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871.
Thirty-seven years since reform and opening up, China has sustained rapid economic growth and urbanization. However, there was inadequate protection of natural, historical, and cultural heritage, especially in the past 17 years, which led to the outcome that urban and rural construction lacked features. To rebuild our urban features during urbanization, and avoid destroying them, we should probe into the reason of lacking features and how to protect them. Therefore, taking Jinan City as an example, this paper explored the crisis and its causes of urban characteristics during the period of rapid urbanization based on discussing roles of spring features, including economic effects, social effects, ecological effects and so on. What is more, this paper listed and analyzed those protection measures taken by Jinan. The results showed that spring groups spewed again and kept for 8 years through those measures, which meant that urban characteristics restored. Thus, Jinan City provides successful and significant reference for other cities in restoring urban features during urbanization construction. Also, the author deemed that cities could recollect their urban features as long as they take reasonable measures. 相似文献
872.
Christina Emmanouil Eumorfia Drositi Vasiliki Vasilatou Evangelia Diapouli Konstantinos Krikonis Konstantinos Eleftheriadis 《毒物与环境化学》2017,99(4):691-709
Investigations on the fluctuation in PM10 air pollution in Volos, a medium-sized industrialized port city in the Mediterranean, are presented for the 5-year period between 2009 and 2014. The levels detected have been examined in relation to legislatively set limits, sampling year, and day of the week. A PM10 spring sampling campaign has been performed in 2014 and metals and other elements in the PM10 mass have been quantified. Source origin has been attempted for the latter sampling campaign and human health risk has been assessed. Results show compliance with the mean annual value of 40 μg m?3 of 2008/50/EC for the city; however, exceedances of the daily quality standard of 50 μg m?3 were frequently recorded. Shifts in PM10 concentrations and in contributing sources have been recorded; nevertheless, longer duration data series are needed for safe deductions. Element measurements have enabled source identification for early summer of 2014, with Earth's crust minerals and anthropogenic sources being the main factors. Cumulative non-carcinogenic risk may exceed the threshold value of 1. Possible involvement of sea salt aerosol and desert dust long-range transport has also been assessed. These results may furnish databases on PM pollution of Greek cities as well as other Mediterranean urban centers with similar characteristics. 相似文献
873.
广州市郊区农业土壤重金属污染评价分析 总被引:13,自引:1,他引:12
采用单项污染指数、单项平均污染指数、算术均数、加权均数、内梅罗污染指数法、聚类分析评价法和主成分分析法对广州市郊区土壤重金属Cu,Pb,Zn,Cr,Ni,Cd,As,Hg污染进行评价.从单项污染指数频率分布可以看出,8种重金属中Hg的污染频率最大,即轻污染、中污染和重污染的出现频率都较大,分别为25.4%,9.3%和16.1%;其次是Cd和Zn,也出现了较高频率的轻污染、中污染和重污染.聚类分析法将8种重金属共分为4组,第1组包括Pb,Ni,As,Cr和Cu,第2组、第3组和第4组分别是Zn,Cd和Hg,这4组的污染指数逐渐增大,并以Hg的污染指数最大.主成分分析中的前2个主成分就已经能解释信息的67.81%,尤其是第一主成分,它能解释接近50%的信息量.第一主成分主要反映重金属Cu,Pb,Zn,Ni,Cd,As和Hg的富集程度,第二主成分主要反映了重金属Cr和Ni的富集信息量以及Hg的释放信息. 相似文献
874.
Schifter I Díaz L Rodríguez R Durán J Chávez O 《Environmental monitoring and assessment》2008,137(1-3):459-470
A remote sensing study was conducted in year 2006 in four locations of the Metropolitan Area of Mexico City (MAMC). Two of
the sites were the same studied back by us in year 2000 and by others in year 1994. A database was compiled containing 11,289
valid measurements for the carbon monoxide (CO), total hydrocarbons (THC), and nitric oxide (NO) exhaust vehicles emissions.
