首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 10 毫秒
1.
2.
依据国家标准和测量不确定度的评定方法,评定水中粪大肠菌群的不确定度.认为不确定度的主要来源为样品保存条件、培养条件、人员操作和判定计数等.通过对地表水和海水样品粪大肠菌群操作过程中的不确定度进行分量计算,建立一种简单的水中粪大肠菌群多管发酵法不确定度评定方法.  相似文献   

3.
In many communities in northern Ghana, the environment has been altered by complex natural and human driven forces with significant impact on the lives of their inhabitants. The need to formulate an improved, holistic and consistent methodological approach to assess the problem is critical for sustainable natural resource management. This paper examines the potential of the DPSIR environmental assessment framework utilizing GIS‐based participatory methodology in the assessment of environmental degradation in northern Ghana. Community truthing tools such as key informant interviews, focus group discussions, participant observation and participatory Geographical Information Systems (GIS) were employed as a means of soliciting societal responses integrated to conventional GIS spatial analysis to measure the indicators of the Driving force–Pressure–State–Impacts–Response (DPSIR) assessment framework. Post classification GIS imagery results show a marked natural vegetation decrease of 634 km2 (42%) of the study area with a corresponding increase of 600 km2 (39%) of grasses and built‐up and barren environment in the period of 14 years from 1990 to 2004. This is attributed to extreme climatic conditions and human driven causes such as poverty, population growth, migration and land tenure system. Poverty reduction strategies, amendment of the Mining and Mineral Law (PNDC law 153), improvement of the existing land tenure system and the control of migrants and Fulani herdsmen from neighbouring Burkina Faso were some of the solutions selected by the research participants, to be emphasized in the National Environmental Action Plan (EPA Act 490). This paper concludes that the DPSIR environmental assessment framework is an effective means of organizing complex environmental information to facilitate policy decision making.  相似文献   

4.
Two northern Minnesota lakes that had been studied in detail 22 years earlier (1958) were restudied to determine the extent of alteration in ecological conditions. Approximately one year after the original investigation, a coal-fired power plant, which incremented sulfate loading by about 6 kg/ha-yr, began operation nine miles away. These lakes lie within a region judged susceptible to acidic precipitation, though each lake, based on its buffering capacity, would be judged only moderately sensitive. In spite of the influence of this plant and other anthropogenic inputs, the change in lake ecology was apparently minimal. Water clarity decreased in both lakes and some alteration in zooplankton community structure was observed. The long-term utility of lake surveys depends upon how carefully and completely conditions can be reconstructed from records and reports. Past surveys generally omit measures of variability for the data, allowing only qualitative comparisons to be drawn. In order to judge the graded responses of aquatic ecosystems, necessary to sound management, quantitative measures are needed.Deceased.  相似文献   

5.
The management of risk from disinfection by-products (DBPs) in drinking water has become a critical issue over the last three decades. The areas of concern for risk management studies include (i) human health risk from DBPs, (ii) disinfection performance, (iii) technical feasibility (maintenance, management and operation) of treatment and disinfection approaches, and (iv) cost. Human health risk assessment is typically considered to be the most important phase of the risk-based decision-making or risk management studies. The factors associated with health risk assessment and other attributes are generally prone to considerable uncertainty. Probabilistic and non-probabilistic approaches have both been employed to characterize uncertainties associated with risk assessment. The probabilistic approaches include sampling-based methods (typically Monte Carlo simulation and stratified sampling) and asymptotic (approximate) reliability analysis (first- and second-order reliability methods). Non-probabilistic approaches include interval analysis, fuzzy set theory and possibility theory. However, it is generally accepted that no single method is suitable for the entire spectrum of problems encountered in uncertainty analyses for risk assessment. Each method has its own set of advantages and limitations. In this paper, the feasibility and limitations of different uncertainty analysis approaches are outlined for risk management studies of drinking water supply systems. The findings assist in the selection of suitable approaches for uncertainty analysis in risk management studies associated with DBPs and human health risk.  相似文献   

