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51.
A modular approach to Integrated Assessment modeling 总被引:1,自引:0,他引:1
In this paper, we present a new approach to model coupling that probably forms the methodological basis of a new generation of Integrated Assessment models. This approach respects the knowledge and expertise that is embodied in existing models and encourages their gradual evolution. Modularity is the guiding principle. Our approach is distinguished by the way modules are coupled which is based on an interplay of a job control module, a numerical coupling module, and a couple of stand-alone functional modules. The numerical coupling module - the core component - serves to treat the feedbacks between the functional modules. A first implemented example that couples an economic and a climate module by means of a two-phase meta-optimization is presented here. The algorithm and mathematical structure behind are discussed as well as important features such as convergence behavior and reliability. 相似文献
52.
土壤重金属污染的灰色模糊评价 总被引:14,自引:1,他引:14
以灰色聚类为基础,提出了灰色模糊聚类分析法,并将其应用于土壤环境质量评价中,经实例分析表明,这是一种较为简便,合理、有效的评价方法。 相似文献
53.
基于B-P神经网络的环境质量评价方法 总被引:3,自引:0,他引:3
提出可将环境质量评价的无论是定量指标还是定性参数转化成"二进制"的"1"或"0",进而将这种二进制数引入B-P网络.通过实例探讨,这种新的B-P网络既适用于定量指标的水质参数又适用于定性指标的水质参数. 相似文献
54.
Ambient Air Quality Monitoring Network Design for Assessing Human Health Impacts from Exposures to Airborne Contaminants 总被引:1,自引:0,他引:1
Existing methods of establishing ambientair quality monitoring networks typically evaluateonly parameters related to ambient concentrations ofthe contaminant(s) of interest such as emissionsource characteristics, atmospheric transport anddispersion, secondary reactions, depositioncharacteristics, and local topography. However,adverse health risks from exposures to airbornecontaminants are a function of the contaminant andthe anatomic and physiologic characteristics of theexposed population. Thus, ambient air qualitymonitoring networks designed for the protection ofpublic health or for epidemiological studiesevaluating adverse health impacts from exposures toambient air contaminants should account for bothcontaminant characteristics and human healthparameters. A methodology has been establishedwhich optimizes ambient air quality monitoringnetworks for assessments of adverse human healthimpacts from exposures to airborne contaminants byincorporating human health risk assessmenttechniques. The use of risk assessment techniquesas the basis for designing ambient air qualitymonitoring networks will help to target limitedfinancial and human resources to evaluate humanhealth risks from exposures to airbornecontaminants. 相似文献
55.
Malcolm S. Field 《Environmental monitoring and assessment》1997,47(1):23-37
Ground-water flow and solute-transport simulation modeling are major components of most exposure and risk assessments of contaminated aquifers. Model simulations provide information on the spatial and temporal distributions of contaminants in subsurface media but are difficult to apply to karst aquifers in which conduit flow is important. Ground-water flow and solute transport in karst conduits typically display rapid-flow velocities, turbulent-flow regimes, concentrated pollutant-mass discharge, and exhibit open-channel or closed-conduit flow. Conventional ground-water models, dependent on the applicability of Darcy`s law, are inappropriate when applied to karst aquifers because of the (1) nonapplicability of Darcian-flow parameters, (2) typically nonlaminar flow regime, and (3) inability to locate the karst conduits through which most flow and contaminant transport occurs. Surface-water flow and solute-transport models conditioned on a set of parameters determined empirically from quantitative ground-water tracing studies may be effectively used to render fate-and-transport values of contaminants in karst conduits. Hydraulic-flow and geometric parameters developed in a companion paper were used in the surface-water model, TOXI5, to simulate hypothetical slug and continuous-source releases of ethylbenzene in a karst conduit. TOXI5 simulation results showed considerable improvement for predicted ethylbenzene-transport rates and concentrations over qualitative tracing and analytical ground-water model results. Ethylbenzene concentrations predicted by TOXI5 simulations were evaluated in exposure and risk assessment models. 相似文献
56.
共振光散射技术是一项在普通荧光分光光度计上进行测量的光散射技术,文章简要介绍了光散射现象,共振光散射的基本原理并作了定量基础讨论,对共振光散射技术在环境分析中的应用作了初步研究。 相似文献
57.
58.
将有时序多目标决策方法应用于地面水环境质量优势的比较,介绍了决策方法的原理和评价步骤。实例分析表明该方法计算过程简便,分辨率高,排序结果与实际环境质量状况相符合。 相似文献
59.
酸性法测定高锰酸盐指数加热时间的选择 总被引:1,自引:0,他引:1
张美萍 《环境监测管理与技术》1997,9(1):38-38
酸性法测定高锰酸盐指数,会因实验条件的差异产生不同的结果。对不同加热时间,加热方式等因素进行了试验,结果表明加热时间以水浴加热沸腾30min或电炉直接加热8min为宜。 相似文献
60.
对GAM水环境预测模型提出了四点不同看法,与有关作者商榷,指出GM(1,1)模型与GAM模型二者并无优劣之差,精度亦相当。 相似文献