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41.
B. K. Sinha Ashok Kumar Deepak Shrivastava Sanjay Srivastava 《Journal of the Indian Society of Remote Sensing》1990,18(3):1-8
In recent years satellite remote sensing techniques have greatly aided identification of fractures/joints/faults in connection with groundwater exploration. However, due to some constraints in filtering out the type of fracture i.e. shear fracture, tensional fracture, mineralised fracture etc. as to their “open or closed” nature from groundwater aspects, there is need of adding geophysical survey, particularly resistivity survey to further enhance the accuracy, and hence minimise drilling failures. The area under study is a part of Ranchi plateau and lithologically comprising of granite-gneiss. The present paper lays stress on an integrated approach for localising well sites through satellite data analysis and resistivity profiling along with vertical electrical sounding which is based on fracture patterns. With this combined effort i.e. firstly considering the surfacial features like drainage, geomorpho-logy, lithology and lineaments, and secondly taking into account geophysical survey aspects, i.e. depth and thickness of fracture zone, lateral extent, different layer parameter, etc., fairly accurate results are achieved. In the presnt study this type of an integrated survey has been carried out in Lohardaga and Gumla districts in Bihar, the results of which are highlighted in the paper. 相似文献
42.
Observed polarization ellipses for fundamental-mode surface waves observed at a digital station in Hawaii deviate from those expected for isotropic models of crust and mantle structure for that region. The anomalous motion occurs as rotations of the ellipse about all three axes in a cartesian corrdinate system. The largest and most consistent deviations occur as anomalous slopes of the ellipse about the horizontal axis transverse to the direction of propagation.The observed orientations and magnitudes of these angles can be explained by models of the upper mantle which contain olivine for which thea-axis dips significantly from the horizontal and which includes a sufficiently thick sedimentary layer (1 km) and a thicker than normal oceanic crust (15 km). The ellipses are also generally inclined from great circle paths about the vertical axis and are tilted about the axis aligned with the propagation direction. Both angles are small and difficult to measure, but the inclination angles are consistent with a model of the upper mantle in which thea-axis of olivine is preferentially oriented in an east-west direction. 相似文献
43.
The man made reservoir, G. B. Pant Sagar at the dam site (24° 15′ N Lat) in the South Mirzapur district of eastern U. P. was investigated in terms of water quality, phytoplankton diversity and production at monthly intervals between January 1987 and December 1987. The reservoir water showed low to moderate dissolved oxygen (4.3 … 7.5 mg/l) and quite low nutrient contents (0.01-0.2 mg l?1). Phytoplankton diversity narrowly fluctuated (3.17-3.74) and mean annual production (149.7 g/m3 · aC) showed a meso- to eutrophic condition. A significant positive correlation was obtained between gross production and phytoplankton density (r = 0.79; P < 0.001) Multiple regression equation (GPP = 11.292 + 0.043 BAC + 0.075 CHL + 0.073 CYN) indicates that Chlorophyta contributed more to gross production due to the presence of a higher number of individuals. 相似文献
44.
The predatory potentiality of G. affinis and P. reticulata fishes on cyclops was tested by ‘no-choice’ and ‘choice’ experiments. In ‘no-choice’ experiments predation increased significantly with the number of cyclops exposed (1, 3, 5, 7 and 10 preys) and decreased with the increase in the water volume (1, 2 and 3 litres) in case of both the fishes. A similar trend for cyclops predation was observed in ‘choice’ experiments. The relative rate of predation of G. affinis and P. reticulata was more in ‘no-choice’ as compared to in ‘choice’ experiments. However, the predatory efficacy of G. affinis was relatively higher than that of P. reticulata in all the experiments. The comparative rate of predation on three zooplanktons by G. affinis and P. reticulata showed that Daphnia spec. was most susceptible to predation by both the fishes. It was followed by calanoids and the least preferred prey being cyclops. 相似文献
45.
