因子分析及其在河网水质综合评价中的应用研究

对因子分析方法在天然水体水质评价中的应用进行研究，证明在数据较为缺乏的情况下，使用因子分析方法可以损失较少信息，减少评价指标，针对主因子进行分析，使水质评价结果更为合理和有效。同时，利用因子的得分值还可以将不同地区进行比较分析。应用因子分析对河网地区典型河流的水质状况进行分析，发现了增长潜力较大的主要因子，并对该地区的水质状况做出了符合实际的总体评价，表明因子分析在水质评价中具有重要应用价值。     

基于主成分分析法的现有水质评价体系改进探讨

针对中国现行的单因子评价法存在水体过保护问题,在系统分析765个国控河流断面水质状况的基础之上,提出利用主成分分析法(PCA)首先识别河流主要污染指标、再以单因子评价法对主要指标进行水质评价的联合应用方法。将单因子评价法、PCA-单因子评价法的评价结果进行比较,两种方法对河流主要污染指标的识别较一致;将PCA和单因子评价法联合应用于水质评价,能更真实、客观地反映河流水质状况,有利于作出科学管理决策。     

在长江水质评价中某些方法的探讨

水质评价是水源管理的一个基本任务,目前水质评价的一个倾向是用多项水质参数建立水质评价的数学模型,通过模型计算出表征水质优劣的评价指标。一般都认为这种方法能简单又概括地反映水体水质状况,并使于作水体污染地区间或变化趋势的对照比较。所以,近年来国内在对水质评价数学模型的研究方面进展也很快。从模型的性质看,其中多属于所谓     

城市河流水质常规评价技术研究

运用综合水质标识指数法,对我国河流水质评价面临的关键技术问题,包括水质评价方法、水质评价项目,水质级别评价,水环境功能区达标评价、水质定性评价、河流及水系整体水质比较、水质随时间和空间变化等作了明确界定,并介绍了在上海河流水质评价中的应用。     

模糊综合评价在天然水体水质评价中的应用研究

采用模糊数学方法,对河网地区面源污染影响较大的代表性河流的水质状况进行综合评价研究。根据监测断面水质污染特点,确定了8个指标作为评价因子,建立了评价因素矩阵,计算出影响因子的权重。在此基础上,提出了模糊综合评价的水质级别,证明该河网地区的污染物主要是氮、磷和有机物。     

基于时域权重矩阵的模糊综合水质评价法及其应用

水质评价作为合理开发和保护水资源的一项重要工作,越来越受到人们重视。传统的模糊综合水质评价方法因未考虑到水质指标权重的季节变化而可能影响评价结果,故对水质指标权重向量进行了改进,提出了时域权重矩阵的概念,并将实测权重向量与时域权重矩阵相结合,进行组合赋权,得到综合权重向量。应用改进的模糊综合评价方法对某引水明渠水质进行综合评价,结果相比于传统模糊综合水质评价法更符合实际。     

模糊综合评价在天然水体水质评价中的应用研究

采用模糊数学方法，对河网地区面源污染影响较大的代表性河流的水质状况进行综合评价研究。根据监测断面水质污染特点，确定了8个指标作为评价因子，建立了评价因素矩阵，计算出影响因子的权重。在此基础上，提出了模糊综合评价的水质级别，证明该河网地区的污染物主要是氮、磷和有机物。     

溶解氧水质质量系数的倒数处理

目前,在评价水质时,溶解氧是个很重要的指标,它反映出水体的污染状况。本文在采用水质质量参数法进行水质评价时,对溶解氧进行倒数处理,用以判断水质状况。 具体步骤如下: 选择的评价参数有:溶解氧、化学耗氧量、氰化物、氟化物、氨氮、挥发酚等六项。 评价模式:     

