Hydrological characterization of Budge Budge and Dum Dum areas of south and north 24 Parganas districts,West Bengal using geoelectric and geochemical methods     

R. K. Majumdar  S. Kar  A. Panda  S. K. Samanta 《Journal of the Geological Society of India》2016,88(3):330-338

Integrated geoelectric, geological and geochemical investigations are carried out in Budge Budge and Dum Dum areas of south and north 24 Parganas district for ascertaining the prevailing hydrological condition and aquifer characteristic with chemical qualities of groundwater for drinking and irrigation purposes. The proposed areas are constituted of alluvium and marine sediments of Quaternary age being a part of Gangetic delta. Vertical electrical soundings (VES) of Budge Budge have delineated four to six layers consisting of top soils, the brackish water zone, clay layer, first fresh water zone, another clay layer and the bottom-most(sixth layer) second fresh water bearing zone. The first fresh water zone is located at a depth of 128 m with thickness of 43 m having resistivity range of 32 ohm.m to 37 ohm.m for VES locations BB2 and BB3. The resistivity of the deeper second fresh water bearing zone is varying from 47 ohm.m to 51 ohm.m. The interpreted VES results significantly correspond with the borehole litholog of Budge Budge area. Similar VES results are also obtained for Dum Dum area showing promising potential aquifer zone especially for VES locations DD3 and DD4. A litho-resistivity relation is also determined for the area. Total TDS content of Budge Budge ground water samples are ranging from 720 mg/l to 4400 mg/l and same is ranging from 1012 mg/l to 1930mg/l for Dum Dum ground water samples. According to IS standard, the value of major cations and anions are near to the permissible limit for Dum Dum but same is not observed in Budge Budge for drinking and irrigation purpose excepting location G7. According to Piper trilinear diagram, the ground water in Budge Budge area is sulphate rich type and in Dum Dum it is fresh in nature. Chemically, the groundwater samples from Dum Dum and Budge Budge is classified as (Ca+Mg+Cl+SO₄) facies. The geochemical parameters like total hardness (TH), sodium adsorption ratio (SAR), soluble sodium percentage (SSP), Kelly’s ratio (KR), magnesium ratio (MR), residual sodium carbonate (RSC), corrosivity ratio (CR), Gibb’s ratio-I&II (GR-I & GR-II), chloro alkaline indices (CAI-I & CAI-II), permeability index (PI), sea water contamination (SWC) are also determined for better understanding of the quality of groundwater in the above areas.  相似文献   

Fugacities and free energies of CO₂ at high pressures and temperatures     

A. J. Majumdar  Rustum Roy 《Geochimica et cosmochimica acta》1956,10(5-6):311-315

Fugacity and free-energy values have been calculated from p-v-t data for CO₂ in the temperature range from 50 to 1000°C, at pressures from 25 to 1400 bars.  相似文献   

Worldwide distribution of polyclyclic aromatic hydrocarbons in urban road dust     

D. Majumdar  B. Rajaram  S. Meshram  P. Suryawanshi  C. V. Chalapati Rao 《International Journal of Environmental Science and Technology》2017,14(2):397-420

Polycyclic aromatic hydrocarbons (PAHs) are considered as one of the most important groups of organic environmental contaminants due to their toxicity, persistence and ubiquity. PAHs have been monitored in urban road dust at various locations worldwide in about last three decades. Resuspension of road dust containing PAHs is an important route of human exposure to PAHs. This paper collates the available information on reported concentrations of PAHs in urban road dust at various worldwide locations classified as industrial, residential, traffic, city and commercial and other areas, reported sources of PAHs and related interpretations. The available information has been reviewed and documented country-wise. Variation in PAHs concentrations over various worldwide locations have been scrutinized, and interestingly, most of the reported average PAHs concentrations were found to be distributed within a very narrow range of values, implying only little variation in average PAH concentrations in spite of great distances between locations, climatic variation and differences in anthropogenic activities.  相似文献   

Textural Classification of Single Band SIR‐B Data over a Part of Brahmaputra Basin,India     

Tapan Jyoti Majumdar  Kamini Kanta Mohanty 《国际地球制图》2013,28(2):62-68

Abstract

Texture is an important spatial feature, useful for identfying objects of regions of interest in an image. There are a number of methods for identification of textural parameters e.g. edgeness, frequency domain analysis, gray tone cooccurrence approach etc. Geologic information in radar images of heavily vegetated areas is contained mostly in the depiction of topography in image texture. Single band SIR/ERS‐1 SAR data posses a problem to the analyst for classification of the various land use/geological classes and generally multidate SAR data are used due to paucity of more number of bands. However, the multidate SAR data classification is not an ideal technique. A new technique, namely, spatial frequency band pass classification technique which generates two or more bands in the Fourier domain using the single band SAR data and then classifies various features of interest using their textural properties has been described here. Result shows higher percentage of classification using Maximum‐Likelihood Classifier (MXL) with two split‐band data as compared to the unsupervised classification of all the bands.  相似文献   

Computerised plotting of bhaskara-I alternate mode brightness temperature data     

K. S. Rao  T. J. Majumdar  D. S. Kamat 《Journal of the Indian Society of Remote Sensing》1984,12(2):53-58

A method has been developed to study the alternate mode BHASKARA SAMIR data with reference to a cartographic referencing system of India. The look angle dependence of the brightness temperature over sea region has been clearly depicted. The change in brightness temperature due to snow/ice in Himalayan region is also identified. A sharp variation of brightness temperature values has been observed at the land-sea crossings.  相似文献   

Morphometric analyses of the 4th order drainage watersheds of the Khowai river basin,Tripura, India -some preliminary results and observations     

