要的意义。利用环境一号卫星数据,对能表征大气污染程度的气溶胶光学厚度进行了反演。提出了用EVI植被指数判定暗像元精细化反演气溶胶光学厚度的方法,该方法能较好地去除部分大气影响,气溶胶光学厚度反演结果与CE318的气溶胶光学厚度结果相关性较高,误差较小,具有较高的精度,反演结果满足精细化要求。反演结果表明,四川盆地内有德阳、成都、眉山和乐山4个气溶胶光学厚度高值区,该高值区呈带状分布且与四川盆地的地形密切相关。     

基于激光雷达的成都市气溶胶光学厚度的时间变化特征研究

利用2013年9月~2014年8月期间成都市基于激光雷达和太阳光度计观测反演的气溶胶光学厚度资料,对激光雷达资料的适用性和气溶胶光学厚度的时间变化特征进行了研究。结果表明:(1)激光雷达与太阳光度计观测反演的气溶胶光学厚度的相关性较高,说明激光雷达的观测结果具有较好的适用性。(2)成都市气溶胶光学厚度整体较高,全年AOD的平均值约为1.00。(3)气溶胶光学厚度的季节差异明显,呈现出冬季最大、秋季和春季次之、夏季最小的特征。(4)月平均气溶胶光学厚度呈"双峰"结构,峰值分别出现在2月和11月,谷值出现在6月;(5)气溶胶光学厚度的日变化特征显著,一天当中12:00达到最大值,17:00左右达到最小值。     

反演同化技术在激光雷达中的应用研究

为增强模式预报准确性,提高激光雷达数据在化学模式中的应用水平,建立激光雷达同化系统,将激光雷达数据引入模式,利用WRF-Chem模拟2016年12月6日~10日一次污染过程,将激光雷达监测的气溶胶光学深度(AOD)反演成近地面PM2.5浓度,通过三维变分同化技术订正模式原始场,调整模式预报结果。实验对比发现,反演同化后水平和垂直方向初始场调整显著,PM2.5、PM10和AQI的预报准确率明显提升,同化后相关性提高了0.05~0.1,预报准确率提高了10%~20%,分级风险评分也不同程度升高,与观测结果接近,优于不同化的预报结果。表明激光雷达数据在模式同化方面表现良好,有广阔的应用空间。     

乌鲁木齐黑碳气溶胶浓度时间变化特征及影响因素分析

利用乌鲁木齐市环境空气超级站中MAAP-5012型黑碳仪对乌鲁木齐市黑碳气溶胶进行连续一年的监测,并结合乌鲁木齐环境空气质量城市站小时数据和日数据及气象数据对黑碳气溶胶变化情况进行综合分析。结果表明:2019年6月至2020年5月乌鲁木齐黑碳气溶胶浓度日均值为1 506(±1 096) ng/m~3,本底值为575 ng/m~3,与国内主要城市相比黑碳浓度相对较低;污染最严重的冬季黑碳浓度为2 414(±1 325) ng/m~3,本底值为825 ng/m~3,较十年前浓度下降明显。乌鲁木齐市黑碳气溶胶浓度随季节变化差异大,冬季>秋季>夏季>春季,24小时昼夜变化整体呈现"夜高昼低"和不典型的"双峰双谷"特征,"周末效应"特征显著。相关性分析结果表明:乌鲁木齐黑碳气溶胶与NO_2、CO的Pearson相关性系数均超过0.8,一元线性拟合度均超过0.7,黑碳气溶胶与环境空气中的污染物NO_2、CO具有高度的同源性。虽然气象因素中温度、湿度、风速与黑碳的Pearson相关性及一元线性拟合效果不佳,但气象因素仍是影响黑碳气溶胶浓度重要因素。     

四川省气溶胶光学厚度时空分布特征

本文利用MODIS气溶胶光学厚度产品,建立了气溶胶光学厚度与PM10/2.5的线性关系。分析了2008年~2012年四川省的气溶胶光学厚度时空分布特征,以成都市为特例分析了2003年~2012年的气溶胶光学厚度时空分布。结果显示:气溶胶光学厚度与PM10/2.5的线性关系较高;川西高原具有较低的气溶胶光学厚度,康定、马尔康、西昌、雅安等地年均气溶胶光学厚度约0.2;四川盆地区域具有较高的气溶胶光学厚度,以成都、德阳等地为代表,年均值在0.8~1.0之间,并具有明显季节变化特征;成都市的气溶胶光学厚度时空分布具有明显的城市特点。这些时空分布的特征与四川省的工业情况、地理位置、气候条件有关。     

