Fast large-scale reionization simulations     

Rajat M. Thomas  Saleem Zaroubi  Benedetta Ciardi  reas H. Pawlik  Panagiotis Labropoulos  Vibor Jeli&#;  Gianni Bernardi  Michiel A. Brentjens  A. G. de Bruyn  Geraint J. A. Harker  Leon V. E. Koopmans  Garrelt Mellema  V. N. Pandey  Joop Schaye  Sarod Yatawatta 《Monthly notices of the Royal Astronomical Society》2009,393(1):32-48

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Non-parametric foreground subtraction for 21-cm epoch of reionization experiments     

Geraint Harker  Saleem Zaroubi  Gianni Bernardi  Michiel A. Brentjens  A. G. de Bruyn  Benedetta Ciardi  Vibor Jeli&#;  Leon V. E. Koopmans  Panagiotis Labropoulos  Garrelt Mellema  ré Offringa  V. N. Pandey  Joop Schaye  Rajat M. Thomas  Sarod Yatawatta 《Monthly notices of the Royal Astronomical Society》2009,397(2):1138-1152

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Waterlogging and flood hazards vulnerability and risk assessment in Indo Gangetic plain   总被引：4，自引：2，他引：2  

A. C. Pandey  Suraj Kumar Singh  M. S. Nathawat 《Natural Hazards》2010,55(2):273-289

The recurrent flooding during monsoon and subsequent waterlogging in the northern Bihar plains and the magnitude of losses due to these hazards indicate the continuing vulnerability of the region to flood and waterlogging. Management of floods and waterlogging hazards in highly flood-prone regions of India, including Bihar state has been largely response oriented with little or no attention to mitigation and preparedness. This paper presents a method for spatial, Geographic Information Systems-based assessment of flood and waterlogging vulnerability and risk in northern Bihar plains. Multitemporal satellite data was used to evaluate the area statistics and dynamics of waterlogging over the period from 1975 to 2008. The flood proneness is evaluated at district level with reference to flood inundation during a period from 1998 to 2008. Census data were used to examine the socio-economic characteristics of the region through computation of population density, cultivators, agricultural labourers, sex ratio, children in age group 0–6 years and literates. The geohazard map derived by combining area prone to waterlogging and flood inundation was multiplied with socio-economic vulnerability map to derive the flood-waterlogging risk map of the region. The result shows that flood and water-logging pose highest risk to the central districts in the northern Bihar plains with 50.95% of the total area under high and very high risk.  相似文献   

Magnetic susceptibility mapping of felsic magmatic lithounits in the central part of Bundelkhand Massif,central India     

Santosh Kumar  S. Raju  Manjari Pathak  Abhishek Pandey 《Journal of the Geological Society of India》2010,75(3):539-548

Late Archaean to Palaeoproterozoic felsic magmatic lithounits exposed in the central part of the Bundelkhand massif have been mapped and their redox series (magnetite vs ilmenite series) evaluated based on magnetic susceptibility (MS) data. The central part of Bundelkhand massif comprises of multiple felsic magmatic pulses (∼2600–2200 Ma), commonly represented by coarse grained granite (CGG-grey granite, CPG-pink granite), medium grained pink granite (MPG), fine grained pink granite (FPG), grey and pink rhyolites and granite porphyry (GP). However, the pink colour of these felsic rocks is the result of hydrothermal fluid-flushing leading to potassic alteration of grey granites. MS values of CGG vary from 0.058 to 14.75×10⁻³ SI with an average of 6.35×10⁻³ SI, which mostly represent oxidized type, magnetite series (73%) granites involving infracrustal (igneous) source materials. CPG (av. MS=3.95×10⁻³ SI) is indeed a pink variety of CGG, the original oxidizing nature of which must have been similar to the bulk of CGG, but has been moderately to strongly reduced because of distinctly more porphyritic nature together with partial assimilation of metapelitic (supracrustal) materials, surmicaceous enclaves, carbonaceous material included in the source materials, and to some extent, induced by hydrothermal and later deformational processes. MPG (av. MS= 1.15×10⁻³ SI) as lensoidal stock-like bodies intrudes the CPG and represent both magnetite series (18%) and ilmenite series (82%) granites, which are probably formed by heterogeneous (mixed) source rocks. GP (av. MS=6.26×10⁻³ SI) occur as dykes (mostly trending NE-SW) intrudes the MPG, CPG and migmatites and bears the nature similar to oxidized type, magnetite series granite. FPG (av. MS= 0.666×10⁻³ SI) trending NE-SW occur as lensoid bodies including a large outcrop, is intrusive into both CPG and MPG, and is moderately to very strongly reduced type, ilmenite series granites, which may be derived by the melting of metapelitic crustal sources. FPG hosting microgranular (mafic magmatic) enclaves commonly exhibit high MS values (7.31–10.22×10⁻³ SI), which appear induced by the mixing and mingling of interacting felsic and mafic magmas prevailed in an open system. Grey (av. MS=10.30×10⁻³ SI) and pink (av. MS=6.72×10⁻³ SI) rhyolites represent oxidized type, magnetite series granites, which may have been derived from infracrustal (magmatic) protoliths. Granite series evaluation of felsic magmatic rocks of central part of Bundelkhand massif strongly suggests their varied redox conditions (differential oxygen fugacity) mostly intrinsic to magma source regions and partially modified by hydrothermal and tectonic processes acting upon them.  相似文献   

