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1.
极端降水具有较强的持续时间不确定性,持续多天的极端降水事件往往具有较大的致灾性,但目前从极端降水持续性角度进行极端降水变化及其环流因素的研究还非常缺乏。利用1961~2018年中国逐日降水格点数据集以及大气环流指数数据,定义持续了2天及以上的极端降水为持续极端降水事件,研究其在中国不同区域发生频次、持续日数以及持续极端降水总量、持续极端降水最大降水量的时空变化和影响因素。结果表明:(1)近60年来,中国持续极端降水事件在较为干旱的地区(蒙新地区、青藏地区)高发且持续时间长,但在较湿润的地区(东部地区)持续极端降水事件强度更高。(2)中国持续极端降水事件的频率和强度均呈现出增加的趋势,但在区域尺度上,东部地区没有明显的变化趋势,越干旱的地区增加趋势越大。各个指数变化趋势的空间分布格局相似。(3)持续极端降水事件对总降水的贡献率呈现出缓慢的增长趋势,东部地区增长趋势不明显。(4)西太平洋副高、南海副高、西太平洋暖池、亚洲区极涡、北半球极涡和中国持续极端降水事件有着显著的相关关系。区域尺度上,西太平洋副高对蒙新地区和青藏地区的影响最大,东部地区则受到西太平洋副高和西太平洋暖池的较大影响。总体上西太平洋副高对于中国持续极端降水事件影响最大,西太平洋副高强度的加强往往会引起中国持续极端降水增多。  相似文献   

2.
以京津冀大气污染传输通道“2+26”城市为对象的区域性雾霾专项治理已经开展两年有余。要判断“2+26”城市治霾方案的实施是否取得了显著成效需要通过科学的实证分析加以验证。采集山东省13个内陆城市2016—2018年每日空气质量指数(AQI)、六种单项污染物(PM 2.5、PM 10、SO 2、NO 2、CO、O 3)浓度以及气象条件等数据,以其中属于“2+26”城市的7城市作为实验组,其余6城市作为对照组,基于双重差分法,对“2+26”城市治霾方案在山东省相关城市的实施效果进行评估,试图分离方案实施所带来的环境效应。结果表明:①“2+26”城市治霾方案的实施总体上有效,对污染传输通道7城市空气质量指数(AQI)指标的降低发挥了显著作用。②“2+26”城市治霾方案对污染传输通道城市的PM 2.5、PM 10、CO浓度的降低有显著贡献,但对SO 2、NO 2和O 3指标的改善贡献并不明显。③对方案进行分时段动态效应分析发现,《京津冀及周边地区2017年大气污染防治工作方案》的发布并未对污染传输通道城市空气质量改善产生立竿见影的效果,而《京津冀及周边地区2017—2018年秋冬季大气污染综合治理攻坚行动方案》《京津冀及周边地区2018—2019年秋冬季大气污染综合治理攻坚行动方案》的落实和执行才是“2+26”城市治霾方案显著见效的保障。该研究在严格遵守双重差分法前提条件的同时,还通过了一系列稳健性检验确保评估结果的可靠性。  相似文献   

3.
In air quality management, reducing emissions from pollutant sources often forms the primary response to attaining air quality standards and guidelines. Despite the broad success of air quality management in the US, challenges remain. As examples: allocating emissions reductions among multiple sources is complex and can require many rounds of negotiation; health impacts associated with emissions, the ultimate driver for the standards, are not explicitly assessed; and long dispersion model run-times, which result from the increasing size and complexity of model inputs, limit the number of scenarios that can be evaluated, thus increasing the likelihood of missing an optimal strategy. A new modeling framework, called the “Framework for Rapid Emissions Scenario and Health impact ESTimation” (FRESH-EST), is presented to respond to these challenges. FRESH-EST estimates concentrations and health impacts of alternative emissions scenarios at the urban scale, providing efficient computations from emissions to health impacts at the Census block or other desired spatial scale. In addition, FRESH-EST can optimize emission reductions to meet specified environmental and health constraints, and a convenient user interface and graphical displays are provided to facilitate scenario evaluation. The new framework is demonstrated in an SO2 non-attainment area in southeast Michigan with two optimization strategies: the first minimizes emission reductions needed to achieve a target concentration; the second minimizes concentrations while holding constant the cumulative emissions across local sources (e.g., an emissions floor). The optimized strategies match outcomes in the proposed SO2 State Implementation Plan without the proposed stack parameter modifications or shutdowns. In addition, the lower health impacts estimated for these strategies suggest that FRESH-EST could be used to identify potentially more desirable pollution control alternatives in air quality management planning.  相似文献   

