共查询到20条相似文献，搜索用时 109 毫秒
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基于聚类分析和判别分析探讨了河流水质空间分析方法,旨在识别采样点的空间相似性与差异性,从而为水质监测网络优化提供支持。该方法首先利用kurtosis和Skewness检验数据分布特征和进行数据对数转化与标准化处理;然后利用聚类分析进行空间相似性分析,确定空间尺度分类情况;最后利用判别分析识别显著性污染指标,以此反映上述空间尺度分类的差异性。以香港后海湾水质管制区为例,结果表明:①通过对数转化显著改善数据分布特征,使绝大部分污染指标呈正态或接近正态分布;②该区域采样点在个案链锁距离与最大链锁距离之比(Dlink/Dmax)×100<35处明显分为3类,它们分别代表轻度、中度、重度污染3种类型,且后两者属于采样点主要属于营养盐和重金属污染类型,需要控制其生活污水、畜牧污染、工业污染和地表径流污染;③后退式判别分析具有良好的指标降维能力,仅需7个显著性污染指标(pH,NH3-N,NO3-N,F.coil,Fe,Ni和Zn)可以反映整体水质的空间差异性,且具有90.65%的正确判别能力;④归纳起来,从3类采样点中选择一个或多个、监测7个显著性污染指标即可全面反映后海湾水质管制区的水质空间特征,实现水质监测网络优化。 相似文献
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通过对北京市平原区监测数据分析显示,电导率和溶解性总固体之间相关系数R2大于0.9,具有较好的相关性,可以通过建立二者之间的线性回归方程对溶解性总固体值进行预测,精度较高。第四系松散孔隙水系统的6个子系统内数据的单独分析显示,对于不同的地下水系统二者之间的相关性不同,预测的精度也不同。用各子系统内数据单独建立的线性回归方程预测出的值相对误差更低。并且当地下水埋藏类型不同时,其相关性也不同,承压水预测的数据更准确。该方法对地下水水质监测工作者,提供一种在野外快速获取可信度较高的溶解性总固体的方法,达到监测出溶解性总固体数据异常点和超标点的快速反应,有针对性的调查,为地下水溶解性总固体质量评价增加准确性。 相似文献
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根据浑河流域的遥感影像获得的数据和景观格局指数统计结果,对浑河水质与景观指数之间相关性进行分析,结果表明:浑河的景观格局指数与水质之间存在相关性,水质的不同指标,与景观格局间的相关性指标程度不同,在一定程度上反映了景观格局对浑河水质的不同影响。 相似文献
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《地下水》2021,(2)
基于天津市东丽区某简易生活垃圾填埋场地下水水质检测数据,对该区域地下水水质自动监测方法进行研究。利用SPSS软件对污染物指标进行因子分析,筛选电导率、浊度和氨氮作为地下水自动监测指标,同时结合地下水监测井口径小,定期洗井和高浓度污染物对监测设备的腐蚀影响等因素,设计了井外自动监测采样系统来实现对垃圾填埋场地下水的监测。对监测结果分析可知:地下水潜水含水层最易受到垃圾填埋场的影响,而承压含水层受影响相对较小,通过水质指标的因子分析结果选择电导率、浊度和氨氮作为垃圾填埋场地下水污染自动监测指标是合适的。研究结果为垃圾填埋场自动在线监测预警提供了技术支持和参考依据。 相似文献
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在现存地下水监测网站中,观测站点分布的任意性、随意性和层次不清以及观测数据的冗余性等问题普遍存在,应用空间聚类原理,对所选研究区域廊坊地下水的监测点位及监测指标分别进行了空间聚类分析,对原始数据和经聚类处理后的数据分别进行了空间变异性评价,结果显示空间聚类分析是有效合理的。试图将空间变异性和空间聚类方法结合起来,为环境监测点的重新布置提供了理论依据,使提高监测效率与监测点的代表性、优化监测网格成为了可能;了解监测指标及监测点位在空间上的相关程度,为环境监测指标的确定提供理论依据,进而为环境管理、污染物控制以及环境资源的综合利用提供基础依据。 相似文献
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文章简单介绍了数学分析方法中相关性分析、聚类分析、因子分析的算法原理,并利用该方法对嘎拉勒外围和躬琼左波两条剖面的岩石地球化学数据进行了处理。对样品进行了R型聚类分析和R型因子分析,并对样本进行了Q型聚类分析和Q型因子分析。所测结果结合矿物学相关知识对矿床成因进行分析,并对分析结果与前人对该矿床的认识进行拟合。从而得出R型因子分析和聚类分析对矿床成因可做某种程度的解释,Q型因子分析和聚类分析对深部岩体预测具有部分解释作用。 相似文献
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水质遥感监测方法可以反映水质在空间和时间上的分布情况和变化,满足目前对水质调查实时、大尺度的评价要求。文章以云南抚仙湖星云湖为研究区,将实测的叶绿素a浓度、悬浮物含量和MODIS遥感数据各波段比值进行相关分析,结果表明:MODIS数据250m分辨率的r2/r1的波段组合能够较好地反演叶绿素a浓度,而500m分辨率的(r4-r3)/(r4+r3)的波段组合对于悬浮物浓度的反演能力最好。通过对它们进行回归关系分析,得到适合抚仙湖星云湖的遥感定量模型。 相似文献
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依据1989年至2019年云南大理地区所辖12个气象站点的气候数据和洱海水质监测资料等文献,分析大理地区气候变化特征和洱海富营养化变化趋势,并总结洱海水质综合营养状态指数与降水量、气温的相互关系。结果表明,1989年至2019年期间,大理地区的年平均气温呈波动上升趋势,气候变暖明显,冬季气温升温幅度最大;年降水量总体呈波动下降趋势,秋季降水量减少最为显著。洱海水质的综合营养状态指数及单因子总氮、总磷、高锰酸盐指数等总体呈升高趋势,而水体透明度呈降低趋势;进一步可分成2个阶段,即2003年之前呈快速上升或下降变化趋势;2003年之后呈波动稳定趋势。洱海综合营养状态指数与年平均气温呈正相关,与年降水量呈负相关关系;总氮、水体透明度分别与年平均气温正相关和负相关,与年降水量则呈负相关和正相关;而总磷与冬季平均气温、高锰酸盐指数与夏季或冬季平均气温均呈正相关关系。年内变化上,洱海污染指数、综合营养状态指数在最近的2015—2019年期间呈现6—10月份明显增高,显示非汛期水质明显好于汛期状况。总之,1989—2019年期间,受大理地区气温升高、降水量减少导致入湖水量减少的影响,洱海综合营养状态指数呈升高趋势,湖泊富营养化进程加剧状况没有得到改善,洱海水环境仍然比较脆弱。 相似文献
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沱江是长江流域上游最重要的支流之一,为了明晰沱江流域水质时空变化特征和防治重点,根据2010—2017年沱江流域36个监测断面水质监测数据,采用单因子评价法和秩相关系数法,从年份、月份、季度和水期4个时间段进行了分析.结果表明:沱江流域水质状况总体上污染较重,但有向好趋势,总磷(TP)为首要污染物,流域断面达标率呈先上升后下降复上升的趋势;水质指标浓度年内变化显著,水质指标浓度丰水期达到最小值,枯水期达到最大值;沱江干流监测断面水质类别好于支流;TP和氨氮(NH3-N)浓度空间变异性较弱,化学需氧量(COD)和生化需氧量(BOD5)浓度则存在较强空间变异性.虽然沱江流域水质有变好趋势,但沱江流域面临的污染问题依然严峻,今后要高度重视污染源治理,尤其是TP的防治工作. 相似文献
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Zhongwu Li Yong Fang Guangming Zeng Jianbing Li Qi Zhang Qingshui Yuan Yamei Wang Fangyi Ye 《Environmental Geology》2009,58(1):101-107
Selecting the Liuyanghe River watershed as an example, using monitoring data of water quality of nearly 10 years and the improved
