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1.
Periphyton colonization and sediment bioassessment were used ina survey to compare the relative environmental condition ofsampling sites located in Florida Bay and four peripheral sloughareas during the summer of 1995. Periphyton biomass, pigmentcontent, tissue quality and community composition weredetermined. In addition, benthic community composition and thetoxicities of whole sediments and associated pore waters weredetermined for two species of rooted macrophytes, an epibenthicinvertebrate and bioluminescent bacteria. Several locational differences were observed for the response parameters.Periphyton biomass was significantly greater in the Taylor Riverand the least in Shell Creek (P < 0.05). Most sediments were notacutely toxic to mysid shrimp nor phytotoxic. However, sedimentsfrom the Taylor River were more phytostimulatory than others (P< 0.05). Contaminant bioresidues were similar at most sites,however, mercury, chromium and nickel concentrations weregreater for periphyton colonized in the Taylor River and TroutCreek areas. Structural characteristics of the periphytic algalcommunity usually were statistically similar but a consistenttrend of lower density and diversity was evident for ShellCreek. The benthic community was the least diverse and dense inthe Canal C-111. The results of this study provide an initialindication of differences in the role of several slough areas aspossible sources of bioavailable contaminants to Florida Baywhich warrants additional investigation.  相似文献   

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3.
为了比较差减法和直接法对水中总有机碳测定结果,分别配制差减法和直接法的工作曲线,并分别通过差减法和直接法对不同水体中的总有机碳含量进行测定。比较测定结果,发现差减法和直接法对较清洁水体样品的TOC测定结果误差不大,而对废水样品的TOC测定结果误差较大。  相似文献   

4.
在企业污染源现场实现污染物排放浓度水平的快速判定和超标风险筛查,对生态环境管理部门提高执法效率、企业提高环境管理水平意义重大。铅是一种对人体危害极大的有毒重金属,目前缺少含铅废气中铅及其化合物的便携式直读检测设备和检测方法。探索性地将X射线荧光光谱(XRF)法应用于铅蓄电池企业含铅废气中铅及其化合物的便携式快速、直读检测。研究结果表明,基于XRF的面密度法适用于铅蓄电池企业含铅废气处理设施后铅及其化合物的快速、直读检测,相对国标方法具有快速、直读、对样品无损、便于复测等特点,可用于铅及其化合物排放浓度水平的快速判定和超标风险筛查。  相似文献   

5.
总有机碳测定的方法分为差减法和直接法。现对测定方法进行改进,将差减法和直接法测定结果结合,先将样品进行酸化初步吹扫,再使用差减法测定总有机碳。试验结果显示,无论在标准曲线、精密度试验、加标回收试验还是标准样品测定方面,改进法均优于直接法测定结果,且能较好地缩短测量时间。  相似文献   

6.
炸药废水中TNR含量直接光度法测定的研究   总被引:2,自引:0,他引:2  
以三硝基间苯二酚 ( TNR)溶于水后 ,溶液呈现出明显的亮黄色 ,据此直接用光度法对炸药废水中 TNR的含量进行了测定 ,并论证了光度法的测试条件。同时以消解测氮法进行印证 ,结果表明方法具有可行性  相似文献   

7.
The productivity of forest sites has been indirectly determined with solo wood production objective in forest management. Forest site productivity should, however, be determined directly in order to implement ecosystem based multipurpose forest management philosophy. This article tackles the problem in distinguishing and mapping forest sites using both direct method and indirect method in Genya Mountain located in central of Artvin State Forest Enterprise. About 112 sample plots were designed and distributed over the area. In each sample plot, soil samples were collected and the classical timber inventory measurements were taken. According to direct method, Soil Moisture Regime (SMR) method is preferred due to a water deficiency in the study area. Water holding capacity was used as an essential criterion for the classification of the forest site. Forest site classifications were assigned regarding the physiographic factors such as landform, aspect, and slope. Five different forest sites classes; dry, moderate fresh, fresh, humid and hygric were determined. According to direct method, the guiding curve was used to generate anamorphic site index (SI) equations and three site index classes; good (SI=I–II), medium (SI=III) and low (SI=IV–V) were determined. Some important differences between the methods were realized. The forest sites determined with site index estimation method indicate that site index I and II is 505.99 ha, III 1095.79 ha and IV and V 992.95 ha, whereas forest sites determined with direct method related to dry site of 937.58 ha, moderate fresh site of 931.90 ha, fresh site of 1,797.71 ha, humid site of 80.48 ha and hygric site of 356.55 ha. The forest site maps of both methods were created using GIS functions. The forest sites of open and degraded areas should be determined according to direct method.  相似文献   

