三峡水库试验性蓄水前后大宁河富营养化状态比较

基于大宁河试验性蓄水阶段(2005-09～2007-09)和正常运行阶段(2008-09～2010-09)的监测数据,对大宁河试验性蓄水前后富营养化状态进行比较,在此基础上运用Carlson的"二维坐标理论"和数理统计分析方法,探究大宁河富营养状态限制因素.结果表明,和试验性蓄水阶段相比,正常运行阶段整个研究区域TSITP呈显著上升趋势,从大宁河回水末端至长江干流,增加幅度沿程依次为23.29%、19.57%、15.58%和14.12%;TSISD和TSITN维持稳定;TSICHL总体维持稳定,仅回水末端(S1)呈上升趋势,上升幅度为17.34%.从长江干流至大宁河回水末端,TSITN、TSITP和TSISD这3个营养状态指数均呈现沿程降低的趋势;TSICHL呈现回水区(S2)和出水口(S3)较高,长江干流(S4)和回水末端(S1)较低.试验性蓄水前后各水文期特征基本呈现一致.TSITN和TSITP水文期特征表现为:汛限期、泄水期>高水位运行期>蓄水期;TSICHL水文期特征表现为:汛限期>蓄水期、泄水期>高水位运行期;TSISD水文期特征表现为:汛限期、泄水期>蓄水期>高水位运行期.正常运行期和试验性蓄水期相比,TSITN、TSITP和TSICHL在各个水文期之间的差异变小.长江干流和大宁河总氮和总磷已经超过了富营养化状态的临界值,因此营养盐并不是水体富营养化状态的限制因素;非藻类浊度控制水下光衰减而成为限制藻类生产力的关键因素.非藻类浊度和水下光照分布受到水文学特征季节动态的强烈干扰.     

污染控制的信息手段及其在中国的应用

在总结对若干发达国家和发展中国家排污者行为所作的实证研究的基础上,论述了信息可以通过市场和社区对排污者行为起到独立的刺激作用;并在介绍对信息手段所做的研究和案例后,对该手段在中国污染控制中的应用进行了初步探讨.     

Development of Environmental Indicator Systems: Experiences from Germany

ABSTACT / Environmental indicator systems aim to improve both the information and communication on the state of the environment and the environmental policy making. They have to fulfill scientific, functional and pragmatic requirements, e.g., consideration of ecological context, transparency and reproducibility, comprehensibility, policy relevance, international comparability, and justifiable expenditure. This paper analyzes the experiences made with the development of the German environmental indicator system and draws general conclusions toward further improvements. For Germany, an indicator system has been developed that uses the pressure-state-response approach proposed by the OECD, together with a classification in 14 environmental themes. According to the general requirements, the main criteria used for selecting the indicators are the ecological significance of the indicator, its quantifiability and data availability, and its comprehensibility and policy relevance. Altogether, about 140 indicators are selected. This high number stresses the need for further high-level aggregation, e.g., using methods developed for the valuation process in LCA. Further improvement is also needed, especially for the development of response indicators and in the area of data systematization.     

封闭型人造景观水体水质控制技术探讨

简要阐述了景观水体的作用、产生的问题,以及应用于景观水体水质控制的各种典型的水处理方法。通过对上海市9个封闭型人造景观水体水质控制措施的调研,探讨了控制该类水体水质的技术路线,分析了控制技术措施,提出了工程实施应用中的主要难题。     

湛江市环境管理信息系统建设研究

湛江市地方环境特点和环保局职能，介绍了该市环境管理信息系统的开发目的，系统，结构设计，主要等，该系统在Ｗｉｎｄｏｗｓ９５环境下，以Ｆｏｘｐｒｏ３．０为主要支持工具，结合其他ＧＩＳ软件，模型采用ＦｏｒｔｒａｎｆｏｒＷｉｎｄｏｗｓＶｉｓｕａｌＣ＋＋４．０为编程语言，建立了全 中文界面的多媒体环境管理信息系统。     

Top-down法计算中国五氯酚钠消费分布

为履行<关于持久性有机污染物(POPs)的斯德哥尔摩公约>,中国将逐渐淘汰POPs的生产和使用,环境介质中POPs浓度监测和处置是履约工作的重要部分,而其消费分布的研究可以为监测和模型计算找出重点区域.采用Top-down法,根据当年全国的五氯酚钠消费,以药物灭螺面积、钉螺面积、血吸虫病流行村数等为替代数据,计算了各省份的五氯酚钠消费分布,并进一步计算出省内各市级地区的五氯酚钠消费分布.从2003年的计算结果来看,五氯酚钠消费最大的是湖北省和湖南省,两省五氯酚钠消费占到全国总消费的72.62%.最主要的地区是湖北省荆州市和湖南省岳阳市、常德市、益阳市,分别占全国总消费的15.25%、12.78%、11.72%、9.89%,总和占到全国总消费的49.64%,上述地区将成为今后研究和监测的重点区域.     

