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271.
就昆明市清水海水源区生态补偿机制进行探讨,以期为生态补偿机制的建立提供借鉴。生态补偿理论结合清水海水源区实际分析。补偿主体是国家、受水区的企业和居民,客体是水资源和生态环境的保护者,以及牺牲发展机会的企业和居民;补偿标准以费用分析法计算,包括水资源保护、水源林建设和管理等方面的投入;补偿方式近期以输血型和造血型补偿结合,远期逐步向生态造血型补偿转变;优先补偿效率高的污染防治措施、退耕还林和测土配方,其次为产业结构调整和水资源管理;补偿时限结合补偿取得的成效、水源区生态产业发展和生态质量状况来确定;补偿资金以政府财政为主、市场为辅。结果表明:应结合清水海的实际,确定生态补偿的主客体、方式、标准和时限,建立生态补偿的保障机制,加强对补偿资金的监管。进一步开展定量化研究,完善清水海水源区生态补偿基础研究,促进生态补偿机制的建立。  相似文献   
272.
Carbonyl compounds are important intermediates in atmospheric photochemistry, but their primary sources are still not understood well. In this work, carbonyls, hydrocarbons,and alkyl nitrates were continuously measured during November 2011 at a rural site in the Yangtze River Delta region of China. Mixing ratios of carbonyls and hydrocarbons showed large fluctuations during the entire measurement. The average level for total measured volatile organic compounds during the pollution episode from 25 th to 27 th November, 2011 was 91.6 ppb, about 7 times the value for the clean period of 7th–8th, November, 2011. To preliminarily identify toluene sources at this site, the emission ratio of toluene to benzene(T/B) during the pollution episode was determined based on photochemical ages derived from the relationship of alkyl nitrates to their parent alkanes. The calculated T/B was5.8 ppb/ppb, significantly higher than the values of 0.2–1.7 ppb/ppb for vehicular exhaust and other combustion sources, indicating the dominant influence of industrial emissions on ambient toluene. The contributions of industrial sources to ambient carbonyls were then calculated using a multiple linear regression fit model that used toluene and alkyl nitrates as respective tracers for industrial emission and secondary production. During the pollution episode, 18.5%, 69.0%, and 52.9% of measured formaldehyde, acetaldehyde, and acetone were considered to be attributable to industrial emissions. The emission ratios relative to toluene for formaldehyde, acetaldehyde, and acetone were determined to be 0.10, 0.20 and0.40 ppb/ppb, respectively. More research on industrial carbonyl emission characteristics is needed to understand carbonyl sources better.  相似文献   
273.
通过以实地调查和京津风沙源治理工程建设任务及投资数据为基础,以县域土地利用及社会经济相关数据作为参考,对内蒙古翁牛特旗京津风沙源治理工程生态效益进行了全面评估。结果表明,内蒙古翁牛特旗森林生态系统服务主要是水源涵养、保护生物多样性和固碳释氧,占总服务价值的86.1%。京津风沙源建设工程在遏制沙化土地蔓延和改善周边区域环境质量等方面效果显著。京津风沙源治理工程在生态、经济、社会方面的贡献巨大,工程建设取得了较好的成效。  相似文献   
274.
The concentrations, profiles, sources and spatial distribution of polycyclic aromatic hydrocarbons (PAHs) were determined in 40 surface soil samples collected from Beijing, Tianjin and surrounding areas, North China in 2007, and all sampling sites were far from industrial areas, roadsides and other pollution sources, and across a range of soil types in remote, rural villages and urban areas. The total concentrations of 16 PAHs ranged from 31.6 to 1475.0 ng/g, with an arithmetic average of 336.4 ng/g. The highest PAH concentrations were measured in urban soils, followed by rural village soils and soils from remote locations. The remote-rural village-urban PAH concentration gradient was related to population density, gross domestic product (GDP), long-range atmospheric transport and different types of land use. In addition, the PAH concentration was well correlated with the total organic carbon (TOC) concentration of the soil. The PAH profile suggested that coal combustion and biomass burning were primary PAH sources.  相似文献   
275.
