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211.
Anjana Pant S. G. Chavan P. S. Roy K. K. Das 《Journal of the Indian Society of Remote Sensing》1999,27(3):133-139
Habitat analysis for sambar in terms of food, cover, water, space and extent of edge in Corbett National Park using remote sensing and GIS has been attempted. Other physical parameters include climate, topography, fire history, disturbance regimes, weeds etc. IRS-IB LISS II data (FCC, hardcopy) on 1:50.000 scale was interpreted to generate vegetation cover and density map. Other maps showing drainage, water bodies, roads, human habitations and contours were prepared using Survey of India topographical maps. During evaluation of sambar habitat information regarding habitat parameters and their tolerance was collected from existing literature as well as during field observations. Twenty-two transects of one km. length were laid down in all the strata randomly to collect information regarding the structure and composition of the forest and also habitat use (direct and indirect evidences) by sambar. This was then integrated using condition-based equations in the GIS domain to generate suitability maps. Actual sightings on the ground to a large extent supported the results. 相似文献
212.
Some evidence of climate change in twentieth-century India 总被引:1,自引:0,他引:1
The study of climate changes in India and search for robust evidences are issues of concern specially when it is known that
poor people are very vulnerable to climate changes. Due to the vast size of India and its complex geography, climate in this
part of the globe has large spatial and temporal variations. Important weather events affecting India are floods and droughts,
monsoon depressions and cyclones, heat waves, cold waves, prolonged fog and snowfall. Results of this comprehensive study
based on observed data and model reanalyzed fields indicate that in the last century, the atmospheric surface temperature
in India has enhanced by about 1 and 1.1°C during winter and post-monsoon months respectively. Also decrease in the minimum
temperature during summer monsoon and its increase during post-monsoon months have created a large difference of about 0.8°C
in the seasonal temperature anomalies which may bring about seasonal asymmetry and hence changes in atmospheric circulation.
Opposite phases of increase and decrease in the minimum temperatures in the southern and northern regions of India respectively
have been noticed in the interannual variability. In north India, the minimum temperature shows sharp decrease of its magnitude
between 1955 and 1972 and then sharp increase till date. But in south India, the minimum temperature has a steady increase.
The sea surface temperatures (SST) of Arabian Sea and Bay of Bengal also show increasing trend. Observations indicate occurrence
of more extreme temperature events in the east coast of India in the recent past. During summer monsoon months, there is a
decreasing (increasing) trend in the frequency of depressions (low pressure areas). In the last century the frequency of occurrence
of cyclonic storms shows increasing trend in the month of November. In addition there is increase in the number of severe
cyclonic storms crossing Indian Coast. Analysis of rainfall amount during different seasons indicate decreasing tendency in
the summer monsoon rainfall over Indian landmass and increasing trend in the rainfall during pre-monsoon and post-monsoon
months. 相似文献
213.
Geochronology of anthropogenic pollutants in riparian wetland sediments of the Lippe River (Germany) 总被引:2,自引:0,他引:2
S. Heim J. Schwarzbauer A. Kronimus R. Littke C. Woda A. Mangini 《Organic Geochemistry》2004,35(11-12):1409
Anthropogenic pollutants were determined in a dated sediment core, collected from a riparian wetland of the Lippe River (Ruhr district, Germany). The historical trend in heavy metals, polycyclic aromatic hydrocarbons, organochlorines, polychlorinated biphenyls and linear alkylbenzenes as well as more recent contaminants such as industrial additives, organotins, synthetic musks, methyltriclosan and some other compounds were determined for the time period between 1930 and 1986. Emission sources, information on technical production and usage, as well as on the individual pollution pathways, with appropriate environmental stability, were considered in the interpretation of the sediment contamination over the past 50 years.Contaminants were analysed and interpreted according to two different criteria: (a) the origin of the main contaminants as related to mining and industrial activities as well as municipal sewage and agricultural effluents and (b) the pollution history. Due to a significant appearance of formerly missing contaminants in sediments deposited since 1970, we suggest classifying contaminants as either common (predating 1970) or modern (postdating 1970).In summary, the study provided a comprehensive reconstruction of the pollution history of the Lippe River system. 相似文献
214.
F. DE MEYER 《Geophysical Prospecting》1984,32(1):37-50
This paper is concerned with an interpretation of the Bouguer anomaly on the Western flank of the Brabant Massif (Belgium). The position, shape, and density contrast of elementary bodies in the upper part of the earth's crust are determined in a purely numerical manner. A batholith-like body and a basin-type structure both adequately account for the observed surface field, at least from a one-sided geophysical and mathematical point of view. Since seismological control is lacking the two models are representative of the ambiguity and indeterminacy of the definitions of the geologic cause of the anomalous features, if the data are restricted to gravity information alone. 相似文献
215.
