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1.
利用新型遥感数据"哨兵-3A"卫星OLCI影像数据,基于其665,681和708 nm波段构建的"荧光基线高度"指数算法,采用SNAP 6.0遥感专业软件,计算了2017年不同季节4个典型日期太湖FLH的全湖分布及蓝藻水华区信号强度特征。以完成了瑞利散射及气体吸收订正的3个波段的遥感反射率数据计算FLH图像,结果表明,FLH数值的"负偏"程度与蓝藻水华强度有很好的对应关系,FLH值"负偏"越大,蓝藻水华越严重,可以作为比较不同季节水华强度的有效遥感指标;富营养化较严重、较为浑浊、以蓝藻为优势种的内陆水体与大洋清洁、非蓝藻优势浮游植物水体的FLH"正偏"信号特征迥异。  相似文献   

2.
富营养化是太湖面临的一个重大环境问题。富营养化预测是湖泊水质变化的有效预警手段。本文选择TN、TP和叶绿素a(Chl-a)三个富营养化重要评价指标,基于Minitab软件的相关性分析,利用MatlabR2010b软件建立了太湖TN、TP和Chl-a变化的BP人工神经网络预测模型。结果表明,在对TN、TP、Chl-a的预测中,训练的均方差在0.02以下,相关系数在0.88以上,测试的均方差在0.17以下,相关系数在0.70以上,具有较强的相关性;Chl-a、TN的模型预测的结果最为理想,TP的预测结果次之,总体结果较好。因此,建立的BP神经网络能较好地预测太湖富营养化指标的变化情况,可作为太湖富营养化管理的一个有效工具。  相似文献   

3.
用灰色聚类法对荔湾湖水质富营养化程度的评价   总被引:37,自引:2,他引:37  
灰色聚类法把湖泊系统当作一个灰色系统来研究,将灰色聚类理论应用于湖泊富营养化程度的评价中,以广州市荔湾湖为例,建立不同的聚类指标所拥有的隶属函数,确定聚类权重值,求得最大聚类系数及聚类结果,得出用灰色聚类法进行湖泊水质富营养化评价,既能体现水质等级界线的模糊性,又能充分利用信息,避免了模糊数学法的不合理之处。因而,灰色聚类法是一种简便、客观、可靠的方法。  相似文献   

4.
通过2015—2019年在淀山湖布设5个采样点,监测总氮、总磷等12项水质指标,运用综合营养状态指数法和潜在性富营养化评价法对该水域富营养化水平进行分析,采用主成分分析法初步确定影响该水域富营养化水平的主要驱动因子。结果表明:监测期间淀山湖水质因子时空分布差异显著。综合营养状态指数法评价结果表明,淀山湖富营养化在轻—中度富营养化水平,并且季节变化规律明显;潜在性富营养化法评价结果表明,监测期间淀山湖以磷限制潜在性富营养为主。驱动因子分析表明硝酸盐氮是该水域富营养化最主要的驱动因子。  相似文献   

5.
湖泊富营养化评价的S型曲线通用表示式   总被引:5,自引:1,他引:5  
在适当设定富营养化指标的“本底”值情况下 ,当指标值用对应于“本底”值的相对值表示时 ,可采用 S型曲线描述湖泊富营养化发展程度 ,从而公式中的参数可视为与指标特性无关 ,采用遗传算法对公式中的参数优化 ,得到对多项指标通用的富营养化程度的指数计算公式 ,并用广义对比因子赋权新方法计算富营养化综合指数。该评价方法物理意义明确 ,计算简单 ,使用方便 ,具有可比性和通用性  相似文献   

6.
江苏省环境监测站标准化建设成效评价   总被引:1,自引:1,他引:0  
江苏省在2013年底通过了国家环境监测站标准化建设整体验收,成为全国第一个整体达到国家建设标准的省份。在总结江苏省主要建设经验的基础上,为定量评估江苏省各级环境监测站标准化建设成效水平,以《国家环境监测站标准化验收评分办法》评价指标为基础,尝试构建环境监测站建设成效评价指标体系,并应用层次分析法确定指标及其权重,共设1项一级指标、5项二级指标和12项三级指标。通过专家综合决策打分,确定各项评价指标的权重值,赋值计算综合成效评价指数。结果表明,全省实验室条件、仪器设备、监测数据、论文发表、能力认证等方面发展迅速,但人员扩编有待进一步加强。该方法为政府部门考核财政资金投入绩效、优化管理决策提供了定量评价参考。  相似文献   

7.
对玉绣河研究河段进行长期监测,确定玉绣河研究河段的主要水质问题是富营养化.选取叶绿素a作为富营养化的指示参数,并确定NH3-N为限制富营养化的控制性因子.以NH3-N为对象建立玉绣河水质模拟模型,利用监测数据在MATLAB环境中通过矩阵计算验证了所建模型的适用性.并利用MATLAB软件模拟了不同情况下的玉绣河水质变化趋势.进而分析了玉绣河目前存在的问题及需要采取的控制措施.  相似文献   

