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201.
The brightness temperatures of the Microwave sensor MSMR (Multichannel Scanning Microwave Radiometer) launched in May 1999
onboard Indian Oceansat-1 IRS-P4 are used to develop a direct retrieval method for latent heat flux by multivariate regression
technique. The MSMR measures the microwave radiances at 8 channels at frequencies of 6.6, 10.7, 18 and 21 GHz at both vertical
and horizontal polarizations. It is found that the surface LHF (Latent Heat Flux) is sensitive to all the channels. The coefficients
were derived using the National Centre for Environmental Prediction (NCEP) reanalysis data of three months: July, September,
November of 1999. The NCEP daily analyzed latent heat fluxes and brightness temperatures observed by MSMR were used to derive
the coefficients. Validity of the derived coefficients was checked within situ observations over the Indian Ocean and with NCEP analyzed LHF for global points. The LHF derived directly from the MSMR brightness
temperature (Tb) yielded an accuracy of 35 watt/m2. LHF was also computed by applying bulk formula using the geophysical parameters extracted from MSMR. In this case the errors
were higher apparently due to the errors involved in derivation of the geophysical parameters. 相似文献
202.
We present numerical simulations of the modified nonlinear Schrödinger equation satisfied by kinetic Alfvén waves (KAWs) leading to the formation of magnetic filaments at different times. The relevance of these filamentary structures to solar wind turbulence and particle heating has also been pointed out. 相似文献
203.
Summary A number of resistivity profiles over quartz reefs have been taken using Wenner and Schlumberger configurations around Dhanbad in order tofind the potential of these for water accumulation. These reefs give rise to both resistivity highs and lows as compared to the background. The results are discussed in the light of known theories. Some suitable sites for water accumulation have been delineated. 相似文献
204.
Prasanta Kumar Behera Kripamoy Sarkar Ashok Kumar Singh A. K. Verma T. N. Singh 《Journal of the Geological Society of India》2016,88(6):725-735
In opencast mining operation, the stability of waste materials stands at high priority from the safety and economic perspective. Poor management of overburden (OB) dump results the instability of slope in an opencast mine. The present paper deals with the stability analysis of dump material of an opencast coal mine at Talcher coal field, Angul district, Odisha, by means of different geotechnical parameters and mineralogical composition affecting the dump slope. The prolonged rainfall in the mining area causes dump failure and loss of valuable life and property. A recent dump failure that occurred in 2013 at Basundhara mines of Mahanadi Coalfields Limited (MCL), Odisha, took 14 lives, and created problems for the mining industry. Most of the dump failure that occurs in the study area are mainly due to increase in pore water pressure as a result of rainfall infiltration. The stability of the waste dump was investigated using the limit equilibrium analysis to suggest an economical, sustainable and safe disposal of the dump in the study area. 相似文献
205.
The concentrations of dissolved boron have been measured during different seasons in three estuaries, the Tapi, Narmada and the Mandovi situated on the western coast of India, to investigate its geochemical behavior and inputs from the localized anthropogenic pressures of industrial effluents and sewage discharge. The measured boron concentrations in these estuaries (except the Tapi during non-monsoon) at salinity ≤0.1 fall in a narrow range?~?2–4 μmol/kg (average B?~?2.4?±?0.8 μmol/kg) within the reported wide range?~?0.1–18.6 μmol/kg for global rivers. The much higher estimate of boron concentration in the Tapi River during non-monsoon is attributed to its possible additional supply from the sewage and/or industrial effluents discharged along the river course. During monsoon, the rains seem to be a significant source of dissolved boron to all the three rivers. The distribution of dissolved boron in each estuary exhibits a conservative behavior during the seasons sampled suggestive of no measurable addition or removal of boron in the estuarine region. The orders of magnitude differences in boron concentration between the river waters and seawater, and the conservative behavior of dissolved boron indicate that its major contributor to the estuaries sampled is seawater. 相似文献
206.