6.
The coal mining region in northern Colombia is one of the largest open pit mining regions of the world. In 2009, there were 8 mining companies in operation with an approximate coal production of ~70 Mtons/year. Since 2007, the Colombian air quality monitoring network has reported readings that exceed the daily and annual air quality standards for total suspended particulate (TSP) matter and particles with an equivalent aerodynamic diameter smaller than 10 μm (PM??) in nearby villages. This paper describes work carried out in order to establish an appropriate clean air program for this region, based on the Colombian national environmental authority requirement for modeling of TSP and PM(10) dispersion. A TSP and PM?? emission inventory was initially developed, and topographic and meteorological information for the region was collected and analyzed. Using this information, the dispersion of TSP was modeled in ISC3 and AERMOD using meteorological data collected by 3 local stations during 2008 and 2009. The results obtained were compared to actual values measured by the air quality monitoring network. High correlation coefficients (>0.73) were obtained, indicating that the models accurately described the main factors affecting particle dispersion in the region. The model was then used to forecast concentrations of particulate matter for 2010. Based on results from the model, areas within the modeling region were identified as highly, fairly, moderately and marginally polluted according to local regulations. Additionally, the contribution particulate matter to the pollution at each village was estimated. Using these predicted values, the Colombian environmental authority imposed new decontamination measures on the mining companies operating in the region. These measures included the relocation of three villages financed by the mine companies based on forecasted pollution levels.  相似文献   

7.
The present study compares the spatial distribution of selected rural land use classes in Italy with two soil indicators (a Soil Quality Index [SQI] and the Maximum potential Water Capacity of the soil [MWC]) at three points in time (1960, 1990 and 2006). Results of the analysis showed that landscape changes reflect a ‘migration’ of both semi-natural (forests, pastures) and agricultural (arable land, vineyards) uses towards areas with lower-quality soils. In particular, the agricultural ‘mosaic’ and shrubland-pasture classes that occupied land in 2006 had significant lower values of both the SQI and MWC compared to 1960. These processes may have implications for the stability of agro-forest ecosystems in the medium term. Due to its versatility, the procedure illustrated represents a monitoring tool for sustainable land management at the regional and country scales.  相似文献   

8.
In the present study, Life Cycle Assessment (LCA) methodology was applied to evaluate the energy consumption and environmental burdens associated with the production of protected crops in an agricultural district in the Mediterranean region. In this study, LCA was used as a 'support tool', to address local policies for sustainable production and consumption patterns, and to create a 'knowledge base' for environmental assessment of an extended agricultural production area. The proposed approach combines organisation-specific tools, such as Environmental Management Systems and Environmental Product Declarations, with the environmental management of the district. Questionnaires were distributed to producers to determine the life cycle of different protected crops (tomatoes, cherry tomatoes, peppers, melons and zucchinis), and obtain information on greenhouse usage (e.g. tunnel vs. pavilion). Ecoprofiles of products in the district were also estimated, to identify supply chain elements with the highest impact in terms of global energy requirements, greenhouse gas emissions, eutrophication, water consumption and waste production. These results of this study enable selection of the 'best practices' and ecodesign solutions, to reduce the environmental impact of these products. Finally, sensitivity analysis of key LCA issues was performed, to assess the variability associated with different parameters: vegetable production; water usage; fertiliser and pesticide usage; shared greenhouse use; substitution of plastics coverings; and waste recycling.  相似文献   

9.
In this study, we asked the Ariaal herders of northern Kenya to answer "why, what and how" they classified landscape, and assessed and monitored the biodiversity of 10 km(2) of grazing land. To answer the "why question" the herders classified grazing resources into 39 landscape patches grouped into six landscape types and classified soil as 'warm', 'intermediate' or 'cold' for the purpose of land use. For the "what question" the herders used soil conditions and vegetation characteristics to assess biodiversity. Plant species were described as 'increasers', 'decreasers' or 'stable'. The decreaser species were mostly grasses and forbs preferred for cattle and sheep grazing and the increasers were mostly woody species preferred by goats. The herders evaluated biodiversity in terms of key forage species and used absence or presence of the preferred species from individual landscapes for monitoring change in biodiversity. For the "how question" the herders used anthropogenic indicators concerned with livestock management for assessing landscape potential and suitability for grazing. The anthropogenic indicators were related to soils and biodiversity. The herders used plant species grazing preferences to determine the links between livestock production and biodiversity. By addressing these three questions, the study shows the value of incorporating the indigenous knowledge of herders into classification of landscape and assessment and monitoring of biodiversity in the grazing lands. We conclude that herder knowledge of biodiversity is related to the use as opposed to exclusive conservation practices. This type of knowledge is extremely valuable to conservation agencies for establishing a baseline for monitoring changes in biodiversity in the future.  相似文献   

