Complex Frequency-Shifted Perfectly Matched Layers for 2.5D Frequency-Domain Marine Controlled-Source EM Field Simulations     

Li  Gang  Zhang  Liang  Goswami  Bedanta K. 《Surveys in Geophysics》2022,43(4):1055-1084

Surveys in Geophysics - For geophysical electromagnetic (EM) forward modeling problems, the accuracy of solutions mainly depends on the numerical modeling method used and the corresponding boundary...  相似文献   

Anisotropic universe with magnetized dark energy     

G. K. Goswami  R. N. Dewangan  Anil Kumar Yadav 《Astrophysics and Space Science》2016,361(4):119

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Physico-chemical conditions of four calc-alkaline granitoid plutons of Chhotanagpur Gneissic Complex,eastern India: Tectonic implications     

B Goswami  P Roy  A Basak  S Das  C Bhattacharyya 《Journal of Earth System Science》2018,127(8):120

Petrography and mineralogy of four calc-alkaline granitoid plutons Agarpur, Sindurpur, Raghunathpur and Sarpahari located from west to east of northern Purulia of Chhotanagpur Gneissic Complex, eastern India, are investigated. The plutons, as a whole, are composed of varying proportions of Qtz–Pl–Kfs–Bt–Hbl±Px–Ttn–Mag–Ap–Zrn±Ep. The composition of biotite is consistent with those of calc-alkaline granitoids. Hornblende–plagioclase thermometry, aluminium-in-hornblende barometry and the assemblage sphene–magnetite–quartz were used to determine the P, T and \(f_{\mathrm{O}_2}\) during the crystallisation of the parent magmas in different plutons. The plutons are crystallised under varying pressures (6.2–2.4 kbar) and a wide range of temperatures (896–\(718{^{\circ }}\hbox {C}\)) from highly oxidised magmas (log \(f_{\mathrm{O}_2}\) \(-11.2\) to \(-15.4\) bar). The water content of the magma of different plutons varied from 5.0 to 6.5 wt%, consistent with the calc-alkaline nature of the magma. Calc-alkaline nature, high oxygen fugacity and high \(\hbox {H}_{2}\hbox {O}_{{\mathrm{melt}}}\) suggest that these plutons were emplaced in subduction zone environment. The depths of emplacement of these plutons seem to increase from west to east. Petrologic compositions of these granitoids continuously change from enderbite (opx-tonalite: Sarpahari) in the east to monzogranite (Raghunathpur) to syenogranite (Sindurpur) to alkali feldspar granite (Agarpur) in the west. The water contents of the parental magmas of different plutons also increase systematically from east to west. No substantial increase in the depth of emplacement is found in these plutons lying south and north of the major shear zone passing through the study area suggesting the strike-slip nature of the east–west shear zone.  相似文献   

The coupled influence of instability indices and DWR data in estimating the squall speed of thunderstorms     

Sutapa Chaudhuri  Sayantika Goswami  Anirban Middey 《Asia-Pacific Journal of Atmospheric Sciences》2013,49(4):451-465

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Prioritization of Malesari mini-watersheds through morphometric analysis: a remote sensing and GIS perspective   总被引：3，自引：2，他引：1  

Dhruvesh P. Patel  Chintan A. Gajjar  Prashant K. Srivastava 《Environmental Earth Sciences》2013,69(8):2643-2656

Geographical information system and remote sensing are proven to be an efficient tool for locating water harvesting structures by prioritization of mini-watersheds through morphometric analysis. In this study, the morphometric analysis and prioritization of ten mini-watersheds of Malesari watershed, situated in Bhavnagar district of Saurashtra region of Gujarat state, India, are studied. For prioritization of mini-watersheds, morphometric analysis is utilized by using the linear parameters such as bifurcation ratio, drainage density, stream frequency, texture ratio, and length of overland flow and shape parameters such as form factor, shape factor, elongation ratio, compactness constant, and circularity ratio. The different prioritization ranks are assigned after evaluation of the compound factor. Digital elevation model from Shuttle Radar Topography Mission, digitized contour, and other thematic layers like drainage order, drainage density, and geology are created and analyzed over ArcGIS 9.1 platform. Combining all thematic layers with soil and slope map, the best feasibility of positioning check dams in mini-watershed has been proposed, after validating the sites through the field surveys.  相似文献   