Javier F. Pacheco Carlos Valds-Gonzlez Hugo Delgado Shri K. Singh F. Ramn Zuiga Carlos A. Mortera-Gutirrez Miguel A. Santoyo Jaime Domínguez Ricardo Barrn 《Journal of South American Earth Sciences》1999,12(6):73
An earthquake swarm occurred during February and March 1997 in the vicinity of the Tancitaro Volcano, in the southern part of the tectonically complex Michoacan Triangle. A study of these events provides an opportunity to map the active faults in the area and to learn if the orientation and the sense of motion on these faults are consistent with the mapped faults and the alignment of cinder cones in the region. The foci of 230 earthquakes, which could be located, are distributed between 10 and 18 km depth, and show an alignment in, roughly, a NE direction. The focal mechanisms and seismic moments of the 27 best-recorded events were determined by waveform modeling of P and S waves. These mechanisms show two distinct patterns. More than 50% of the solutions are left-lateral strike–slip mechanisms with a normal component. The preferred fault plane strikes NE. Another group of events, probably caused by triggered seismicity on the Chapala–Oaxaca fault zone, shows left-lateral strike–slip mechanisms with a large-thrust component on NW-trending faults. S wave splitting shows 1–2.5% crustal-anisotropy. The direction of the anisotropy coincides with the NE alignment of events, and the preferred nodal plane. This is also the alignment of cinder cones, suggesting that preexisting fractures and cracks are responsible for the seismicity and anisotropic behavior of the crust. The resulting stress orientation, NE compression, is the one expected for the fore-arc region. We conclude that although Michoacan Triangle lies in the Trans-Mexican Volcanic Belt, it does not form part of this stress province where the stress orientation is NS extension. 相似文献
207.
208.
R. D. Lokhande V. M. S. R. Murthy K. B. Singh 《Geotechnical and Geological Engineering》2013,31(2):793-799
Subsidence is a gradual or sudden depression of the ground on the surface due to extraction of minerals from underground. It occurs in two forms, namely, trough and pot-hole subsidence. Trough subsidence is a depression covering a large surface area, whereas pot-hole subsidence is a localized phenomenon which occurs due to sudden collapse of overburden into the underground voids. Pot hole is extremely hazardous as it does not give any prior indication before its occurrence. Several pot-holes have occurred in the recent past in the coal mines of South Eastern Coalfield Limited and therefore the study assumes great importance. This paper presents the mechanism, behaviour and critical influencing parameters concerning pot-holes. Field investigations and analysis carried out on pot-holes which occurred in some of the Indian coal mines are presented for highlighting the importance of the same. 相似文献
209.
Birendra P. Singh 《Journal of the Geological Society of India》2013,81(3):361-368
Additional latest Middle Cambrian polymerid trilobites are recorded from the Teta Member (Karsha Formation) along the Tangze-Yogma-Kuru section, Kurgiakh Valley, southeastern Zanskar, Northwest Himalaya. It includes record of a new genus Pianspis Saito & Sakakuru, 1936 of family Lisianiidae and others associated fauna comprises of Neoanomocarella asiatica (Lisianiidae), Parablackwelderia sp., (Damesellidae) and two undetermined pygidium and one unidentified cranidia. All these specimens are collected from the level representing the Lejopyge acantha Zone of Guzhangian Stage (Cambrian Series 3) of the Middle Cambrian. The fauna is mainly correlated with the South China, North Korea, Kazakhastan, Uzbekistan, Siberia and Australia. 相似文献
210.
Rupsha Banerjee Josey Kamanda Cynthia Bantilan Naveen P. Singh 《Natural Hazards》2013,65(3):1443-1464
This paper examines the relationship between local institutions and adaptation to climate variability in four semi-arid villages in India. Based on a qualitative survey, it draws attention to the constraints that farming households face, the role of institutions, and the implications for their capacities to adapt. Using an institutional framework, the study examines the role of local institutions in facilitating community adaptation to perceived climate variability. It was found that at the institutional and community level farmers rely on government schemes that provide social safety nets and the private sector such as moneylenders as sources of adaptation options regarding access to credit. Serious constraints emerged, however, in terms of adaptation to what may be a more challenging future. These constraints were further explored by means of grounded theory. The lack of collective feeling and action has hindered bargaining for better market prices and the development of alternate livelihood options. The need for better financial inclusion and access to more formal systems of finance is necessary to increase the overall adaptive capacity of households. During crisis situations or climatic shocks, the absence of these systems means the sale of household assets and resources especially among small and landless groups of farmers. Overall, rural households perceive that public, civic, and private institutions play a significant role in shielding them against the adverse effects of climate variability. The perceived importance of different institutions is, however, different across different categories of farmers, women, and labourers. 相似文献