10.
Maps illustrating the different degrees of vulnerability within a given area are integral to environmental protection and management policies. The assessment of the intrinsic vulnerability of karst areas is difficult since the type and stage of karst development and the related underground discharge behavior are difficult to determine and quantify. Geographic Information Systems techniques are applied to the evaluation of the vulnerability of an aquifer in the alpine karst area of the Sette Comuni Plateau, in the Veneto Region of northern Italy. The water resources of the studied aquifer are of particular importance to the local communities. This aquifer must therefore be protected from both inappropriate use as well as possible pollution. The SINTACS and SINTACS P(RO) K(ARST) vulnerability assessment methods have been utilized here to create the vulnerability map. SINTACS P(RO) K(ARST) is an adaptation of the parametric managerial model (SINTACS) to karst hydrostructures. The vulnerability map reveals vast zones (81% of the analyzed areas) with a high degree of vulnerability. The presence of well-developed karst structures in these highly vulnerable areas facilitate water percolation, thereby enhancing the groundwater vulnerability risk. Only 1.5 of the studied aquifer have extremely high-vulnerability levels, however these areas include all of the major springs utilized for human consumption. This vulnerability map of the Sette Comuni Plateau aquifer is an indispensable tool for both the effective management of water resources and as support to environmental planning in the Sette Comuni Plateau area.  相似文献   

11.
This essay evaluates the historical development and current background of human-environment relationships in Italy. The Italian landscape consists of very varied terrain, and periodically suffers from all kinds of natural hazard, especially earthquakes, landslides, floods, and accelerated soil erosion. Some measure of environmental conservation was achieved by the Etruscans and Romans, but the Classical period also marked the beginning of serious lowland waterlogging, malarial infestation, upland soil erosion, and deforestation, which all increased during the Middle Ages. From the Renaissance to the 18th century, there was a diffusion of planned landscapes and carefully managed estates; but by the 20th century, many rural areas could not support growing populations and much land was in need of improvement. Underdevelopment and latifundium agriculture increased the vulnerability to environmental hazards of the Mezzogiorno (Italian South), while the subsequent disappearance of the peasant culture seems not to have led to greatly improved conservation or land management. Poorly farmed or managed landscapes and poorly maintained historic towns have undergone some virtually irreversible degradation, especially with respect to landslides and earthquake damage. Elsewhere in Italy, unchecked urbanization, weak planning laws, and their inadequate enforcement have helped both to reduce environmental quality, by overdevelopment of valued landscapes, and to increase natural disaster vulnerability, by encouraging occupance of natural hazard zones. Although there are signs that the government is beginning to respond to the cumulative effect of environmental degradation, the measures are insufficient to reverse the overall trend toward decadence that characterizes human-land relationships in Italy.  相似文献   

12.
In a certain sense, uncertainty andignorance have been recognized in science andphilosophy from the time of the Greeks.However, the mathematical sciences have beendominated by the pursuit of certainty.Therefore, experiments under simplified andidealized conditions have been regarded as themost reliable source of knowledge. Normally,uncertainty could be ignored or controlled byapplying probability theory and statistics.Today, however, the situation is different.Uncertainty and ignorance have moved intofocus. In particular, the global character ofsome environmental problems has shown that theproblems cannot be disregarded. Therefore,scientists and technologists have in many wayscome into a new situation. The Chernobylaccident is a dramatic example, however,problems such as a possible greenhouse effect,a possible reduction of the ozone layer, and soon are all of the same type. These encompasstotally different problems than scientists andtechnologists are traditionally trained to dealwith. In these cases, the standard use ofstatistics has to change, the burden of proofshould be reversed, one should draw ondifferent kinds of expertise, and, in general,science should be ``democratized.'  相似文献   

