Geochemistry and toxicity of sediment porewater in a salt-impacted urban stormwater detention pond

A comprehensive study was carried out to investigate the impacts of road salts on the benthic compartment of a small urban detention facility, Rouge River Pond. Although the pond is an engineered water body, it is representative of many small urban lakes, ponds and wetlands, which receive road runoff and are probable high impact areas. Specific objectives of the study were to document the porewater chemistry of an aquatic system affected by elevated salt concentrations and to carry out a toxicological assessment of sediment porewater to determine what factors may cause porewater toxicity. The results indicate that the sediment porewater may itself attain high salt concentrations. The computations show that increased chloride levels have important implications on the Cd complexation, augmenting its concentration in porewater. The toxicity tests suggest that the toxicity in porewater is caused by metals or other toxic chemicals, rather than high levels of chloride.     

Evolution rates and PCB content of surface films that develop on impervious urban surfaces

Surface films on impervious surfaces mediate the fate of organic contaminants in urban areas. Using sheltered 3-mm diameter glass beads as a surrogate impervious urban surface, studies in downtown Toronto showed that surface films developed at a consistent rate of 1.6–2.6 nm day⁻¹. Linear film growth was observed up to and including the last day of three studies of 89-, 273-, and 84-day duration. Total PCB content (sum of 15 PCB congeners) also increased linearly, at a similar rate as the surface film. A complementary study using unsheltered beads showed that up to 80% of film mass and PCB content were removed by film wash-off during rain events. The film growth rate on beads exposed at a rural site, 200 km northeast of Toronto, was 12–20 times lower with PCB burdens that were 7–22 times lower compared to Toronto. Based on these findings, it is estimated that approximately 56–226 g of PCBs are captured by a 70 nm thick film covering just the horizontal surface area of Toronto. This is a substantial quantity of PCB that is available for rapid surface–air exchange and wash-off.     

“一带一路”倡议背景下哈萨克斯坦地区综合脆弱性的空间分异特征分析

系统评估沿线国家环境社会系统的发展状态,识别典型地区的脆弱性特征,对于绿色"一带一路"建设至关重要。本文集成了脆弱性与恢复力的概念内涵,构建了综合脆弱性评价指标体系,利用TOPSIS法和障碍度模型对哈萨克斯坦各州的综合脆弱性进行系统评价,分析其空间分异特征和影响因素。结果显示:(1)哈萨克斯坦综合脆弱性总体上处于中度水平,空间上呈现西高东低的特点,西部各要素脆弱性均处于中高位,东部整体脆弱性相对较低,中部则呈现多样性特征;(2)要素间关系复杂,脆弱性降低的瓶颈因素主要集中在资源使用和保障、社会系统保障等方面;(3)系统提升哈萨克斯坦环境社会系统的韧性,需要强化产业结构转型、基础设施建设与生态环境保护,在这些方面中国可以提供强有力的合作条件与经验。     

106国道沿线样带区农村空心化土地整治潜力研究

基于典型调查资料和社会经济统计数据,在构建农村空心化评价指标体系并定量评判106国道沿线样带区县域农村空心化程度的基础上,结合自然条件和土地资源特点、农村居民点用地的有关法律规定,采用专家集成法选取与现实潜力转化有关的自然、社会、经济等10个指标建立综合指标体系,对空心村整治的自然适宜性、社会接受性、经济可行性进行了综合评价;将计算得到的农村空心化指数与现实转化潜力系数作为综合修正系数,对理论潜力进行修正,结合农村居民点整治潜力测算公式,测算出106国道沿线样带区不同农村空心化演进类型的现状潜力和远景潜力。研究表明:106国道沿线样带区县域农村空心化指数为0.18~0.82,现实转化潜力系数为0.07~0.32; 2009、2020年农村居民点整治的现实潜力分别为93 219.4、145 430.0 hm²,村庄整治增地率分别为6.8%、11.4%。研究将为空心村整治和新农村建设规划决策提供科学依据。     