High values of ozone (O3) occur frequently in the dry spring season; thus, understanding the evolution characteristics of volatile organic compounds (VOCs) in spring is of great significance for preventing O3 pollution. In this study, a total of 101 VOCs from April 16 to May 21, 2019, were quantified using an online gas chromatography mass spectrometer/flame ionization detector (GCMS/FID). The results indicated that the observed concentration of total VOCs (TVOCs) was 30.4 ± 17.0 ppbv, and it was dominated by alkanes (44.3%), followed by oxygenated VOCs (OVOCs) (17.4%), halocarbons (12.7%), aromatics (9.5%), alkenes (8.2%), acetylene (5.3%) and carbon disulfide (2.5%). The average mixing ratio of VOCs showed obvious diurnal variation (high at night, low during daytime). We conducted a source apportionment study based on 32 major VOCs using positive matrix factorization (PMF), and coal + biomass burning (25.2%), diesel exhaust (16.0%), gasoline exhaust + evaporation (17.4%), secondary + long-lived species (16.7%), biogenic sources (4.3%), industrial emissions (9.3%) and solvent use (11.2%) were identified as major sources of VOCs. In addition to local emissions, most of the atmospheric VOCs were derived from long-distance air masses (65.7%), and the average mixing ratio of VOCs in the northwest direction was 29.4 ppbv. Combined with the results of the potential source contribution function (PSCF) indicate that research should focus on the local emissions of combustion, transportation sources and solvents usage to control atmospheric VOCs. Additionally, transmission of the northwest air mass is an important component that cannot be ignored during spring in Beijing.  相似文献   
276.
Significant iron release from cast iron pipes in water distribution systems (WDSs), which usually occurs during the source water switch period, is a great concern of water utilities because of the potential occurrence of “red water” and customer complaints. This study developed a new method which combined in-situ water stagnation experiments with mathematical models and numerical simulations to predict the iron release caused by source water switch. In-situ water stagnation experiments were conducted to determine the total iron accumulation in nine cast iron pipes in-service in Beijing when switching the local water to treated Danjiangkou Reservior water. Results showed that the difference in the concentration increment of total iron in 24 hr (ΔCITI,24), i.e. short-term iron release, caused by source water switch was mainly dependent on the difference in the key quality parameters (pH, hardness, nitrate, Larson Ratio and dissolved oxygen (DO)) between the two source waters. The iron release rate (RFe) after switch, i.e. long-term iron release, was closely related to the pipe properties as well as the DO and total residual chlorine (TRC) concentrations. Mathematical models of ΔCITI,24 and RFe were developed to quantitatively reveal the relationship between iron release and the key quality parameters. The RFe model could successfully combine with EPANET-MSX, a numerical simulator of water quality for WDSs to extend the iron release modeling from pipe level to network level. The new method is applicable to predicting iron release during source water switch, thus facilitating water utilities to take preventive actions to avoid “red water”.  相似文献   
277.
大气甲烷的源和汇   总被引:13,自引:0,他引:13  
本文通过总结国内外大气甲烷源汇研究的最新进展,论述了全球大气甲烷的源汇平衡预算及其不确定性,给出了全球及中国大气甲烷源汇预算的最新成果,并指出了今后的研究方向和重点.  相似文献   
278.
Integrated Approaches in Urban Storm Drainage: Where Do We Stand?   总被引:1,自引:0,他引:1  
Integrated approaches to urban stormwater drainage management are being increasingly advocated as necessary for advancing more sustainable and holistic management of urban water environments. In this paper, the status of integrated approaches in the management of urban stormwater discharges to receiving waterways is summarized. The starting point of the paper is with the recent scientific contributions, revealing that integration is being pursued and implemented predominantly at two conceptual levels. These include 1) integrating the technical system with the receiving waterway environment, and 2) considering the interaction and influence of the human system with the technical system through processes such as stakeholder and public participation. Additionally, it is argued that the evolving shift towards the implementation of water-quality-based strategies advances the need for further development and application of integrated models and approaches. The cases of online physically based models for predictive control and integrated source control and public participation are presented as examples of such ongoing developments in pursuit of integrated urban stormwater management.  相似文献   
279.
长江源区生物多样性保护研究   总被引:3,自引:0,他引:3  
生物多样性具有生态、社会和经济多重价值.长江源区生物多样性不但关系到当地经济发展和人民生存安全,而且关系到整个长江流域的可持续发展,甚至影响到全球气候.分析了长江源区生物多样性的特点及区域生物多样性遭受严重破坏的原因,提出了保护长江源区生物多样性的对策措施:①加强对长江源自然保护区的建设;②适当控制人口数量,进行必要的生态移民;③加强基本生产和生活条件建设;④加大立法与执法力度,严禁偷猎、盗采野生动植物;⑤在保护中开发利用.  相似文献   
280.
室内空气中颗粒物对人体健康的影响   总被引:5,自引:0,他引:5  
随着国民经济的快速发展和工业,城市化水平的不断提高,人们的工作,生活和居住条件得到了大幅度的改善,同时,由于建筑,室内装修,家具和现代家电与办公器材等造成的室内环境污染也引起了人们的高度重视。为此,本文介绍了国内外在室内空气颗粒物的来源,成分,浓度和粒径分布及其对人体健康影响等方面的研究进展,并提出了控制室内空气颗粒物污染的对策。  相似文献   
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