“大气国十条”实施以来京津冀PM_(2.5)控制效果评估报告

2013年9月13日,国务院颁布了《大气污染防治行动计划》(简称"大气国十条"),提出了京津冀地区2017年PM2.5浓度比2012年下降25%,北京市PM2.5年均浓度控制在60μg/m3左右的目标。"大气国十条"实施以来,北京、天津和河北相继出台了对应的行动计划,分别从"控煤"、"控车"、"控尘"、"控工业污染"和"控新建项目污染"等方面部署了防治措施。中科院"大气灰霾追因与控制"研究团队从观测和模拟的角度对该区域控制措施的实际效果开展了评估,以期为后续防治措施的制定提供参考。与2013年相比,京津冀2014年SO2和NO2大气平均浓度下降约20%,PM2.5大气平均浓度下降约10%;其中河北SO2、NO2和PM2.5的下降幅度最显著。上述污染物浓度在冬季比夏季降低更显著。与2013年冬季相比,京津冀2014年冬季PM2.5中硫酸盐的比例略有下降,硝酸盐的比例略有增加。模式模拟表明,2013年和2014年该区域气象场无明显变化,由于控制措施的实施导致污染物排放清单的变化,进而导致2014年冬季京津冀PM2.5浓度下降,但对夏季PM2.5浓度无有利影响,并存在臭氧污染的潜在风险,与观测结果吻合。在实施京津冀大气污染联防联控过程中,控制重点应向河北倾斜。     

南京市餐饮企业大气污染物排放清单构建的研究

餐饮油烟污染是现代都市重点关注的环保问题之一。南京市餐饮企业主要分布在人口密集的主城区和城市建成区,特大型、大型、中型、小型餐饮单位油烟净化设施安装率分别94.9%、81.2%、73.6%、58.7%,相应油烟净化率的算术平均值分别80%、69%、55%、35%。本研究构建了南京市2018年餐饮企业大气污染物排放清单,PM10、PM2.5、BC、OC和VOCs的排放量分别为524.46t、419.57t、8.52t、293.70t和367.12t。     

吉林市不同利用方式土壤有机质含量的测定

实验对比分析不同利用方式下(园林,耕地,草地,江边土,城市绿地)土壤有机质及腐殖质组成特点。研究表明:土壤有机质含量及TOC含量均为:园林土耕地土江边土草地土城市绿地土。腐殖酸总碳量分别为8.93g/kg、8.18g/kg、2.59g/kg、1.93g/kg、1.81g/kg。腐殖酸占总碳比例最高的为园林土壤:28.98%;最低的为城市绿地:22.86%。其H_A/F_A分别为1.69、1.52、1.34、1.15、1.03。     

青岛市大气颗粒物PM2.5污染特征动态分析

基于2016年5月至2017年4月青岛市主城区大气自动监测站实时发布的数据,统计分析颗粒物PM2.5浓度的时空变化规律,并对PM2.5与其它颗粒物之间的相关性和影响因素进行了分析。结果表明,PM2.5颗粒物质量浓度在1月份达到最高为68.8μg/m~3,8月份是全年最低为17.8μg/m~3;冬、春季PM2.5浓度较高,而夏、秋季PM2.5颗粒物浓度相对较低;从空间分布特征情况分析发现仰口站PM2.5年均浓度为23.59μg/m~3,为青岛市区最低,李沧区子站和黄岛区子站PM2.5年均浓度较高分别为44.13μg/m3和48.66μg/m~3;根据PM2.5颗粒物与其它颗粒物之间的相关曲线看,PM2.5与SO_2、NO_2、O_3之间呈现显著正相关,SO_2、NO_2、O_3浓度的升高都会引起PM2.5颗粒物浓度增大,其来源相同或相关。     

中国南部天然常绿阔叶林的凋落物养分归还

自1989年至1992年对江西省九连山自然保护区的天然常绿阔叶林通过凋落物约为4.3t/hm2.a-4.7t/hm2.a。养分归还量氮、磷、钾、钠、钙和镁各为68kg/hm2.a-85kg/hm2.a,3.1kg/hm2.a-3.8kg/hm2.a,21kg/hm2.a-kg/hm2.a,4.4kg/hm2.a-6.8kg/hm2.a,113kg/hm2.a-160kg/hm2.a和19kg/hm2.a-28kg/hm2.a。氮和磷的归还量小于而钙的归还量大于热带雨林。     