A. M. C. Srivastava 《Journal of Geodesy》1984,58(4):510-517
The astrogeodetic—gravimetric method based on the principle of least—squares solution has been used to determine the geocentric
Indian geodetic datum making use of the available nongeocentric astrogeodetic data and the gravimetric geocentric geoidal
heights in the form of smoothened values. Everett's method of interpolation has been used to obtain the smoothened geoidal
heights at the astrogeodetic stations in India from the available generalized values at 1°×1° corners. The values of the geoidal
height and deflections of the vertical at the geodetic datum Kalianpur H.S. so obtained have the negligible difference from
the values computed earlier by the same method using directly computed gravimetric geoidal heights at the astrogeodetic stations,
indicating that the use of the interpolated values in the astrogeodetic—gravimetric method employed would be an economical
approach of absolute orientation of a nongeocentric system if the gravimetric geoidal heights are available at 1°×1° corners
in the area of interest. 相似文献
46.
47.
F.H. Chamalaun S.N. Prasad F.E.M. Lilley B.J. Srivastava B.P. Singh B.R. Arora 《Tectonophysics》1987,140(2-4):247-255
The geomagnetic variation data from the 1979 Indian array experiment have been reanalyzed and reexamined using the hypothetical event analysis technique. The contour map of the |Z/H ratio replicates distinctive anomaly in northwest India previously delineated in maps of the Fourier coefficients. The anomaly reveals the presence of a significant conductor under the Ganga basin. The contour map has been used to derive a response profile perpendicular to the strike of the anomaly, for comparison with 2-D numerical models. An excellent fit was found for a conductor at a depth of 32 km, with a width of 110 km and a conductivity contrast of 1000. This result places the conductor deep within the lithosphere. In the absence of supporting data the origin of the conductor is difficult to resolve. However, it is thought to be related to pressure-released partial melting, caused by fracturing of the Indian crust during the collision of India with Asia. 相似文献
48.
The relative toxicities of seven non insecticidal chemicals to Mesocyclops leuckarti were tested. The relative toxicity of each chemical is given as under: Chlorine water > Potassium permanganate > Cetavlon > Quicklime > Common alum > Savlon > Sodium bicarbonate. 相似文献
49.
The Precambrian phosphorites of Bijawar Group of rocks show characteristics of a epicontinental sea with restricted and very shallow marine environment of formation along some shoals, which existed during the iron-rich Precambrian times. These phosphorite deposits located in the Hirapur-Bassia areas show extensive leaching of carbonate and phosphate minerals during episodes of weathering. X-ray diffraction studies indicated that carbonate-flourapatite is the major apatitic phase in these phosphorites while crandallite developed on the surface outcrops. There is a general tendency for the depletion of CO2 in these apatites leading to formation of flourapatite. This CO2 is an indicator of hidden weathering in the rocks. Major and trace element determinations of phosphorite have been used to indicate various correlation factors responsible for the concentration of elements in these Precambrian leached phosphorites.The paper is a contribution to the aims and objectives of IGCP Project 156The paper is dedicated to Prof. Dr. R. C. Misra, who as a teacher and guide had been a source of inspiration to the senior author for the last two decades 相似文献
50.
AnnGIS: Integration of GIS and a Continuous Simulation Model for Non-Point Source Pollution Assessment 总被引:1,自引:0,他引:1
Puneet Srivastava Rick L. Day Paul D. Robillard & James M. Hamlett 《Transactions in GIS》2001,5(3):221-234
Non-Point Source (NPS) models and monitoring data are often used to evaluate management practices and develop NPS pollution control plans. Application of a dynamic NPS model requires efficient input data acquisition, storage, organization, reduction, and analysis accompanied by manipulation, interpretation, reporting, and display of model outputs. A Geographic Information System (GIS) helps extract, store, and organize input data as well as manipulate and display model outputs. This paper illustrates the development of an integrated GIS system for a continuous simulation, pollutant-loading model, AnnAGNPS ( Ann ualized AG ricultural N on- P oint S ource Pollution). The integrated system, called AnnGIS, was developed using the ArcView GIS and related program extensions. Using AnnGIS, modeling studies and management plans can be efficiently and easily developed. AnnGIS helps store, organize, and manipulate spatial and tabular data, extract spatial input parameters, develop analysis scenarios, and visualize input and output data in spatial, tabular, and graphical forms. AnnGIS is generic in nature (not limited to a particular geographic location) and can be successfully used in regions for which AnnAGNPS is designed. AnnGIS's powerful graphical user interface and reference data sets facilitate efficient and informed decision-making concerning agricultural non-point pollution control and management. 相似文献