乱挖矿山毁绿 暴露生态保护之殇

<正>浙江省诸暨市次坞镇新徐坞杨村一些无证矿多年疯狂私挖乱采,破坏林木、尾矿扬尘污染环境,危害当地生态环境,汛期雨季也给附近村民带来安全隐患。合理开发利用当地矿产资源,发展地方经济是     

Aerosol chemistry and the effect of aerosol water content on visibility impairment and radiative forcing in Guangzhou during the 2006 Pearl River Delta campaign

Optical and chemical aerosol measurements were obtained from 2 to 31 July 2006 at an urban site in the metropolitan area of Guangzhou (China) as part of the Program of Regional Integrated Experiment of Air Quality over Pearl River Delta (PRIDE-PRD2006) to investigate aerosol chemistry and the effect of aerosol water content on visibility impairment and radiative forcing. During the PRIDE-PRD2006 campaign, the average contributions of ammonium sulfate, organic mass by carbon (OMC), elemental carbon (EC), and sea salt (SS) to total PM_2.5 mass were measured to be 36.5%, 5.7%, 27.1%, 7.8%, and 3.7%, respectively. Compared with the clean marine period, (NH₄)₂SO₄, NH₄NO₃, and OMC were all greatly enhanced (by up to 430%) during local haze periods via the accumulation of a secondary aerosol component. The OMC dominance increased when high levels of biomass burning influenced the measurement site while (NH₄)₂SO₄ and OMC did when both biomass burning and industrial emissions influenced it. The effect of aerosol water content on the total light-extinction coefficient was estimated to be 34.2%, of which 25.8% was due to aerosol water in (NH₄)₂SO₄, 5.1% that in NH₄NO₃, and 3.3% that in SS. The average mass-scattering efficiency (MSE) of PM₁₀ particles was determined to be 2.2 ± 0.6 and 4.6 ± 1.7 m² g⁻¹ under dry (RH < 40%) and ambient conditions, respectively. The average single-scattering albedo (SSA) was 0.80 ± 0.08 and 0.90 ± 0.04 under dry and ambient conditions, respectively. Not only are the extinction and scattering coefficients greatly enhanced by aerosol water content, but MSE and SSA are also highly sensitive. It can be concluded that sulfate and carbonaceous aerosol, as well as aerosol water content, play important roles in the processes that determine visibility impairment and radiative forcing in the ambient atmosphere of the Guangzhou urban area.     

机场周边大气中非甲烷总烃时空分布特征

为了研究机场周边大气中非甲烷烃的污染情况,于2011年4月21日起连续5天对某机场起降点附近2个采样点以及对照点农田区的大气中NMHCs进行测定.结果表明,NMHCs的含量为飞机开始滑行点（3.22mg/m3）＞降落点（2.92mg/m3）＞农田区（2.91 mg/m3）,均超出以色列的标准（2.0mg/m3）.非甲烷总烃在一天中下午16点达到最小值.飞机的起降对周边大气NMHCs排放有一定的影响.而对照点农田排放可能是当地NMHCs排放的重要来源. 3个采样点中,排放的碳氢化合物以非甲烷烃为主,占总烃的63.4％.NMHCs和总烃的线性关系良好,用统计回归的方法得到了研究区总烃和非甲烷烃的换算公式.     

Estimating the reduction of urban PM10 concentrations by trees within an environmental information system for planners

Trees have been widely quoted as effective scavengers of both gaseous and particulate pollutants from the atmosphere. Recent work on the deposition of urban aerosols onto woodland allows the effect of tree planting strategies on airborne aerosol concentrations to be quantified and considered within the planning process. By identifying the potential planting locations in the local authority area, and applying them within a dispersion and deposition model, the potential magnitude of reduction in the ambient concentration of PM(10), achievable through urban tree planting, has been quantified for two UK cities. As part of the Environmental Information Systems for Planners (EISP), flow diagrams, based on planning decisions, have incorporated output from the model to make decisions on land use planning ranging from development plans and strategic planning, to development control. In this way, for any new developments that contribute to the local PM(10) level, the mitigation by planting trees can be assessed, and in some cases, reductions can be sufficient to meet air quality objectives for PM(10).     