4.
Particulate air pollution in Lanzhou China   总被引:4,自引:0,他引:4  
Chu PC  Chen Y  Lu S  Li Z  Lu Y 《Environment international》2008,34(5):698-713
Concentrations of total suspended particles (TSP) and PM(10) in Lanzhou China have been kept high for the past two decades. Data collected during the intensive observational period from October 1999 to April 2001 show high TSP and PM(10) concentrations. Starting from November, the PM(10) pollution intensifies, and reaches mid to high alert level of air pollution, continues until April next year, and is at low alert level in the summer. In the winter and spring, the TSP concentration is 2-10 times higher than the third-level criterion of air quality (severe pollution). Effects of intrinsic factors (sources of pollution) and remote preconditions (propagation of dust storms) for severe PM(10) and TSP pollution in Lanzhou are analyzed.  相似文献   

5.
The subtropical coastal zone of Paraná state in southern Brazil is only 80 km long yet environmentally diverse, with relatively pristine coastal landscapes and high marine and coastal biodiversity supporting important artisanal fishing grounds. However, this region began to change in the early 1970s. The development of industrial harbors, as well as unregulated tourism and urban settlement and pollution caused the loss of natural habitats. In addition, commercial shrimp trawlers began to operate in the adjacent shallow shelf areas. Biodiversity was seriously affected, and local fish stocks have decreased drastically in the last four decades. This article describes a long-term program to protect coastal habitats, recover marine biodiversity and diversify the economic base of fishing communities in order to guarantee fish stocks for future generations, hence preserving the social and cultural identities of these communities. Although it is difficult to change traditional fishing practices, fishing communities may exploit alternate components of the marine biological resources in order to achieve environmental, social and cultural sustainability in the long term.  相似文献   

6.
Traditionally, contamination of air has been evaluated primarily by chemical analyses of indicator contaminants and these studies have focused mainly on compounds associated with particulates. Some reports have shown that air contaminants can produce specific biological effects such as toxicity mediated by the aryl hydrocarbon receptor (AhR) or modulation of the endocrine system. This study assessed the dioxin-like toxicity, anti-/estrogenicity, anti-/androgenicity and anti-/retinoic activity of both the particulate and gas phase fractions of air in two regions with different types of pollution sources and a background locality situated in an agricultural area of Central Europe. The first region (A) is known to be significantly contaminated by organochlorine pesticides and chemical industry. The other region (B) has been polluted by historical releases of PCBs, but the major current sources of contamination are probably combustion sources from local traffic and heating. Samples of both particle and gas fractions produced dioxin-like (AhR-mediated) activity, anti-estrogenic and antiandrogenic effects, but none had any effect on retinoid signaling. AhR-mediated activities were observed in all samples and the TEQ values were comparable in both fractions in region A, but significantly greater in the particulate fraction in region B. The greater AhR-mediated activity corresponded to a greater coincident antiestrogenicity of both phases in region B. Our study is the first report of antiestrogenicity and antiandrogenicity in ambient air. Anti-androgenicity was observed in the gas phase of all regions, while in the particulate phase only in one region due to the specific type of pollution in that area. Even though based on concentrations of individual compounds, except for the OCPs, the level of contamination of the two regions was similar, there were strong differences in responses in the bioassays between the two regions. Moreover, AhR-mediated activity and antiestrogenic potencies were greater in region B, where the pollution level according to the chemical analysis was similar or less than in the other region, which indicates the presence of other atmospheric pollutants with specific effects. The results document the advantage and utility of the simultaneous use of bioassays and chemical analysis in risk assessment of complex environmental samples.  相似文献   

7.
利用2008年1月~2012年12月期间成都市市区与其周边14个城镇的逐日空气污染指数(API)数据,采用去趋势互相关分析法(DCCA分析)研究区域城市间大气污染的相关性及其随时间演变规律。结果表明:成都市区与其周边城镇大气污染的空气污染存在一定程度的相关性,并且在不同的月份,相关性会随之发生变化。这种相关性具有长期持续特征,具体表现为在一定的时间尺度上成都市区与其周边城镇大气污染的相关性随时间的变化并不遵循经典的马尔可夫过程,即不随时间呈现指数快速衰减,而是以幂律形式随时间缓慢衰减。进一步,结合不同月份间区域大气平均流场的分布特征,探讨了DCCA分析结果的科学性。研究结果说明,在特定地理环境和气象条件控制下,成都市及其周边城市之间已经存在明显的相互输送和耦合作用,成都地区大气污染已由局地性污染转变为区域性大气污染。城市间污染物输送的长期相关影响机制极有可能在特定月份加重成都市区的空气污染状况,这在成都市区及其周边城镇的规划建设中必须加以特别重视  相似文献   

