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1.
This study presents the application of multivariate statistical tools for the evaluation of spatial variations and the interpretation of water quality data obtained in a monitoring program of Lis river basin surface water, Portugal. Twenty-seven physicochemical and microbiological parameters were determined in six water sampling campaigns at 16 monitoring sites during the period from September 2003 to November 2006. Correlation analysis, principal component analysis, and cluster analysis were performed to evaluate the main water pollution sources and to characterize the spatial distribution of water pollution profiles in river basin. The results achieved with the statistical methodologies led to distinguish natural and anthropogenic pollution sources. Additionally, monitoring sites with similar water pollution profile were identified, indicating that some monitoring locations can be changed to improve the spatial characterization of water quality in the river basin. CBO, CQO, P, and N were identified as significant variables affecting spatial variations, namely in the Lis river middle reach. Besides the identification of main pollution sources, the applied statistical tools were able to identify spatial patterns of water pollution in Lis river basin, which further helps in the reassessment of the number and location of monitoring sites.  相似文献   

2.
The aim of this study was to investigate the seasonal and spatial variations in surface water quality at the mid-Black Sea coast of Turkey. The samples were collected from ten monitoring stations including rivers and sea water during the years from 2007 to 2008. The samples were analyzed for 25 parameters: total carbon, total inorganic carbon, total organic carbon, chromium, cadmium, copper, lead, iron, nickel, manganese, phenol, surfactants, ammonium, nitrite and nitrate-nitrogen, total phosphorus, adsorbable organic halogen, sulfate, hardness, dissolved oxygen, pH, temperature, total dissolved solids, electrical conductivity, and salinity. Multivariate statistical techniques, cluster analysis (CA) and factor analysis/principal component analysis (FA/PCA), were applied to analyze the similarities among the sampling sites to identify the source apportionment of pollution parameters in surface waters. The results indicate that seven factors for river water explained 82.24% of the variance. In seawater, seven factors account for 89.65% of the total variance. Varifactors obtained from factor analysis indicate that the parameters responsible for water quality variations are mainly related to organic pollution (municipal effluents), inorganic pollution (industrial effluents and waste disposal areas), nutrients (agricultural runoff), and dissolved salts (soil leaching and runoff process).  相似文献   

3.
为探讨一种适用于大尺度、多断面和长时间的水质评价方法,用系统聚类分析将2000—2002年黄河6个监测断面的90个水质样本分为7组,并用判别分析验证了结果的可靠性。其主要程序为:利用多元方差分析对各断面多年水质监测样本进行空间尺度上的显著差异性分析,识别出具有显著差异的样本,然后通过系统聚类分析把上述样本进行聚类分组,最后应用判别分析方法对各组样本进行水质评价,此方法的特点为在不损失信息的前提下能大大减轻水质评价工作量,且客观可信、分辨率高,并能综合反映总体与个别特征。结果表明,黄河流域干流从上游到下游水质总体状况呈逐渐下降趋势,上游水质一般为Ⅰ-Ⅲ类,而中游和下游水质基本为Ⅳ-Ⅴ类和超Ⅴ类。  相似文献   

4.
Baking and 2‐g mixograph analyses were performed for 55 cultivars (19 spring and 36 winter wheat) from various quality classes from the 2002 harvest in Poland. An instrumented 2‐g direct‐drive mixograph was used to study the mixing characteristics of the wheat cultivars. A number of parameters were extracted automatically from each mixograph trace and correlated with baking volume and flour quality parameters (protein content and high molecular weight glutenin subunit [HMW‐GS] composition by SDS‐PAGE) using multiple linear regression statistical analysis. Principal component analysis of the mixograph data discriminated between four flour quality classes, and predictions of baking volume were obtained using several selected mixograph parameters, chosen using a best subsets regression routine, giving R2 values of 0.862–0.866. In particular, three new spring wheat strains (CHD 502a‐c) recently registered in Poland were highly discriminated and predicted to give high baking volume on the basis of two mixograph parameters: peak bandwidth and 10‐min bandwidth.  相似文献   

