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SINGH R KUMAR V SHARMA S BEHL RK SINGH BP NARULA N 《应用与环境生物学报》2005,11(6):751-755
ThepracticaluseofAzotobacterchroococcumasbiofertilizer hasbeenincreasinglyidentifiedinrecentyears.Oftentheefficacy ofthesebacteriaisassessedonthebasisofcropresponseswithout knowingthesurvival,persistenceandcompetitiveabilityofthein troducedstrain.Inoculat… 相似文献
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Chandrashekar JS Babu KL Somashekar RK 《Journal of environmental biology / Academy of Environmental Biology, India》2003,24(3):223-227
Lake and river water is the prime source for drinking, irrigation and other domestic purposes. Bellandur Lake is one of the major Lakes of Bangalore city. The addition of effluents from urbanized Bangalore city has changed the characteristics of the Lake from being a natural ecologically healthy Lake to an artificial reservoir of domestic sewage and industrial effluents. The DO of the Bellandur Lake water ranged from 3.8-6.3 mg/l. The Bellandur lake water BOD ranged from 89-99 mg/l due to absorption of pollutants by aquatic flora in lake system. If the present state of affairs continues for long, the Bellandur Lake may soon become an ecologically inactive Lake. 相似文献
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A. Shahnawaz M. Venkateshwarlu D. S. Somashekar K. Santosh 《Environmental monitoring and assessment》2010,161(1-4):83-91
Water quality assessment and freshwater fish diversity of Bhadra river, Western Ghats, Karnataka was examined. River water was clear except at one station (BV Site) with rocky and sandy substrate. The mean water quality of study sites were as following, pH 6.98, air temperature 22.66°C, water temperature 20.16°C, dissolved oxygen 8.74 mg/l, total hardness 27 mg/l, alkalinity 48 mg/l (as CaCO3), conductivity 135.5 mhos/cm, COD (15.16 mg/l), and BOD (3.78 mg/l), respectively. Altogether, 56 species of fish representing 31 genera and 15 families were recorded. The Cyprinid family was dominant in the present study. Various diversity index packages have been used to assess the fish diversity. Fish diversity is also correlated with physicochemical variables. 相似文献
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P. Ravikumar K. Venkatesharaju R. K. Somashekar 《Environmental monitoring and assessment》2010,163(1-4):643-653
Groundwater is almost globally important for human consumption as well as for the support of habitat and for maintaining the quality of base flow to rivers, while its quality assessment is essential to ensure sustainable safe use of the resources for drinking, agricultural, and industrial purposes. In the current study, 28 groundwater samples were collected around Vrishabhavathi valley region of Bangalore South Taluk to assess water quality and investigate hydrochemical nature by analyzing the major cations (Ca2?+?, Mg2?+?, Na?+?, K?+?) and anions $(\text{HCO}_{3}^{-}$ , Cl???, F???, $\text{SO}_{4}^{2-}$ , $\text{NO}_{3}^{-}$ , $\text{PO}_{4}^{3-}$ , $\text{CO}_{3}^{2-})$ besides some physical and chemical parameters (pH, electrical conductivity, alkalinity, and total hardness). Also, geographic information system-based groundwater quality mapping in the form of visually communicating contour maps was developed to delineate spatial variation in physico-chemical characteristics of groundwater samples. Piper trilinear diagram was constructed to identify groundwater groups (hydrochemical facies) using major anionic and cationic concentration and it was found that majority of the samples belongs to $\text{Ca}^{2+}-\text{Mg}^{2+}-\text{Cl}^{-}-\text{SO}_{4}^{2-}$ and $\text{Ca}^{2+}-\text{Mg}^{2+}-\text{HCO}_{3}^{-}$ hydrochemical facies. Wilcox classification and US Salinity Laboratory hazard diagram suggests that 92.86% of the samples were falling under good to permissible category and C3–S1 groups, respectively, indicating high salinity/low sodium. 相似文献
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Ravikumar P Venkatesharaju K Prakash KL Somashekar RK 《Environmental monitoring and assessment》2011,179(1-4):93-112
Anekal Taluk lies in the southern part of the of Bangalore urban district, known for Bannerghatta wildlife sanctuary, Jigani industrial estate, silk industry, and the electronics city, the pride of India and hub of Bangalore's information technology. In the present study, evaluation of geochemistry of 28 representative bore wells samples from Anekal Taluk was undertaken. It was found that most of the samples (92.9%) belong to Ca(2+?)-Mg(2+?)-Cl(?-?) -SO2??water type with Ca-Mg-Cl and Ca-Cl hydrochemical facies. The groundwater sources were further categorized as normal chloride (32.14%) and normal sulfate (100%) water types based on Cl and SO(4) concentrations. Majority of the samples (64.3%) belong to C3-S1 water class, indicating water with high salinity and low sodium. Positive index of base exchange indicates the chloro-alkaline equilibrium in the study area. Groundwater potential zonation map for Anekal Taluk was generated using multiparametric and weighted overlay method using the spatial analyst tool in ArcGIS v9.2. Accordingly, five distinct classes corresponding to good(high), moderate (medium), moderate to poor (low), poor (very low), and poor to nil (very low) groundwater potential zones were identified in the region. Of this, 85.27% of the study area belongs to good/high to moderate/medium groundwater potential and only 14.73% belonging to moderate/poor to nil groundwater potential zones. 相似文献
