海南文昌火箭发射场雷电环境分析

利用海南省18个气象台站的雷暴人工观测资料和海南闪电定位网的观测资料,分析了海南文昌火箭发射场的雷暴特征和雷电环境,结果表明:海南岛的中部和北部雷暴活动较强,西部、东部和南部近海地区的雷暴活动较弱,文昌发射场处在北部较强的雷暴区;采用Krigine(克里格)方法拟合的结果为文昌火箭发射场雷暴日数的年变化从1982年以后逐渐减少,发射场一年中各月都有雷暴发生,4-10月为雷暴高发期;发射场西部、西北部和北部区域雷暴活动较其它区域要强,79%的雷电流强度小于40 kA,而只有5.9%的雷电流强度大于60 kA,一天中闪电的发生有两个高峰时段,一个出现在凌晨5时到6时,另一个时段出现在14时到18时,午后15时左右是闪电活动最频繁的时段。     

基于渗流-应力耦合分析的野鸡尾尾矿坝稳定性研究

基于渗流场与应力场耦合机理,对柿竹园野鸡尾尾矿坝进行稳定性研究。研究渗流-应力的耦合效应,提出了渗流-应力耦合以及渗流体积力计算的实施方案;建立二维的有限元渗流-应力耦合计算模型,分析了考虑耦合效应时的尾矿坝渗流场、位移场、应力场;最终分析了不同耦合关系对于渗流量、位移场、等效渗透集中力以及应力场的影响。研究结果表明:当前水力条件下,尾矿坝稳定性良好;尾矿坝主要受水平渗透力作用,初期坝坝顶、坝脚以及坝底等处应力集中;尾矿坝的渗流-应力作用不容忽视,不同的耦合关系对于x方向位移、渗透力的预测影响巨大;考虑渗流-应力耦合关系得到的主应力、剪应力以及竖向位移,比不考虑耦合效应时大。     

A regulatory perspective on the radiological impact of NORM industries: the case of the Spanish phosphate industry

Radioactive and chemical risks coexist in NORM industries although they are usually addressed separately by regulations. The European Union (EU) has developed extensive legislation concerning both matters, which has been diversely reflected in national policies. We consider the case of the Spanish phosphate industry and analyse to which extent regulatory mandates have reduced the historical and ongoing radiological impact on the environment of phosphate facilities. Although no specific radiological constraints on effluent monitoring and release or on waste disposal have yet been imposed on NORM industries in Spain, other environmental regulations have achieved a substantial reduction on the phosphate industry impact. Nevertheless, a more efficient control could be established by eliminating the current conceptual and practical separation of chemical and radioactive risks in NORM industries. We highlight research needs to accomplish so and propose shorter-term measures that require active cooperation among the regulatory bodies involved.     

漓江上游植被覆盖度时空变化对地表热场影响

自20世纪80年代以来,桂林漓江由于上游森林遭受破坏出现水生态环境快速恶化的趋势。地表热场的时空变化直接影响森林蒸散及水文效应。因此,对漓江上游1989~2006年5景TM/ETM+卫星图像,利用归一化植被指数反演植被覆盖度,利用单窗算法反演地表温度,提出归一化温度使不同时相地表热场具有可比性,分析植被覆盖度时空变化对地表热场的影响。结果表明,在空间上,地表温度随植被覆盖度的增加而降低,在植被覆盖度很高或很低时,这种影响相对变弱;在时间上,漓江上游1989~2000年植被中、高度覆盖面积从96.1%逐年下降到65.9%,导致归一化地表温度数值较高的像元比例相应增加;2000~2006年植被中、高度覆盖面积逐渐恢复上升到90.8%,但仍略低于1989年,使得归一化地表温度数值较高的像元比例相应减少。植被覆盖可以有效地降低漓江上游地表温度     

河流近域土地利用格局与水质相关性分析——以巢湖流域为例

以河流近域土地利用构成与水环境质量间定量关系为研究对象,基于巢湖流域40个水质监测断面和320个河流近域作用区,运用GIS空间分析功能计算不同尺度作用区内土地利用构成,借助相关分析、冗余分析(RDA)等数理统计手段,分析土地利用构成与水质指数间的相关关系;并分析和比较了流域内山区和平原地区土地利用构成与水质之间关系。结果表明,巢湖流域近河道地区土地利用构成对各水质指数有重要影响,且受地形因素影响。其中,建设用地对河流水质恶化具有明显作用;河流沿岸林地布局能显著改善水质,尤其是对氨氮和高锰酸盐指数敏感;耕地面积变化与水质相关性不显著。RDA冗余分析证实了不同尺度下的土地利用类型对水环境影响具有尺度效应。研究成果对巢湖流域水环境管理具有重要的实际指导意义,并为同类研究提供借鉴     

Policy and Science Implications of the Framing and Qualities of Uncertainty in Risks: Toxic and Beneficial Fish from the Baltic Sea

Policy and research issues in the framing and qualities of uncertainties in risks are analyzed, based on the assessments of dioxin-like compounds (DLCs) and other ingredients in Baltic Sea fish, a high-profile case of governance. Risks are framed broadly, to then focus on dioxins and beneficial fatty acids, fish consumption, human health, and science-management links. Hierarchies of uncertainty (data, model, decision rule, and epistemic) and ambiguity (of values) are used to identify issues of scientific and policy contestation and opportunities for resolving them. The associated complexity of risks is illustrated by risk–benefit analyses of fish consumption and by evaluations of guideline values, highlighting value contents and policy factors in presumably scientific decision criteria, and arguments used in multi-dimensional risk and benefit comparisons. These comparisons pose challenges to narrow assessments centered, for e.g., on toxicants or on food benefits, and to more many-sided and balanced risk communication and management. It is shown that structured and contextualized treatment of uncertainties and ambiguities in a reflexive approach can inform balances between wide and narrow focus, detail and generality, and evidence and precaution.     