5.
6.
A computerized 2‐g direct drive mixograph was used to study the mixing characteristics of flours milled from a range of breadmaking cultivars obtained from five separate locations around the UK, providing 54 flour samples. Fifteen parameters were extracted from each mixograph trace using the Mixsmart software program and correlated with baking volume using partial least squares multiple regression statistical analysis to give a prediction of baking volume. Location had a considerable influence on the prediction of baking volume. Excellent predictions of baking volume were obtained from flours from individual locations (R2 = 0.805–0.995), but predictions based on all cultivars without discriminating locations were poor. When mixograph and baking volume data for each cultivar were averaged over all five locations, a very high correlation was obtained (R2 = 0.999). Preparation of flour samples using rapid, small‐scale milling procedures (Brabender Quadrumat Jr. mill and Perten 3100 hammer mill) did not have any adverse effect on prediction of baking volume. Mixograph parameters obtained from six commercial glutens of varying quality gave good correlations with test baking volumes, based on 6% gluten addition to a control flour.  相似文献   

7.
Two fungal strains producing ligninolytic enzymes and having the potential to decolorize distillery effluent were isolated from the soil of a distillery effluent contaminated site. DNA was isolated from the pure cultures of these fungi and polymerase chain reaction (PCR) amplification of their internal transcribed spacer (ITS) region of nuclear ribosomal DNA was carried out. Further, the DNA was sequenced and the comparison of generated sequence with database led to their identification as Penicillium pinophilum TERI DB1 and Alternaria gaisen TERI DB6 respectively. These two isolates along with one isolate of Pleurotus florida EM 1303 were assessed for their ligninolytic enzyme activity in culture filtrate as well as after solid state fermentation on two substrates wheat straw and corncob powder. Ergosterol was measured to assess the growth of fungi on solid media. Both P. pinophilum TERI DB1 and A. gaisen TERI DB6 were found to produce laccase, manganese-dependent peroxidases (MnP) and lignin peroxidases (LiP). The immobilized fungal biomass was then used for decolorization of the post biomethanated wastewater from the distillery. Reduction in color up to the magnitude of 86, 50 and 47% was observed with P. florida, P. pinophilum and A. gaisen respectively.  相似文献   

8.
秦皇岛市地下水环境质量评价与分析   总被引:5,自引:0,他引:5  
针对秦皇岛市地下水位下降,环境污染日益严重的现实,开展了以海水入侵区为主的地下水质综合评价与分析。在全市境内布设76眼监测井,用单因子法和综合法对地下水质量进行了评价,并对地下水水质变化趋势进行了分析。研究结果表明:Ⅰ类水只占5.3%.Ⅱ、Ⅲ水占14.5%,Ⅳ类及超Ⅳ类水占到80%以上,其中Ⅴ类水占40%。主要污染物有Fe、Mn、NO3-N、Cl、总硬度等。地下水质监测动态变化显示:总硬度、Cl^-、矿化度、F-等呈上升趋势,其中总硬度和Cl^-上升达75X,说明海水入侵的影响很大。  相似文献   

9.
Surface water quality monitoring is one of the responsibilities of a number of provincial and federal environmental departments in Canada. In Saskatchewan, the Ministry of Environment is responsible for the province water quality monitoring network. The sampling effort was initiated 40 years ago and has been ongoing since, with varying degrees of spatial and temporal coverage. The main objective of the Saskatchewan monitoring network is the assessment of ambient water quality status. In addition, one of the main uses of the generated water quality data is the calculation of a Water Quality Index. The adequacy of the monitoring network to perform these tasks needs to be validated. The objective of this study is to provide a statistical assessment of two of the monitoring network main aspects, the water quality variables and their sampling frequency. A new rationalization approach is applied for the assessment and reselection of water quality variables. The proposed approach provides, in a systematic way, the optimal combinations of variables to continue measuring, variables that may be redundant and could be considered for discontinuance, and variables that may need to be added to the list of variables being measured. The confidence interval around the mean is used as the main criterion for the sampling frequency assessment. A design chart is provided for the sampling frequency assessment, which is easy to use, and provides an initial assessment of the number of samples required to provide a mean value with a predefined error percentage.  相似文献   