机动车排放检测运行体系的相关研究

机动车污染物排放标准与其检测方法是相辅相成的，不同的机动车检测方法对应不同的机动车排放污染物限值。该文主要对机动车排放检测运行体系中的怠速和简易工况检测方法进行了对比性研究，并对机动车实施常规检测的年检和监督手段的路检进行了对比分析，从而得出：工况法检测对于尾气排放情况的模拟要优于怠速法检测，并可对NOx进行有效控制，所以建议在有条件的地区，应该尽量实施工况法检测：年检和路检的数据有较大的差异，反映出对在用车的监督不力，今后应加强；高排放车辆的贡献率所占的比例与发达国家相比太小，说明机动车总体控制水平较低。     

“一带一路”视域下环境保护问题的战略定位与治理体系

环境保护是"一带一路"建设的重要议题,它所面临的挑战更多源于沿线国家和地区经济发展任务繁重与生态环境先天脆弱之间的矛盾。仅仅依靠单个政府部门或某一政策,或者仅仅依靠单个国家或地区的某一倡议与行动,均不足以应对"一带一路"建设中的跨国环境风险,这将倒逼国内与国际社会提升环境保护的战略地位,构建新型环境治理体系。"一带一路"沿线的各地政府不仅要发挥生态环保的示范作用,还要建立横向若干部门和纵向各级政府的协同治理机制,完善环境保护跨国合作制度,鼓励企业、NGO组织与民间力量、智库共同参与环境治理。     

海口市城区不同下垫面降雨径流污染特征

分析海口市4种主要下垫面的径流水质,研究其污染程度和变化规律,并与国内其他城市进行对比。监测项目包括pH、SS、COD_Cr、TN、TP、Pb、Cr、Cd、Zn、石油类。结果表明,各下垫面径流水样水质较好,除路面径流COD_Cr超过《地表水环境质量标准》(GB 3838—2002)V类标准2倍,其他水质指标均达到标准要求;各污染物浓度初期较高,随降雨历时降低并趋于稳定,绿地径流污染物浓度下降速率比路面与屋面缓慢;相比国内其他海边城市,海口城区污染程度较轻。     

Risk analysis for road and rail transport of hazardous materials: a GIS approach

An approach to transportation risk analysis for road and rail transport of dangerous goods is proposed, which is based on the use of geographic information systems (GIS) to manage territorial information, coupled with a product data bank in a risk evaluation tool. Such an approach enables to accurately take into account the local data affecting risk analysis, such as population, accident rate, and weather conditions along all the route, by means of a system which can be easily updated. The resulting risk evaluation tool assists in the step of route identification and allows to rapidly perform an accurate transportation risk analysis, for a single transportation event as well as for multiple substances, trips and itineraries.     

道路交通环境影响评价的物元模型

分析了城市道路交通环境影响因素,提出了一套道路交通环境影响评价指标体系,并应用物元分析理论建立了相应的评价物元模型     

上海城市街道峡谷道路绿化模式研究

街道峡谷在上海城市中普遍存在,街道峡谷中污染气体的扩散受到屋顶风向、风速、高宽比、峡谷两侧建筑物的对称性、高度分布和街区形状等因素的影响。文章对适合于不同街道峡谷形式的、较为典型的道路绿化模式进行了研究。结果表明,上海城市街道峡谷中的道路绿化模式可归纳为:梯级递进式、斑块复合式、疏朗开敞式、模纹花镜式和独立行道树式5种。当街道峡谷与主导风垂直:(1)街道峡谷的W/H>5且为平行型峡谷时,绿化模式应采用梯级递进式或疏朗开敞式;(2)街道峡谷的W/H为0.6～5且为平行型峡谷时,绿化模式在迎风侧采用流朗开敞式、背风侧采用模纹花镜式,或者两侧都采用模纹花镜式;(3)街道峡谷的W/H<0.6且为平行型峡谷时,绿化模式应采用模纹花镜式或独立行道树式;(4)街道峡谷的W/H<0.6且为递升型峡谷时,绿化模式在迎风侧采用斑块复合式或模纹花镜式,背风侧采用模纹花镜式或独立行道树式;(5)街道峡谷的W/H<0.6且为递降型峡谷时,绿化模式可采用模纹花镜式或独立行道树式;当街道峡谷与主风向平行:宽、高比大的街道绿化模式应采用梯级递进式或斑块复合式,当街道峡谷的高度是宽度的倍数时,道路绿化宜采用疏朗开敞式或独立行道树式。