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1.
In numerous studies, spatial and spectral aggregations of pixel information using average values from imaging spectrometer data are suggested to derive spectral indices and the subsequent vegetation parameters that are derived from these. Currently, there are very few empirical studies that use hyperspectral data, to support the hypothesis for deriving land surface variables from different spectral and spatial scales. In the study at hand, for the first time ever, investigations were carried out on fundamental scaling issues using specific experimental test flights with a hyperspectral sensor to investigate how vegetation patterns change as an effect of (1) different spatial resolutions, (2) different spectral resolutions, (3) different spatial and spectral resolutions as well as (4) different spatial and spectral resolutions of originally recorded hyperspectral image data compared to spatial and spectral up- and downscaled image data. For these experiments, the hyperspectral sensor AISA-EAGLE/HAWK (DUAL) was mounted on an aircraft to collect spectral signatures over a very short time sequence of a particular day. In the first experiment, reflectance measurements were collected at three different spatial resolutions ranging from 1 to 3 m over a 2-h period in 1 day. In the second experiment, different spectral image data and different additional spatial data were collected over a 1-h period on a particular day from the same test area. The differently recorded hyperspectral data were then spatially and spectrally rescaled to synthesize different up- and down-rescaled images. The normalised difference vegetation index (NDVI) was determined from all image data. The NDVI heterogeneity of all images was compared based on methods of variography. The results showed that (a) the spatial NDVI patterns of up- and downscaled data do not correspond with the un-scaled image data, (b) only small differences were found between NDVI patterns determined from data recorded and resampled at different spectral resolutions and (c) the overall conclusion from the tests carried out is that the spatial resolution is more important in determining heterogeneity by means of NDVI than the depth of the spectral data. The implications behind these findings are that we need to exercise caution when interpreting and combining spatial structures and spectral indices derived from satellite images with differently recorded geometric resolutions.  相似文献   

2.
This paper analyzes how changes in hydrological conditions can affect the water quality of a temporary river that receives direct inputs of sewage effluents. Data from 12 spatial surveys of the Vène river were examined. Physico-chemical parameters, major ion, and nutrient concentrations were measured. Analyses of variance (ANOVA) and multivariate analyses were performed. ANOVA revealed significant spatial differences for conductivity and major ion but no significant spatial differences for nutrient concentrations even if higher average concentrations were observed at stations located downstream from sewage effluent discharge points. Significant temporal differences were observed among all the parameters. Karstic springs had a marked dilution effect on the direct disposal of sewage effluents. During high-flow periods, nutrient concentrations were high to moderate whereas nutrient concentrations ranged from moderate to bad at stations located downstream from the direct inputs of sewage effluents during low-flow periods. Principal component analysis showed that water quality parameters that explained the water quality of the Vène river were highly dependent on hydrological conditions. Cluster analysis showed that when the karstic springs were flowing, water quality was homogeneous all along the river, whereas when karstic springs were dry, water quality at the monitoring stations was more fragmented. These results underline the importance of considering hydrological conditions when monitoring the water quality of temporary rivers. In view of the pollution observed in the Vène river, “good water chemical status” can probably only be achieved by improving the management of sewage effluents during low-flow periods.  相似文献   

3.
This work aimed to evaluate the effect of sewage sludge application as fertilizer on the plasticity of functional characteristics of species commonly found in the Caatinga. The research was developed in the nursery of the Federal Institute of Education, Science and Technology of Ceará (IFCE), Quixadá campus, located in northeastern Brazil. Three treatments were applied: raw sludge, sanitized sludge, and no manipulation. In each treatment, five species were planted, each with five individuals, totaling 75 individuals, which were tagged, and 4 months after germination, they were destroyed to obtain dry matter content (TMSF) from leaf, stem (TMSC), fine root (TMSRF), and thick root (TMSRG); leaf area; height and diameter of the seedling; and length above and below the ground. The sanitized sludge was responsible for giving higher values for leaf area, height of the seedlings, and diameter and length of stem and root. However, the dry matter content of the fine roots was higher in the treatment without manipulation. At the community level, as TMSRG increased, TMSC also increased, the same occurred between TMSRG and TMSRF, TMSC and TMSRF, and stem length and leaf area. In the treatment without manipulation, there was a positive correlation between leaf area, height and plant diameter, and negative correlation between root length and plant diameter. Thus, it can be concluded that the use of sanitized sludge is a good tool to increase the availability of soil resources, conferring to individuals’ greater dry matter content, greater leaf area, and higher height and diameter above the ground.  相似文献   

