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991.
The groundwater level represents a critical factor to evaluate hillside landslides. A monitoring system upon the real-time
prediction platform with online analytical functions is important to forecast the groundwater level due to instantaneously
monitored data when the heavy precipitation raises the groundwater level under the hillslope and causes instability. This
study is to design the backend of an environmental monitoring system with efficient algorithms for machine learning and knowledge
bank for the groundwater level fluctuation prediction. A Web-based platform upon the model-view controller-based architecture
is established with technology of Web services and engineering data warehouse to support online analytical process and feedback
risk assessment parameters for real-time prediction. The proposed system incorporates models of hydrological computation,
machine learning, Web services, and online prediction to satisfy varieties of risk assessment requirements and approaches
of hazard prevention. The rainfall data monitored from the potential landslide area at Lu-Shan, Nantou and Li-Shan, Taichung,
in Taiwan, are applied to examine the system design. 相似文献
992.
Agunbiade FO Olu-Owolabi BI Adebowale KO 《Environmental monitoring and assessment》2012,184(1):89-102
The accumulation patterns of ten metals in tissues of plant, Eichornia crassipes, and fishes, Hydrocynus forskahlii and Oreochromis mossambicus, were modeled with simple fuzzy classification (SFC) to assess toxic effects of anthropogenic activities on the coastal biota.
The plant sample was separated into root, stem, and leaves and the fishes into bones, internal tissues, and muscles. They
were analyzed for As, Cd, Cr, Cu, Ni, Pb, V, Fe, Mn, and Zn after wet oxidation of their dried samples. The results were converted
into membership functions of five accumulation classes and aggregated with SFC. The classification results showed that there
was no metal accumulation in the plant parts while the fishes were classified into low accumulation category. The internal
tissues of the fishes had higher metal accumulation than the other parts. Generally, Fe and Mn had highest concentrations
in the biota but are natural to the area and may not constitute significant risk. Cr had the highest transfer and accumulation
from the coastal water into the aquatic lives and may be indicative of risk prone system being a toxic metal. Metal contaminations
in the zone had not significantly accumulated in the biota making them less prone to risk associated with metal accumulation. 相似文献
993.
The total petroleum hydrocarbons (TPH) pollution in regional agricultural soils was investigated. Seventy soil samples collected
from surface layers (0–20 cm) and horizons of five selected pedons in the vicinity of a petrochemical complex in Guangzhou,
China were analyzed, and the vertical variation and spatial variability of TPH were evaluated. The TPH concentration in top
soils around the petrochemical complex ranged from 1,179.3 to 6,354.9 mg kg − 1, with the average of 2,676.6 mg kg − 1. Furthermore, significant differences between land-use types showed that the TPH concentration in top soils was strongly
influenced by accidental spills. Both the TPH trends in pedons and the identified hot-spot areas also showed that the accidental
explosions or burning accidents were mainly responsible for the pollution. The results reported here suggest that the regular
monitoring and inspection shall be conducted for safety and to avoid or minimize the accidents, and the effective measures
should be taken to remediate the contaminated areas and to assure that the important industrialization of Guangzhou area would
not mean human health risks near the petrochemical complex. 相似文献
994.
Karadag A 《Environmental monitoring and assessment》2012,184(3):1617-1632
This paper is a summary of a project changed into a book named by “Changing Environment, City and Identity in Soma with the
Geographical Evaluations” issued on May 2005. In this research, Soma, which is one of the most remarkable districts in Manisa
in the West Anatolia from the point of economical figures, is assessed with its physical environment potential, improving
economical activities and changing socio-economical structure. Owing to the open coal basins in the northeast and southwest
of the district where lignite is produced and the impact of the thermic power plant near the city centre, Soma has changed
on a large scale. This change has introduced some environmental problems into the district such as the devastation of the
forestry land; the infertility of farming land; and soil, water and air pollution. Even though the change under discussion
has led to many problems to deal with, it has also influenced its socio-economical structure to a large extent and revealed
new type of inhabitants having different life expectations and aims. In conclusion, in this article, changing environment
and city structure after lignite processing and thermic station establishment in Soma are discussed through the effective
geographical factors. The new city profile formed by the local dynamics in question is evaluated according to the data obtained
by the studies made in the neighbourhood. 相似文献
995.