Jay P. Majumdar 《Journal of the Indian Society of Remote Sensing》1982,10(3):49-53

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Analysis of multi-channel seismic reflection and magnetic data along 13° N latitude across the Bay of Bengal     

D. Gopala Rao  G. C. Bhattacharya  M. V. Ramana  V. Subrahmanyam  T. Ramprasad  K. S. Krishna  A. K. Chaubey  G. P. S. Murty  K. Srinivas  Maria Desa  S. I. Reddy  B. Ashalata  C. Subrahmanyam  G. S. Mital  R. K. Drolia  S. N. Rai  S. K. Ghosh  R. N. Singh  R. Majumdar 《Marine Geophysical Researches》1994,16(3):225-236

Analysis of the multi-channel seismic reflection, magnetic and bathymetric data collected along a transect, 1110 km long parallel to 13° N latitude across the Bay of Bengal was made. The transect is from the continental shelf off Madras to the continental slope off Andaman Island in water depths of 525 m to 3350 m and across the Western Basin (bounded by foot of the continental slope of Madras and 85° E Ridge), the 85° E Ridge, the Central Basin (between the 85° E Ridge and the Ninetyeast Ridge), the Ninetyeast Ridge and the Sunda Arc. The study revealed eight seismic sequences, H1 to H8 of parallel continuous to discontinuous reflectors. Considering especially depth to the horizons, nature of reflection and on comparison with the published seismic reflection results of Currayet al. (1982), the early Eocene (P) and Miocene (M) unconformities and the base of the Quaternary sediments (Q) are identified on the seismic section. Marked changes in velocities also occur at their boundaries.In the Western Basin the acoustic basement deepening landward is inferred as a crystalline basement overlain by about 6.7 km of sediment. In the Central Basin possibly thicker sediments than in the Western Basin are estimated. The sediments in the Sunda Arc area are relatively thick and appears to have no distinct horizons. But the entire sedimentary section appears to be consisting of folded and possibly faulted layers.The comparatively broader wavelength magnetic anomalies of the Central Basin also indicate deeper depth of their origin. Very prominent double humped feature of the 85° E Ridge and broad basement swell of the Ninetyeast Ridge are buried under about 2.8 km thick sediments except over the prominent basement high near 92° E longitude. The positive structural relief of the buried 85° E Ridge in the area is reflected in magnetic signature of about 450 nT amplitude. Flexural bulge of the 85° E Ridge and subsidence of the Ninetyeast Ridge about 24 cm my^–1 rate since early Eocene period have been inferred from the seismic sequence analysis.  相似文献   

Validation of ERS-1 and High-Resolution Satellite Gravity with in-situ Shipborne Gravity over the Indian Offshore Regions: Accuracies and Implications to Subsurface Modeling     

Sirsendu Chatterjee  Rudradeb Bhattacharyya  Laju Michael  Kolluru Sree Krishna  Tapan Jyoti Majumdar 《Marine Geodesy》2007,30(3):197-216

Geoid and gravity anomalies derived from satellite altimetry are gradually gaining importance in marine geoscientific investigations. Keeping this in mind, we have validated ERS-1 (168 day repeat) altimeter data and very high-resolution free-air gravity data sets generated from Seasat, Geosat GM, ERS-1 and TOPEX/POSEIDON altimeters data with in-situ shipborne gravity data of both the Bay of Bengal and the Arabian Sea regions for the purpose of determining the consistencies and deviations. The RMS errors between high resolution satellite and ship gravity data vary from 2.7 to 6.0 mGal, while with ERS-1 data base the errors are as high as 16.5 mGal. We also have generated high resolution satellite gravity maps of different regions over the Indian offshore, which eventually have become much more accurate in extracting finer geological structures like 85° E Ridge, Swatch of no ground, Bombay High in comparison with ERS-1satellite-derived gravity maps. Results from the signal processing related studies over two specific profiles in the eastern and western offshore also clearly show the advantage of high resolution satellite gravity compared to the ERS-1 derived gravity with reference to ship gravity data.  相似文献   

Multivariate Spatial Modeling for Geostatistical Data Using Convolved Covariance Functions   总被引：1，自引：0，他引：1  

Anandamayee Majumdar  Alan E. Gelfand 《Mathematical Geology》2007,39(2):225-245

Soil pollution data collection typically studies multivariate measurements at sampling locations, e.g., lead, zinc, copper or cadmium levels. With increased collection of such multivariate geostatistical spatial data, there arises the need for flexible explanatory stochastic models. Here, we propose a general constructive approach for building suitable models based upon convolution of covariance functions. We begin with a general theorem which asserts that, under weak conditions, cross convolution of covariance functions provides a valid cross covariance function. We also obtain a result on dependence induced by such convolution. Since, in general, convolution does not provide closed-form integration, we discuss efficient computation. We then suggest introducing such specification through a Gaussian process to model multivariate spatial random effects within a hierarchical model. We note that modeling spatial random effects in this way is parsimonious relative to say, the linear model of coregionalization. Through a limited simulation, we informally demonstrate that performance for these two specifications appears to be indistinguishable, encouraging the parsimonious choice. Finally, we use the convolved covariance model to analyze a trivariate pollution dataset from California.  相似文献   

Quasi-normal modes of a black hole     

N. Panchapakesan  Bhabani Majumdar 《Astrophysics and Space Science》1987,136(2):251-257

The quasi-normal modes of a black hole are calculated requiring that the ingoing amplitudes vanish at infinity. The amplitude is obtained by making the solutions valid close to and far away from the horizon. The normal-modes are obtained in the form of polynomial solutions.  相似文献