8.
Air pollution and other environmental hazards are often imperceptible and need to be made publicly visible. The paper argues for the importance of visualizations in drawing public attention to imperceptible hazards and in providing the public with access to empirical data describing the risks. It also argues for critical inquiry into hazards’ selective visibility as it is produced by visualizations. The impact of visualizations and their selective visibility are considered through the example of a public art project called Particle Falls installed in 2014 in Pittsburgh, a city with a long history of both ignoring air pollution and working to ameliorate this problem. I examine the impact and selective visibility of Particle Falls by considering the underlying production of data, as well as context and support systems for this visualization, and by comparing it with other visualizations of local air quality.  相似文献   

9.
利用2013年11月武汉市逐日空气质量资料、地面气象观测资料、NCEP/NCAR再分析资料和L波段雷达探空资料,通过WRF模式模拟空气污染生消过程中的局地气象条件变化,探讨特殊地形条件下边界层结构变化和局地环流在污染物生消过程中的作用和影响。结果表明:(1)武汉地区当背景环流场强的时候,由地形引起的局地流场对污染物扩散的影响就弱,反之当背景环流场弱的时候, 地形对流场影响明显:夜间为山风,白天为谷风。夜间山风与偏西北气流及偏东气流在武汉及周边地区辐合,形成气流汇聚带,在武汉地区形成一个反复污染带,即由地形引起的局地流场对污染物扩散的贡献就大;(2)武汉地区发生空气污染时,地面湿度较高,边界层呈上干下湿状态,其特征为暖而干且有偏东小风,这导致污染物不断堆积和重污染过程的形成。  相似文献   

10.
丽江古城的旅游发展与水污染研究   总被引:2,自引:0,他引:2  
许多发展中国家和地区视旅游业为增加收入和多样化产业结构的捷径。本文中,丽江古城利用淡水资源作为景观用水发展旅游业。近年来。其旅游业快速发展并保持旺盛的增长态势,这种发展情况对优质淡水资源的需求越来越大,在此过程中,古城内水体水质却在下降。对水质恶化的原因和所造成的影响进行详细调查是根本解决目前这种水资源不可持续利用方式的前提和依据。调查结果表明。水质恶化主要是由于古城旅游业发展过程中的不合理因素,如商铺、餐饮店和客栈数量的惫剧增加以及管理失效造成的,并对当地经济、居民生活质量和环境质量产生了负面影响。然后,提出了三条水资源管理措施以应对目前的水污染,促进丽江古城旅游业的可持续发展。  相似文献   

11.
城市边缘带土地利用特征与土壤资源压力   总被引:17,自引:1,他引:16  
城市边缘带作为城乡交互作用界面,根据其形成机制可划分为不同类型,而土地利用/覆被空间结构的高度复杂性、土地利用形式在时间序列上的强烈可变性是所有边缘带类型的重要共有特征。在快速城市化背景下,城市边缘带土壤资源压力日趋严峻,一方面,土地利用的非农流转导致土壤资源特别是耕地资源面积快速萎缩,直接威胁农业生产和区域粮食安全;另一方面,“三废”物质向城市边缘带的扩散和集聚导致土壤环境容量明显下降,土壤质量严重退化,不仅影响农产品品质,而且对区域生态环境支撑能力产生严重影响。因此,开展城市边缘带土地利用变化及其土壤资源与环境的影响研究刻不容缓。  相似文献   

12.
运用协整检验和Granger因果检验方法,考察了三峡库区重庆段1992-2009年经济发展与农业面源污染之间的相互关系。研究结果表明:①经济增长是影响三峡库区重庆段农业面源污染的主要原因,且种植业、养殖业和农村生活三大类污染源排放量与农村经济发展之间都具有协整关系;②短期内农业生产总值的变化引起三类农业污染源排放量的同方向变动,长期来看,农村经济发展对农业面源污染有减缓作用,这与传统的环境—经济增长库兹涅茨倒U型曲线所揭示的一般规律相同;③农业经济的发展和种植业、养殖业的污染排放量具有双向的因果关系,但是经济发展是农村生活污染排放量增长的原因,农村生活污染排放量不是经济增长的原因,它们之间是单向因果关系。因此,我们要密切关注库区经济增长对环境质量带来的负面效应,必须依赖科学技术进步,提高种植业中化肥、农药、农膜和秸秆等的利用率,根据当地农业发展的特点以及与河流的远近,规划好农业、林业、畜牧业的结构,大力发展环保型、生态型农业,以减轻农业面源污染,实现农业经济增长与保持环境质量之间的相互协调。  相似文献   

