北京典型道路交通环境机动车黑碳排放与浓度特征研究

本研究对2009年北京市典型道路(北四环中路西段)进行实际交通流监测和调研,分析了总车流量、车型构成和平均速度的日变化规律.应用北京机动车排放因子模型(EMBEV模型)和颗粒物黑碳排放的研究数据,计算该路段的黑碳平均排放因子和排放强度.根据同期观测的气象数据,应用AERMOD模型对道路黑碳排放进行了扩散模拟,并根据城市背景站点和道路边站点的监测数据对模拟结果进行了验证.研究表明,该路段黑碳平均排放因子与重型柴油车在总车流中所占比例呈现出极强的相关性,由于北京市实行货车区域限行制度,日间时段总车流的平均黑碳排放因子为(9.3±1.2)mg·km-1·veh-1,而夜间时段上升至(29.5±11.1)mg·km-1·veh-1.全天时均黑碳排放强度为17.9~115.3g·km-1·h-1,其中早(7:00—9:00)晚(17:00—19:00)高峰时段的黑碳排放强度分别为(106.1±13.0)g·km-1·h-1和(102.6±6.2)g·km-1·h-1.基于同期监测数据验证,AERMOD模型的模拟效果较好.模拟时段的道路黑碳排放对道路边监测点的平均浓度贡献为(2.8±3.5)μg·m-3.由于局地气象条件差异,日间和夜间的机动车排放对道路边黑碳的模拟浓度存在显著差异.日间时段,小型客车排放对道路边站点的黑碳浓度贡献最高,达(1.07±1.57)μg·m-3;其次为公交车,达(0.58±0.85)μg·m-3.夜间时段货车比例明显上升,其黑碳排放占主导地位,贡献浓度(2.44±2.31)μg·m-3.     

规划环境影响评价中公众参与探讨研究

公众参与作为规划环境影响评价的重要组成部分,具有重要的作用和意义。公众参与可以提高规划环境影响评价的有效性、提高规划的合理性及环保性。结合规划环评的应用实例,归纳了规划环评公众参与的参与对象、参与形式等,指出目前规划环评公众参与在应用中存在公众参与对象局限、规定和程序不明确、公民环保意识差等问题,建议采用多种形式开展公众参与环评,同时建议相关部门制定法律条文等进一步明确公众参与环评的规定和程序,提高信息公开度和民众的环保意识。     

环境影响评价中公众参与影响因素及方式分析研究

针对环境影响评价中公众参与影响因素及方式分析问题,介绍了环境影响评价中公众参与的特征,包括公开性、双向性和参与性,对公众参与的影响因素进行了分析,主要分析了利害关系人、法律制度、公共政策、市场经济发展水平和社会信息化程度,探讨了公众参与有效性要素的措施,主要有公众人员的选择、公众赋予的权力、参与时间的选择、解决矛盾能力和公众参与形式,在环境影响评价中进行公众参与不仅是环境影响评价本身的需要,同时也是中国民主制度的体现。     

公路项目环评中低时速单车噪声源强研究

由于缺乏低时速单车噪声源强估算模式,低等级公路项目噪声预测结果常与实际监测结果存在较大偏差。文中通过实测各车型车辆在低时速条件下时速和单车辐射声级(Lmax)数据,运用统计软件分析两者间的关系,并通过实测过往车辆数据进行验证。结果显示沿用《公路建设项目环境影响评价规范》(以下简称《06规范》)中的公式计算低车速源强可能会造成结果偏低,建议采用下列式子估算低车速单车噪声源强:小型车L=21.5 lgV+34.96(15≤V≤63),中型车L=10.4 lgV+59.29(15≤V≤53),大型车15≤V≤48(15≤V≤48)。     

昆明市建设项目环境影响评价公众参与现状研究

以昆明市为研究对象,深入分析现阶段环境影响评价公众参与中存在的主要问题,并提出改进的对策建议。     

事故车辆影响下的城市三车道道路交通流仿真

为探究事故车辆对城市三车道道路交通影响机制,首先,分析考虑事故车辆的城市三车道道路交通流特征;然后,构建左车道优先且考虑主动抢道和被动抢道行为的元胞自动机交通流模型;最后;研究事故持续时间td变化时事故车辆分别位于M道和R道的城市道路交通流演化.结果 表明:事故车辆会形成交通瓶颈,呈现上游车辆聚集下游车辆稀疏的时空特征...     

