Application and evaluation of kriging and cokriging methods on groundwater depth mapping

Groundwater and water resources management play a key role in conserving the sustainable conditions in arid and semi-arid regions. Applying some techniques that can reveal the critical and hot conditions of water resources seem necessary. In this study, kriging and cokriging methods were evaluated for mapping the groundwater depth across a plain in which has experienced different climatic conditions (dry, wet, and normal) and consequently high variations in groundwater depth in a 12 year led in maximum, minimum, and mean depths. During this period groundwater depth has considerable fluctuations. Results obtained from geostatistical analysis showed that groundwater depth varies spatially in different climatic conditions. Furthermore, the calculated RMSE showed that cokriging approach was more accurate than kriging in mapping the groundwater depth though there was not a distinct difference. As a whole, kriging underestimated the real groundwater depth for dry, wet, and normal conditions by 5.5, 2.2, and 5.3%, while cokriging underestimations were 3.3, 2, and 2.2%, respectively; which showed the unbiasedness in estimations. Results implied that in the study area farming and cultivation in dry conditions needs more attention due to higher variability in groundwater depth in short distances compared to the other climate conditions. It is believed that geostatistical approaches are reliable tools for water resources managers and water authorities to allocate groundwater resources in different environmental conditions.     

Multivariate analysis of heavy metals concentrations in river estuary

Multivariate statistical techniques such as multivariate analysis of variance (MANOVA) and discriminant analysis (DA) were applied for analyzing the data obtained from two rivers in the Penang State of Malaysia for the concentration of heavy metal ions (As, Cr, Cd, Zn, Cu, Pb, and Hg) using a flame atomic absorption spectrometry (F-AAS) for Cr, Cd, Zn, Cu, Pb, As and cold vapor atomic absorption spectrometry (CV-AAS) for Hg. The two locations of interest with 20 sampling points of each location were Kuala Juru (Juru River) and Bukit Tambun (Jejawi River). MANOVA showed a strong significant difference between the two rivers in terms of heavy metal concentrations in water samples. DA gave the best result to identify the relative contribution for all parameters in discriminating (distinguishing) the two rivers. It provided an important data reduction as it used four parameters (Zn, Pb, Cd and Cr) affording 100% correct assignations. Results indicated that the two rivers were different in terms of heavy metals concentrations in water, and the major difference was due to the contribution of Zn. A negative correlation was found between discriminate functions (DF) and Cr and As, whereas positive correlation was exhibited with other heavy metals. Therefore, DA allowed a reduction in the dimensionality of the data set, delineating a few indicator parameters responsible for large variations in heavy metal concentrations. Correlation matrix between the parameters exhibited a strong evidence of mutual dependence of these metals.     

Thiamethoxam degradation by <Emphasis Type="Italic">Pseudomonas</Emphasis> and <Emphasis Type="Italic">Bacillus</Emphasis> strains isolated from agricultural soils

Twelve bacterial species were evaluated to know the degradation pattern of thiamethoxam in liquid medium. All the bacterial species could actively degrade phorate in a mineral salt medium containing phorate (50 μg ml^–1) as sole carbon source. As these species have ability to degrade, we used these for the degradation of thiamethoxam—a neonicoitinoids. Screening of 12 active phorate-metabolizing bacterial species resulted in selection of Bacillus aeromonas strain IMBL 4.1 and Pseudomonas putida strain IMBL 5.2 causing 45.28 and 38.23 % thiamethoxam (50 μg ml^?1) reduction, respectively, in 15 days as potential thiamethoxam degrading species. These two bacterial species grew optimally at 37 °C under shake culture conditions in MSMT medium raised with initial pH of 6.0–6.5 and use of these optimum cultural conditions resulted in improved thiamethoxam degradation by these bacterial species. These species caused maximum thiamethoxam degradation only in the presence of thiamethoxam as sole source of carbon and energy and the same was reduced in the presence of easily metabolize able carbon (C₀ and C₁) and nitrogen ((N₀, N₁ and N₂) sources. This could be attributed to involvement of repressible metabolic pathways, reactions of which are inhibited by the presence of easily available nutrients for growth. Besides above, qualitative analysis of thiamethoxam residues by gas liquid chromatography revealed complete metabolization of thiamethoxam without detectable accumulation of any known thiamethoxam metabolites.     