Role of traditional conservation practice: highlighting the importance of Shivbari sacred grove in biodiversity conservation

Recognizing the importance of sacred groves in biodiversity conservation and management, and the recent threats to them, the present study was conducted in Shivbari sacred grove of Himachal Pradesh. The study aimed at documenting the floral wealth of Shivbari and promoting plantation of indigenous species in participation with local people. For this, systematic field surveys in different seasons were conducted in Shivbari from April 2005 to November 2009, and liaison was maintained with the local community and temple management authority for gaining insight into the history and problems of Shivbari and initiating plantation activities. A total of 69 flowering plant species were identified inside the grove, which include 14 trees, 9 shrubs, 3 lianas and 43 herbs. This represents almost 2% of the total flowering plant species occurring in the state of Himachal Pradesh. Mallotus philippensis followed by Putranjiva roxburghii was the most dominant tree species. Adhatoda zeylanica was the most common shrub species, while Achyranthes aspera was the most common herb species. The grove harbours 23 plants species that are in high demand in the market, and at the same time also influences the microclimate of the area. The temperature inside the grove was significantly lower than the temperature outside the grove. The recent changes in socio-economic status of the local people and a shift towards market-oriented economy have threatened the survival of Shivbari. However, the deeply held beliefs of the pilgrims, local people and priest offer a ray of hope. During the course of the study, 3,000 plants were planted inside the grove out of which 60% have survived.     

Phosphorus losses through agricultural tile drainage in Nova Scotia, Canada

Tile drainage water from agricultural fields commonly exceeds environmental guidelines for phosphorus (P) in rivers and streams. The loss of P through artificial drainage is spatially and temporally variable, and is related to local factors. This study characterizes variability in total P (TP) and soluble reactive P (SRP) concentrations in weekly drainage samples from 39 agricultural fields in Nova Scotia, Canada, from April 2002 through December 2003. We examined connections between P concentrations and the factors: (i) soil texture; (ii) discharge flow rate; (iii) soil test P (STP); (iv) manure type; and (v) crop cover. Generally, variability between fields and samples was great, and fields with standard deviations exceeding the mean for TP, SRP, and flow rate were 71, 54, and 79%, respectively. It was evident that poultry and swine manure contributed to high STPs, and to constantly high TP concentrations with high proportions of SRP. Concentrations varied from week to week, and particularly in April, May, October, and November when the greatest TP, SRP, and flow rate averages were measured. Mean TP concentrations exceed the USEPA (1994) TP guideline of 0.10 mg L(-1) at 82% of the fields, and periodically concentrations more than 10 times, and occasionally more than 50 times higher than the guideline were found. The proportion of SRP in TP had a tendency to be higher when TP levels were high in coarse textured soils. In Nova Scotia, dairy manure is most often applied on permanent cover crops, which did not show as much P concentration variability as crop rotations. Daily or hourly observation of short-term increases in P concentrations related to the described factors would help to characterize the changes in P concentrations observed during frequent heavy drainage flow events.     

Downward shortwave radiation estimation and spatial assessment on sites over complex terrain applying integrative approach of MTCLIM-XL,interpolation, RS and GIS

Downward shortwave radiation (DSR) is a highly variable solar source on spatiotemporal basis and essential for energy and agriculture systems, while its calculations are helpful in the environment-related studies, climatology, and monitoring fire risk. Statistical methods developed to extrapolate values of climatic variables and radiation could fail to generate reliable findings of DSR over a complex terrain without considering local topographic factors. In the present study, we proposed an integrative approach of MTCLIM-XL extrapolation with remote sensing (RS) and geographic information system (GIS) to estimate real-time DSR and its spatial potential over surfaces of contrasting elevated sites on a mountainous terrain of Quetta (Pakistan).Based on methodological approach, remote sensing data product of high-resolution DEM (SRTM 30m) was processed to extract topographic data, and meteorological data were obtained from a base site, Subsequently, MTCLIM-XL executed the simulation to calculate the daily-based DSR (W/m²).Spatial distribution of DSR was generated by applying deterministic interpolation with complementing quantification of Hillshade analysis for spatially obstructive surfaces, and resultant spatial hotspot-based potential was assessed on basis of specified threshold level (above 250 W/m² = 2 kW h/m²) over the specified area. We observed usable potential of DSR at target sites and its spatial distribution during the study period of 2015 to April 2016. Using EUMETSAT CMSAF data as a standard, the validation demonstrates agreeable results of low RMSE and high correlation coefficient values for selected sites, except some sites with relatively high elevations and irregular gradients. Analysis of solar zenith angle to evaluate its inverse relation with increment in DSR values shows agreeable high inverse relation, while the negative trend for only some sites features relatively high rugged topography. In conclusion, MTCLIM-XL with RS and GIS integration manifests as a reliable approach for estimation and spatial potential assessment-based exploration of DSR over complex terrain having no ground data, while prospectively it will complement to the environment-related studies on local to mesoscale.