中国南部天然常绿阔叶林的凋落物养分归还

自1989年至1992年对江西省九连山自然保护区的天然常绿阔叶林通过凋落物归还到枯枝落叶层的养分量进行了测定.凋落物的干重约为6.4t/hm2·a～8.8t/hm2·a,其中叶凋落物约为4.3t/hm2·a～4.7t/hm2·a.养分归还量氮、磷、钾、钠、钙和镁各为68kg/hm2·a～85kg/hm2·a,3.1kg/hm2·a～3.8kg/hm2·a,21kg/hm2·a～67kg/hm2·a,4.4kg/hm2·a～6.8kg/hm2·a,113kg/hm2·a～160kg/hm2·a和19kg/hm2·a～28kg/hm2·a.氮和磷的归还量小于而钙的归还量大于热带雨林.     

北京建城区公园绿地的房产增值效应评估

本文首先采用问卷调查获取了北京城区15个公园周边76个居住小区的房地产资料,然后采用享乐价格法分析了公园对房地产价格的影响距离及其增值系数,最后基于北京市2009年第七次园林绿化资源普查数据,评估了建成区1.81万hm2公园绿地对周边土地增值的影响。结果表明：在北京建成区,公园绿地能明显影响附近房地产价格,平均增值系数达10.9%,不过这种增值作用仅能影响到距离公园1.38km内的居住用地。据此推算,北京市建城区公园绿地能够促进12.56万hm2土地升值,增值的总价值为55.02亿元/a,约合单位面积公园绿地增值43.79万元/（hm2a）,相当于特级绿地养护管理标准的2倍多（15元/（m2a））。该研究对于揭示绿地资源的社会经济价值以及建设管理决策方面具有重要参考意义。     

生态园林景观设计对大气颗粒物浓度变化的影响分析

针对城市生态系统中,大气颗粒物浓度污染严重,城市空气受到严重影响,城市园林不能充分发挥其作用,为了能让城市园林植物能充分吸收大气颗粒物,净化城市空气发挥主要作用,本文以天津市生态园林景观为研究背景,分析生态园林景观设计对大气颗粒物浓度变化的影响分析。以天津市中常见园林植物种类为研究目标,具体为常绿阔叶类植物、常绿针叶类植物、落叶阔叶类植物3类植物,运用空气气溶胶再发生器检测上述3种植物吸附滞留大气中颗粒物的总悬浮颗粒物(TSP)、PM10及PM2.5等颗粒物含量。实验结果显示:不同种类园林植物单位面积吸附滞留颗粒物能力不同,其中对总悬浮颗粒物吸附量最高植物为常绿针叶类植物,吸附量分别为15.41μg·cm~(-2),吸附量最低为常绿阔叶类植物(3.19μg·cm~(-2));对PM10吸附量高及最低植物种类是落叶阔叶类植物及常绿阔叶类植物,吸附量分别是(1.561μg·cm~(-2))、(0.289μg·cm~(-2));PM2.5吸附能力最强的植物为常绿针叶类植物(0.944μg·cm~(-2))。三类园林植物在不同月份对大气颗粒物吸附量存在差异,三类园林植物叶片层次对滞留颗粒物也存在影响,为生态园林选择植物种类提供最优方案。     

石家庄市大气颗粒物污染特征研究

选取石家庄市6个点位,采用重量法进行大气中TSP、PM10、PM2.5的采样和分析,利用相关系数法对测定结果进行相关性分析,得到其相关系数。分析结果表明,石家庄市PM10和PM2.5污染严重,TSP与PM10和PM10与PM2.5有良好的线性关系,相关系数分别为0.9425和0.9119;PM10/TSP平均值为0.75,PM2.5/PM10平均值为0.56,细颗粒物污染严重。     

西北地区植被保持土壤效应评估

植被的土壤保持功能评估是生态安全研究中的重要内容之一.现有研究中缺乏较大尺度、较高精度的土壤保持估算.基于通用水土流失方程与年尺度风蚀预报方程,估算西北地区土壤现实侵蚀量与潜在侵蚀量,得出植被土壤保持物质量与价值量,并进行土壤保持效益分区.结果表明:植被土壤水蚀保持量高值集中在秦巴山区一带,其值超过5000t/(hm2·a);青海东南部三江源地区植被土壤水蚀保持量在(500～2000)t/(hm2·a);而1万t/(hm2.a)以上的植被土壤风蚀保持量样本很少,集中在天山、西祁连山、三江源三大区域;沙漠内部几乎不发生植被土壤保持作用.单位面积价值量大于2亿元/km2的像元几乎全部位于陕南和陇东南的秦巴山区中.黄土高原土壤保持价值量也多在1000万元/kim2以上.最后统计土壤保持价值总量,进行县域单元的土壤保持生态效益分级,并阐述了4种县域生态建设定位.     