The chemical forms and ecological risk of As were characterized in the sediment of the Daliao River System (DRS), which has
been affected by long-term intensive industrial, urban, and agricultural activities. Twenty-seven samples of surface sediment
were collected and analyzed for total As content and that of its chemical forms. The results indicated that the average total
As content in the sediment was 9.83 mg kg − 1 but that the levels ranged from 1.57 to 83.09 mg kg − 1. At the sites near cities, mining sites, and the estuary of the DRS, it is likely that adverse effects on aquatic organisms
occur, due to As levels in the sediment that are often higher than the threshold effect level and occasionally higher than
the probable effect level. A selectively sequential extraction indicated that the majority of As in the sediment was bound
to Fe oxides (62.1%), with moderate proportions of residual As (19.8%), specifically adsorbed As (17.9%), and a low proportion
of non-specifically adsorbed As (1.1%). In addition, the content of Fe in the sediment was positively and significantly correlated
with the contents of amorphous and crystalline Fe oxide-bound As, confirming the crucial role of Fe oxides in immobilizing
high amounts of As in superficial environments. The average molar ratio of As to Fe was 1.18 × 10 − 4 in the surface sediment of the DRS, similar to that of natural Fe oxides, but much lower than that of synthesized Schwertmannite.
Therefore, the release of As under reduced and low pH conditions can cause serious problems for water resources and for living
organisms. 相似文献
996.
The analysis of heavy metals is very important for assessing the feasibility of the agricultural utilization for the municipal
sludge. In this paper, a four-step sequential extraction method was applied to extract heavy metals (Cu, Zn, Mn, Cr, and Ni)
in municipal sludges from seven individual wastewater treatment plants located in Jilin and Heilongjiang Province, China,
for estimating the mobility and bioavailability of the metal ions in the agricultural application. The total concentrations
of heavy metals and their chemical fractions after the sequential extraction were determined. Principal component analysis
(PCA) was applied to analyze the relations of heavy metals fractions in the municipal sludges. Experimental results indicated
that the total concentrations of Cu, Zn, Cr, and Ni in all sludge samples were below the threshold values set out by the Chinese
legislation (GB18918-2002). Specially, Zn had a high bioavailability and mobility, Cu and Cr had potential bioavailability,
while Mn mainly existed in the residual fraction of municipal sludge. On the other hand, Ni had different mobility in different
municipal sludge. PCA results were confirmed by the environmental behavior of heavy metals. 相似文献
997.
Warren C Duzgoren-Aydin NS Weston J Willett KL 《Environmental monitoring and assessment》2012,184(2):1107-1119
Hurricanes are relatively frequent ecological disturbances that may cause potentially long-term impacts to the coastal environment.
Hurricane Katrina hit the Mississippi Gulf Coast in August 2005, and caused a storm surge with the potential to change the
trace element content of coastal surface sediments. In this study, surface estuarine and marine sediments were collected monthly
following the storm from ten sites along the Mississippi Gulf Coast (Mobile Bay, Grand Bay Bayous Heron and Cumbest, Pascagoula,
Ocean Springs, Biloxi Gulf, Back Biloxi Bay, Gulfport Gulf, Gulfport Courthouse Rd, and Gulfport Marina). Concentrations of
V, Cr, Mn, Fe, Co, Ni, Zn, As, Cd, and Pb were measured by inductively coupled plasma–mass spectrometry to evaluate their
temporal and spatial variations in the year following Hurricane Katrina. Sediments were characterized by pH, particle size
distribution and total carbon and nitrogen content. Trace element contents of the sediments were determined in both <2 mm
and <63 μm grain size fractions. Results revealed no significant temporal and spatial variability in trace element concentrations,
in either size fraction. Potential ecological risk of the sediments was assessed by using NOAA SQuiRTs’ guideline values;
most concentrations remained below probable adverse effects guidelines to marine organisms suggesting that trace elements
redistributed by Hurricane Katrina would not cause an adverse impact on resident organisms. Instead, the concentrations of
trace elements were site-dependent, with specific contaminants relating to the use of the area prior to Hurricane Katrina. 相似文献
998.
