Can further mitigation of ammonia emissions reduce exceedances of particulate matter air quality standards?

Several studies point out the importance of agricultural emissions to particulate matter (PM) concentrations, and particularly of NH₃ emissions to PM_2.5. Our study used three different chemical transport models (CHIMERE, EMEP and LOTOS-EUROS) to quantify the reductions of PM_2.5 and PM₁₀ concentrations due to reductions of NH₃ emissions beyond the Gothenburg Protocol (GP), as well as due to the GP alone compared to 2009. Simulations of PM_2.5 and PM₁₀ concentrations using 2009 meteorology were undertaken for five emission scenarios: 2009 emissions (as the reference simulation), GP emissions in 2020, and further 10%, 20% and 30% NH₃ emission reductions in EU27 beyond the GP. The modelling results for the scenarios with further 10%, 20% and 30% NH₃ agriculture emission reductions in EU27 beyond the GP show that the reduction achieved in PM concentrations is not linear with the emission reductions. In fact, the results from the study show that the impact of ammonia emissions reduction is significantly more efficient when the emission reduction rises. Moreover, based on the evaluation on 2009, the modelling study shows that the expected impact of ammonia emissions on the formation of particulate ammonium was underestimated by all models. This would imply that the role of ammonia on PM concentration and exceedances of PM_2.5 and PM₁₀ limit values is likely to be even larger than quantified in this study. This study shows that the implementation of the emission reductions imposed by the revised GP for 2020 will not suffice to achieve compliance with PM limit values everywhere in Europe; hence further European and local measures may be considered. NH₃ emissions from agriculture can be further reduced with the implementation of proven and feasible measures (substitution of fertilizers, improved storage of manure, way fertilizer injections, etc., …), in order to reduce PM concentrations and their impacts on human health across Europe.     

Seasonal variation and sources of atmospheric polycyclic aromatic hydrocarbons in a background site on the Tibetan Plateau

The study of atmospheric polycyclic aromatic hydrocarbons (PAHs) in northeastern Tibetan Plateau with fragile ecological environment and complex atmospheric circulation system is blank. To understand the characteristics and sources of persistent organic pollutants in the atmosphere of the northeastern Tibetan Plateau, we monitored levels in the central Qilian Mountain. From 2016 to 2017, we collected 45-pair (particle + gas) samples using active air samplers to investigate the sources, transport paths, and their influencing factors. Sources of PAHs were analysed with a source diagnostic model, and atmospheric transport paths were calculated. The concentration range for ∑₁₅PAHs was 439–4666 pg/m³, and the average was 2015 pg/m³. The PAHs in central Qilian Mountain are mainly low molecular weight (LMW) PAHs. Winter concentrations of PAHs were higher than those in summer. The transport of PAHs is mainly affected by westerlies, and there are seasonal differences. Source analysis showed that PAHs mainly came from coal and biomass combustion and vehicle emissions, with seasonal differences. This study clarifies the concentration and seasonal variation of PAHs in the northern Tibetan Plateau, which is conducive to understanding the atmospheric transport process and fate of pollutants. The background site of Qilian Mountains located in the Silk Road economic belt has the value and significance of long-term observation of pollutants.     

Erratum

The influence of soil macro-porosity and manure on atrazine (6-chloro-N-ethyl-N′-(1-methylethyl)-1,3,5-triazine-2,4-diamine) transport was investigated under laboratory conditions using disturbed and undisturbed soil columns. The macro-porosity in the soil column was obtained with CT scanning technique. Liquid manure was applied at the surface of soil column, 19 cm long and 8 cm in diameter, at a rate of 60 m³/ha. Experimental results revealed that atrazine moves faster through the soils in the presence of manure compared to soil without application of manure. The average time for elusion and the relative peak concentration in the disturbed soil column without manure was 14.5 h and 3.1%, respectively compared to 11.0 h and 6.9% in the presence of manure, respectively. Similar behavior was observed in the case of disturbed soil columns. Soil macro-porosity has shown large impact on atrazine transport, especially in the presence of manure.     

基于ANP方法的社区事故应急能力评估指标权重的确定

在分析社区在重大事故应急救援中特殊作用和地位的基础上,指出开展社区事故应急能力评估的目的和意义。简要分析化工型社区事故危险性和应急特点,综合考虑社区事故应急能力的各类影响因素,构建化工型社区事故应急能力评估指标体系。选择网络分析法对社区事故应急能力进行评估,建立社区事故应急能力评估指标体系的网络层次结构模型,并利用网络分析法计算各指标的权重。该方法将较好地考虑社区事故应急能力评估指标体系之间存在相互影响和反馈关系的特点,从而提高对社区事故应急能力评价的可靠性和准确性。     

