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71.
72.
Bhanu?PratapEmail author Dwarika?Prasad?Dobhal Rakesh?Bhambri Manish?Mehta Vinod?Chandra?Tewari 《Regional Environmental Change》2016,16(3):643-658
Understanding the glacier mass balance is necessary to explain the rate of shrinkage and to infer the impact of climate change. The present study provides an overview of the glacier mass balance records by glaciological, geodetic, hydrological and accumulation-area ratio (AAR) and specific mass balance relationship methods in the Indian Himalaya since 1970s. It suggests that the mass balance measurements by glaciological methods have been conducted for ten glaciers in the western Himalaya, four glaciers in the central Himalaya and one in the eastern Himalaya. Hydrological mass balance has been conducted only on Siachen Glacier from 1987 to 1991. Geodetic method has been attempted for the Lahaul–Spiti region for a short time span during 1999–2011 and Hindu Kush–Karakoram–Himalaya region from 2003 to 2008. We compared in situ specific balance data series with specific mass balance derived from AAR and specific mass balance relationship. The results derived from existing and newly presented regression model based on AAR and specific mass balance relationship induced unrealistic specific mass balance for several glaciers. We also revised AAR0 and ELA0 based on available in situ AAR and specific mass balance data series of Indian Himalayan glaciers. In general, in situ specific and cumulative specific mass balance observed over different regions of the Indian Himalayan glaciers shows mostly negative mass balance years with a few positive ones during 1974–2012. On a regional level, the geodetic studies suggest that on the whole western, the central and the eastern Himalaya experienced vast thinning during the last decade (2000s). Conversely, Karakoram region showed slight mass gain during almost similar period. However, the glaciological, hydrological and geodetic mass balance data appear to exhibit short time series bias. We therefore recommend creation of benchmark glaciers network for future research to determine the impact of climate change on the Himalayan cryosphere. 相似文献
73.
Sorption of alpha and beta hydrophobic endosulfan in a Vertisol from southeast region of Turkey 总被引:1,自引:0,他引:1
Aye Dilek Atasoy Ahmet Ruhi Mermut Halil Kumbur Faruk nce Hüdaverdi Arslan Emel Deniz Avc 《Chemosphere》2009,74(11):1450-1456
Endosulfan has been applied to control numerous insects in a variety of food and non-food crops. Limited information is available on dynamics of this pesticide in the soil. The objective of this research was to determine the adsorption–desorption behavior of the alpha (α) and beta (β) endosulfan in a Vertisol from the southeast region of Turkey, where cotton is the main crop in the large irrigated lowlands. The α and β endosulfan were adsorbed considerably and Freundlich adsorption–desorption isotherms fitted the α and β endosulfan data (R2 > 0.98). Freundlich adsorption coefficients (Kf) for the α endosulfan ranged between 21.63 and 16.33 while for the β endosulfan they were between 14.01 and 17.98 for the Ap and Bw2 horizons. The difference of Kf values of α and β endosulfan for two horizons were explained with the slight difference in the amount of organic matter and clay, but considerable difference in Fe contents of the two horizons. Alpha and β endosulfan Kfd values were 118.03 and 45.81 for the Ap and 48.08 and 68.71 for the Bw2 horizons. Higher adsorption and desorption behavior of the endosulfan isomers for the same horizon was attributed to poor physical bonding between the endosulfan molecule and the surfaces of fundamental soil particles. This fact is thought to increase the effective use of endosulfan in agriculture with a possibility of its movement to the surface and groundwater in the Vertisol studied. 相似文献
74.
75.
Erkara IP Asan A Yilmaz V Pehlivan S Okten SS 《Environmental monitoring and assessment》2008,144(1-3):31-41
Alternaria and Cladosporium, known as the most allergenic spores were first collected by means of Durham gravimetric sampler from Eskisehir atmosphere from January 1, 2000 to December 31, 2001. The daily, monthly and annual variations in spores/cm(2) of Cladosporium and Alternaria were recorded. During this period, a total of 10.231 spores belonging to Cladosporium and Alternaria genera were recorded. Of these spores, 5,103 were identified in 2000 and 5,128 in 2001. While 63.09% of the total spores were those of Cladosporium, 36.91% were of Alternaria. Relationships between airborne fungal spore presence and meteorological conditions were statistically investigated. A Shapiro-Wilk test revealed that the airborne Cladosporium and Alternaria spores differed from a normal distribution. Thus, a Friedmann test was performed followed by a Pearson Correlation Analysis. The effects of rainfall, temperature and wind speed on Cladosporium and Alternaria numbers were non-significant according to the sites and months (p > 0.05), but the effects of relative humidity on Cladosporium and Alternaria numbers were significant (p < 0.01). Spore concentrations reached to their highest levels in May 2001. 相似文献
76.