4.
Contaminated water are recognized as a potential source of Cryptosporidium oocysts. In Italy studies on the environmentalspread of the parasite are still scarce even if a high frequencyof serological responses could suggest high rates of endemic Cryptosporidium infections. In this investigation theoccurrence of the parasite in water samples from a municipalwastewater treatment plant was monitored with the aim to evaluatepossible correlation between oocysts and bacterial indicators,pathogens and physico-chemical parameters using a multivariateanalysis. Data collected showed high numbers of oocysts, with ahigh percentage of positive samples and a significant correlationwith pH, redox potential and total organic carbon. No correlationwas found between Cryptosporidium concentration and that of the other microrganisms. The results, through a probing statistical analysis, show that none of the selected microrganisms was a reliable predictor of the presence of theparasite.  相似文献   

5.
Relationships between natural macrobenthic communities and aquatic environmental conditions have been recently used to perform the Biological Monitoring Water Quality (BMWQ) score system for assessing freshwater quality in the Iberian Peninsula. In this paper, the second version of the BMWQ score system is applied to two selected field studies (organic and nonorganic pollution) in order to illustrate the suitable functional character of this method. The total BMWQ (t-BMWQ) score and the average BMWQ (a-BMWQ) score are calculated, and their relationships with diversity indices are also examined. The BMWQ method appears to be very sensitive to changes in freshwater quality generated by simple organic pollution, but this method appears to be less sensitive to changes generated by complex nonorganic pollution. In addition, both scores are more sensitive measures to assess macroinvertebrate response to organic pollution than total density and diversity indices, exhibiting higher positive coefficients of linear correlation with Camargo's diversity index than with Shannon's and MacArthur's diversity indices. However, the a-BMWQ score is more sensitive to changes in family composition than the t-BMWQ score, whereas this latter score is more sensitive to family richness and sample size. In this sense, the use of the a-BMWQ score is recommended for the biological assessment of freshwater quality degradation in the Iberian Peninsula. More information is obtained for less effort when the a-BMWQ score is used.  相似文献   

6.
A comprehensive monitoring program was conducted during 2005-2007 to investigate seasonal variations of hydrologic stability and water quality in the Yeongsan Reservoir (YSR), located at the downstream end of the Yeongsan River, Korea. A principal component analysis (PCA) was performed to identify factors dominating the seasonal water quality variation from a large suite of measured data--11 physico-chemical parameters from 48 sampling sites. The results showed that three principal components explained approximately 62% of spatio-seasonal water quality variation, which are related to stratifications, pollutant loadings and resultant eutrophication, and the advective mixing process during the episodic rainfall-runoff events. A comparison was then made between YSR and an upstream freshwater reservoir (Damyang Reservoir, DYR) in the same river basin during an autumn season. It was found that the saline stratification and pollutant input from the upstream contributed to greater concentrations of nutrients and organic matter in YSR compared to DYR. In YSR, saline stratification in combination with thermal stratification was a dominant cause of the longer period (for two consecutive seasons) of hypoxic conditions at the reservoir bottom. The results presented here will help better understand the season- and geography-dependent characteristics of reservoir water quality in Asian Monsoon climate regions such as Korea.  相似文献   

7.
The groundwater quality assessment for the drinking and irrigation purpose is carried out in the Kandivalasa River Sub Basin covered with khondalitic suite (Garneti ferrous, Sillimanite, Gneiss) of rocks, near Cheepurupalli town of Vizianagaram district, Andhra Pradesh, India. The analysis for the groundwater quality for drinking has shown the slightly alkaline nature and high values of alkalinity in the study area. A very high concentration of total dissolved solids value is observed at one pocket where there has been contamination by many fertilizer industries located nearby the study area. The groundwater is highly affected by the nitrate. Higher fluoride values are obtained at few pockets. Most of the samples in the study area are categorized as very hard category. According to the Piper trilinear diagram, it can be observed that the carbonate hardness and secondary salinity have occupied at major part of study area. From the analysis of sodium adsorption ratio, salinity hazard, sodium percentage, residual sodium carbonate, and Kelly’s ratio, all the groundwater samples except at few locations fell under the category of good to excellent for irrigation. The prepared integrated groundwater quality maps for the drinking purpose and agricultural purposes are indicating that, by and large, the low-lying areas are having poor groundwater quality than the uplands for drinking as well as agricultural needs which means that the groundwater quality of the basin is following the topography.  相似文献   