8.
介绍了直接吸收显色法分析水质硫化物中,气体分离管在实际操作中存在的缺点和氢氧化钾溶液替换气体分离管的优点,并通过实验来论证替换的可行性。  相似文献   

9.
Propagation of the oil spilling from a damaged oil tanker is considered in a limited sea area. The accident consequences are evaluated by means of direct and adjoint oil concentration estimates in ecologically sensitive zones. While the direct estimates are preferable to get a comprehensive idea of the oil spill impact on the whole area, the adjoint ones are useful and economical in studying the sensitivity of the oil concentration in some zones to variations in the accident site and oil spill rate from the tanker. Thanks to special boundary conditions set at the inflow and outflow parts of the open boundary, the main and adjoint oil transport problems are both well-posed according to Hadamard (1923). The estimates obtained in Skiba (1996a) are generalized to the three dimensions. Balanced, absolutely stable 2nd-order finite-difference schemes based on the splitting method are constructed for the two- and three-dimensional cases, both. The main and adjoint schemes are compatible in the sense that at every fractional step of the splitting algorithm, the one-dimensional split operators of both the schemes satisfy a discrete form of the Lagrange identity (Marchuk, 1995). In the special unforced and non-dissipative case, the schemes have two conservation laws each. Each split problem is solved by the factorization method.  相似文献   

10.
For monitoring and controlling the extent and intensity of an invasive species, a direct multi-date image classification method was applied in invasive species (salt cedar) change detection in the study area of Lovelock, Nevada. With multidate Compact Airborne Spectrographic Imager (CASI) hyperspectral data sets, two types of hyperspectral CASI input data and two classifiers have been examined and compared for mapping and monitoring the salt cedar change. The two types of input data are all two-date original CASI bands and 12 principal component images (PCs) derived from the two-date CASI images. The two classifiers are an artificial neural network (ANN) and linear discriminant analysis (LDA). The experimental results indicate that (1) the direct multitemporal image classification method applied in land cover change detection is feasible either with original CASI bands or PCs, but a better accuracy was obtained from the CASI PCA transformed data; (2) with the same inputs of 12 PCs, the ANN outperforms the LDA due to the ANN’s non-linear property and ability of handling data without a prerequisite of a certain distribution of the analysis data.  相似文献   

11.
A method for estimating the impact of industrial emissions is suggested and applied to the Guadalajara City Metropolitan Area (GCMA). The method is based on solutions to the pollution transport model and its adjoint. Two equivalent direct and adjoint mean pollution concentration estimates are considered for ecologically important zones of the GCMA. The dependence of these estimates on the number, positions and emission rates of industrial plants, as well as on the wind and initial pollution distribution in the GCMA is qualitatively and quantitatively examined. It is shown that the adjoint model solutions serve as the influence functions providing valuable information on the role of each of the industrial plants in polluting different zones within the GCMA. These solutions have been calculated with a balanced and absolutely stable second-order finite-difference scheme based on the splitting method. A method for an optimal allocation of a new industrial plant is considered.  相似文献   

12.
Land use/land cover (LULC) has a profound impact on economy, society and environment, especially in rapid developing areas. Rapid and prompt monitoring and predicting of LULC’s change are crucial and significant. Currently, integration of Geographical Information System (GIS) and Remote Sensing (RS) methods is one of the most important methods for detecting LULC’s change, which includes image processing (such as geometrical-rectifying, supervised-classification, etc.), change detection (post-classification), GIS-based spatial analysis, Markov chain and a Cellular Automata (CA) models, etc. The core corridor of Pearl River Delta was selected for studying LULC’s change in this paper by using the above methods for the reason that the area contributed 78.31% (1998)–81.4% (2003) of Gross Domestic Product (GDP) to the whole Pearl River Delta (PRD). The temporal and spatial LULC’s changes from 1998 to 2003 were detected by RS data. At the same time, urban expansion levels in the next 5 and 10 years were predicted temporally and spatially by using Markov chain and a simple Cellular Automata model respectively. Finally, urban expansion and farmland loss were discussed against the background of China’s urban expansion and cropland loss during 1990–2000. The result showed: (1) the rate of urban expansion was up to 8.91% during 1998–2003 from 169,078.32 to 184,146.48 ha; (2) the rate of farmland loss was 5.94% from 312,069.06 to 293,539.95 ha; (3) a lot of farmland converted to urban or development area, and more forest and grass field converted to farmland accordingly; (4) the spatial predicting result of urban expansion showed that urban area was enlarged ulteriorly compared with the previous results, and the directions of expansion is along the existing urban area and transportation lines.  相似文献   