10.
Eighteen bread wheat (Triticum aestivum L.) and two durum wheat genotypes (Triticum turgidum L.) were used to explore relationship among their morpho-physiological traits. Two separate field experiments were conducted at the Experimental Station, College of Agricultural, Shiraz University. Each experiment was designed as a randomized completed block with three replications. Twenty-five morpho-physiological drought resistance related traits were measured and multivariate statistical techniques were used to consider these relationships. Based on the results of the factor analysis, electrolyte leakage (EL) had the highest positive correlation, while membrane stability index (MSI) had the highest negative correlation with the first factor, canopy temperature depression (CTD). It could be clearly detected that these two variables had high effect on canopy temperature and the genotype with lower EL and higher MSI resulted in lower canopy temperature. This factor also showed that reactive oxygen species (ROS) related traits and plant water relationship related traits had significant effect on CTD. Since yield stability (YS) had the highest coefficient in factor 3, this factor was the most important one showing effective variables on this trait, thus this factor's suggested name was YS. The significant positive correlations with factor 3 were relative water protected (RWP), which is a new index, and cellular membrane stability (CMS). This result clearly shows that new index of RWP can be an efficient indirect criterion to screen higher YS genotypes together with CMS. Cluster analysis grouped variables into three clusters. These results were confirmed by the results of principal and discriminate function analysis. In addition, the results of the factor analysis for considering relationships among measured traits were confirmed through the cluster analysis.  相似文献   

11.
Available (extractable by diethylenetriaminepentaacetic acid, DTPA) manganese (Mn) and zinc (Zn) micronutrient concentrations in acidic agricultural soils from western Greece and their relationships with physicochemical soil parameters were evaluated by sampling and analyzing 82 representative topsoil samples. Manganese concentration in the studied soil samples (on average 31.67 mg kg?1) was of both sufficient and high levels, according to the Ministry of Agriculture, Fisheries, and Food of the United Kingdom (MAFF classification, in 15.9% and 79.3% of the soil samples, respectively). In contrast, 39% of the soil samples were classified as very low and 58.5% as low in respect to the available Zn concentration (on average 1.36 mg kg?1). Nevertheless, 9.8% of the studied soils contained less Zn than is commonly accepted as plant‐growth critical level. The dataset was treated using multivariate statistics to describe the relationships of the micronutrients in the studied soils and the factors that influence these relationships. Factor analysis identified soil acidity as the main factor affecting available Mn concentration and phosphate fertilizer application as the main contributor to plant‐available Zn concentration.  相似文献   

12.
Multivariate statistical analyses were used to assess the contents and distributions of trace elements in agricultural soils in Xinzhou of Shanxi Province, China, and to identify their sources. Samples with high levels of trace elements were concentrated in eastern Xinzhou, with contents declining from the east to west. Principal component and redundancy analyses revealed strong correlations among Co, Cu, Mn, Ni, Se, V, and Zn contents, suggesting that these elements were derived from similar parent materials. There were also strong correlations between the contents of these elements and soil properties. Contents of Cd and Pb were significantly higher in the agricultural soil samples than in the background soil samples (P < 0.05), and were higher in areas with higher levels of gross domestic product but decreased with distance to the nearest road. Therefore, human activities appear to have a strong influence on the Cd and Pb distribution patterns. A novel artificial neural network (ANN) model, using environmental input data, was used to predict the soil Cd and Pb contents of specified test dates. The performances of the ANN model and a traditional multilinear model were compared. The ANN model could successfully predict Cd and Pb content distributions, projecting that soil Cd and Pb contents will increase by 128% and 25%, respectively, by 2020. The results thus indicated that the economic condition of an area has a greater effect on trace element contents and distributions in the soil than the scale of the economy itself.  相似文献   

13.
The aim of this study is to examine the horizantal and vertical spatial changes of soil quality (SQ) in rice-cultivated soils located on the Bafra Deltaic Plain—one of the most important alluvial deltaic plains and production centers of Turkey. The study examines these spacial changes by calculating the soil quality index (SQI) for soils 0–30 cm and 30–60 cm deep. For SQI calculations, seventeen potential physicochemical SQ indicators of eighty-three soil samples were assessed. Quality indicators to be used in these calculations were selected by considering the clay content, correlation relationship, and principal components analysis (PCA) of potential quality indicators. Clay, silt, sand, electrical conductivity (EC), exchangeable calcium (Caexc), and exchangeable magnesium (Mgexc) were selected as quality indicators, and silt was found to be the most important quality indicator for both soil depths. The SQ of researched soils changed from low to high for both soil depths.  相似文献   

14.
非点源污染是生态环境建设中遇到的关键问题之一,本文以四川省盐亭农业生态试验站流域的地下水为例,通过设定降雨量参数,将降雨量与地下水非点源污染负荷联系起来,分别研究了地下水磷素与地下水氮素随降雨量的变化情况。研究发现两个研究区的TP、TN浓度与降雨量的相关性十分明显,相关系数R^2分别为0.987、0.947 5、0.933 1和0.901 8,而其他形态的氮和磷与降雨量的相关性并不明显;另外,研究发现地下水非点源TN污染主要是由于NO3-N浓度变化引起的,地下水非点源磷污染主要是由于颗粒态磷浓度变化引起的。  相似文献   