8.
介绍了基于生命周期影响评价模型的干预--效应法,以及该法包括的环境效应类型的确定、环境干预因子的识别与归类、按当量因子法汇总、数据标准化和赋权评估5个技术步骤,并以广州市2003年监测数据为基础,对广州市酸化、富营养化和光化学臭氧合成效应作了研究.结果表明,广州市2003年排放的酸化污染负荷量约为379.5×103 t SO2当量,主要污染物是SO2的排放(占57.4%);富营养化污染负荷量为657.7×103 t NO3-当量,其中最大排放源来自人类生活(占38.4%);光化学臭氧合成污染负荷量为46.4×103 t C2H4当量,主要来自于公路交通运输(占69.8%).赋权评估表明广州市区域性的环境效应主要为光化学臭氧合成,其环境负荷为32.358×103人当量,其次为富营养化和酸化效应,环境负荷分别为8.138×103人当量和7.915×103人当量.  相似文献   

9.
对富营养化评价标准进行插值获取大量的样本,建立了基于BP人工神经网络的富营养化评价模型。将模型应用于评价深圳市13座主要水库的富营养化状况,对其成因进行分析,并提出了对策与建议。研究结果表明,石岩水库与深圳水库为轻度富营养化,占评价水库总数的15.4%;西丽水库等11座水库为中营养,占评价水库总数的84.6%。人工神经网络用于建立湖库富营养评价模型是适合的。  相似文献   

10.
以徐州市云龙湖东西两湖区为对象,研究其不同功能区水质状况,从而为云龙湖水体保护提供理论依据。在云龙湖东湖、西湖区各设置3个采样点,监测水体中总氮、总磷、高锰酸盐指数和溶解氧指标;采用熵权法确定各水质指标权重,继而对水质进行定量综合评价。评价结果表明:云龙湖水体水质为III类,其中TN、TP超标明显,水体已呈现富营养化;不同功能区水质差异明显,东湖区水质优于西湖区,云龙湖功能区划分对水质有显著性影响。  相似文献   

11.
In order to enrich and improve the groundwater quality assessment system, a new coupled assessment model based on rough set attribute reduction and the technique for order preference by similarity to ideal solution (TOPSIS) was proposed. The proposed model was applied in the groundwater quality assessment of a semi-arid area, northwest China. The results show that most chemical indices except NH (4) (+) , F(-), and Mn meet the Standards for Drinking Water of China and the groundwater quality overall is good. All assessed water samples are found to be fit for human consumption according to the comprehensive assessment results. Rough set attribute reduction for groundwater quality assessment is practical. The assessment results after attribute reduction show a good consistency with those before attribute reduction. Rough set attribute reduction and TOPSIS evaluation coupled model is clear in ideas and simple in calculation, and evaluation results are reasonable as well. The coupled model can be applied to solve many multiple criteria decision making problems such as groundwater quality assessment.  相似文献   

12.
Pedestrian bridges can not only allow traffic to run more smoothly but also reduce vehicle fuel consumption and emission exhaust. Taking various factors into account is essential when making a benefit assessment for a pedestrian bridge. This paper establishes an integrated benefit evaluation method for pedestrian bridges. Factors that influence integrated benefits are classified into four categories: traffic, environment, resource, and maintenance. According to these factors, five evaluation indexes, which include vehicle delay profit and loss value (PLV), pedestrian delay PLV, exhaust emission PLV, fuel consumption PLV, and greening maintenance cost, were introduced into the benefits evaluation. Three methods were used to obtain these factors: traffic simulation, a mathematical model, and empirical values. Finally, an example is demonstrated to verify this method, and the results show that the method is reliable in practice.  相似文献   

13.
Parameterization strategy impacts models' outputs and the associated uncertainty. This is particularly true for transient regional groundwater models where parameters can only be weakly constrained by insufficient observations. However, this is rarely investigated under any particular model structure. This study bridges this gap using a regional groundwater model developed to understand the impact of coal seam gas extraction on groundwater systems in a probabilistic framework. Two different parameterization schemes were implemented for hydraulic conductivity and specific storage. The first method solely relies on the relationship between hydraulic properties and burial depths. The second more complex strategy allows more spatial variations of hydraulic parameters using pilot points. The study provides new insights and practical guidance on the application of groundwater modelling for environmental impact assessment. The results suggest that the choice of model parameterization has a significant influence on predictive uncertainty. The model using the simple parameterization provides predictions with a much wider range than the model with a more sophisticated parameterization. This is because that the lowly parameterized model tends to generate more extreme effective hydraulic parameter fields unless the parameterization simplification converts the inverse problem to a (close to) well-posed problem that rarely exists for applied regional groundwater modelling. The potential impact of model parameterization should be discussed explicitly in groundwater modelling applications to support decision making to avoid misinterpretation of the modelling results.  相似文献   