北京市大气污染治理现状及面临的机遇与挑战

"大气十条"实施以来,全国城市PM_(2.5)浓度呈下降趋势,预期能够实现国家规定的2017年空气质量改善目标。若按现有力度措施,北京市2017年PM_(2.5)浓度达到年均值60μg/m~3左右的目标难以实现,同时臭氧(O_3)污染迅速抬头。未来两年必须下决心采取超常规措施破解北京大气污染防治中的若干难点问题,才能突破大气污染治理瓶颈,达到预定目标。     

Robust prediction of hourly PM2.5 from meteorological data using LightGBM

Retrieving historical fine particulate matter (PM_2.5) data is key for evaluating the long-term impacts of PM_2.5 on the environment, human health and climate change. Satellite-based aerosol optical depth has been used to estimate PM_2.5, but estimations have largely been undermined by massive missing values, low sampling frequency and weak predictive capability. Here, using a novel feature engineering approach to incorporate spatial effects from meteorological data, we developed a robust LightGBM model that predicts PM_2.5 at an unprecedented predictive capacity on hourly (R² = 0.75), daily (R² = 0.84), monthly (R² = 0.88) and annual (R² = 0.87) timescales. By taking advantage of spatial features, our model can also construct hourly gridded networks of PM_2.5. This capability would be further enhanced if meteorological observations from regional stations were incorporated. Our results show that this model has great potential in reconstructing historical PM_2.5 datasets and real-time gridded networks at high spatial-temporal resolutions. The resulting datasets can be assimilated into models to produce long-term re-analysis that incorporates interactions between aerosols and physical processes.     

Pathways of China's PM2.5 air quality 2015–2060 in the context of carbon neutrality

Clean air policies in China have substantially reduced particulate matter (PM_2.5) air pollution in recent years, primarily by curbing end-of-pipe emissions. However, reaching the level of the World Health Organization (WHO) guidelines may instead depend upon the air quality co-benefits of ambitious climate action. Here, we assess pathways of Chinese PM_2.5 air quality from 2015 to 2060 under a combination of scenarios that link global and Chinese climate mitigation pathways (i.e. global 2°C- and 1.5°C-pathways, National Determined Contributions (NDC) pledges and carbon neutrality goals) to local clean air policies. We find that China can achieve both its near-term climate goals (peak emissions) and PM_2.5 air quality annual standard (35 μg/m³) by 2030 by fulfilling its NDC pledges and continuing air pollution control policies. However, the benefits of end-of-pipe control reductions are mostly exhausted by 2030, and reducing PM_2.5 exposure of the majority of the Chinese population to below 10 μg/m³ by 2060 will likely require more ambitious climate mitigation efforts such as China''s carbon neutrality goals and global 1.5°C-pathways. Our results thus highlight that China''s carbon neutrality goals will play a critical role in reducing air pollution exposure to the level of the WHO guidelines and protecting public health.     

Contrasting trends of PM2.5 and surface-ozone concentrations in China from 2013 to 2017

Although much attention has been paid to investigating and controlling air pollution in China, the trends of air-pollutant concentrations on a national scale have remained unclear. Here, we quantitatively investigated the variation of air pollutants in China using long-term comprehensive data sets from 2013 to 2017, during which Chinese government made major efforts to reduce anthropogenic emission in polluted regions. Our results show a significant decreasing trend in the PM_2.5 concentration in heavily polluted regions of eastern China, with an annual decrease of ∼7% compared with measurements in 2013. The measured decreased concentrations of SO₂, NO₂ and CO (a proxy for anthropogenic volatile organic compounds) could explain a large fraction of the decreased PM_2.5 concentrations in different regions. As a consequence, the heavily polluted days decreased significantly in corresponding regions. Concentrations of organic aerosol, nitrate, sulfate, ammonium and chloride measured in urban Beijing revealed a remarkable reduction from 2013 to 2017, connecting the decreases in aerosol precursors with corresponding chemical components closely. However, surface-ozone concentrations showed increasing trends in most urban stations from 2013 to 2017, which indicates stronger photochemical pollution. The boundary-layer height in capital cities of eastern China showed no significant trends over the Beijing–Tianjin–Hebei, Yangtze River Delta and Pearl River Delta regions from 2013 to 2017, which confirmed the reduction in anthropogenic emissions. Our results demonstrated that the Chinese government was successful in the reduction of particulate matter in urban areas from 2013 to 2017, although the ozone concentration has increased significantly, suggesting a more complex mechanism of improving Chinese air quality in the future.     

