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21.
The land use information collected for Dehlon block of Ludhiana district, Punjab from the analysis of the IRS-1B LISS-II data for the year 1993 and IRS PAN data for the year 1997 and SOI topographical maps for 1964 revealed a large change in the area of different land use categories during the period from 1964 to 1997. The agricultural land covering an area of about 94.14 per cent in 1964 reduced to 90.26 per cent in 1997. while the area under rural settlements increased from 312 ha in 1964 to 1162 ha in 1997. An extra area of about 169 ha under waste land was added during the period under study making total waste land area to about 400 ha in 1997. However, the block lacks the forest cover of the required limit. Considerable change in living environment was observed in the block. Number of persons per unit settlement area (ha) being 213.3 in 1964 reduced to 97.1 in 1991; it indicate that the living standard of the people of the block has improved with the changed cropping pattern and increased agricultural production during the period from 1964 to 1991. 相似文献
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Pooja Mahapatra Hans van der Marel Freek van Leijen Sami Samiei-Esfahany Roland Klees Ramon Hanssen 《Journal of Geodesy》2018,92(1):21-32
Deformation estimates from Interferometric Synthetic Aperture Radar (InSAR) are relative: they form a ‘free’ network referred to an arbitrary datum, e.g. by assuming a reference point in the image to be stable. However, some applications require ‘absolute’ InSAR estimates, i.e. expressed in a well-defined terrestrial reference frame, e.g. to compare InSAR results with those of other techniques. We propose a methodology based on collocated InSAR and Global Navigation Satellite System (GNSS) measurements, achieved by rigidly attaching phase-stable millimetre-precision compact active radar transponders to GNSS antennas. We demonstrate this concept through a simulated example and practical case studies in the Netherlands. 相似文献
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Suryachandra A. Rao Ashish R. Dhakate Subodh K. Saha Somnath Mahapatra Hemantkumar S. Chaudhari Samir Pokhrel Sobhan K. Sahu 《Climatic change》2012,110(3-4):709-719
Observations have shown that the Indian Ocean is consistently warming and its warm pool is expanding, particularly in the recent decades. This paper attempts to investigate the reason behind these observations. Under global warming scenario, it is expected that the greenhouse gas induced changes in air–sea fluxes will enhance the warming. Surprisingly, it is found that the net surface heat fluxes over Indian Ocean warm pool (IOWP) region alone cannot explain the consistent warming. The warm pool area anomaly of IOWP is strongly correlated with the sea surface height anomaly, suggesting an important role played by the ocean advection processes in warming and expansion of IOWP. The structure of lead/lag correlations further suggests that Oceanic Rossby waves might be involved in the warming. Using heat budget analysis of several Ocean data assimilation products, it is shown that the net surface heat flux (advection) alone tends to cool (warm) the Ocean. Based on above observations, we propose an ocean-atmosphere coupled positive feedback mechanism for explaining the consistent warming and expansion of IOWP. Warming over IOWP induces an enhancement of convection in central equatorial Indian ocean, which causes anomalous easterlies along the equator. Anomalous easterlies in turn excite frequent Indian ocean Dipole events and cause anti-cyclonic wind stress curl in south-east and north-east equatorial Indian ocean. The anomalous wind stress curl triggers anomalous downwelling oceanic Rossby waves, thereby deepening the thermocline and resulting in advection of warm waters towards western Indian ocean. This acts as a positive feedback and results in more warming and westward expansion of IOWP. 相似文献
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R Chaurasia D C Loshali S S Dhaliwal Minakshi P K Sharma M Kudrat A K Tiwari 《Journal of the Indian Society of Remote Sensing》1996,24(2):115-123
Remote sensing applications have been operationalised in most of the natural resources management themes and at present the trend is on integrated surveys to arrive at sustainable developmental packages. In accordance with the IMSD project, the Tehsil Talwandi Sabo in district Bathinda has been selected for integrated survey and resource management analysis. In the present study multidate remote sensing data has been analysed to map existing land use and temporal changes. The study in Talwandi Sabo suggests that land use pattern in the tehsil is not similar to that of general land use pattern prevailing in the State. The area under settlements show many fold increase while there is no increase in forest land. Sandy areas comprising sand dunes (levelled and unlevelled) require suitable management for proper ecosystem balance. 相似文献
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Sedimentological study of the digitated lobes of gravel and associated sediments in the north of Durgapur results in identification
of five major facies. Facies analysis indicates the sediments were deposited from an alluvial fan that has prograded in to
an inferred shallow body of water. The analysis also suggests debris flow deposits dominate proximal part, modified grain
flow and turbidity current the middle part and current generated channel and non-channel deposits in the distal part of the
alluvial fan — fan-delta sequence. 相似文献
27.
We present a signal processing approach using discrete wavelet transform (DWT) for the generation of complex synthetic aperture radar (SAR) images at an arbitrary number of dyadic scales of resolution. The method is computationally efficient and is free from significant system-imposed limitations present in traditional subaperture-based multiresolution image formation. Problems due to aliasing associated with biorthogonal decomposition of the complex signals are addressed. The lifting scheme of DWT is adapted to handle complex signal approximations and employed to further enhance the computational efficiency. Multiresolution SAR images formed by the proposed method are presented. 相似文献