Collaborative emergency management: better community organising, better public preparedness and response

Community coordination requires communication and planning of precautions to take when faced with a severe threat of disaster. The unique case of the four Florida hurricanes of 2004--Charley, Frances, Ivan, and Jeanne--is used here to assess community responses to repeated threats of hurricanes. The paper examines how effectiveness in coordinating community disaster response efforts affects future public preparedness. The findings suggest that pre-season planning, open communication between emergency managers and elected officials, and the use of technology all had a significant impact on community responses. The repeated threat scenario indicates that emergency managers must work vigilantly to keep residents informed of the seriousness of a situation. The study describes how emergency managers in Florida countered public complacency during four hurricanes in six weeks. The strategies identified as useful by public managers in the context of hurricanes are applicable to other natural and man-made disasters.     

Analysis of patterns and ecological security trend of modern oasis landscapes in Xinjiang, China

Ecological security has become so important that it will affect the national security and social sustainable development. In this paper, a case study on the ecological security indexes of modern oasis landscapes in Beitun Oasis, Xinjiang, was carried out. The spatial neighbouring parameters, such as the contiguous length, measure of area and patch quantity of oasis landscape patches, affected by desert landscape patches were calculated by using GIS-based buffer analysis, the method of calculating ecological security indexes of oasis landscape was developed, and the dynamic changes of patterns and ecological security indexes of the oasis landscapes since recent 30 years were analyzed. The results showed that soil salinization or alkalization and paludification were major factors affecting the ecological security in Beitun Oasis. Therefore, measures should be taken actively to prevent and control secondary salinization and paludification. The ecological security indexes of the oasis landscape in 1972, 1990 and 2005 were 78.91, 82.28 and 83.86, respectively, which showed the degree of security is improving, and the environment was developing harmoniously between human and nature. The methods of evaluating ecological security based on the spatial neighbouring relations between landscape patches can be used to reflect preliminarily the ecological security patterns of landscapes.     

交通限行对大气颗粒物及PM2.5中二NFDA1英的影响

为了研究北京大气颗粒物和二NFDA1英(PCDD/Fs)的污染状况以及评估交通限行对大气颗粒物和PCDD/Fs的影响。利用同位素稀释高分辨率气相色谱/高分辨率质谱(HRGC/HRMS)联用法和USEPA 1613B 标准方法,以中国地质大学(北京)东门为采样点,采集大气PM_2.5、PM₁₀、TSP样品,对北京市交通限行期间以及交通限行前后等不同交通状况下颗粒物浓度及大气PM_2.5中17种2,3,7,8-PCDD/Fs污染特征进行了监测。结果表明,PM_2.5、PM₁₀、TSP的日均质量浓度在交通限行前分别为126、202、304 μg/m³,限行期间分别为39、78、93 μg/m³,限行结束后分别为79、126 μg/m³。PM_2.5中17种PCDD/Fs的质量浓度(毒性浓度)3个时段分别为1 804 fg/m³(70 fg I-TEQ/m³)、252 fg/m³ (9 fg I-TEQ/m³)和1 196 fg/m³ (48 fg I-TEQ/m³)。北京市交通限行期间颗粒物浓度和二 NFDA1 英浓度显著低于交通限行前后,交通源减排措施的实施是大气颗粒物和二 NFDA1英污染水平降低的主要原因,从减排效果看,交通源减排措施对大气细颗粒物(PM_2.5)的控制效果明显好于大气粗颗粒物。     

上海城区交通干道黑碳污染调查

采用设置在上海市中心城区交通主干道旁空气质量自动监测站2018年1—12月的观测数据,分析黑碳气溶胶(BC)污染特征及其与PM_(2.5)、SO_2、NO_x、CO、O_3、苯、甲苯、乙苯、二甲苯和气象参数的相关性。结果表明,观测期间内,BC小时均值为(3 038±22) ng/m~3,ρ(BC)在ρ(PM_(2. 5))中占比为(11. 48±0. 12)%。日内ρ(BC)变化呈双峰型,各月份之间ρ(BC)变化不大。ρ(BC)与风速呈负相关,与PM_(2. 5)、NO_x、CO、苯、甲苯、乙苯和二甲苯呈正相关。