synthesis pollution index method to evaluate the water quality, the research studied the temporal and spatial characteristics
of surface water quality of a typical basin in the red soil hilly region, and analyzed reasons for the surface water quality
change. The results indicated the improved synthesis pollution index had a better serviceability than other methods, such
as, Pollution Index method, Fuzzy Evaluation method, Grey-System method etc. As for the temporal characteristic, because of
no-point source pollution, the water quality of Liuyanghe River watershed had become a more and more serious problem over
a ten-year period. The spatial characteristic indicated that the pollution degree increased from upstream to downriver. Water
quality upstream was better, and the content of the heavy metals was higher in the middle of the river, and the pollution
of ammonia nitrogen intensified downriver. The result suggested the improved universal pollution index could be used in the
assessment of the water environment. 相似文献
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该文给出了 Q 型聚类分析的原理和计算方法,并结合清凉泉水源地的污染问题进行了研究。通过长系列的水质监测资料,查明了清凉泉水源地水质动态变化特征,并对特征污染因子进行了聚类分析,基本查明了清凉泉水源地的污染途径,得到了较满意的结果。 相似文献
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Spatial characteristics of surface water quality in the Haicheng River (Liao River basin) in Northeast China 总被引：2，自引：1，他引：1
Spatial variations of the water quality in the Haicheng River during April and October 2009 were evaluated for the national monitoring program on water pollution control and treatment in China. The spatial autocorrelation analysis with lower Moran’s I values displayed the spatial heterogeneity of the 12 physicochemical parameters among all the sampling sites of the river. The one-way ANOVA showed that all variables at different sampling sites had significant spatial differences (p < 0.01). Based on the similarity of water quality characteristics, cluster analysis grouped the 20 sampling sites into three clusters, related with less polluted, moderately polluted and highly polluted sites. The factor analysis extracted three major factors explaining 76.4 % of the total variance in the water quality data set, i.e., integrated pollution factor, nitrogen pollution factor and physical factor. The results revealed that the river has been severely polluted by organic matter and nitrogen. The major sources leading to water quality deterioration are complex and ascribed to anthropogenic activities, e.g., domestic and industrial wastewater discharges, agricultural runoff, and animal rearing practices. 相似文献
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Application of meteorological and vegetation indices for evaluation of drought impact: a case study for Rajasthan, India 总被引：3，自引：1，他引：2
Drought is a serious climatic condition that affects nearly all climatic zones worldwide, with semi-arid regions being especially
susceptible to drought conditions because of their low annual precipitation and sensitivity to climate changes. Drought indices
such as the standardized precipitation index (SPI) using meteorological data and vegetation indices from satellite data were
developed for quantifying drought conditions. Remote sensing of semi-arid vegetation can provide vegetation indices which
can be used to link drought conditions when correlated with various meteorological data based drought indices. The present
study was carried out for drought monitoring for three districts namely Bhilwara, Kota and Udaipur of Rajasthan state in India
using SPI, normalized difference vegetation index (NDVI), water supply vegetation index (WSVI) and vegetation condition index
(VCI) derived from the Advanced Very High resolution Radiometer (AVHRR). The SPI was computed at different time scales of