基于感官指数的城市水体景观功能评价

针对城市水体以景观功能为主的典型特点,以及与此对应评价方法的缺失,以昆明翠湖为研究对象,提出了基于感官指数的城市水体景观功能评价方法。选择反映藻类繁殖状况的总氮(TN)、总磷(TP)、叶绿素(Chl-a)和反映感官性状的透明度(SD)等4个单一指标综合为感官指数,作为景观水质评价因子,结合国内外现有水质标准中涉及到的4个指标的标准值,建立适宜的景观水质评价标准。采用灰色聚类分析法对第三方水质监测数据和指标标准值进行数学解析与拟合。结果表明,该方法的评价结果能很好的反映水体的景观功能现状,并能有效研判同一水体不同区域的景观水质现状,为污染源的解析提供依据。研究成果为城市水体景观功能水质状态评价提供了新的方法和典型案例。     

秋季艾比湖流域水质综合分析与评价

河流综合水质评价是水环境治理中的基础性工作。于2014年10月在艾比湖流域的55个采样点采集地表水样,将pH、COD、溶解氧(DO)作为评价因子,采用单因子污染指数法、内梅罗污染指数法和综合污染指数法进行了水质评价,并探讨了艾比湖流域的总体污染状况。结果表明:(1)艾比湖流域4种水体污染程度为河流裸露湖床水库农田灌溉水;(2)艾比湖流域中部区域的水质污染最严重,西部和东部区域的水质仍处于清洁状态。本研究为干旱区流域地表水资源的治理与保护提供参考依据。     

基于因子分析法优选河流水体中氮浓度预测方法的研究

定量的河流水体中氮浓度预测方法有很多种,如何优选出预测精度较高的方法一直是学术界多年来致力于研究的重点。本研究采用因子分析法对预测方法的精度评价指标进行分析,并建立了预测方法精度的评价模型,对回归分析法、神经网络法、灰色系统法和增长率统计法4种水体氮浓度预测方法进行综合评估,优选出精度较高的河流水体氮浓度预测模型——BP神经网络预测模型。结果表明,此评估模型对类似研究具有一定的参考价值,能为选择出合适的河流水体氮浓度预测方法提供依据。     

Assessment and rationalization of water quality monitoring network: a multivariate statistical approach to the Kabbini River (India)

The establishment of an efficient surface water quality monitoring (WQM) network is a critical component in the assessment, restoration and protection of river water quality. A periodic evaluation of monitoring network is mandatory to ensure effective data collection and possible redesigning of existing network in a river catchment. In this study, the efficacy and appropriateness of existing water quality monitoring network in the Kabbini River basin of Kerala, India is presented. Significant multivariate statistical techniques like principal component analysis (PCA) and principal factor analysis (PFA) have been employed to evaluate the efficiency of the surface water quality monitoring network with monitoring stations as the evaluated variables for the interpretation of complex data matrix of the river basin. The main objective is to identify significant monitoring stations that must essentially be included in assessing annual and seasonal variations of river water quality. Moreover, the significance of seasonal redesign of the monitoring network was also investigated to capture valuable information on water quality from the network. Results identified few monitoring stations as insignificant in explaining the annual variance of the dataset. Moreover, the seasonal redesign of the monitoring network through a multivariate statistical framework was found to capture valuable information from the system, thus making the network more efficient. Cluster analysis (CA) classified the sampling sites into different groups based on similarity in water quality characteristics. The PCA/PFA identified significant latent factors standing for different pollution sources such as organic pollution, industrial pollution, diffuse pollution and faecal contamination. Thus, the present study illustrates that various multivariate statistical techniques can be effectively employed in sustainable management of water resources. Highlights ? The effectiveness of existing river water quality monitoring network is assessed ? Significance of seasonal redesign of the monitoring network is demonstrated ? Rationalization of water quality parameters is performed in a statistical framework     

Study on the dynamics of algal bloom and its influence factors in Tolo Harbour, Hong Kong.

