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341.
The effects of biologically active carbon (BAC) filtration on haloacetic acid (HAA) levels in plant effluents and distribution systems were investigated using the United States Environmental Protection Agency’s Information Collection Rule (ICR) database. The results showed that average HAA5 concentrations in all locations were 20.4 μg·L-1 and 29.6 μg·L-1 in ICR plants with granular activated carbon (GAC) and ICR plants without GAC process, respectively. For plants without GAC, the highest HAA levels were observed in the quarters of April to June and July to September. However, for plants with GAC, the highest HAA levels were observed in the quarters of April to June and January to March. This HAA level profile inversely correlated well with water temperature, or biologic activity. For GAC plants, simulated distribution samples matched well with distribution system equivalent samples for Cl3AA and THMs. For plants with and without GAC, simulated distribution samples overestimated readily biodegradable HAAs in distribution systems. The study indicated that through HAA biodegradation, GAC process plays an important role in lowering HAA levels in finished drinking water.  相似文献   
342.
343.
Density-dependent emigration has been recognized as a fitness enhancing strategy. Yet, especially in the modelling literature there is no consensus about how density-dependent emigration should quantitatively be incorporated into metapopulation models. In this paper we compare the performance of five different dispersal strategies (defined by the functional link between density and emigration probability). Four of these strategies are based on published functional relationships between local population density and emigration probability, one assumes density-independent dispersal. We use individual-based simulations of time-discrete metapopulation dynamics and conduct evolution experiments for a broad range of values for dispersal mortality and environmental stochasticity. For each set of these conditions we analyze the evolution of emigration rates in ‘monoculture experiments’ (with only one type of dispersal strategy used by all individuals in the metapopulation) as well as in selection experiments that allow a pair-wise comparison of the performance of each functional type. We find that a single-parameter ‘asymptotic threshold’ strategy - derived from the marginal value theorem - with a decelerating increase of emigration rate with increasing population density, out-competes any other strategy, i.e. density-independent emigration, a ‘linear threshold’ strategy and a flexible three-parameter strategy. Only when environmental conditions select for extremely high emigration probabilities (close to one), strategies may perform approximately equally. A simple threshold strategy derived for the case of continuous population growth performs even worse than the density-independent strategy. As the functional type of the dispersal function implemented in metapopulation models may severely affect predictions concerning the survival of populations, range expansion, or community changes we clearly recommend to carefully select adequate functions to model density-dependent dispersal.  相似文献   
344.
简述了新时期环境监测数据产品内涵,分析了当前数据产品在信息化程度、深度开发、数据质量和信息公开等方面存在的问题;提出,要不断提高数据产品的信息化水平,推进其深度开发,要立足于服务社会和管控需求,加强数据产品可追溯能力建设,针对现各部门存在的"数据孤岛"问题,增强各部门间监测数据的可比性,推进区域污染物排放、空气环境质量、水环境质量等信息公开,为政府决策提供准确的技术支持,为公众、企业提供优质服务。  相似文献   
345.
以 Visual Studio 2005为开发平台,C#为开发语言,ArcEngine为 GIS 组件,SQL Server 2005为数据库管理系统,设计和实现了云南省土壤污染防治和管理信息系统的土壤环境质量评价、统计结果溯源查询和制图。该系统根据土壤环境质量评价、统计结果给定查询条件,据此逆向进行溯源筛选,查询出符合条件的原始采样点及其对应的相关信息,包括当前行信息、野外记录信息、检出限信息,显示及 Excel导出结果,并应用 GIS 的地图渲染更直观地展现查询结果。  相似文献   
346.
