首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
"十二五"期间,南充市城区空气质量于2014年之后有所改善,2015年达标率为74.37%,同比上年上升7.61个百分点;城区酸雨污染状况不断改善,酸雨频率和酸度逐年下降。城区主要污染物为可吸入颗粒物(PM10)和细颗粒物(PM_(2.5)),根据污染源排放情况,结合2016年3~4月细颗粒物(PM_(2.5))源解析结果,PM_(2.5)的来源主要为机动车尾气、二次无机源、燃煤、工业工艺源、扬尘、生物质燃烧等,严格控制机动车尾气和VOCs排放应为今后首要工作任务。  相似文献   

2.
水泥工业是重要的PM_(2.5)排放源之一,因此有必要对水泥生产线污染源PM_(2.5)排放进行监测。介绍了水泥生产线污染源PM_(2.5)监测的主要仪器和方法,并对监测数据进行了分析。  相似文献   

3.
2015—2017年秦皇岛市环境空气质量有所好转,SO_2、CO、PM_(10)和PM_(2.5)污染程度呈现下降趋势,NO_2和O_3污染程度呈现上升趋势,主要污染物为PM_(10)和PM_(2.5)。秦皇岛市大气污染的主要因素有工业废气、机动车尾气、扬尘和燃煤等,是典型的复合型污染。建议通过加强工业污染源治理、强化机动车尾气治理、推进扬尘治理、加强燃煤锅炉治理、推广清洁能源、完善大气预警应急体系等污染防治对策来改善秦皇岛市环境空气质量。  相似文献   

4.
为了评估分析枣庄市不同来源污染物排放强度削减与大气环境质量变化之间的关系,使用统计方法和正定矩阵因子分解法对枣庄市2020年第一季度大气污染变化特征和污染来源进行了解析,探究了枣庄市大气固体悬浮微粒浓度变化影响机制。结果表明:2020年第一季度PM2.5、PM10、NO2、SO2浓度较2019年同期显著下降,但枣庄市采暖季内社会活动造成的正常排放仍高于大气环境容量;受新冠疫情影响,2020年较2019年PM2.5源因子浓度削减最大的为机动车源(46.5%)和工业源(17.9%),应长期采取机动车减排、产业结构调整等措施,科学规划“十四五”大气污染防治。  相似文献   

5.
基于全面的实地调研,获取了广安市2016年各典型污染源的活动水平数据,以城市大气污染物排放清单编制技术手册为指导,采用排放因子法,建立了广安市2016年大气污染源排放清单,并分析了主要污染源排放特征。结果表明,2016年广安市SO_2、NO_X、CO、PM_(10)、PM_(2.5)、VOCs、NH_3总排放量分别为31 706 t、28 084 t、115 874 t、56 415 t、19 710 t、24 774 t以及39 484 t。SO_2排放主要来自工业源;NO_X排放主要来自工业源和移动源;CO排放主要来自工业源、民用燃烧源及移动源;PM_(10)和PM_(2.5)排放来自工业源、扬尘源和露天秸秆焚烧;VOCs主要来自工业源、移动源以及溶剂使用源;NH_3主要来自农业排放。  相似文献   

6.
基于2014年南充市大气污染源排放清单调查,通过实地调研、现场测试与统计年鉴等获得活动水平数据,采用排放系数法估算建立排放清单。结果表明道路机动车保有量为877 197辆,摩托车、载客汽车、载货汽车占比分别为61.8%、29.9%、8.3%。道路移动源CO 39 631.2t,NO_X26 448t、VOCs 20 544t、HC 3 648t、PM101 777t、PM_(2.5)1 600t、SO2391.7t,主要污染物为CO、NO_X和VOCs。柴油重型载货汽车、柴油轻型载货汽车、柴油大型载客汽车是NO_X、SO2、PM10和PM_(2.5)主要排放源,普通摩托车、其他燃料小型载客汽车是CO、VOCs主要排放源。普通摩托车和汽油中型载货汽车是HC主要排放源。非道路移动源污染物总量NO_X2 322t,CO 1 173t,HC 657.2t、PM 467.7t、PM_(2.5)252.9t、VOCs 179.8t。农业机械对CO、PM_(2.5)、PM、THC排放贡献率高,分别为49.5%、50.2%、48.3%、30.0%;工程机械对NO_X、PM_(2.5)、PM、THC的贡献率高,分别为51.4%、40.3%、38.9%、39.3%;船舶对VOCS排放贡献为90.3%。顺庆、高坪、嘉陵的CO、NO_X、THC、PM排放贡献率较高,蓬安VOCS排放贡献率较高。  相似文献   

