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121.
河流水环境质量综合评价方法比较研究 总被引:12,自引:0,他引:12
提出了对河流水环境质量综合评价方法的基本要求,对水环境质量评价方法的现状进行了研究,并通过对各种方法的 比较,探讨了今后水环境质量综合评价方法的发展方向。 相似文献
122.
用对二甲氨基苯甲醛分光光度法测定水中水合肼,将显色剂用量由5.0 m L降至3.0 m L,比色皿厚度由30 mm增至50 mm,水样酸度由1 mol/L降至0.5 mol/L,同时增加低浓度校准曲线,实现对其方法检出限的优化。结果表明,优化后方法检出限由0.007 8 mg/L降至0.001 0 mg/L,精密度及加标回收率均符合规范要求,能够保证低浓度水样的准确测定。 相似文献
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Emerging approaches to water resources development and management typically highlight equity and productivity as two main objectives. In the context of integrated water resources management within a river basin, managers and stakeholders often need a comparative assessment of different options for water augmentation and/or allocation. Pitting such options against predefined objectives, such as equity and productivity, requires an assessment of the effects that available options will have on these objectives. Available documentation indicates that not only does the interpretation of such objectives vary widely, but also the available methods for assessing equity and productivity run into significant limitations in the availability of adequate data. This limitation has largely kept decision makers from gaining a comprehensive overview of equity and productivity scenarios, whether within or across sectors, that could facilitate better‐informed decisions. To address this methodological gap, this article scrutinizes different notions associated with equity and water productivity, and limitations in prevalent assessment methods with the view to develop and demonstrate pragmatic methodologies for assessing equity and productivity in data‐scarce contexts. The discussion and findings are based on a review of relevant literature and empirical and consultative research work in the Olifants River basin in South Africa. The demonstrated methodologies for assessing equity and productivity, besides being useful in data‐scarce contexts, are insightful for initiating several policy measures and also for exploring the relationship between equity and water productivity. 相似文献
125.
K. Abbaspour V. Matta P. Huggenberger C. A. Johnson 《Journal of contaminant hydrology》2000,40(4):196
The investigation of contaminated sites is usually a long and expensive process. It is therefore desirable to use a combination of methodologies in an integrative approach that can reduce redundant information gathering. The objective of this study was to examine the usefulness of 2 non-intrusive exploration techniques in a contaminated site investigation. Borehole positioning based on geophysical measurements was compared to positioning based on the Bayesian expert system for flow-field modeling. The goal set at the field site was the assessment of the type and load of contaminants transported from the landfill site to the adjacent aquifer and the extent of leachate plumes within the groundwater. The two methods made different demands on information gathering and were found to be complementary. The geophysical approach focused attention on the waste compartments at the site and on mixing plumes in the adjacent aquifer but could not, without prior information, provided information on the flow field. The Bayesian approach to flow-field modeling determined areas of greatest model uncertainty at the model boundaries. The model highlighted areas of greatest uncertainty that might otherwise have been overlooked and provided information on the most likely mean direction of the leachate plumes. It was concluded that both methods contribute to a site investigation and should be used before additional drilling is carried out. 相似文献
126.
利用 2 2 0辆某轻型客车制动性能台试检测所得大量样本数据 ,对其 6项制动性能指标进行了统计分析 ,并得出了各项制动性能指标的实测合格率。轻型客车的制动性能检测与分析 ,对发现存在的问题 ,指导设计制造和使用维修单位改进工作 ,确保道路交通安全及车辆的行驶安全性具有重要作用。 相似文献
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分析和阐明地表水环境质量灰关联评价中关联度向量r中各分量的信息荷载,在满足定量、连续、分级的条件下构造了水环境质量系数C,C由首数水质级别数K和尾数水质差异E组成。水环境质量系数既能表示水质级别,又能准确区别同级水质差异。在应用特例中介绍了模糊级别的区分和级别跳跃现象。最后介绍了应用中注意的问题。 相似文献
129.
流域生态补偿意愿的WTP与WTA差异性研究: 基于辽河中游地区居民的CVM调查 总被引:6,自引:0,他引:6
如何揭示利益相关者生态补偿的真实意愿不但是生态系统服务支付研究的难点问题,也是政府及管理部门制定生态补偿政策的关键问题。为此,论文通过对辽河流域中游地区的7个主要城市进行实地调研,采用条件价值评估法,利用同一受访者同时测量其支付意愿值(WTP)和受偿意愿值(WTA)的技术手段来检验其真实补偿意愿,研究结果显示,受访地区居民保护流域生态环境和水资源的WTP为59.39元/(人·a),WTA为248.56/(人·a);同时,针对同一受访者给出的WTP与WTA之间的较大差异性利用回归分析方法,得出其呈现不对称性的主要原因是受访者的收入水平和年龄。最后,在对研究结果进行差异性分析的基础上,提出了辽河流域生态补偿意愿差异性的研究结论和政策建议。 相似文献
130.