Ecological metrics of biomass removed by three methods of purse-seine fishing for tunas in the eastern tropical Pacific Ocean

An ecosystem approach to fisheries management is a widely recognized goal, but describing and measuring the effects of a fishery on an ecosystem is difficult. Ecological information on the entire catch (all animals removed, whether retained or discarded) of both species targeted by the fishery and nontarget species (i.e., bycatch) is required. We used data from the well-documented purse-seine fishery for tunas (Thunnus albacares, T. obesus, and Katsuwonus pelamis) in the eastern tropical Pacific Ocean to examine the fishery's ecological effects. Purse-seine fishing in the eastern tropical Pacific is conducted in 3 ways that differ in the amount and composition of target species and bycatch. The choice of method depends on whether the tunas are swimming alone (unassociated sets), associated with dolphins (dolphin sets), or associated with floating objects (floating-object sets). Among the fishing methods, we compared catch on the basis of weight, number of individuals, trophic level, replacement time, and diversity. Floating-object sets removed 2-3 times as much biomass as the other 2 methods, depending on how removal was measured. Results of previous studies suggest the ecological effects of floating-object sets are thousands of times greater than the effects of other methods, but these results were derived from only numbers of discarded animals. Management of the fishery has been driven to a substantial extent by a focus on reducing bycatch, although discards are currently 4.8% of total catch by weight, compared with global averages of 7.5% for tuna longline fishing and 30.0% for midwater trawling. An ecosystem approach to fisheries management requires that ecological effects of fishing on all animals removed by a fishery, not just bycatch or discarded catch, be measured with a variety of metrics.     

Recent advances in electrochemical decontamination of perfluorinated compounds from water: a review

● Recent advances in the electrochemical decontamination of PFAS are reviewed. ● Underlying mechanisms and impacting factors of these processes are discussed. ● Several novel couped systems and electrode materials are emphasized. ● Major knowledge gaps and research prospects on PFAS removal are identified. Per- and polyfluoroalkyl substances (PFAS) pose serious human health and environmental risks due to their persistence and toxicity. Among the available PFAS remediation options, the electrochemical approach is promising with better control. In this review, recent advances in the decontamination of PFAS from water using several state-of-the-art electrochemical strategies, including electro-oxidation, electro-adsorption, and electro-coagulation, were systematically reviewed. We aimed to elucidate their design principles, underlying working mechanisms, and the effects of operation factors (e.g., solution pH, applied voltage, and reactor configuration). The recent developments of innovative electrochemical systems and novel electrode materials were highlighted. In addition, the development of coupled processes that could overcome the shortcomings of low efficiency and high energy consumption of conventional electrochemical systems was also emphasized. This review identified several major knowledge gaps and challenges in the scalability and adaptability of efficient electrochemical systems for PFAS remediation. Materials science and system design developments are forging a path toward sustainable treatment of PFAS-contaminated water through electrochemical technologies.     

The Effectiveness of Management Interventions Used to Control Ragwort Species

Ragwort (Senecio jacobaea and S. aquaticus) causes major losses to agricultural revenue and induces livestock morbidity throughout parts of Europe, North America, and Australasia. The introduction of legislation in the U.K. and Australia has meant that landowners can be prosecuted if the plant spreads to adjacent land, which has led to an increase in activities attempting to control these species. Commonly used interventions include natural enemies, herbicide applications, manual and mechanical removal. Through the use of explicit systematic methodology involving comprehensive searches and detailed inclusion criteria, data from primary research are collated for each type of intervention. Meta-analyses show that 2,4-D, Asulam, Clopyralid, and MCPA are effective at reducing ragwort densities. However, when the datasets were analysed for their effectiveness against individual species, 2,4-D and MCPA were only effective against S. jacobaea, while Asulam was only effective against S. aquaticus. Natural enemies Longitarsus jacobaeae and a combination of L. jacobaeae and Tyria jacobaeae appear to have the potential to reduce S. jacobaea densities. Only applying T. jacobaeae does not appear to significantly reduce S. jacobaea densities, but does reduce the number of capitula per plant, seeds per capitula, viability of seeds, and dry weight of the plants. There is insufficient experimental evidence available to assess other interventions such as manual or mechanical removal. Further research into these types of interventions is recommended, as well as more detailed reporting of site characteristics and experimental design to allow full investigation of each intervention to explain possible reasons for variations in their effectiveness.     

Prioritizing highway safety improvement projects: A multi-criteria model and case study with SafetyAnalyst

This paper presents a multi-criteria model for prioritizing highway safety improvement projects, in which a set of criteria related to the project’s technical, economic, and social impacts are properly weighted in consideration. The proposed model features an Analytical Hierarchy Process (AHP) framework to tackle the multi-criteria decision making problem. Different from the conventional AHP, this paper adds a fuzzy scale level between the criteria level and the alternative level, which offers the advantage of preventing the vagueness and uncertainty on judgments of the decision-maker(s). Such a unique modeling feature is further embedded with a non-linear optimization formulation to maximize the consistency in pair-wise comparison and weight estimation for each criterion. Case study results reveal that the proposed model is efficient not only for selecting the most suitable project for a specific site, but also for determining the priorities for implementing those suitable projects among multiple sites given the budget constraint. Comparative study between the proposed model and the existing ranking methods has also indicated its capability to capture the comprehensive impacts of all contributory factors which have been neglected by most existing single multi-criteria approaches during the safety project selection process. The clarity of model inputs, ease of synthesizing the final score of each candidate project, and the interpretation of results with respect to different selection criteria offer its best potential to be used as an effective tool for highway safety managers to assess and refine the safety improvement investments.