13.
退化生态系统的诊断特征及其评价指标体系   总被引:32,自引:1,他引:32  
退化生态系统具有结构和功能简化、生产力和抗逆力低、生物多样性下降等基本诊断特征,由于区域背景和人类活动干扰的差异,生态系统退化具有不同的类型、过程和阶段。为了定量地研究退化生态系统,文中分别建立了土壤、植被、大气、水体,以及农业生态系统、区域自然-人类复合生态系统退化的评价指标体系,其中,土壤退化指标包括物理退化、化学退化、生物退化和土壤污染四类指标;植被退化则从数量、结构、功能与生产力、品质四个  相似文献   

14.
农业非点源污染对太湖水质的影响:发展态势与研究重点   总被引:35,自引:6,他引:35  
太湖水污染的主要症结是水体中氮、磷不断富集导致的富营养化,而随着区内化肥用量的不断增加和集约化畜禽殖业的发展,流域内农业非点源营养物质的排放将保持持续上升的势头。要实现使太湖水变清的目的,必须把农业非点源营养物的排放控制在最低的水平,为了达到这一目标,今后应加强:(1)农业养分流失的定量化研究;(2)非点源污染物的转移转化特征研究;(3)农业非点源污染高风险区的识别;(4)农业非点源污染的控制与管理对策研究。  相似文献   

15.
雾霾污染是困扰中国经济发展的重大民生与环境问题。基于改进产出密度模型,运用地统计和空间计量模型分析长三角城市2015~2017年雾霾污染空间格局和影响因素。研究发现:(1)雾霾污染存在季节性变化特征并且各城市雾霾污染状况逐渐好转。(2)雾霾污染具有显著的局域集聚特征和空间异质性,杭州、宁波和台州呈现低-低集聚特征,而滁州、扬州、镇江和泰州为高-高集聚型,污染区域集中于省界处,污染程度自西北向东南逐渐降低。雾霾污染存在显著的城际空间正相关和空间溢出效应,周边城市雾霾污染对本地区会产生负影响。(3)长三角城市人口集聚、研发投入、产业结构、工业烟粉尘排放及城市建设均对雾霾污染产生正向影响,对外开放、能源消耗以及降水等因素对雾霾污染产生负向影响;雾霾污染与经济增长之间不存在库兹涅茨曲线关系。经济集聚通过优化生产要素的空间分布与组合、共享治污基础设施等,形成雾霾污染抑制作用。  相似文献   

16.
Public education campaigns, to be successful, must repeat simple, consistent messages over time, using various sources and media. During the 2000, 2001, and 2002 ozone seasons, the North Central Texas Council of Governments (NCTCOG) employed a four-pronged, multimedia approach to educate the public about air quality in the Dallas/Fort Worth (DFW) region. The four-pronged approach included several varied information sources:The new Air Pollution Watch/Warning system based on public health and designed using standard meteorological terminology with notices delivered via e-mail, over the radio, during TV weather forecasts, and on electronic road signs.A revamped Web page, including information about current air quality, ozone exceedances, clean air public meetings, and how to "Do Your Share for Cleaner Air".A PowerPoint presentation used to explain the basics of ozone air pollution, the new Air Pollution Watch/Warning system, and the new Dallas/Fort Worth Clean Air Plan to a variety of constituencies, including the media, scientific/technical/academic groups, elected officials, and community/civic organizations.Newsletter updates, published in the Environmental Resources Department's InsidER (with a circulation of around 1500), to educate and keep the public up-to-date about various air quality issues.This paper provides details about the four-pronged approach, and how it incorporates principles of successful public education campaigns.  相似文献   

17.
Several studies have shown that a significant amount of daily air pollution exposure, in particular Black Carbon (BC), is inhaled during bicycle trips. Previously, the instantaneous BC exposure of cyclists was modeled as the sum of a background concentration and a local traffic related component based on a local assessment of traffic noise. We present a fast and low cost methodology to achieve a city-wide assessment of yearly average BC exposure of cyclists along their trips, based on a city-wide mobile noise sensing campaign.The methodology requires participatory sensing measurements of noise, partially combined with BC and/or other air pollutants sensitive to local traffic variations. The combined measurements cover the spatial and meteorological variability and provide the data for an instantaneous exposure model. The mobile noise-only measurements map the full city; and yearly meteorology statistics are used to extrapolate the instantaneous exposure model to a yearly average map of in-traffic air pollution exposure. Less than four passages at each segment along the network with mobile noise equipment are necessary to reach a standard error of 500 ng/m3 for the yearly average BC exposure.A strong seasonal effect due to the BC background concentration is detected. The background contributes only 25% to the total trip exposure during spring and summer. During winter the background component increases to 50–60%. Engine related traffic noise along the bicyclist's route is a valid indicator of the BC exposure along the route, independent of the seasonal background. Low exposure route selection results in an exposure reduction of 35% in winter and 60% in summer, sensitive to the weather conditions, specific trip attributes and the available alternatives.The methodology is relevant for further research into the local effects of air pollution on health. Mobile noise mapping adds local traffic data including traffic dynamics into the air pollution exposure assessments. Local policy makers and urban planners can use the results to support the implementation of low exposure infrastructure, create awareness through route planners and achieve behavioral changes toward active travel modes.  相似文献   