Contamination by organochlorine compounds in the edible tissue of four sturgeon species from the Caspian Sea (Iran)

This study focused on accumulation of organochlorine compounds (OCs), including dichloro-diphenyl-trichloroethanes (DDTs), hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs), and polychlorinated biphenyls (PCBs) accumulation in the muscle of four sturgeon (Persian sturgeon, Acipenser persicus; Stellate sturgeon, Acipenser stellatus; Ship sturgeon, Acipenser nudiventris and Beluga sturgeon, Huso huso) from the southern Caspian Sea. The DDT group was prominent in all of the sturgeon muscle tested constituting almost half or more of the total organochlorine content. Contaminant concentration generally followed this order: DDTs>PCBs>HCHs>HCB. The OCs concentrations in Beluga sturgeon (H. huso) were the highest and over four times higher than in the next highest species (A. nudiventris). From an ecotoxicological point of view, the concentrations of OCs in experimental fishes do not reflect a comparatively clean and pollution-free environment; however, results from this study shown that the inflow of organic pollutants into the Caspian Sea has been reduced when compared with prior studies. Levels of measured OCs in sturgeon were relatively low, but the level of some OCs in some of the specimens tested exceeded the guidelines for food; therefore, the maximum allowable daily consumption rate for sturgeon from this watershed may be limited by DDTs and PCBs content for high risk populations.     

Humanarzneimittel im aquatischen Ökosystem

Goal

In the Brandenburg State Office for the Environment an approach to assess the potential risk of drug residues in aquatic ecosystems has been developed based on an investigation of the consumption amounts in 1999 to identify or to exclude a potential environmental risk of important human drugs and further to define priority substances for monitoring programs in Brandenburg in the future.

Method

This assessment approach tested with 60 drug agents is based on an exposure estimation considering the main path for the entry human—waste water—sewage plant—surface water, on a substance specific analysis of effects and on an analysis of the environmental fate as compartment distribution, bioaccumulation and persistence.

Results

In Brandenburg surface waters the drug agent concentration for eight of the considered substances is supposed to be greater than 1 μg/l and for at least 13 of the considered substanoes the PNEC in aquatic ecosystems is assumed to be lower than 1 μg/l. A potential risk for the environment can be seen for the antibiotics Ciprofloxacin-HCl and Clarithromycin, the disinfectants Benzalkonium Chloride, Cocospropylendiaminguaniacetat, Glucoprotamine, Laurylpropylenediamine and Polyvidone-iodine, the sexual hormon Ethinylestradiol, the antidiabetic Metformin-HCl, the antiepileptic Carbamazepine and the lipid regulator Clofibrinic acid on the basis of effects because their PEC:PNEC-relation is about 1 or higher. For further 19 drug agents an environmental risk is to be assumed because of their environmental behaviour without support by ecotoxicological data at present.

Conclusion

Although there is only a small base of valid ecotoxicological data, this risk assessment shows that adverse effects in the aquatic environment by some drug agents cannot be excluded. However, it should be noted that this first assessment gives only a crude orientation. Appropriate test data are necessary to refine the assessment in future.     

Impact of air pollution on floral morphology of Cassia siamea Lamk

Cassia siamea plants growing at two different sites (polluted and non-polluted) on two important roads of Agra city exhibited significant differences in their flowering phenology and floral morphology. The flowering in plants growing at polluted site is delayed and there was a marked reduction in flowering density, flowering period, size of floral parts, pollen fertility, fruit and seed-set. SEM observations revealed the presence of well developed glandular structures and reduction in the number and size of large stomata on the anther surface at polluted site. These changes were found to be closely associated with the extent of air pollution caused mainly by significant in the number of automobiles.     

Environmental perception during rapid population growth and urbanization: a case study of Dhaka city

Dhaka city in Bangladesh has been passing through a hasty process of urbanization and population growth since the last few decades. Rapid growth of population, unplanned urbanization and industrialization in the periphery has generated pressure to the changes in land use pattern, which has also caused huge urban expansion. This expansion process is engulfing cultivated land, vegetation, wetlands and water bodies without considering their environmental impacts. This study argues that these changes and their scale of environmental impacts or sufferings are not equally distributed among the dwellers in Dhaka city. It seeks to explore variations of environmental qualities on the basis of people’s perceptions. The study finds that the dwellers in the city perceive their neighborhood environment differently, which may affect environmental qualities of the area and their sustainable management as well. Therefore, it is imperative to consider spatial variations and inequalities of environmental opportunities or sufferings in urban planning of Dhaka city.     

Environmental friendly extraction of walnut bark-based juglone natural colorant for dyeing studies of wool fabric

Environmental Science and Pollution Research - Environmental friendly products particularly natural dyes are going to be much popular around the globe due to their non-toxic and bio-degradable...     

Mapping farmers’ vulnerability to climate change and its induced hazards: evidence from the rice-growing zones of Punjab,Pakistan

Environmental Science and Pollution Research - In developing countries like Pakistan, agriculture constitutes the primary source of support for the majority of rural and the adjacent urban...