8.
Cities across the globe are considered as major anthropogenic sources of greenhouse gases (GHG), yet very few efforts has been made to monitor ambient concentration of GHG in cities, especially in a developing country like India. Here, variations in the ambient concentrations of carbon dioxide (CO2) and methane (CH4) in residential, commercial, and industrial areas of Delhi are determined from fortnightly daytime observations from July, 2008 to March, 2009. Results indicate that the average daytime ambient concentration of CO2 varied from 495 to 554 ppm in authorized residential areas, 503 to 621 ppm in the slums or jhuggies in the unauthorized residential areas, 489 to 582 ppm in commercial areas, and 512 to 568 ppm in industrial areas with an average of 541?±?27 ppm. CH4 concentration varied from 652 to 5,356 ppbv in authorized residential areas, 500 to15,220 ppbv in the unauthorized residential areas, 921 to 11,000 ppbv in the commercial areas, and 250 to 2,550 ppbv in the industrial areas with an average of 3,226?±?1,090 ppbv. A low mid-afternoon CO2 concentration was observed at most of the sites, primarily due to strong biospheric photosynthesis coupled with strong vertical mixing.  相似文献   

9.
The effect of fireworks on air quality was assessed from the ambient concentrations of various air pollutants (SO2, NO2, PM10 and TSP) during Diwali festival in Hisar city (India), in November 1999. The extensive use of fireworks was found to be related to short-term variation in air quality. During the festival the concentration of SO2 was observed to be increased approximately 10-fold at few sites, whereas the concentrations of NO2, PM10 and TSP increased 2-3 times, compared to the data collected on a typical winter day in December 1999. The maximum NO2 concentration was observed a day after the festival. The diurnal pattern of the above pollutants showed a slight increase in the night. The levels of these pollutants observed during Diwali were found to be moderately high, which can be associated with serious health impacts.  相似文献   

10.
The monitoring of eutrophication can be performed by measuring the turnover times of amino acids in watermasses using the Wright-Hobbie uptake kinetics approach.The substrate specificity of amino acids varies greater with turnover times than with sampling location in watermasses with a certain water type. Thus a specific substrate among the essential amino acids should be selected to use for measuring the turnover time, in order to monitor precisely the state of trophic excitation within the steady-state oscillation in a certain aquatic system. On the other hand, either singular or plural substrates among the essential amino acids can be used for measuring the turnover time for the identification of a watermass, relevant to eutrophication.  相似文献   

11.
The flow of heavy metals (Cu, Ni, Cr, Cd, Zn, Pb) and cyanide in the Kokomo, Indiana collection system and wastewater treatment plant is analyzed. The primary objective is to determine the relative contributions of domestic and non-domestic sources to the total pollutant load in the system, and to assess the levels of discharge control required for the disposal of municipal sludge by landfill or agricultural landspreading. Sampling was conducted at point source locations, in major sewer trunk-and feeder lines, and at the treatment plant. Production and waste treatment data are presented for point sources sampled for the purpose of characterizing metal and cyanide discharges as a function of these parameters. A heavy metal mass balance is attempted for the treatment plant. Metal removal factors are presented for various plant operations. A simple statistical approach is presented for the design of a cost-effective sampling program for correlating point source and trunkline pollutant sampling. The purpose is to minimize the amount of sampling required to account for pollutants seen in trunkline and treatment plant streams in terms of discharges from specific point sources.  相似文献   

12.
This research investigated the spatiotemporal variation of water quality in the Gilgel Gibe reservoir, Ethiopia, using physicochemical water quality parameters. Nonparametric tests and multivariate statistical techniques were used to evaluate data sets measured during dry and rainy seasons. Electrical conductivity (EC), pH, biochemical oxygen demand (BOD5), total phosphorus (TP), total nitrogen (TN), nitrate (NO3?), total dissolved solids (TDSs), and total suspended solids (TSSs) were all significantly different among seasons (Mann-Whitney U test, p?<?0.01). In addition, principal component analysis distinguished dry season samples from wet season samples. The dry season was positively associated with EC, pH, TP, TN, NO3?, TDS, and TSS and negatively associated with BOD5. The wet season was in contrast associated with high values of turbidity, soluble reactive phosphorus (SRP), water temperature, and dissolved oxygen (DO). Within the reservoir, spatial variation was observed for some of the water quality parameters, with significant difference at p?=?<?0.05. Overall, high nutrient concentrations suggest eutrophic conditions, likely due to high nutrient loading from the watershed. Levels of TSS, attributed to inputs from tributaries, have been excessive enough to inhibit light penetration and thus have a considerable impact on the aquatic food web. Our findings indicate that the reservoir is at high risk of eutrophication and siltation, and hence, urgent action should target the planning and implementation of integrated watershed management for this and similar reservoirs in the region.  相似文献   