7.
长沙市空气自动站周边区域大气污染物排放源清单   总被引:1,自引:0,他引:1       下载免费PDF全文
以长沙市空气自动站周边3 km为研究对象,基于统计年鉴和实地调查,获得了该地区2015年储存运输源、废弃物处理源、工艺过程源、化石燃料固定燃烧源、农业源、生物质燃烧源、扬尘源、移动源8个源类的活动水平数据。以大气污染物排放源清单编制技术指南为依据,建立了2015年长沙市空气自动站周边3 km区域NH_3、NO_x、PM_(10)、PM_(2.5)、SO_2、VOCs等6项污染物的源排放清单。结果表明,2015年长沙空气自动站周边3 km内,8类大气污染源排放的NH_3、NO_x、PM_(2.5)、PM_(10)、SO_2、VOCs总量分别为53.65t、4 899.35t、1 846.09t、6 257.75t、989.49t、4 383.31t。NH_3、NO_x、PM_(2.5)、PM_(10)、SO_2、VOCs排放量最大的源分别是农业源、移动源、扬尘源、扬尘源、化石燃料固定燃烧源和移动源,贡献率分别为98.45%、84.24%、60.82%、85.90%、97.33%、49.88%。优化道路交通、减少燃煤、减少建筑工地扬尘排放可促进长沙市空气自动站周边空气质量改善。  相似文献   

8.
2013—2017年南昌市环境空气PM_(10)、PM_(2.5)浓度总体呈逐年下降趋势,2017年,PM_(10)、PM_(2.5)年均浓度分别为76μg/m~3和41μg/m~3。污染主要来源于机动车尾气、燃煤、工艺过程、扬尘、餐饮油烟等,同时还受区域传输和不利扩散气象条件影响。针对南昌市颗粒物污染现状、原因,提出了加强机动车尾气污染防治;加大工业污染源综合治理力度;严控煤炭消费总量,调整燃煤结构;提高城市精细化管理水平,有效控制扬尘污染;加强科学研究及其能力建设的防治对策和建议。  相似文献   

9.
本研究分析PM_(2.5)中有机碳和元素碳的质量浓度变化特征,对昌吉市典型区域昌吉州环保局2016-01月至2017-01月采集的大气细颗粒物(PM_(2.5))样品,利用美国(Sunset Lab Inc)大气气溶胶元素碳与有机碳仪分析了其中的有机碳(OC)和元素碳(EC)浓度水平、污染特征及其可能来源,以期为深入了解昌吉市颗粒物污染现状,制定大气污染防治对策提供依据。结果表明:昌吉市OC和EC的质量浓度范围分别为0.13~46.71μg/m3和0.05~8.25μg/m~3,5月份质量浓度最小,EC的质量浓度月分布无明显变化,OC和EC最大浓度均出现在2月。OC的质量浓度季节变化特征呈现冬季秋季夏季春季;EC的质量浓度季节变化特征呈现冬季秋季夏季春季。在不同的季节,OC的浓度变化比较明显,EC排放相对稳定。对各季节OC、EC相关性分析中可以看出,昌吉市OC、EC相关性表现为夏季最强,春秋次之,表明昌吉市夏、春、秋OC、EC具有相似来源或大气扩散过程,主要来源于交通源机动车尾气的排放;冬季相关性较低,说明OC和EC来源复杂,冬季进入采暖期,采暖期燃煤燃气增加,排放量增大,排放源结构复杂,大气污染可能受多种源共同影响。  相似文献   