In the event of a natural or anthropogenic disturbance, environmental resource managers require a reliable tool to quickly
assess the spatial extent of potential damage to the seagrass resource. The temporal availability of the Landsat 5 Thematic
Mapper (TM) imagery provided a suitable option to detect and assess damage of the submerged aquatic vegetation (SAV). This
study examined Landsat TM imagery classification techniques to create two-class (SAV presence/absence) and three-class (SAV
estimated coverage) SAV maps of the seagrass resource. The Mahalanobis Distance method achieved the highest overall accuracy
(86%) and validation accuracy (68%) for delineating the seagrass resource (two-class SAV map). The Maximum Likelihood method
achieved the highest overall accuracy (74%) and validation accuracy (70%) for delineating the seagrass resource three-class
SAV map. The Landsat 5 TM imagery classification provided a seagrass resource map product with similar accuracy to the aerial
photointerpretation maps (validation accuracy 71%). The results support the application of remote sensing methods to analyze
the spatial extent of the seagrass resource. 相似文献
999.
Cruceru I Iancu V Petre J Badea IA Vladescu L 《Environmental monitoring and assessment》2012,184(5):2783-2795
A simple, sensitive and reliable HPLC-FLD method for the routine determination of 4-nonylphenol, 4-NP and 4-tert-octylphenol, 4-t-OP content in water samples was developed. The method consists in a liquid–liquid extraction of the target analytes with dichloromethane at pH 3.0–3.5 followed by the HPLC-FLD analysis of the organic extract using a Zorbax Eclipse XDB C8 column, isocratic elution with a mixed solvent acetonitrile/water 65:35, at a flow rate of 1.0 mL/min and applying a column temperature of 40°C. The method was validated and then applied with good results for the determination of 4-NP and 4-t-OP in Ialomi?a River water samples collected each month during 2006. The concentration levels of 4-NP and 4-t-OP vary between 0.08–0.17 μg/L with higher values of 0.24–0.37 μg/L in the summer months for 4-NP, and frequently <0.05 μg/L but also between 0.06–0.09 μg/L with higher values of 0.12–0.16 μg/L in July and August for 4-t-OP and were strongly influenced by sesonial and anthropic factors. The method was also applied on samples collected over 2 years 2007 and 2008 from urban wastewaters discharged into sewage or directly into the rivers by economic agents located in 30 Romanian towns. Good results were obtained when the method was used for analysis of effluents discharged into surface waters by 16 municipal wastewater treatment plants, during the year 2008. 相似文献
1000.
Kharroubi A Gargouri D Baati H Azri C 《Environmental monitoring and assessment》2012,184(6):4001-4014
Concentrations of selected heavy metals (Cd, Pb, Zn, Cu, Mn, and Fe) in surface sediments from 66 sites in both northern and
eastern Mediterranean Sea–Boughrara lagoon exchange areas (southeastern Tunisia) were studied in order to understand current
metal contamination due to the urbanization and economic development of nearby several coastal regions of the Gulf of Gabès.
Multiple approaches were applied for the sediment quality assessment. These approaches were based on GIS coupled with chemometric
methods (enrichment factors, geoaccumulation index, principal component analysis, and cluster analysis). Enrichment factors
and principal component analysis revealed two distinct groups of metals. The first group corresponded to Fe and Mn derived
from natural sources, and the second group contained Cd, Pb, Zn, and Cu originated from man-made sources. For these latter
metals, cluster analysis showed two distinct distributions in the selected areas. They were attributed to temporal and spatial
variations of contaminant sources input. The geoaccumulation index (I
geo) values explained that only Cd, Pb, and Cu can be considered as moderate to extreme pollutants in the studied sediments. 相似文献