14.
根据高风险移动放射源辐射安全风险特点与辐射事故经验反馈,结合辐射安全监管部门和企业实际,在充分调研的基础上,构建高风险移动放射源辐射安全风险管控评价指标体系,体系分为目标层、准则层和方案层,准则层8项指标,方案层40项指标。采用层次分析法确定各指标权重,运用模糊综合评价方法对甘肃省7家高风险移动放射源企业进行评价,结果表明决策层指标权重较大,与实际情况相符。  相似文献   

15.
The slacks-based measure (SBM) model based on the constant returns to scale has achieved some good results in addressing the undesirable outputs, such as waste water and water gas, in measuring environmental efficiency. However, the traditional SBM model cannot deal with the scenario in which desirable outputs are constant. Based on the axiomatic theory of productivity, this paper carries out a systematic research on the SBM model considering undesirable outputs, and further expands the SBM model from the perspective of network analysis. The new model can not only perform efficiency evaluation considering undesirable outputs, but also calculate desirable and undesirable outputs separately. The latter advantage successfully solves the "dependence" problem of outputs, that is, we can not increase the desirable outputs without producing any undesirable outputs. The following illustration shows that the efficiency values obtained by two-stage approach are smaller than those obtained by the traditional SBM model. Our approach provides a more profound analysis on how to improve environmental efficiency of the decision making units.  相似文献   

16.
This is the second part of the study on sensitivity analysis of the technique for order preference by similarity to ideal solution (TOPSIS) method in water quality assessment. In the present study, the sensitivity of the TOPSIS method to the index input data was investigated. The sensitivity was first theoretically analyzed under two major assumptions. One assumption was that one index or more of the samples were perturbed with the same ratio while other indices kept unchanged. The other one was that all indices of a given sample were changed simultaneously with the same ratio, while the indices of other samples were unchanged. Furthermore, a case study under assumption 2 was also carried out in this paper. When the same indices of different water samples are changed simultaneously with the same variation ratio, the final water quality assessment results will not be influenced at all. When the input data of all indices of a given sample are perturbed with the same variation ratio, the assessment values of all samples will be influenced theoretically. However, the case study shows that only the perturbed sample is sensitive to the variation, and a simple linear equation representing the relation between the closeness coefficient (CC) values of the perturbed sample and variation ratios can be derived under the assumption 2. This linear equation can be used for determining the sample orders under various variation ratios.  相似文献   

17.
The municipal solid waste management (MSW) evaluation is usually evaluated in subjective and qualitative in nature described in linguistic information; it is very difficult for expert groups to express the preferences using exact numerical values. A MSW expert group is consulted in order to mirror how government officials might reach a cause-effect model regarding MSW management in Metro Manila. A critical issue regarding this is how the expert group can better evaluate the MSW management criteria in uncertainty. A cause and effect model development can help the processing of decision making problem. The Decision Making Trial and Evaluation Laboratory (DEMATEL) not only can convert the relations between cause and effect of criteria into a model but also can be used as a way to handle the inner dependences within a set of criteria. The post survey is further discussed and proved the validity result.  相似文献   

18.
Cultural heritage is being addressed by a number of charters and conventions and it is clear that its consideration within decision-making processes is progressively becoming a real challenge, both for developers and public authorities. Against this background, this paper reviews the environmental assessment framework developed by the European Community, as this should increasingly influence decision making about cultural heritage in an urban setting. The legislative framework for access to environmental information is also reviewed because of its relevance to the decision-making process.The Directives on Environmental Impact Assessment and Strategic Environmental Assessment both require a consideration of cultural heritage in decision making. This requirement can go some way to addressing the paradox in the European Community's position whereby the community wishes to conserve and enhance its own cultural identity whilst, at the same time, cultural heritage is usually defined at a local level. The present paper suggests that, given their flexibility, the two European Community directives on environmental assessment constitute a promising opportunity to address this seeming paradox, but that there is a significant gap between legal obligations and the methodological tools to meet them.  相似文献   

19.
Harmonization exercises organized by the European Communities in the 1970s on biological water assessment methods for running waters, because the usual methods were difficult or impossible to apply, explicitly stressed the need for development of standardized sampling procedures for monitoring large and deep rivers and canals. To meet this objective, an extensive monitoring campaign was organized in Belgium and The Netherlands to test the efficiency of artificial substrates colonized by macroinvertebrates as an alternative for natural communities sampled with a handnet. Two types of artificial substrates were tested: a Belgian substrate, composed of a plastic netting filled with medium-sized pieces of brick, and a Dutch substrate consisting of a stainless steel box filled with marbles. The collected biocoenoses were compared qualitatively and quantitatively. Water quality was assessed by means of several biotic indexes. The results show that both the Belgian and the Dutch artificial substrate sampler can replace the usual samples obtained by means of a handnet, and provide a correct assessment. A major drawback of the use of artificial substrates in uncontrolled monitoring sites remains the unforeseen losses. For that reason the cost price of the substrates may have to be considered when making a selection.  相似文献   

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