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Drought hazard assessment using geoinformatics over parts of Chotanagpur plateau region, Jharkhand, India 总被引:4,自引:3,他引:1
Swati Pandey A. C. Pandey M. S. Nathawat Manoj Kumar N. C. Mahanti 《Natural Hazards》2012,63(2):279-303
Recurrent drought events in the Palamu district of Jharkhand state and the magnitude of drought losses primarily toward agricultural production in this dominantly monocropped region indicate the continuing susceptibility of the society to drought. This paper presents a method for spatial, geoinformatics-based assessment of agricultural, meteorological, and hydrological drought hazard in Palamu district. It was hypothesized that the key climatic, biophysical and social factors that define agricultural drought hazard were soils, geomorphology, drainage density, land use, and relief, whereas for meteorological drought hazard, it is rainfall, coefficient of variation of rainfall and for hydrological drought hazard, it is lithology, depth to water table, aquifer yield, and surface water bodies. The framework for the derivation of an agricultural, meteorological, and hydrological drought hazard map was created through the development of a numerical weighting scheme to evaluate the drought potential of the classes within each factor. A cumulative map created through spatial join of all the three types of drought provided a drought hazard scenario in totality. The area with different severity of drought hazards under cumulative drought hazards scenario (viz. very low (8.9?%), low (24.2?%), moderate (29.2?%), high (20.13), and very high (17.3?%)) revealed high drought proneness of the area and the usefulness of geoinformatics in better spatial prognosis of drought hazards. 相似文献
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Variation in absolute abundance, size and coiling direction ratio of the planktic foraminifera Globorotalia menardii during the late Quaternary have been studied in three cores, collected along a north-south transect from the northeastern Indian Ocean. Increased abundance and larger size is observed during the warm interglacial period, whereas, smaller and fewer G. menardii specimens are noted during the cold glacial periods. A comparatively better match between absolute abundance, size and oxygen isotopic composition of foraminifera as compared to carbon isotopic composition at all the locations indicates that the abundance and size of G. menardii is more affected by seawater temperature and salinity as compared to productivity changes. The amplitude and frequency of temporal changes in the abundance and size of G. menardii vary from core-to-core, indicating the influence of site-specific physico-chemical conditions. In comparison to the abundance and size, the coiling direction of G. menardii does not show any systematic change in any of the cores. The majority of the specimens coil sinistrally. We conclude that the absolute abundance and variation in the average size of G. menardii can be used to infer past climatic changes. However, the variation in coiling direction of G. menardii appears to be unaffected by late Quaternary paleoclimatic variations in the north-eastern Indian Ocean. 相似文献
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A. N. V. Satyanarayana U. C. Mohanty N. V. Sam Swati Basu V. N. Lykossov 《Journal of Earth System Science》2000,109(2):293-303
An attempt has been made to study the marine boundary layer characteristics over Bay of Bengal using BOBMEX (Bay of Bengal
and Monsoon Experiment) pilot experiment data sets, which was conducted between 23rd October and 12th November 1998 on board
ORV Sagar Kanya. A one-dimensional multilevel atmospheric boundary layer with TKE-ε closure scheme is employed to study the
marine boundary layer characteristics. In this study two synoptic situations are chosen: one represents an active convection
case and the other a suppressed convection. In the present article the marine boundary layer characteristics such as temporal
evolution of turbulent kinetic energy, height of the boundary layer and the airsea exchange processes such as sensible and
latent heat fluxes, drag coefficient for momentum are simulated during both active and suppressed convection. Marine boundary
layer height is estimated from the vertical profiles of potential temperature using the stability criterion. The model simulations
are compared with the available observations. 相似文献
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Adnan K. M. Mehedi Ying Liu Sarker Swati Anindita Yu Man Eliw Moataz Sultanuzzaman Md. Reza Huq Md. Enamul 《GeoJournal》2021,86(4):1981-1998
GeoJournal - Risk and uncertainty are distinctive features of agricultural cultivation, which significantly affect the production and income. Risk management is an important way for farmers to... 相似文献
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A method of analysis for the uplift capacity of pile anchors in cohesionless soil is proposed using Kötter’s equation that facilitates computation of the distribution of soil reaction on the axis-symmetric failure surface, which is assumed to be the frustum of a cone with a characteristic angle of inclination with the pile–soil interface. A closed-form solution for the uplift capacity is obtained with no requirement of any charts or tables. Empirical relations using available literature are proposed for expressing critical embedment ratio and computation of net uplift capacity. The results are compared with a set of experimental data for 28 cases, ranging from loose to dense cohesionless soil up to maximum embedment ratio of 40, vis-à-vis available theoretical solutions. The proposed method leads to the predictions that are in good agreement with the experimental results. It further demonstrates the successful application of Kötter’s equation in the estimation of uplift capacity of pile anchors. 相似文献
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Munendra Singh Amit Kumar Singh Swati Nupur Srivastava Sandeep Singh A. K. Chowdhary 《Environmental Earth Sciences》2010,59(8):1703-1715
In the northern part of the Indian sub-continent, the Gomati River (a tributary of the Ganga River) was selected to study
the dynamics of Arsenic (As) mobilization in fluvial environment of the Ganga Plain. It is a 900-km-long, groundwater-fed,
low-gradient, alluvial river characterized by monsoon-controlled peaked discharge. Thirty-six water samples were collected
from the river and its tributaries at low discharge during winter and summer seasons and were analysed by ICP-MS. Dissolved
As and Fe concentrations were found in the range of 1.29–9.62 and 47.84–431.92 μg/L, respectively. Arsenic concentration in
the Gomati River water has been detected higher than in its tributaries water and characteristically increases in downstream,
attributed to the downstream increasing of Fe2O3 content, sedimentary organic carbon and silt-clay content in the river sediments. Significant correlation of determination
(r
2 = 0.68) was also observed between As and Fe concentrations in the river water. Arsenic concentrations in the river water
are likely to follow the seasonal temperature variation and reach the level of World Health Organization’s permissible limit
(10 μg/L) for drinking water in summer season. The Gomati River longitudinally develops reducing conditions after the monsoon
season that mobilize As into the river water. First, dissolved As enters into pore-water of the river bed sediments by the
reductive dissolution of Fe-oxides/hydroxides due to microbial degradation of sedimentary organic matter. Thereafter, it moves
upward as well as down slope into the river water column. Anthropogenically induced biogeochemical processes and tropical
climatic condition have been considered the responsible factors that favour the release of As in the fluvial environment of
the Ganga Plain. The present study can be considered as an environmental alarm for future as groundwater resources of the
Ganga–Brahmaputra Delta are seriously affecting the human–environment relationship at present. 相似文献
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