Pesch R Pehlke H Jerosch K Schröder W Schlüter M 《Environmental monitoring and assessment》2008,136(1-3):313-325
In this article a concept is described in order to predict and map the occurrence of benthic communities within and near the
German Exclusive Economic Zone (EEZ) of the North Sea. The approach consists of two work steps: (1) geostatistical analysis
of abiotic measurement data and (2) calculation of benthic provinces by means of Classification and Regression Trees (CART)
and GIS-techniques. From bottom water measurements on salinity, temperature, silicate and nutrients as well as from punctual
data on grain size ranges (0–20, 20–63, 63–2,000 μ) raster maps were calculated by use of geostatistical methods. At first
the autocorrelation structure was examined and modelled with help of variogram analysis. The resulting variogram models were
then used to calculate raster maps by applying ordinary kriging procedures. After intersecting these raster maps with punctual
data on eight benthic communities a decision tree was derived to predict the occurrence of these communities within the study
area. Since such a CART tree corresponds to a hierarchically ordered set of decision rules it was applied to the geostatistically
estimated raster data to predict benthic habitats within and near the EEZ. 相似文献
77.
This study was investigated the density and monthly distribution of indoor and outdoor microfungi in six different residential houses in Tekirdag City through the exposure of Petri dishes containing Rose-Bengal Streptomycin Agar media. Samples were collected in 1-month intervals over a period of 12 months between March, 2001, and February, 2002. We used 432 Petri dishes and counted a total of 4,205 microfungi colonies, 1,790 from indoor air and 2,415 from outdoor air. As a result, 42 species belonging to 12 genera were identified. The most frequent fungal genera were Penicillium (28.61%), Cladosporium (16.08%) and Alternaria (15.98%). While Penicillium (40.61%) and Cladosporium (15.92%) were the dominant genera of indoor air, Alternaria (20.62%) and Penicillium (19.71%) were isolated most frequently from outdoor air (Table 3). Alternaria citri (10.15%) and Penicillium brevicompactum (10.15%) were found to be the most frequent among the 42 identified species. While P. brevicompactum (19.55%) and Aspergillus niger (6.37%) were the most frequent indoor species, A. citri (13.37%) and Cladosporium cladosporioides (8.20%) were the most frequent outdoor species. Linear Regression Analysis was applied to determine whether or not there was a relationship between the number of colonies of isolated fungal genera and meteorological factors during the research period. Correlations between the presence of Aspergillus and temperature, relative humidity, duration of sunny periods and agents of air pollution such as SO(2) and PM were statistically significant. No significant correlations, however, were found between other fungal genera and environmental variables. 相似文献
78.
Nevzat Damla Uğur Cevik Ali Ihsan Kobya Ahmet Celik Necati Celik 《Environmental monitoring and assessment》2010,170(1-4):457-466
The activity concentrations of 226Ra, 232Th, and 40K in lime and gypsum samples used as building materials in Turkey were measured using gamma spectrometry. The mean activity concentrations of 226Ra, 232Th, and 40K were found to be 38 ± 16, 20 ± 9, and 156 ± 54 Bq kg???1 for lime and found to be 17 ± 6, 13 ± 5, and 429 ± 24 Bq kg???1 for gypsum, respectively. The radiological hazards due to the natural radioactivity in the samples were inferred from calculations of radium equivalent activities (Raeq), indoor absorbed dose rate in the air, the annual effective dose, and gamma and alpha indices. These radiological parameters were evaluated and compared with the internationally recommended limits. The experimental mass attenuation coefficients (μ/ρ) of the samples were determined in the energy range 81–1,332 keV. The experimental mass attenuation coefficients were compared with theoretical values obtained using XCOM. It is found that the calculated values and the experimental results are in good agreement. 相似文献
79.
The objective of this research was to assess the degradation of fipronil [5-amino-1-(2,6-dichloro-alpha,alpha,alpha -trifluoro-p-tolyl)-4-trifluoromethylsulfinylpyrazole-3-carbonitrile] in soils from sugar cane fields in Northeastern Brazil. Degradation experiments were carried out under laboratory conditions (controlled temperature and in the dark), where sterile and non-sterile soils (Ustoxs) were incubated [under moisture content of 55% of the water holding capacity (WHC)] and analyzed for fipronil disappearance and metabolite formation. Microbial communities present in the soil degrade fipronil. However, biodegradation seems to be dependent on the bioavailability of the fipronil and the half-life according to the zero-order model. Fipronil degradation rate appeared to be biphasic. Degradation fipronil ranged from 83 days (initial concentration = 978 ng g(-1); short-term experiment) to 200 days (initial concentration = 689 ng g(-1); long-term experiment). This an initial slower rate followed by a faster rate after 90 days of incubation may lead to shorter half-life than that calculated with the zero-order model. The sulfone derivative (an oxidation product) was the predominant metabolite, but the sulfide (a reduction product) and amide (a hydrolysis product) derivatives were also formed under non-sterile conditions after 120 days of incubation. The metabolites underwent further biodegradation, particularly the sulfone derivative. Bioavailability appears to affect fipronil degradation in soils with an effective capacity to adsorb fipronil (such as Ustoxs), while redox potential was important for the formation of metabolites. Despite the fine texture, more aerobic sites were present, thus favoring the formation of the sulfone metabolite over that of the sulfide metabolite. Therefore, microaggregation of Ustoxs, with high clay content, played a very important role in determining the types of metabolites formed. 相似文献
80.