The complex variables boundary element method (CVBEM) is used to study interaction between a circular opening and fractures originating from its boundary in a piecewise homogeneous plane. A new complex hypersingular equation for piecewise homogeneous media with a circular opening is obtained. The equation is solved using the CVBEM technique with circular and straight boundary elements and polynomial approximations (with square root asymptotics for crack tip elements) for the unknown functions. The algorithm is verified through comparison with known semi‐analytical and numerical solutions that involve interaction between a circular opening and specific systems of cracks or other openings. New numerical results concerning the interaction of the circular opening with the cracks and circular inclusions are presented. The method is applied to an important problem in the petroleum industry: modelling propagation of hydraulic fractures in the vicinity of a borehole. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
216.
S. Pradhan V. K. Sehgal K. K. Bandyopadhyay R. N. Sahoo P. Panigrahi C. M. Parihar S. L. Jat 《Journal of the Indian Society of Remote Sensing》2018,46(2):321-326
The best and commonly used ground-based sensor to monitor crop growth, ASD FieldSpecPro Spectroradiometer (Analytical Spectral Devices, Boulder, CO, USA) is a passive sensor, which can be used under adequate light condition. However, now-a-days active sensors such as GreenSeeker? (GS) handheld crop response (Trimble Agriculture division, USA) are used for monitoring crop growth and are flexible in terms of timeliness and illumination conditions besides being cheaper than the ASD. Before its wide use, the suitability and accuracy of GS should be assessed by comparing the NDVI measured by this instrument with that by ASD, under diverse wheat growing conditions of India. Keeping this in view, the present experiment was undertaken with the following objectives: (1) to find out the temporal variation of NDVI measured both by ASD and GS treatments, (2) to find out relationship between the NDVI measured through ASD and GS and, (3) to evaluate the suitability of GS for NDVI measurements. It was observed that the numerical value of NDVI as measured by GS was always significantly (P < 0.05) lower than that measured by ASD for all the experiments under study. The NDVI-ASD and NDVI-GS were significantly positively correlated (P < 0.01) with the correlation coefficients being +0.94, +0.88 and +0.87 for irrigation and nitrogen experiment, irrigation and cultivars experiment, and tillage, residue and nitrogen experiments, respectively. Further, the regression equation developed between the NDVI-ASD and NDVI-GS: [NDVI-GS = 1.070 × (NDVI-ASD ? 0.292] can be successfully used to compute the NDVI of ASD from that computed by GS. 相似文献
217.
218.
P. C. Padhy R. K. Nayak V. K. Dadhwal M. Salim D. Mitra S. B. Chaudhury P. R. Rao K. H. Rao C.B. S. Dutt 《Journal of the Indian Society of Remote Sensing》2016,44(1):135-143
An empirical model is developed and used with remotely sensed predictors: sea surface temperature (SST) and chlorophyll-a concentration (Chl-a), to compute surface water partial pressure of carbon dioxide (pCO2w) and air-sea fluxes of CO2 in the Hooghly estuary and its adjacent coastal oceans. In situ observations used here were based on measurements carried out in this region during winter and summer periods in 2008. The estimated pCO2w compares well with the in situ observations at root mean square error ±18 μatm. In winter, estimated pCO2w ranges between 320 and 500 μatm with large values (>400 μatm) on the south-western and south-eastern flanks of the coastal domain and lower values (340–375 μatm) on the main-channel. In summer, it remained spatially uniform at 450 μatm. Extrapolation of the results over the study region based on the Moderate Imaging Specroradiometer (MODIS) measured SST and Chl-a suggests that the region is a strong source of atmospheric CO2 during the summer with net release of 0.095 Tg C year?1 (equivalent to mean flux of 90 molC m?2 year?1) and is a weak source during the winter with net release of 0.006 Tg C yr?1 (0.5 molC m?2 year?1) from the geographical extent of 6000 Km2 area. 相似文献
219.
没实习单位可去、无企业导师指导、没实际东西可学是导致遥感领域硕士研究生就业难的主要原因,而不同的教育理念会对学生培养有不同程度的影响。文中将耦动理论运用到实践中,在校企合作、双导师制和前沿科技讲座互动式教学3个方面进行改革创新,注重理论与实践的互动、专硕教育与职业的衔接,为培养遥感领域研究生实践能力、工作能力提供参照。 相似文献
220.
Journal of Geographical Systems - In this paper, we investigate the relationship between adverse economic circumstances and the desire of Dutch households to move up or down the urban hierarchy. We... 相似文献