Considerable research indicates that a wide range of socio-economic factors influence attitudes and perceptions about environmental hazards and risks, and that social trust in those who manage a hazard is strongly correlated to judgements about risks and benefits. We suggest that there are three steps that lead to environmental risk perceptions: acquisition of information, interpretation and synthesis of different pieces of information, and understanding of that information in light of previous knowledge, perceptions, or attitudes. In this study we presented 211 college students in the sciences and non-sciences with ecological and exposure information using text, tables and maps to examine the factors that affect information acquisition and interpretation concerning ecological issues at a fictitious hazardous waste site. Students were allowed about an hour to read the materials and answer questions. The percent of students answering each question correctly varied from 4 to 82%, indicating that some questions were extremely difficult to answer. We attributed these differences to variations in the number of places information was presented (in text, tables, maps, or a combination) and the complexity of the information (how many pieces of information were required to answer the question correctly). The correlation between the number of students answering each question correctly and these combined measures (frequency, complexity) was −0.72. Thus, although there were differences in accuracy concerning ecological information as presented in this study, the major differences were accounted for by how the information was presented, and how much information was required. This suggests that risk communicators should carefully determine which ecological information is critical for the target audience, and ensure that it is presented several times (in different forms). That a lower percentage of people correctly answered questions that required synthesizing several pieces of information suggests that this complexity should be reduced where possible, or that the pieces of information should be tied clearly to the conclusion. Self-declaration of effort and perceptions of safety of the site did not markedly influence the relationship between accuracy, difficulty of finding information, and complexity of information. Other possible confounding variables (i.e., science vs non-science major) only accounted for about 27% of the variation in student’s overall score on ecological questions; age, ethnicity, and gender did not enter as significant variables. We cannot manage environmental hazards with appropriate stakeholder input unless we understand how to present environmental information to achieve a full understanding. Protection of human health and the environment requires that people understand ecological and exposure information, particularly on buffer lands.  相似文献   
347.
上海市工业区大气污染预警监测信息平台研究与设计   总被引:1,自引:0,他引:1  
根据上海市工业区大气污染排放特征,在构建大气特征污染监控网络的基础上,搭建了工业区大气污染预警监测信息平台,并研究了适用于大气特征污染自动站的通信传输规范,确保数据联网和应用。平台设置了大气质量监控、大气数据管理、污染源一厂一档、大气质量分析评价、污染源溯源分析、应急监测数据管理、智能移动终端查询等7个子系统,可为上海市工业区大气污染预警和管控提供实时监测数据。  相似文献   
348.
为了解无锡市地下水水质状况,于2010年10—12月对无锡地区145口地下水井进行采样分析。以地理信息系统为技术手段,对不同土地利用类型和地下水类型的水污染物监测结果进行综合评价。结果表明,无锡全市地下水达标率为45.52%,整体水质情况处于"较好"级别;NH3-N、Mn和Fe为无锡市地下水的主要污染物;无锡市农业和建设用地区域地下水的污染程度整体要高于水体和林地区域;承压层的地下水污染较为严重。提出,无锡市管理部门应根据地下水污染现状,对地下水资源进行动态监测(包括水量和水质监测),并采取强有力的保护与治理措施,以实现区域水资源的持续利用。  相似文献   
349.
Information seeking is completely ignored in research on aviation psychology and more generally in issues of air transport safety. But information seeking occupies a central place in the pilots’ work. And this activity is undergoing an important development: the transition from paper to electronic documents. A contribution to the assessment of this transition is presented here. The assessment is focused on deterioration of information access, understanding and exploitation, and their possible negative consequences in terms of reliability. The exploitation of the documentation by pilots, and particularly the information seeking activity, are described and linked to their contexts (i.e. the main tasks of flying that require information seeking). Then an users test is presented where some information-seeking tasks are evaluated in terms of cost and errors, by comparing electronic and paper documents. The results show that electronic documents provide new functions that seem useful but also that too many new functions generate difficulties. Then it seems that pilots need some time to learn how to use these new documents. Reducing attention needed to perform a task such as calculation is risky. Some aspects of information seeking by the pilots should be better analysed and evaluated.  相似文献   
350.
Tran P  Shaw R  Chantry G  Norton J 《Disasters》2009,33(1):152-169
Linking community knowledge with modern techniques to record and analyse risk related data is one way of engaging and mobilising community capacity. This paper discusses the use of the Geographic Information System (GIS) at the local level and the need for integrating modern technology and indigenous knowledge into disaster management. It suggests a way to mobilise available human and technical resources in order to strengthen a good partnership between local communities and local and national institutions. The paper also analyses the current vulnerability of two communes by correlating hazard risk and loss/damage caused by disasters and the contribution that domestic risk maps in the community can make to reduce this risk. The disadvantages, advantages and lessons learned from the GIS flood risk mapping project are presented through the case study of the Quang Tho Commune in Thua Thien Hue province, central Viet Nam.  相似文献   
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