10.
利用后向轨迹模式计算2014年1月1日~2014年12月31日以攀枝花市为起始点的后向轨迹,并结合攀枝花市PM_(2.5)的实测浓度数据,通过聚类分析法、潜在源贡献因子法(PSCF)和浓度权重轨迹分析法(CWT)研究不同来源区域对攀枝花市PM_(2.5)浓度的贡献影响。结果表明:攀枝花市的西南区域与云南省的交界地区最有可能是攀枝花市PM_(2.5)的贡献源区。攀枝花市西南区域本地排放的PM_(2.5)污染物及其前体物和来自攀枝花市西南方向的气团对攀枝花市的PM_(2.5)浓度影响最大。  相似文献   

11.
ABSTRACT: Mathematical models for predicting watershed surface flow responses are available, most of which are elaborate nonlinear numerical surface and channel flow models linked with infiltration models. Such models may be used to make predictions for ungaged areas, assuming an acceptable fitting of the model to the topography and roughness of the real system. For some application purposes, these models are impractical because of their complexity and expensive computer solutions. A procedure is developed that uses a complex model of an ungaged area to derive a simpler parametric nonlinear system model for repetitious simulation with input sequences. The predicted flow outputs are obtained with the simpler model at significant savings of money and time. The procedures for constructing a complex kinematic model of a 40 acre (161,880 m2) reference watershed and deriving the simpler system model are outlined. The results of predictions from both models are compared with a selected set of measured events, all having essentially the same initial conditions. Peak discharges ranged from 3 to 118 ft3/sec (0.085 to 3.34 m3/sec), which includes the largest event of record. The inherent limitations of lumped systems models are demonstrated, including the bias caused by their inability to model infiltration losses after rainfall ceases. Computer costs and times for the models were compared. The derived simple model has a cost advantage when repeated use of a model is required. Such an applications hydrologic model has an engineering tradeoff of reduced accuracy, and lumping bias, but is more economical for certain design purposes.  相似文献   

12.
Fire and logging in nutrient-poor temperate forests with certain ericaceous understory plants may convert the forests into heaths. The process of disturbance-induced heath formation is documented by using examples ofCalluna in western Europe,Kalmia in Newfoundland, andGaultheria (salal) in coastal British Columbia. In a cool, temperate climate, rapid vegetative growth ofCalluna, Kalmia, and salal following disturbance results in increasing organic accumulation (paludification), nutrient sequestration, soil acidification, and allelochemicals. These are thought to be the main reasons to conifer regeneration failure in disturbed habitats. If continuation in forest is a land-use objective, then temperate forests with an ericaceous understory should not be logged unless effective silvicultural methods are devised to control the ericaceous plants and restore forest regeneration. Preharvest vegetation control may be considered as an option. Failure to control the understory plants may lead to a long-term vegetation shift, from forest to heathland, particularly in nutrient-poor sites. Successful methods of controllingKalmia andGaultheria, however, have yet to be developed. While theKalmia- andGaultheria- dominated heathlands are undesirable in Canada and the Pacific Northwest, a wide range ofCalluna heathlands of western Europe are being conserved as natural and seminatural vegetation.  相似文献   

13.
ABSTRACT: Sustained interest in and concern about the health status of the aquatic environment has resulted in extensive research focused on (1) effects of pollution on survival, growth, and reproduction of resource species at all life stages; (2) diseases of fish and shellfish, as they may be related to pollution and as they may serve as indicators of environmental stress; and (3) contaminant body burdens in fish and shellfish - their effects on the aquatic animals and their potential effects on humans. Effects, lethal and sublethal, of pollutants on life history stages of fish and shellfish have been documented, as have impacts on local stocks in badly degraded habitats, but as yet there has been no adequate quantitative demonstration of effects on entire aquatic species - probably because of the difficulty in sorting out relative effects of the many environmental factors that influence abundance. Sublethal effects, especially those that result in disease, have been examined intensively, and some diseases and disease syndromes have been associated statistically with pollution. Other pollution indicators (biochemical, physiological, genetic, behavioral, and ecological) have also received some attention, as have body burdens of contaminants in aquatic species. Research, especially that conducted during the past decade, has done much to clarify the many pathways and toxic effects of contaminants on aquatic animals, and has also helped to identify mechanisms for survival of fish and shellfish in the presence of environmental changes caused by human activities.  相似文献   