13.
We propose and evaluate a mode-of-action based test battery of low-complexity and in-vitro bioassays that can be used as a routine monitoring tool for sewage treatment efficiency and water quality assessment. The test battery comprises five bioassays covering five different modes of toxic action. The bioluminescence inhibition test with Vibrio fischeri and a growth rate inhibition test with the green algae Pseudokirchneriella subcapitata are measures of non-specific integrative effects. A second endpoint in the algae test, the specific inhibition of the efficiency of photosynthesis, gives an account of the presence of herbicides. An enzymatic assay covers an important aspect of insecticidal activity, the inhibition of the acetylcholine esterase activity. Estrogenic effects are assessed with the yeast estrogen screen (YES) and genotoxicity with the umuC test. Three field studies, each lasting six to seven consecutive days, were undertaken at a sewage treatment plant (STP) in Switzerland. Samples were collected in summer and late autumn, under dry and rainy conditions. None of the bioassays gave positive results with raw water in whole effluent toxicity testing. Therefore, water samples from various sites during wastewater treatment and from surface water were enriched with solid-phase extraction. The focus was on non-volatile compounds of average to moderate hydrophobicity, a range that includes most pesticides, biocides and pharmaceuticals. Various polar solid phases were evaluated for their extraction efficiency, disturbance by matrix components and overall performance. We finally selected a mixture of a polymeric sorbent and a C18-sorbent, Lichrolut EN and RP-18 or, alternatively, Empore SDB-RPS disks. All bioassays gave clear and robust responses with the SPE extracts. With the bioassay data the treatment efficiency of the STP can be assessed with respect to different modes of toxic action and accordingly different groups of micropollutants. Furthermore, the data allowed for a comparison between the effluent and the receiving river. In all bioassays the primary effluent had a strong effect and this effect was reduced after passing the STP. Treatment efficiency was high (typically over 90%) but varied from bioassay to bioassay, which is expected because each bioassay detects different types of micropollutants and therefore we cannot expect a common answer.  相似文献   

14.
The 1990's time series in Hong Kong for various components oftotal suspended particulate matter (TSP) and PM10 have beenanalyzed in order to assess two distinct types of anthropogenicinput. The first of these relates to the immense reclamation andconstruction activities for new developments and airportconstruction. The concentrations of crustal components inPM10 (= TSP – PM10) were found to peak at the time ofthis maximum activity. A second type of anthropogenic input,ambient lead from petrol vehicles, has decreased in Hong Kongand now represents a regional background. Ambient bromine nowarises mainly from the seasalt source.  相似文献   

15.
There is increasing recognition that protozoa is very useful in monitoring and evaluating water ecological healthy and quality. In order to study the relationship between structure and function of protozoan communities and water qualities, six sampling stations were set on Lake Donghu, a hypereutrophic subtropical Chinese lake. Microbial communities and protists sampling from the six stations was conducted by PFU (Polyurethane foam unit) method. Species number (S), diversity index (DI), percentage of phytomastigophra, community pollution value (CPV), community similarity and heterophy index (HI) were mensurated. The measured indicators of water quality included total phosphorus (TP), dissolved oxygen (DO), Chemical oxygen demand (COD), NH(4)(+), NO(2)(-) and NO(3)(-). Every month water samples from stations I, II, III, IV were chemically analyzed for a whole year, Among the chemically analyzed stations, station I was the most heavily polluted, station II was the next, stations III and IV had similar pollution degrees. The variable tendencies of COD, TP, NH(3), NO(2)(-), NO(3)(-), and DO during the year was approximately coincident among the six stations. Analysis from the community parameters showed that the pollution of station 0 was much more serious than others, and station V was the most slight. Of the community parameters, CPV and HI were sensitive in reflecting the variables of the water quality. Community similarity index was also sensitive in dividing water qualities and the water quality status of different stations could be correctly classified by the cluster analysis. DI could reflect the tendency of water quality gradient, species number and percentage of Phytomastigophora was not obvious in indicating the water quality gradient.  相似文献   