15.
在滹沱河流域平原区,人类活动和气候变化是造成浅层地下水区域性下降的双重因素,人类活动在浅层地下水从"天然一人工"二元影响转化过程中在时空上经历了怎样的变化,是值得探讨的问题.选用综合指数法,通过筛选人类活动对浅层地下水干扰指标、建立评价体系,对滹沱河流域平原区在不同时代的人类活动对浅层地下水的干扰程度进行了量化研究.研究结果表明,空间上,不同时代都表现出从西部向东部干扰程度逐渐减小;从整个研究区看,干扰程度增大的趋势从西部向东部逐渐推进;干扰程度从分级简单的0~0.4发展到目前0.2~1.0不同级别共存的复杂分布状态.时间上,随着时间的推移,整个研究区的干扰程度都表现出增强趋势,在不同地区增强幅度不一致;人类活动对浅层地下水干扰影响经历了从不占据主导作用→逐渐占据主导作用→几乎完全占据主导作用.  相似文献   

16.
平潭岛地下水脆弱性评价   总被引:2,自引:0,他引:2  
在分析平潭岛地质和水文地质条件的基础上,采用DRASTIC模型法,对岛内地下水系统的脆弱性进行评价。评价结果表明:平潭岛大部分区域地下水脆弱性程度较高,特别是滨海平原区脆弱性程度更高,受污染的可能性很大。希望能为今后开采利用地下水资源提供科学参考。  相似文献   

17.
伊犁河流域土壤盐分与地下水关系的关联分析   总被引:1,自引:0,他引:1  
《土壤通报》2013,(3):561-566
根据2009年伊犁河流域土壤盐分与地下水条件的监测和取样分析资料,运用灰色关联分析法,对伊犁河流域3月、6月、9月与11月的土壤盐分与地下水埋深、矿化度、电导率、pH值与主要离子进行了关联分析。分析研究表明:研究区表层土壤盐分平均含量为1.37 g kg-1,属于轻度盐渍化土壤。地下水矿化度平均值为2.50 g L-1,属于微咸水。在关联排序中,地下水埋深、矿化度、电导率、SO42-、Cl-、Mg2+、Na+与土壤盐分变化的关联性较强;地下水pH、K+与Ca2+与土壤盐分变化的关联度低,均小于0.321;地下水Mg2+含量与土壤盐分关联度最高,为0.606。灌溉对地下水pH、矿化度、电导率、Mg2+、Cl-离子变化的影响不大,而对地下水埋深、Na+、SO42-、K+与Ca2+离子变化的影响较明显。为了防止土壤次生盐渍化,应该加强对地下水中Mg2+、Na+与Cl-离子的控制与管理。  相似文献   

18.
泥石流沟谷因泥石流类型和发育阶段不同而具有多种形态,对其进行研究具有十分重要的理论和实际意义。通过对小江流域32条灾害性泥石流沟的流域面积、主沟长、平均沟床比降、流域平均宽度进行统计分析,得出了几点结论,为泥石流危险度评价和防治工作提供了参考。  相似文献   

19.
虎峪沟泥石流特征及其危险度评价   总被引:2,自引:1,他引:2  
虎峪沟位于山西省太原市西山地区,该区泥石流的发生直接威胁着太原市城西一带居民的生命财产安全。为进一步查清该区泥石流的危害程度,以虎峪沟潜在泥石流为研究对象,在其流域地质坏境调查的基础上,对西山地区构造活动、河流下切形成的复杂地形地貌、自然风化及人类工程活动堆积的松散堆积物物源、不均衡降雨等各种作用相伴生的地质过程进行了研究,并进一步采用危险度评价分析方法对虎峪沟泥石流进行了分析。结果表明,虎峪沟泥石流的危险度Rd为0.768,属高度危险的泥石流沟,若爆发仍将对下游造成威胁。  相似文献   

20.
杨陵区地表水及地下水环境质量评价   总被引:2,自引:1,他引:2  
水在人类的生存过程中起着至关重要的作用,面对目前日愈衰竭的水资源,如何才能提高水质及其利用率已成为人们关注的焦点。现就杨陵地区的地表水及地下水选取不同的断面,实际采样并监测分析。其监测项目涉及到NH4+、NO3-、NO2-、PO43-、F-、S2-、Cr6+、Cu、P  相似文献   

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