14.
In water stressed regions, water managers are exploring new horizons that would help in long‐range streamflow forecasts. Oceanic‐atmospheric oscillations have been shown to influence streamflow variability. In this study, long‐lead time streamflow forecasts are made using a multiclass kernel‐based data‐driven support vector machine (SVM) model. The extended streamflow records based on tree ring reconstructions were used to provide a longer time series data. Reconstructed data were used from 1658 to 1952 and the instrumental record was used from 1953 to 2007. Reconstructions for oceanic‐atmospheric oscillations included the El Niño‐Southern Oscillation, Pacific Decadal Oscillation, Atlantic Multidecadal Oscillation, and North Atlantic Oscillation. Streamflow forecasts using all four oscillations were made with one‐year to five‐year lead times for 21 gages in the western United States. This is the first study that uses both instrumental and reconstructed data of oscillations in SVM model to improve streamflow forecast lead time. SVM model was able to provide “satisfactory” to “very good” forecasts with one‐ to five‐year lead time for the selected gages. The use of all the oscillation indices helped in achieving better predictability compared to using individual oscillations. The SVM modeling results are better when compared with multiple linear regression model forecasts. The findings are statistical in nature and are expected to be useful for long‐term water resources planning and management.  相似文献   

15.
Urban ecological systems: scientific foundations and a decade of progress   总被引:9,自引:0,他引:9  
Urban ecological studies, including focus on cities, suburbs, and exurbs, while having deep roots in the early to mid 20th century, have burgeoned in the last several decades. We use the state factor approach to highlight the role of important aspects of climate, substrate, organisms, relief, and time in differentiating urban from non-urban areas, and for determining heterogeneity within spatially extensive metropolitan areas. In addition to reviewing key findings relevant to each state factor, we note the emergence of tentative "urban syndromes" concerning soils, streams, wildlife and plants, and homogenization of certain ecosystem functions, such as soil organic carbon dynamics. We note the utility of the ecosystem approach, the human ecosystem framework, and watersheds as integrative tools to tie information about multiple state factors together. The organismal component of urban complexes includes the social organization of the human population, and we review key modes by which human populations within urban areas are differentiated, and how such differentiation affects environmentally relevant actions. Emerging syntheses in land change science and ecological urban design are also summarized. The multifaceted frameworks and the growing urban knowledge base do however identify some pressing research needs.  相似文献   

16.
Urban gardens are important sources of sustenance for communities with limited access to food. Hence, this study focuses on food production in gardens in the Toledo metropolitan area in Northwest Ohio. We administered surveys to 150 garden managers from November 2014 to February 2015 in our attempt to better understand how neighbourhood racial composition and poverty levels are related to staffing and voluntarism, food production and distribution, the development of infrastructure, and the adoption of sustainability practices in urban gardens. The results from 30 gardens are presented in this paper. We used Geographic Information Systems to map the gardens and overlay the map with 2010 census data so that we could conduct demographic analyses of the neighbourhoods in which the gardens were located. Though the gardens were small – two acres or less – up to 46 varieties of food were grown in a single garden. Gardens also operated on small budgets. Food from the gardens was gifted or shared with friends, family, and neighbourhood residents. Gardens in predominantly minority neighbourhoods tended to have fewer institutional partners, less garden infrastructure, and had adopted fewer sustainable practices than gardens in predominantly White neighbourhoods. Nonetheless, residents of predominantly minority and high-poverty neighbourhoods participated in garden activities and influenced garden operations. Volunteering and staffing were racialised and gendered.  相似文献   