In this paper, the semi-enclosed bay named Tolo Harbour and Channel in Hong Kong, which was frequently attacked by red tides, was used as a case study. Data sets related to marine water quality, river nutrients, and meteorological conditions recorded between 1988 and 1999 were chosen for statistical analysis. A multivariate analysis showed that algal growth, represented by the chlorophyll a concentration, had obvious spatial and temporal variations in the study area. The chlorophyll a concentration had a consistently decreasing trend from the inner part of the Harbour and surface waters to the outer part and bottom waters. The temporal variations had a markedly seasonal variation with high bioproductivity in spring and winter. There were long-term fluctuations in the chlorophyll a concentration with a high-low-high pattern in the study period. Nutrients and hydrological and meteorological conditions were important factors of algal bloom. Besides nitrogen, which was the most critical factor of algal bloom for the whole water body, total phosphorus in the surface waters and phosphate (PO4) and silica (SiO2) in the bottom waters also showed strongly positive or negative correlations with the chlorophyll a level. For the meteorological conditions, global solar radiation was the key factor of massive algal bloom in the study period, while rainfall and wind direction were the most important factors of seasonal variation.     

Temporal and spatial variations in the relationship between urbanization and water quality

With the development of economy, most of Chinese cities are at the stage of rapid urbanization in recent years, which has caused many environmental problems, especially the serious deterioration of water quality. Therefore, the research of the relationship between urbanization and water quality has important theoretical and practical significance, and it is also the main restriction factor in the urbanization advancement. In this work, we investigated the impact of urbanization on the water quality of the nearby river. We established a comprehensive environmental assessment framework by combining urbanization and water quality, and one model was designed to examine the impact of urbanization on the water quality in Jinan from 2001 to 2010 with factor component analysis. The assessment of urbanization level was accomplished using a comprehensive index system, which was based on four aspects: demographic urbanization, economic urbanization, land urbanization, and social urbanization. In addition, synthetic pollution index method was utilized to assess the water pollution of Xiaoqing River in the study area. Through the analysis of regression curves, we conclude that (1) when the urbanization level is below 25 %, the relationship is low and irregular; (2) if the urbanization level varies between 25 and 40 %, there will be an irreversible degradation of stream water quality; (3) there is a positive correlation between urbanization and pollution levels of urban river after the adjustment period; and (4) land and demographic aspects have the highest independent contribution. This study is a useful reference for policymakers in terms of economic and environmental management.     

Organic pollutants in the Odra river ecosystem

The paper presents the results of the analysis of water and bottom sediment samples from different locations along the Odra river, collected during eight campaigns in the years 1997-2000. All the basic organic pollutants were determined. Pollution of water with PCBs was negligible while with PAHs was not critical. Concentrations of volatile organochlorine compounds in water were the highest in Brzeg Dolny and its surroundings. Concentrations of tetrachloroethene were exceptionally high in the Szczecin Lagoon. The Odra sediments were non-polluted or only slightly polluted with PCBs, pesticides and different classes of volatile organic pollutants. However, PAHs were present in rather large concentrations, especially in the upper course of the Odra river. The data obtained contributed to the evaluation of pollutants discharges to the Baltic sea via Szczecin Lagoon as well as to the characterization of pollution sources (point sources and area sources) in the Odra catchment area.     

粤西某市小容量河流水污染综合控制研究

对粤西某石化城河段几种主要污染物进行了容量计算 ,发现即使工业污染源全部达标 ,其水质状况与目标的差距仍较大 ,据此提出小容量河流的观点。为保护水环境 ,结合流域实际情况 ,本文提出改变以往单纯依靠工业污染源达标控制手段 ,而采用多手段相结合的综合管理模式来改善水环境的观点 ,并以中长期水环境规划年内目标值为依据 ,分析了本方法的有效性、经济性和可操作性 ,由此对其他具相似条件小容量河流的城市水环境管理起到借鉴性作用。     

Characterising the hydrological regime of an ungauged temporary river system: a case study