Modelling of land use land cover change using earth observation data-sets of Tons River Basin,Madhya Pradesh,India     

Sudhir Kumar Singh  Prosper Basommi Laari  Sk. Mustak  Prashant K. Srivastava  Szilárd Szabó 《国际地球制图》2013,28(11):1202-1222

Abstract

An integrated Markov Chain and Cellular Automata modelling (CA MARKOV), multicriteria evaluation techniques have been applied to produce transition probability. The unsupervised method was employed to classify the satellite images of year 1985, 1995, 2005 and 2015 to meet the magnitude of LULC change. Results showing the spatial pattern of the sub-basin is largely influenced by the biophysical and socio-economic drivers leading to growth of agricultural lands and built-up area in the basin. Simulated plausible future LULC changes for 2025 which is based on a CA MARKOV that integrates Markovian transition probabilities computed from satellite-derived LULC maps and a CA contiguity spatial filter (5 × 5). Further, the fragmentation analysis was performed to check the fragmentation scenario in the year 2025. The result for year 2025 with reasonably good accuracy will be useful to the planners, policy- and decision-makers.  相似文献   

Ptychodus decurrens Agassiz (Elasmobranchii: Ptychodontidae) from the Upper Cretaceous of India     

Omkar Verma  Guntupalli V.R. PrasadAnjali Goswami  Varun Parmar 《Cretaceous Research》2012,33(1):183-188

Although a very high invertebrate faunal diversity is known from the outcrops of the Ariyalur group in the Cauvery Basin, southern India, little is known about its vertebrate fauna. Recent fieldwork in the badland exposures of the Karai Formation (Upper Cenomanian-Lower Turonian) near Garudamangalam in the basin has yielded two teeth belonging to the Late Cretaceous shark Ptychodus decurrens (Ptychodontidae). The fossil record of Ptychodus decurrens from the southern continents is very poor, being known from a single Late/Middle Albian occurrence in Australia. This finding documents the first record of fossil P. decurrens in India and second from a Gondwanan landmass, and provides the first evidence of a cosmopolitan, Pangaean, distribution of the species during the Albian-Turonian and additional insights into the palaeoecology of the Cauvery Basin during the deposition of the Karai Formation.  相似文献   

Appraisal of the prevalence of severe tropical storms over Indian Ocean by screening the features of tropical depressions     

Chaudhuri  Sutapa  Middey  Anirban  Goswami  Sayantika  Banerjee  Soumita 《Natural Hazards》2012,61(2):745-756

Natural Hazards - Tropical cyclones are one of the nature’s most violent manifestations and potentially the deadliest of all meteorological phenomena. It is a unique combination of violent...  相似文献   

Characterization and Risk Evaluation of Tea Industry Coal Ash for Environmental Suitability          下载免费PDF全文

Linee Goswami  Prasanta Raul  Banashree Sahariah  Satya Sundar Bhattacharya 《洁净——土壤、空气、水》2014,42(10):1470-1476

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Above Ground Forest Phytomass Assessment in Southern Gujarat     

Prashant Patil  Sarnam Singh  V. K. Dadhwal 《Journal of the Indian Society of Remote Sensing》2012,40(1):37-46

Spectral modeling of above ground biomass (AGB) with field data collected in 48 field sites representing moist deciduous forest in Surat district is reported. Models were generated using LISS-III and MODIS data. The plot-wise field data was aggregated to MODIS pixel (250 m) using area weightages of forest/vegetation. The study reports that above ground phytomass varied from 6.13 t/ha to 389.166 t/ha while AGB phytomass estimated using area-weights for sites of 250×250 m, ranged from 5.534 t/ha to 134.082 t/ha. The contribution of bamboo in AGB has been found very high. The analysis indicated that the highest correlation between AGB phytomass and red band (R) of MODIS satellite data of October was (R²=0.7823) and R²=0.6998 with both NDVI of October data as well as NDVI_max. High correlation (R²=0.402) with IR band of February month was also found. The phytomass range obtained by using MODIS data varies from 0.147 t/ha to 182.16 t/ha. The mean biomass is 40.50 t/ha. Total biomass is 31.44 Mt. The mean Carbon density is 19.44 tC/ha in forest areas. The study is validation of region-wise spectral modeling approach that will be adopted for mapping vegetation carbon pool of the India under National Carbon Project of ISRO-Geosphere Biosphere Programme.  相似文献