Valid measurements were binned for each pollutant by the vehicle specific power (between −5 and 20 kW tonne−1) for the 2000 and 2006 databases. The mean average CO, THC, and NO emissions for year 2006 were determined to be 1.10 ± 0.18 vol.%,
299 ± 88.4 ppm, and 610 ± 115.0 ppm, respectively. Matching the vehicle driving patterns of the fleet measured in year 2000
with the emissions factors obtained in this work, allows estimating the trends in the exhaust emissions of vehicles in the
MAMC. The adjusted results of the remote sensing study performed in year 2006 shows that the fleet has decrease 22% in CO
and 17% in NO emissions, with small change in total hydrocarbons emissions. The improvements could be related with the introduction
in year 2001 of vehicles that met tighter emissions standards, particularly for nitrogen oxides. 相似文献
875.
通过龙门山区域的德阳市6个县市农用地土壤中镉的采样监测,分析了该区域镉的分布特征及区域分异原因,并对其环境生态风险进行了评价。结果表明,德阳市农用地土壤中镉含量总体水平为0.11~4.68 mg/kg,呈现西北到东南逐渐降低的分布特征;西北部绵竹和什邡市农用地土壤中镉出现超标的范围较广,2个城市约62.5%的监测点土壤中镉出现超标,且绵竹市农用地土壤中镉超标程度和生态风险程度最重,绵竹地区约25%的监测点土壤中镉出现了轻中度超标;监测区域土壤中镉出现较重生态风险点共有4个,均出现在绵竹;但较高含量的镉在该区域并非大范围连片存在;区域农用地土壤中镉异常的来源主要为龙门山中段的地质背景和部分以矿石为原料企业的综合影响。 相似文献
876.
贵阳市夏季大气颗粒物及多环芳烃污染特征研究 总被引:3,自引:2,他引:1
采集贵阳市老城区夏季5个典型监测点(太慈桥、贵州师范大学、大西门、省政府及省植物园)的样品进行PM2.5、PM10质量浓度分析。同时对PM2.5中PAHs的质量浓度进行分析。结果表明:贵阳市夏季PM2.5和PM10浓度排序均为太慈桥省政府大西门贵州师范大学省植物园,且PM2.5和PM10之间有良好的相关性,PM10=0.931 3 PM2.5+0.019 4,R2=0.996 7,PM2.5污染较重。此外,5个监测点总PAHs和苯并(a)芘的分析结果均为太慈桥省政府大西门贵州师范大学省植物园,苯并(a)芘浓度均未超标。 相似文献
877.
City action is critical to achieving global visions for sustainability such as the UN’s Sustainable Development Goals (SDGs). However, SDG ‘localisation’ is complex procedure, with divergent outcomes depending on context and diverse city processes. This paper considers the operational challenges faced by city actors in taking on the SDGs, and subsequent implications for initiating local (and global) sustainability transitions. We analyse emergent approaches to SDG localisation within the Asia–Pacific, using a policy analysis framework (transition management) to assess transformation potential. We find that SDG localisation can influence urban sustainability, but effective implementation requires sufficient data, resourcing, and guidance—which are not readily, nor equally available to all city governments. City-to-city peer learning can accelerate SDG uptake, but realising the transformative ambition set out by the SDGs will require an approach to localisation that clearly demonstrates why and how any city government can and should engage with global sustainability frameworks. 相似文献
878.
879.
人类工程活动诱发地面塌陷是城市地质灾害的主要类型之一。广州市主城区地面塌陷灾害频发且损失特别严重。本文采用信息量数学模型与GIS技术结合对其地面塌陷灾害进行危险性评价;选取了断裂构造、地壳稳定性、第四系覆盖层厚度、基岩岩性、地下水动力条件、地表人类活动强度和地下活动强度等7个指标中的21个变量构建了危险性评价指标体系;应用ArcGIS9.0软件参与了数据的采集、管理、分析和评价结果表达等过程,将广州市地面塌陷灾害危险性分为极不稳定级、不稳定级、次不稳定级、基本稳定级和稳定级等五个等级,极不稳定级主要分布在主城区西北角,次不稳定级分布面积最广。 相似文献
880.