18.
Transboundary transport of air pollution is a serious environmental concern as pollutant affects both human health and the environment. Many numerical approaches have been utilized to quantify the amounts of pollutants transported to receptor regions, based on emission inventories from possible source regions. However, sparse temporal–spatial observational data and uncertainty in emission inventories might make the transboundary transport contribution difficult to estimate. This study presents a conceptual quantitative approach that uses transport pathway classification in combination with curve fitting models to simulate an air pollutant concentration baseline for pollution background concentrations. This approach is used to investigate the transboundary transport contribution of atmospheric pollutants to a metropolitan area in the East Asian Pacific rim region. Trajectory analysis categorized pollution sources for the study area into three regions: East Asia, Southeast Asia, and Taiwan cities. The occurrence frequency and transboundary contribution results suggest the predominant source region is the East Asian continent. This study also presents an application to evaluate heavy pollution cases for health concerns. This new baseline construction model provides a useful tool for the study of the contribution of transboundary pollution delivered to receptors, especially for areas deficient in emission inventories and regulatory monitoring data for harmful air pollutants.  相似文献   

19.
岷江上游干暖河谷与元江干热河谷的气候特征比较研究   总被引:8,自引:0,他引:8  
利用岷江上游和元江(红河上游)河谷区的多年气象观测资料,通过对两河谷区的光、热、水、风等气候因子的综合分析、比较,得出结论:两河谷区的日照时数均较多,日照充足,干热河谷的日照时数要比干暖河谷多。干热河谷的平均温度要比干暖河谷要高。两河谷均是气温的年较差较小,月较差较大;降水的地区差异大,有明显的干雨季之分,降水均集中在雨季,降水量干热河谷多于干暖河谷;两河谷均是山谷风大,定时风显著,风速均是干季大,雨季小。两河谷局地小气候均呈现复杂多样特征。在干热河谷中上段,光热资源较丰富,而水分资源不协调,导致水分构成了该地区发展的主要限制因子;而在干暖河谷中上段,光照可满足需要,热量和水分不足,构成了限制因子,特别在中段河谷的部分地区缺水更甚,干旱年份可影响到树木生长。对两河谷气候特征的对比、分析, 可为两流域在退耕还林、山地生态环境的治理和恢复提供科学依据。  相似文献   

20.
Human civilization is currently facing two particular challenges: population growth with a strong trend towards urbanization and climate change. The latter is now no longer seriously questioned. The primary concern is to limit anthropogenic climate change and to adapt our societies to its effects. Schools are a key part of the structure of our societies. If future generations are to take control of the manifold global problems, we have to offer our children the best possible infrastructure for their education: not only in terms of the didactic concepts, but also with regard to the climatic conditions in the school environment. Between the ages of 6 and 19, children spend up to 8 h a day in classrooms. The conditions are, however, often inacceptable and regardless of the geographic situation, all the current studies report similar problems: classrooms being too small for the high number of school children, poor ventilation concepts, considerable outdoor air pollution and strong sources of indoor air pollution.There have been discussions about a beneficial and healthy air quality in classrooms for many years now and in recent years extensive studies have been carried out worldwide. The problems have been clearly outlined on a scientific level and there are prudent and feasible concepts to improve the situation. The growing number of publications also highlights the importance of this subject. High carbon dioxide concentrations in classrooms, which indicate poor ventilation conditions, and the increasing particle matter in urban outdoor air have, in particular, been identified as primary causes of poor indoor air quality in schools. Despite this, the conditions in most schools continue to be in need of improvement. There are many reasons for this. In some cases, the local administrative bodies do not have the budgets required to address such concerns, in other cases regulations and laws stand in contradiction to the demands for better indoor air quality, and sometimes the problems are simply ignored.This review summarizes the current results and knowledge gained from the scientific literature on air quality in classrooms. Possible scenarios for the future are discussed and guideline values proposed which can serve to help authorities, government organizations and commissions improve the situation on a global level.  相似文献   

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