16.
Street dust was collected from five roads with different traffic volumes in the metropolitan area of Beijing and separated into five size fractions. Concentrations of polycyclic aromatic hydrocarbons (PAHs) adsorbed on street dust in different size ranges and their correlation with specific surface area and total organic carbon (TOC) were investigated. Results show that the concentration of 16-PAHs of sieved samples ranges from 0.27 to 1.30 mg/kg for all the sampling sites. Particles smaller than 40 μm in diameter have the highest 16-PAHs concentration among all of the size ranges for street dust from the four sampling sites with vehicles running on. PAHs with three or four rings account for 68% of the overall 16-PAHs on average. Remarkable positive correlation exists between 16-PAHs concentration and specific surface area with R 2 values from 0.7 to 0.96 for the four sampling sites with vehicles running on. The relationship between the concentration of 16-PAHs and TOC is less clear.  相似文献   

17.
Tris(chloro-isopropyl)phosphate (TCPP) was identified by GC-MS by comparing mass spectra and retention times to original standards. The concentrations in wastewater of a sewage treatment plant's influent and effluent were analysed (520 ng l(-1) and 380 ng l(-1), respectively (mean values). The concentrations of TCPP in the wastewater inflow exhibited a high variability. The elimination of this compound in the sewage treatment plant also exhibits a high variability but is low. Additionally the concentrations in sewage sludge of the same plant were determined (mean value 5100 ng g(-1) dry weight; 1700 ng g(-1) wet weight, respectively). For a comparison sludge samples from twenty other plants were analysed. In these samples concentrations ranging from 1000-20000 ng g(-1)(dry weight) were determined. Thus sorption to sludge does occur to some extent.  相似文献   

18.
加油站在线监控模块在油气回收设施长效管理中的应用   总被引:1,自引:0,他引:1  
以上海市为例,分析了加油站油气回收设施的运行现状,以及存在的内部管理制度落实不到位、治理设施维保难落实等问题,并在此基础上提出了加油站在线监控模块的设计思路。对加油站的跟踪测试表明,应用汽油枪气液比在线监控数据,有助于及时判定故障和报修,降低油气回收设备的维护成本;应用油罐压力在线监控数据,可以有效反映卸油时的油气泄漏情况,便于对卸油全过程实施监控。  相似文献   

19.
Size fractionated particulate matter (PM) was collected in summer and winter from Beijing, China for the characterization of an expanded list of PAHs and evaluation of air pollution metrics. Summertime ΣPAHs on PM was 14.6 ± 29(PM 1.5), 0.88 ± 0.49(PM 1.5-7.2) and 0.29 ± 0.076(PM 7.2) ng m(-3) air while wintertime concentrations were 493 ± 206(PM 1.5), 26.7 ± 14(PM 1.5-7.2) and 5.3 ± 2.5(PM 7.2) ng m(-3) air. Greater than 90% of the carcinogenic PAHs were concentrated on PM(1.5). Dibenzopyrene isomers made up a significant portion (~30%) of the total carcinogenic PAH load during the winter. To our knowledge, this is the first report of dibenzopyrenes in the Beijing atmosphere and among the few studies that report these highly potent PAHs in ambient particulate matter. Lifetime risk calculations indicated that 1 out of 10,000 to over 6 out of 100 Beijing residents may have an increased risk of lung cancer due to PAH concentration. Over half of the lifetime risk was attributed to Σdibenzopyrenes. The World Health Organization and Chinese daily PM(10) standard was exceeded on each day of the study, however, PAH limits were only exceeded during the winter. The outcomes of the air pollution metrics were highly dependent on the individual PAHs measured and seasonal variation.  相似文献   

20.
Quality assessment of water is essential to ensure sustainable safe use of it for drinking, agricultural, and industrial purposes. For the same purpose the study was conducted for the samples of water of Sambhar lake city and its adjoining areas. The standard methods of APHA were used to analysis 15 samples collected from hand pumps and tube wells of the specified area. The analytical results show higher concentration of total dissolved solids, electrical conductivity sodium, nitrate, sulfate, and fluoride, which indicate signs of deterioration but values of pH, calcium, magnesium, total hardness, and carbonate are within permissible limits as per WHO standards. From the Hill-piper trilinear diagram, it is observed that the majority of groundwater from sampling stations are sodium?Cpotassium?Cchloride?Csulfate type water. The values of sodium absorption ratio and electrical conductivity of the groundwater were plotted in the US salinity laboratory diagram for irrigation water. Only the one sample fall in C3S1 quality with high salinity hazard and low sodium hazard. Other samples fall in high salinity hazard and high sodium hazard. Chemical analysis of groundwater shows that mean concentration of cation is in order sodium > magnesium > calcium > potassium while for the anion it is chloride > bicarbonate > nitrate > sulfate.  相似文献   

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