长输油气管线安全生产事故监测预警平台设计与实现

阐述了适用于长输油气管线安全生产事故应急救援全过程的事故监测预警平台的整体结构和实现要点,主要从长输油气管线的工作运行和事故特点出发,结合安全生产事故应急救援过程中各环节的业务需求,提出监测预警平台的建设目标和适用范围,对平台的需求进行分析,并进一步对平台的构建思路进行讨论。其中重点从应急预防、应急准备、应急响应和应急恢复四个阶段的应急任务和需求入手,提炼出长输油气管线安全生产事故监测预警平台在＂后端应急指挥中心＂、＂现场应急指挥中心＂及＂移动指挥所＂等多个位置和场景下的建设目标和功能框架,并对平台设计与实现过程中可能涉及到的平台总体结构设计、平台软硬件及网络支撑环境、平台数据采集传输与共享模式等方面进行了简要描述。     

20世纪80年代以来洪湖流域营养物质输移模拟研究

选择位于长江中游的洪湖流域作为研究对象，应用流域分布式水文模型SWAT，探讨现代农业条件下流域面源营养盐输移的规律。模拟时段选择为1983～2002年。模拟的边界条件设置为自然地形、土壤、现代农业生产及土地利用方式，其中土壤资料包括营养盐（N和P）、有机质含量、粒径等理化参数。径流量与营养盐输出模拟结果与实测值有较好的吻合程度，可以通过置信度95％的显著性检验。模拟结果显示，现代农业条件下流域营养盐输出，TN和TP浓度变化有明显的季节特征，体现了区域耕作方式、径流对营养盐输出浓度的影响。模拟时段内营养盐输出浓度呈明显增长趋势，体现了农药化肥的施用对流域营养盐输移的影响。     

要重视承灾体的考察研究

本文指出当前在灾害研究中对承灾体考察研究重视不够的偏向;进而论述了加强承灾体的研究对制定减灾对策、提高减灾活动的社会经济效益的重要性和必要性。     

FHD-1型质子磁力仪的改进与完善

根据FHD 1型质子磁力仪在实际使用过程中存在的一些问题 ,以及一些用户提出的建议和要求 ,对FHD 1型质子磁力仪的实时时钟、标定方法、通用性与适应性、抗干扰能力方面进行了改进和完善 ,本文对此作介绍。     

RESOLUTION OF IMPACTS OF RUNOFF EVENTS ON A WATER SUPPLY RESERVOIR WITH A ROBOTIC MONITORING NETWORK1

A robotic water quality monitoring network is used to resolve the coupled patterns of a natural tracer, specific conductance (SC), and metrics of light scattering and turbidity for Schoharie Creek and downstream Schoharie Reservoir, with particular emphasis on the impacts of runoff events. Strong relationships between these parameters and streamflow, and the propensity for this tributary to plunge in the reservoir in summer and fall based on its lower temperature, are reported. The entry of this stream, the primary tributary, into the reservoir as a turbid density current during runoff events is depicted as distinct and vertically coincident subsurface SC minima and peaks in measures of light scattering. The magnitudes of these signatures imparted to the reservoir's water column are demonstrated to be strongly dependent on the magnitude of the runoff event. The time course of the diminishment of these signatures and longitudinal differences in turbidity within the reservoir are described. The documented patterns of SC and metrics of light scattering provided by the robotic monitoring network offer a rare opportunity to support development and testing of a turbidity model with the necessary attributes of fine temporal and spatial resolution.     

关中地区秋冬季颗粒物二次有机碳的估算

2017年9月4日~2018年1月19日期间分别在关中地区的5个主要城市西安（XA）,渭南（WN）,铜川（TCH）,宝鸡（BJ）,咸阳（XY）设置采样点进行PM_2.5,PM₁₀颗粒物手工采样观测,采用热光透射法（TOT）分析碳组分,最小值法估算二次有机碳（SOC）浓度,结果显示PM_2.5与PM₁₀中SOC平均浓度分别为（7.44±5.54）,（9.62±7.49）μg/m³,一次有机碳（POC）平均浓度分别为（7.04±2.59）,（9.33±4.33）μg/m³,不同粒径颗粒物中SOC各点位的浓度值分布表现基本相同为XY > XA > WN > BJ > TCH.PM_2.5中SOC含量为8.76%,OC占比为48.03%,PM₁₀含量为6.28%,OC占比为48.09%,季节分布均呈现为秋季低冬季高,关中地区SOC污染严重.后向轨迹聚类分析结果显示污染气团传输主要是关中地区局部污染和西北,东北方向传输,其中局部污染轨迹的数量占比较多,浓度较高.低空传输与近地面风向风速及污染物分布存在差异,结合关中地区盆地地形,静风频率高,边界层低等多种因素造成颗粒物中SOC浓度较高,其中BJ点位易受到东北气团的污染物传输累积.