13.
This paper studies mountain hut infrastructure in the Alps as an important element of ecotourism in the Alpine region. To improve the decision-making process regarding the implementation of future infrastructure and improvement of existing infrastructure in the vulnerable natural environment of mountain ecosystems, a new decision support model has been developed. The methodology is based on qualitative multi-attribute modelling supported by the DEXi software. The integrated rule-based model is hierarchical and consists of two submodels that cover the infrastructure of the mountain huts and that of the huts’ surroundings. The final goal for the designed tool is to help minimize the ecological footprint of tourists in environmentally sensitive and undeveloped mountain areas and contribute to mountain ecotourism. The model has been tested in the case study of four mountain huts in Triglav National Park in Slovenia. Study findings provide a new empirical approach to evaluating existing mountain infrastructure and predicting improvements for the future. The assessment results are of particular interest for decision makers in protected areas, such as Alpine national parks managers and administrators. In a way, this model proposes an approach to the management assessment of mountain huts with the main aim of increasing the quality of life of mountain environment visitors as well as the satisfaction of tourists who may eventually become ecotourists.  相似文献   

14.
我跟随意大利友人坚尼一起去意大利.看冬景。坚尼是一个非常不错的小伙子,在米兰市郊拥有一套四十来平方米的小公寓。到达他那公寓的时候是周六晚上,吃了晚饭后觉得有些累,也没想出去玩,洗漱完了便直接上床睡觉。  相似文献   

15.
Little attention was paid to growing air quality concerns until about a decade earlier in India. Indian Government started continuous monitoring of the urban air quality in Taj corridor area to protect the heritage monuments like Agra Fort, Fatehpur Sikri, the bird sanctuary at Bharatpur National Park and also the human health associated with air pollution. The aim of this study was to address air quality assessment using fuzzy synthetic evaluation model. The model was designed for four air pollutants (sulphur dioxide, nitrogen dioxide, suspended particulate matters and respirable suspended particulate matter). In the present paper, an approach is demonstrated for the determination of fuzzy air quality index by aggregating the four pollutants. The model also considers the weights of individual pollutants during aggregation. The weights of individual pollutants were determined using analytical hierarchical process. The model was applied for air quality assessment in four monitoring stations situated in Taj Trapezium Zone.  相似文献   

16.
在分析测定水中挥发性酚时,对影响测量的各个因素:标准物质、使用量器、分析仪器、校准曲线、试样的重复性及回收率进行分析,建立满足测量不确定度所需的数学模型,并对不确定度进行评定,其结果能如实反应测量的置信度和准确度。  相似文献   

17.
对化学需氧量测定的不确定度进行合理评定,应充分考虑测定过程中的不确定度来源。建立了重铬酸钾法测定水样中化学需氧量不确定度的数学模型,对组成化学需氧量的各个因子的不确定度分量进行了详尽的分析和计算,得出了本次样品CODCr的测定结果为72.2mg/L,扩展不确定度为3.8mg/L。  相似文献   

18.
采用纳氏试剂法测定废水中氨氮含量,其不确定度来源于标准曲线、取样体积和样品的重复测定,通过对测定过程涉及到的标准储备液、标准曲线绘制、标准曲线拟合、取样体积、移液管等因素进行分析,确定其产生的不确定度,进而提高测量的准确度。实验结果表明,通过对废水中氨氮不确定度的评定,能够准确反映实验过程中产生的不确定度的所有来源。  相似文献   

19.
杨志红 《环境技术》2006,24(2):14-17
本文对滴定法测定高锰酸盐指数的不确定度进行分析,找出影响不确定度的因素,对不确定度进行评估,如实反映测量的置信度和准确性.  相似文献   

20.
The geology, relief, neotectonics, climate, and vegetation of Basilicata make the region vulnerable to landslides, but the number of reported landslides in the region has increased over recent centuries, and this has been interpreted as a result of changes in land use. This interpretation is confirmed by documentary evidence presented in this article (concentrating on the example of the town of Grassano, where urban landslides are an almost exclusively 20th-century phenomenon), which shows the increase in landslides to have been real, rapid, and caused by humankind.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号