Impacts of Surface Gold Mining on Land Use Systems in Western Ghana

Land use conflicts are becoming increasingly apparent from local to global scales. Surface gold mining is an extreme source of such a conflict, but mining impacts on local livelihoods often remain unclear. Our goal here was to assess land cover change due to gold surface mining in Western Ghana, one of the world’s leading gold mining regions, and to study how these changes affected land use systems. We used Landsat satellite images from 1986–2002 to map land cover change and field interviews with farmers to understand the livelihood implications of mining-related land cover change. Our results showed that surface mining resulted in deforestation (58%), a substantial loss of farmland (45%) within mining concessions, and widespread spill-over effects as relocated farmers expand farmland into forests. This points to rapidly eroding livelihood foundations, suggesting that the environmental and social costs of Ghana’s gold boom may be much higher than previously thought.     

Dietary patterns and blood levels of PCDDs, PCDFs, and dioxin-like PCBs in 1656 Japanese individuals

The association between dietary patterns and blood dioxin levels has not been fully investigated. The present study population consisted of 755 men and 901 women (aged 15-73 years) living in 90 different areas of 30 prefectures of Japan. Dietary habits were assessed by inquiring about the consumption frequency of 28 foods, food groups and beverages. In addition, the blood levels of 29 polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzo-furans (PCDFs), and dioxin-like polychlorinated biphenyl (DL-PCBs) congeners were determined by high-resolution gas chromatography/mass spectrometry. The median total toxicity equivalent (TEQ) in the blood, which was calculated on the basis of the toxicity equivalency factors of WHO (2005), was 16 pg TEQ g⁻¹ lipid. Principal component analysis identified five dietary patterns: Healthy diet (high intake of vegetables and fruits); Meat/High fat intake (high intake of meat, meat products, and eggs); Seafood and Alcohol (high intake of fish, shellfish, and alcoholic beverages); Miscellaneous; and Milk products and Alcohol intake (high intake of milk, Milk products, and alcoholic beverages). After adjusting for sex, age, body mass index, and smoking habits, the Seafood and Alcohol pattern scores were significantly related to higher blood levels of total TEQ and PCDDs/PCDFs/DL-PCBs, and the Milk products and Alcohol pattern scores were correlated with higher blood levels of DL-PCBs. More detailed analysis showed that the intake frequencies for alcoholic beverages and seafood were independently and positively associated with total TEQ and the TEQ of PCDFs and DL-PCBs. The association between alcoholic beverage intake and PCDDs was also significant. Analysis of dietary patterns may be useful for identifying the dietary characteristics of individuals with a high dioxin body burden.     

An overview of the methods used in the characterisation of natural organic matter (NOM) in relation to drinking water treatment

Natural organic matter (NOM) is found in all surface, ground and soil waters. During recent decades, reports worldwide show a continuing increase in the color and NOM of the surface water, which has an adverse affect on drinking water purification. For several practical and hygienic reasons, the presence of NOM is undesirable in drinking water. Various technologies have been proposed for NOM removal with varying degrees of success. The properties and amount of NOM, however, can significantly affect the process efficiency. In order to improve and optimise these processes, the characterisation and quantification of NOM at different purification and treatment processes stages is important. It is also important to be able to understand and predict the reactivity of NOM or its fractions in different steps of the treatment. Methods used in the characterisation of NOM include resin adsorption, size exclusion chromatography (SEC), nuclear magnetic resonance (NMR) spectroscopy, and fluorescence spectroscopy. The amount of NOM in water has been predicted with parameters including UV-Vis, total organic carbon (TOC), and specific UV-absorbance (SUVA). Recently, methods by which NOM structures can be more precisely determined have been developed; pyrolysis gas chromatography-mass spectrometry (Py-GC-MS), multidimensional NMR techniques, and Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). The present review focuses on the methods used for characterisation and quantification of NOM in relation to drinking water treatment.     

中国并网光伏发电系统的经济性与环境效益

太阳能已成为世界各国公认的最为理想的替代能源,其应用规模不断扩大.但光伏发电系统高昂的成本,成为限制其发展的关键因素.本文应用净现值和单因素敏感性分析工具,建立了光伏发电成本的计算模型,以我国34个省会城市作为研究案例,对井网光伏发电系统进行了经济性和环境效益分析.结果显示:在目前政府初始投资补贴一半的情况下,并网光伏发电成本介于0.83-2.29元/kWh之间.即便在光照资源最丰富的地区,并网光伏发电仍无法与常规能源发电相竞争.在影响并网光伏系统发电成本的诸多影响因素中,政府初始投资补贴额度、水平面太阳能辐射量和投资密度的敏感性最强;CDM资金的注入对光伏发电成本的降低具有积极的作用.激励政策方面,出台合适的、稳定的上网电价对启动国内光伏市场最为有效.光伏发电系统的环境效益是指光伏发电的减排环境效益扣除系统发电环境成本的余额.经计算并网光伏发电具有显著的环境效益,其环境效益为0.0165元/kWh.本研究对于国家制定光伏发电的激励政策和成本分摊机制具有重要的参考价值.