北京城市建成区内绿色空间配置格局的时空变化

本文利用高分辨率遥感影像Rapid Eye数据对北京绿色空间进行分类,并在此基础上分析城市建成区内绿色空间面积、覆盖率、人均绿色空间等指标的变化,多方面地反映了城市建成区内绿色空间的变化情况。研究结论如下:12000-2010年北京城市建成区绿色空间面积、绿色空间覆盖率和人均绿色空间面积总体上均在增加;22000-2010年人工林和草地占绿色空间总面积比例持续增加,农田所占比例持续下降;2000-2010年不同类型绿色空间之间发生转换,主要趋势是旱地转换为天然草丛/灌草丛、苗圃与果园;32000-2010年五环以内绿色空间面积和绿色空间覆盖率基本保持稳定,五环以外城市建成区绿色空间面积持续增加,绿色空间覆盖率先增加后减少。     

大气14CO2观测：碳排放评估的新方法

我国作为碳排放大国,面临着碳达峰、碳中和（以下简称“双碳”）目标任务和国际碳减排压力。因此,准确的碳排放数据对于评估“双碳”目标和国际履约非常重要。联合国政府间气候变化专门委员会（IPCC）报告推荐将二氧化碳（CO₂）观测与大气反演结合来“自上而下”地校验“自下而上”的碳排放清单,并指出加入大气¹⁴CO₂观测可以更准确地校验碳排放清单。放射性碳同位素（ ¹⁴C）是化石源CO₂最准确的示踪剂,已被国际社会广泛推荐用于碳排放评估。文章基于大气¹⁴CO₂观测的国际发展趋势和国内的紧迫状况,建议加大支持力度,建立大气¹⁴CO₂观测网络;开展培训,统一相关标准,积极参与国际交流;尽快开展¹⁴CO₂观测与大气反演相结合的研究。以此使我国的碳排放研究水平与国际接轨,并提高碳排放数据的可靠性,进而服务国家的“双碳”目标和气候外交谈判。     

我国油品对机动车尾气排放的影响及升级经济性分析

提升油品质量、降低机动车污染物排放,对改善我国空气质量至关重要。通过隧道试验测试了道路机动车污染物排放水平,从我国8大城市加油站收集的汽柴油样品实测了其硫含量和烃类组成等指标,用先进的烟雾箱系统模拟了汽油车和柴油车尾气直接排放和二次反应生成的颗粒物,并探讨了机动车尾气对细颗粒物(PM2.5)的综合贡献与油品之间的关系。在分析我国油品升级所需的脱硫、重整、加氢等技术需求的基础上,初步估算了我国汽柴油全面升级的直接投资需求。文章也揭示了突破柴油发动机和柴油深加工技术对我国机动车减排的重要意义。     

天津市郊区休闲农庄农地游憩价值评估

农地游憩价值是农地资源价值的重要组成部分,通过对农地游憩价值的评估,可以促进城郊农地的合理有效利用,为纠正市场配置农地资源失灵提供理论依据。本文以天津市西青区杨柳青庄园和水高庄园为例,通过问卷调查共获得765份有效样本数据,运用改进后的旅行成本法,在剔除了非游憩价值部分和评估区域内非农地部分,分别对比评估了两庄园内农地的游憩价值。结果显示,杨柳青庄园和水高庄园游客的人均消费者剩余分别为86.98元和94.15元,人均旅行费用为386.16元和322.03元;杨柳青庄园农地年游憩价值为2.62亿元,单位面积游憩价值为628.90万元/hm²;水高庄园农地年游憩价值为2.19亿元,单位面积游憩价值为241.54万元/hm²。     

Economic complexity and the green economy

Which countries are likely to have the productive capabilities to thrive in the green economy? How might countries reorient their existing industrial structures to be more competitive in an environmentally friendly world? To investigate these questions, this paper develops a novel methodology for measuring productive capabilities to the green economy. By constructing a new comprehensive dataset of traded green products and drawing on economic complexity methods, we rank countries in terms of their ability to export complex green products competitively. We show that higher ranked countries are more likely to have higher environmental patenting rates, lower CO₂ emissions, and more stringent environmental policies even after controlling for per capita GDP. We then examine countries' potential to transition into green products in the future and find strong path dependence in the accumulation of green capabilities. Our results shed new light on green industrialisation and have a number of implications for green industrial policy.