17.
All major journalism ethical codes explicitly state that journalists should protect editorial copy from undue influence by outside sources. However, much of the previous research on agricultural information has concentrated on what information various media communicate (gatekeeping studies) or communication's role in increasing innovation adoption (diffusion studies). Few studies have concentrated specifically on organizational and structural constraints that might adversely affect agricultural journalists' ethical standards; those that have, focus largely on farm magazines. A study of newspaper reporters who cover agricultural news found that the most pressing ethical concern is the effect of advertiser (agri-business) pressure on editorial copy, and that their concerns in general parallel those of farm magazine writers and editors. The majority reported being in situations in which they might be exposed to advertiser pressure, including pressures to change or withhold editorial copy. Large minorities suggested that advertising pressures affect the overall environment in which agricultural journalists work, and more than one in ten said they allow advertiser pressures to influence editorial decisions. The newspaper reporters who cover agricultural beats showed slightly more resistance to advertiser pressure than did farm magazine editors in a parallel study.  相似文献   

18.
Mapped environmental classifications are defined using various procedures, but there has been little evaluation of the differences in their ability to discriminate variation in independent ecological characteristics. We tested the performance of environmental classifications of the streams and rivers of France that had been defined from the same environmental data using geographic regionalization and numerical classification of individual river valley segments. Test data comprised invertebrate assemblages, water chemistry, and hydrological indexes obtained from sites throughout France. Classification performance was measured by analysis of similarity (ANOSIM). Geometric regions defined by a regular grid and without regard to environmental variables and a posteriori classifications based on clustering the test datasets defined lower and upper bounds of performance for a given number of classes. Differences in classification performances were generally small. The ANOSIM statistics for the a posteriori classifications were around twice that of all environmental classifications, including geometrically defined regions. The hydro-ecoregions performed slightly better for the invertebrate data and the network classification performed slightly better for the chemistry and hydrological data. Our results indicate that environmental classifications that are defined using different procedures can be comparable in terms of their ability to discriminate variation of ecological characteristics and that alleged differences in performance arising from different classification procedures can be small relative to unexplained variation. We conclude that definition procedures might have little effect on the performance of large-scale environmental classifications and decisions over which procedures to use should be based primarily on pragmatic considerations.  相似文献   

19.
Collisions with deer and other large animals are increasing, and the resulting economic costs and risks to public safety have made mitigation measures a priority for both city and wildlife managers. We created landscape models to describe and predict deer-vehicle collision (DVCs) within the City of Edmonton, Alberta. Models based on roadside characteristics revealed that DVCs occurred frequently where roadside vegetation was both denser and more diverse, and that DVCs were more likely to occur when the groomed width of roadside right-of-ways was smaller. No DVCs occurred where the width of the vegetation-free or manicured roadside buffer was greater than 40 m. Landscape-based models showed that DVCs were more likely in more heterogeneous landscapes where road densities were lower and speed limits were higher, and where non-forested vegetation such as farmland was in closer proximity to larger tracts of forest. These models can help wildlife and transportation managers to identify locations of high collision frequency for mitigation. Modifying certain landscape and roadside habitats can be an effective way to reduce deer-vehicle collisions.  相似文献   

20.
The maintenance of biodiversity is urged from many quarters and on grounds ranging from aesthetic considerations to its usefulness, particularly for biotechnology. But regardless of the grounds for preserving biodiversity, writers are generally in agreement that it should be preserved. But, in examining the various references biodiversity, such as species diversity, genetic diversity, and habitat diversity, it is apparent that we cannot aim to preserve biodiversityas such, since there are a number of conflicts in any such undertaking. In preserving one aspect of biodiversity, we damage another aspect. Five arguments which attempt to ground our moral concern for biodiversity are reviewed and critiqued, not only for their consistency but also for their power to move us to action. The final section of the paper shows how conflicts in the values of personal and environmental health can impair ethical action and especially policy formation.An earlier version of this paper was read at the conference on Agriculture, Food, and Human Values: Tradition and Change, Orlando, Florida, October 7–9, 1987.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号