Statistical analysis of Soft X-ray solar flares during solar cycles 21, 22 and 23     

Navin Chandra Joshi  Neeraj Singh Bankoti  Seema Pande  Bimal Pande  Wahab Uddin  Kavita Pandey 《New Astronomy》2010,15(6):538-546

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Application of the WEPP model for prioritization and evaluation of best management practices in an Indian watershed     

A. Pandey  V. M. Chowdary  B. C. Mal  M. Billib 《水文研究》2009,23(21):2997-3005

The pre‐calibrated and validated physically based watershed model, water erosion prediction project (WEPP) was used as a modelling tool for the identification of critical watersheds and evaluation of best management practices for a small hilly watershed (Karso) of India. The land use/cover of the study area was generated using IRS‐1C LISS‐III (linear imaging self scanner) satellite data. The watershed and sub‐watershed boundaries, drainage, slope and soil map of the study area were generated using ARC/INFO geographic information system (GIS). The WEPP model was finally applied to the Karso watershed which lies within Damodar Barakar catchment of India to identify the critical sub‐watersheds on the basis of their simulated average annual sediment yields. Priorities were fixed on the basis of ranks assigned to each critical sub‐watershed based on the susceptibility to erosion. The sub‐watershed having the highest sediment yield was assigned a priority number 1, the next highest value was assigned a priority number 2, and so on. Subsequently, the model was used for evaluating the effectiveness of best management practices (crop and tillage) for conservation of soil for all the sub‐watersheds. On the basis of this study, it is realized that cash crops like soyabean should be encouraged in the upland portion of the sub‐watersheds, and the existing tillage practice (country plough/mould board plough) may be replaced by a field cultivation system for conservation of soil and water in the sub‐watersheds. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

Surface-level moisture transport over the Indian Ocean during southwest monsoon months using NOAA/HIRS data     

C. M. Kishtawal  N. Gautam  S. Jaggi  P. C. Pandey 《Boundary-Layer Meteorology》1994,69(1-2):159-171

Surface-level moisture transport over the Indian Ocean has been computed using NOAA/HIRS data for the years 1980, 1981 and 1984. The global relation between monthly mean surface-level humidity and precipitable water (Liu, 1986) has been applied for the computation of surface-level humidity using monthly mean satellite-derived water vapour. The monthly mean surface wind fields over the Indian ocean provided by Florida State University have been used for the surface-level moisture flux computations. Our analysis indicates net positive surface-level moisture flux divergence over the Arabian Sea and negative moisture flux divergence over the Bay of Bengal. It has also been found that evaporation over the Arabian Sea is a variable quantity and forms a significant part of the net moisture budget over the Arabian Sea. The relative contribution of cross-equatorial flux and evaporation from the Arabian Sea has been studied for all three years.  相似文献   

Atmospheric temperature profile for a tropical region from TIROS-N microwave sounding unit     

B S Gohil  A K Sharma  P C Pandey 《Journal of Earth System Science》1981,90(3):263-271

Atmospheric temperature profiles have been derived using 53·74 GHz, 54·96 GHz and 57·95 GHz channels data from the Microwave Sounding Unit onboard TIROS-N. For this purpose regression coefficients have been derived using MONEX-79 radiosonde data during the period May to July 1979. The temperature profiles derived at a few selected places were closer to radiosonde profiles than the profiles derived using standard regression coefficients for the tropical region supplied by NOAA.  相似文献   

Terrestrial heat flow in the North Island of New Zealand     

Om Prakash Pandey 《Journal of Volcanology and Geothermal Research》1981,10(4):309-316

Large variations in terrestrial heat flow from 21 to 209 mW/m² have been observed over the North Island, New Zealand. This is generally in good agreement with the pattern of existing geological and geophysical observations. A high heat flow zone with a value of 92 ±3 mW/m², which corresponds to melting temperatures near the base of the crust, is delineated in the northern part of the Taranaki Basin. In the rest of the island, heat flow appears to be low to normal, but some isolated high values are also found. Observed results are interpreted in terms of crust and mantle structure in a region of plate subduction.  相似文献   

Hydrobiological Parameters as an Indicator of Water Pollution in the Chilwa Lake,Gorakhpur     

K. Pandey  J. P. Shukla 《洁净——土壤、空气、水》1982,10(1):113-116

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