1, 2, 3, 6, 9 and 12 months using monthly rainfall data. The NDVI and WSVI were correlated to the SPI and it was observed
that for the three stations, the correlation coefficient was high for different time scales. Bhilwara district having the
best correlation for the 9-month time scale shows late response while Kota district having the best correlation for 1-month
shows fast response. On the basis of the SPI analysis, it was found that the area was worst affected by drought in the year
2002. This was validated on the basis of NDVI, WSVI and VCI. The study clearly shows that integrated analysis of ground measured
data and satellite data has a great potential in drought monitoring. 相似文献
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A quality study of the drained water from Maddhapara Granite Mine underground tunnel was undertaken to study their hydrochemical variations and suitability for various uses employing chemical analysis, basic statistics, correlation matrix (r), cluster analysis, principal component/factor analyses, and ANOVA as the multivariate statistical methods. The results of chemical analysis of water show the modest variation in their ionic assemblage among different sampling points of the tunnel where Ca–HCO3 type of hydrochemical facies is principally dominated. The correlation matrix shows a very strong to very weak positive, even negative, correlation relationship, suggesting the influence of different processes such as geochemical, biochemical processes, and multiple anthropogenic sources on controlling the hydrochemical evolution and variations of water in the mine area. Cluster analysis confirms that cluster 1 contains 68.75% of total samples, whereas cluster 2 contains 31.25%. On the whole, the dominated chemical ions of first cluster groups are Ca and HCO3, suggesting a natural process similar to dissolution of carbonate minerals. The second cluster group consisted of Cl? and SO4 2? ions representing natural and anthropogenic hydrochemical process. The results of PCA/FA analysis illustrate that different processes are involved in controlling the chemical composition of groundwater in the mine area. The factor 1 loadings showed that pH, EC, TDS, Na, Mg, chloride, and sulfate which have high loading in this factor are expected to come from carbonate dissolution to oxidation conditions. One-way ANOVA describes the significance of dependent variables with respect to independent variables. ANOVA gives us the idea that EC, K+, Fetotal, SO 4 2 , As, and Pb are the most important factors in controlling spatial differences in water quality in this tunnel. But different results have been encountered for different independent variables which might be due to dissimilar sources of water. From the qualitative analysis, it is clear that water quality is not very favorable for aquatic creatures as well as for drinking purposes. The water can be used for irrigation purposes without any doubt as SAR and RSC analysis provides good results. Moreover, the results of this research confirmed that the application of multivariate statistical analysis methods is apposite to inferring complex water quality data sets with its possible pollution sources. At the end, this research recommends (1) as water becomes more and more important, water treatment plants should be built before the water being used; (2) a detailed water step utilization plan should be set beforehand to guarantee tunnel water being used effectively; and (3) after the water being used for agriculture, elements in crops should be monitored continuously to ensure that ions and compounds that come from the tunnel water are lower than guideline values for human beings health. 相似文献