Temporary streams are characterised by specific hydrological regimes, which influence ecosystem processes, groundwater and surface water interactions, sediment regime, nutrient delivery, water quality and ecological status. This paper presents a methodology to characterise and classify the regime of a temporary river in Southern Italy based on hydrological indicators (HIs) computed with long-term daily flow records. By using a principal component analysis (PCA), a set of non-redundant indices were identified describing the main characteristics of the hydrological regime in the study area. The indicators identified were the annual maximum 30- and 90-day mean (DH4 and DH5), the number of zero flow days (DL6), flow permanence (MF) and the 6-month seasonal predictability of dry periods (SD6). A methodology was also tested to estimate selected HIs in ungauged river reaches. Watershed characteristics such as catchment area, gauging station elevation, mean watershed slope, mean annual rainfall, land use, soil hydraulic conductivity and available water content were derived for each site. Selected indicators were then linked to the catchment characteristics using a regression analysis. Finally, MF and SD6 were used to classify the river reaches on the basis of their degree of intermittency. The methodology presented in this paper constitutes a useful tool for ecologists and water resource managers in the Water Framework Directive implementation process, which requires a characterisation of the hydrological regime and a ‘river type’ classification for all water bodies.     

The influence of the scale of mining activity and mine site remediation on the contamination legacy of historical metal mining activity

Globally, thousands of kilometres of rivers are degraded due to the presence of elevated concentrations of potentially harmful elements (PHEs) sourced from historical metal mining activity. In many countries, the presence of contaminated water and river sediment creates a legal requirement to address such problems. Remediation of mining-associated point sources has often been focused upon improving river water quality; however, this study evaluates the contaminant legacy present within river sediments and attempts to assess the influence of the scale of mining activity and post-mining remediation upon the magnitude of PHE contamination found within contemporary river sediments. Data collected from four exemplar catchments indicates a strong relationship between the scale of historical mining, as measured by ore output, and maximum PHE enrichment factors, calculated versus environmental quality guidelines. The use of channel slope as a proxy measure for the degree of channel-floodplain coupling indicates that enrichment factors for PHEs in contemporary river sediments may also be the highest where channel-floodplain coupling is the greatest. Calculation of a metric score for mine remediation activity indicates no clear influence of the scale of remediation activity and PHE enrichment factors for river sediments. It is suggested that whilst exemplars of significant successes at improving post-remediation river water quality can be identified; river sediment quality is a much more long-lasting environmental problem. In addition, it is suggested that improvements to river sediment quality do not occur quickly or easily as a result of remediation actions focused a specific mining point sources. Data indicate that PHEs continue to be episodically dispersed through river catchments hundreds of years after the cessation of mining activity, especially during flood flows. The high PHE loads of flood sediments in mining-affected river catchments and the predicted changes to flood frequency, especially, in many river catchments, provides further evidence of the need to enact effective mine remediation strategies and to fully consider the role of river sediments in prolonging the environmental legacy of historical mine sites.     

Liming of River Audna,Southern Norway: a large-scale experiment of benthic invertebrate recovery

This study describes the recovery of sensitive invertebrates after liming of the anadromous part of River Audna in 1985. The river lost its salmon population during 1960-1970. The aim of the liming was to produce a water quality with pH > 6.0 and ANC > 20 microg L(-1) and to reduce the content of labile aluminum. Highly sensitive invertebrates like the mayfly Baetis rhodani were not found in the river before liming. Two years after liming, several sensitive invertebrate species showed a positive response. B. rhodani was then recorded at 2 sites in the lower part of the river. In the following 5 years several species of sensitive invertebrates recolonized the whole limed reach of the river and became numerous. Ten years after liming the snail Lymnaea peregra was recorded in the river. The dispersa of this species was also very fast and after 5 years it was found at all investigated sites in the limed main river covering a reach of 40 km. Reduced sulfur deposition in the area also resulted in water-quality improvements in th unlimed stretches of River Audna. Comparisons between limed and unlimed localities indicated that the water quality and the critical limits of sensitive species are the ma factors determining the fauna composition in River Audna independent of the reason for the change in water quality.