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Tree species diversity and composition in logged and unlogged rainforest of Kudremukh National Park, South India 总被引:5,自引:0,他引:5
Nagaraja BC Somashekar RK Raj MB 《Journal of environmental biology / Academy of Environmental Biology, India》2005,26(4):627-634
Species composition and diversity in logged and unlogged forests were assesed to understand the regeneration of the residual stand twenty years after logging in Kudremukh National Park, South India. Relative density, frequency and basal area were measured by Point Centered Quarter method to calculate the diversity and stand quality. The logged forest harbored lower stem density of mature trees (508 ha(-1)) than unlogged ones (630 ha(-1)). Indeed, logging operations increased the species diversity in the regenerative phase (seedling phase) due to the creation of larger canopy gaps. The extra radiation reaching the ground, facilitated the colonization of early and late secondary species. Ramakrishanan Index of Stand Quality (RISQ) values in logged forest was higher in comparison with unlogged forest, indicating the dominance of early and late secondary species, especially at sapling phase. The light demanding secondary forest species contribute higher percentage to the overall tree population in logged forest. It is observed from the study that a sufficient period of felling cycle should be practiced to reinstate the same set of species prevailed before logging. 相似文献
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Prakash KL Somashekar RK 《Journal of environmental biology / Academy of Environmental Biology, India》2006,27(4):633-637
Water as a resource, basic amenity and universal solvent is shared by population. The physicochemical and biological quality study of Anekal Taluk has been taken up to evaluate its suitability for potable purposes. 1026 water samples were collected from bore well, hand pumps of 272 villages covering in Anekal Taluk. The quality of groundwater has been made through the analysis of pH, colour, electrical conductivity, turbidity, total dissolved solids, alkalinity, chlorides, total hardness, calcium, fluoride, nitrate, sulphate, iron and E. coli. The quality of groundwater assessed in the study area is discussed in detail. 相似文献
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Venkatesha Raju K Somashekar RK Prakash KL 《Environmental monitoring and assessment》2012,184(1):361-373
The purpose of this research work was to appraise extent of heavy metals in sediment and the degree to which its quality tainted
seasonally and spatially in river Cauvery. In this study, heavy metals such as Fe, Zn, Ni, Mn, Pb, Cu, Co, Cd and Cr were
analysed in sediments. Results were compared with sediment quality guidelines from various derived criteria. Twenty-five sampling
points were selected based on geographical proximity of agricultural fields and industrial discharges; river-tributary confluence
points; settlements located along the river bank; ritual and recreational activities. Sampling was done for the period of
3 years (2007 to 2009). Digestion of the samples was done by microwave-assisted digestion technique. Analysis was carried
out using flame furnace atomic absorption spectrophotometer, and results are expressed in micrograms per gram. The mean concentration
of Fe (11144 μg/g) followed by Mn (1763.3 μg/g), Zn (93.1 μg/g), Cr (389 μg/g), Ni (27.7 μg/g), Cu (11.2 μg/g), Pb (4.3 μg/g),
Co (1.9 μg/g) and Cd (1.3 μg/g) remained within the levels of sediment quality guidelines. Multivariate statistical techniques
such as principal component analysis and cluster analysis (CA) were employed to better comprehend the controlling factors
of sediment quality and spatial homogeneity among the stations. The sediment geo-accumulation index (Igeo) showed maximum value of Cd (2.69) and least value of Mn (−1.44). The geo-accumulation class (Igeo class) was in the sequence as follows: Cd>Zn>Pb>Cr>Cu>Co>Ni>Fe>Mn. Negative total geo-accumulation indices (Itot) revealed that mean concentration of heavy metals in the river bed sediment are lower than their respective shale values.
The statistical analysis of inter-metallic relationship revealed the high degree of correlation among the metals indicated
their identical behaviour during transport. This study concludes that insignificant geo-accumulation with metals except Cd
(moderate contamination), Pb and Zn (slight contamination) principally in downstream stretch may perhaps deteriorate the sediment
quality due to intensification anthropogenic influences. It also proves that extent of existing metal concentrations in sediments
of river Cauvery in Karnataka not exceeded the toxic limit, and there is no peril to the aquatic life. 相似文献