13.
改进密切值法在阳澄湖水质评价中的应用   总被引:2,自引:0,他引:2  
以阳澄湖水质分析为例,利用改进密切值法分别对其东、中、西3个湖区湖体水质进行评价。结果表明,在复杂的湖泊生态系统水质评价中,该方法不仅具有模型构建简便灵活、计算量小、结果直观的特点,而且区别于以往笼统的将不同时段、不同区域湖体水质判断为某一类标准的评价模式,能够客观准确地分析不同时空的水质分布规律,预判水质变化趋势,同时区别于将污染指标等权处理或忽略指标权重的评价方式,通过引进熵权法计算权重判断主要污染因子,使湖泊生态系统水质评价结果更真实合理。  相似文献   

14.
用直接加热代替水浴加热测定高锰酸盐指数   总被引:6,自引:0,他引:6  
在地表水高锰酸盐指数酸性法分析中,通过对2种加热方法的实验对比,结果表明,直接加热法具有省时、省力,且精密度、准确度均能满足环境监测规范要求等优点,特别适用于大批量样品分析。  相似文献   

15.
In this study, an interval-fuzzy two-stage chance-constrained integer programming (IFTCIP) method is developed for supporting environmental management under uncertainty. The IFTCIP improves upon the existing interval, fuzzy, and two-stage programming approaches by allowing uncertainties expressed as probability distributions, fuzzy sets, and discrete intervals to be directly incorporated within a general mixed integer linear programming framework. It has advantages in uncertainty reflection, policy investigation, risk assessment, and capacity-expansion analysis in comparison to the other optimization methods. Moreover, it can help examine the risk of violating system constraints and the associated consequences. The developed method is applied to the planning for facility expansion and waste-flow allocation within a municipal solid waste management system. Violations of capacity constraints are allowed under a range of significance levels, which reflects tradeoffs between the system cost and the constraint-violation risk. The results indicate that reasonable solutions for both binary and continuous variables have been generated under different risk levels. They are useful for generating desired decision alternatives with minimized system cost and constraint-violation risk under various environmental, economic, and system-reliability conditions. Generally, willingness to take a higher risk of constraint violation will guarantee a lower system cost; a strong desire to acquire a lower risk will run into a higher system cost.  相似文献   

16.
高光谱遥感在土壤重金属污染监测中的应用   总被引:2,自引:0,他引:2  
综述了高光谱遥感直接监测土壤重金属污染及利用植被重金属胁迫光谱数据间接监测重金属污染区域的各种方法,分析了反演模型存在的问题,提出了引入人工智能技术、高维矩阵和数据挖掘算法,以及寻求更好的数据同化模型等提高反演精度的后续研究方向。  相似文献   

17.
苏北农村主要水体氮磷污染及防治   总被引:2,自引:0,他引:2  
由于大量使用化肥及排放各类污水已造成苏经农村主要水体搂磷严重污染,并具有氮素富营养型及水文期变化特征。防治污染的方法是采用一些针对性措施对污染严重水域进行直接治理;加强监测,掌握污染动态,推广测土配方的施肥技术;加强对各类污水的治理。  相似文献   

18.
用鱼类急性毒性试验分析死鱼事故原因   总被引:1,自引:0,他引:1  
采用鱼类急性毒性试验方法分析、判断死鱼事故原因,不仅快速、简单、灵敏、直观,社会效益好,而且解决了单用几个理化测试数据,难以分析说明死鱼事故直接原因的难题,适于推广使用。  相似文献   

19.
The flow cytometry (FC) has been used to detect Giardia cysts and Cryptosporidium oocysts quantitatively and instantaneously in this study. The experimental results showed that FC is potential to become a more precise method for the detection of Giardia and Cryptosporidium in water. This study also evaluated the staining efficiencies for three commercial antibodies. After staining Cryptosporidium oocysts with direct immunofluorescent antibodies in water samples, two populations were detected in the scatter-plots (FL1 versus SSC) of the FC. The Cryptosporidium oocysts and Giardia cysts are significantly separated from other particles while stained with direct immunofluorescent antibodies produced by Meridian Diagnostics and WaterborneTM Inc.  相似文献   

20.
作为环境统计的重大改革举措之一,国家重点监控企业环境统计数据直报于2013年开始在全国试运行。随着直报工作的逐步深入,如何在高时效的前提下确保数据质量是直报工作面临的关键问题。归纳了目前学术界对数据质量问题的认识及改进建议,分析了中国现行环境统计数据质量存在的主要问题和原因,结合环境保护部门目前正在试运行的国控源直报系统,客观分析了国控源直报系统在环境数据质量控制方面的具体做法和特点,并针对该项制度在全国层面的进一步实施提出了建议。  相似文献   

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