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71.
M. S. S. Nagaraju G. P. Obi Reddy A. K. Maji Rajeev Srivastava P. Raja A. K. Barthwal 《Journal of the Indian Society of Remote Sensing》2011,39(1):51-61
The study area is characterized by low and fluctuating rainfall pattern, thin soil cover, predominantly rain-fed farming with low productivity coupled with intensive mining activities, urbanization, deforestation, wastelands and unwise utilization of natural resources causing human induced environmental degradation and ecological imbalances, that warrant sustainable development and optimum management of land resources. Spatial information related to existing geology, land use/land cover, physiography, slope and soils has been derived through remote sensing, collateral data and field survey and used as inputs in a widely used erosion model (Universal Soil Loss Equation) in India to compute soil loss (t/ha/yr) in GIS. The study area has been delineated into very slight (<5 t/ha/yr), slight (5–10 t/ha/yr), moderate (10–15 t/ha/yr), moderately severe (15–20 t/ha/yr), severe (20–40 t/ha/yr) and very severe (>40 t/ha/yr) soil erosion classes. The study indicate that 45.4 thousand ha. (13.7% of TGA) is under moderate, moderately severe, severe and very severe soil erosion categories. The physiographic unit wise analysis of soil loss in different landscapes have indicated the sensitive areas, that has helped to prioritize development and management plans for soil and water conservation measures and suitable interventions like afforestation, agro-forestry, agri-horticulture, silvipasture systems which will result in the improvement of productivity of these lands, protect the environment from further degradation and for the ecological sustenance. 相似文献
72.
Abani R Samal Raja R Sengupta Richard H Fifarek 《Journal of Earth System Science》2011,120(4):583-593
Linear trends of anomalously high gold values in the Florida Canyon gold deposit, Nevada have been identified using a combination
of contour maps of gold (Au) concentration developed with a geographic information system (GIS) and variogram maps created
using a geostatistical analysis package. These linear trends are interpreted to represent major fault zones that exerted a
prinicipal control on gold mineralization and therefore imparted a spatial anisotropy to gold concentrations. 相似文献
73.
Dipak Ghosh Argha Deb Swarup Ranjan Sahoo Subrata Haldar Rosalima Sengupta 《Natural Hazards》2011,58(3):877-889
This paper reports the measurement of radon concentration in well water at the site of Jalpaiguri (26°32′N, 88°46′E) near
the active fault zone of West Bengal, India. Radon concentration has been measured in well water with the help of solid-state
nuclear track detectors (SSNTD). The study indicates a positive correlation between radon anomaly and earthquake. The data
of radon content in well water have been compared with that in soil gas at the same site. 相似文献
74.
We present properties of intensity oscillations of a sunspot in the photosphere and chromosphere using G band and Ca II H filtergrams from Hinode. Intensity power maps as function of magnetic field strength and frequency reveal reduction of power in the G band with an increase in photospheric magnetic field strength at all frequencies. In Ca II H, however, stronger fields exhibit more power at high frequencies, particularly in the 4.5–8.0 mHz band. Power distributions in different locations of the active region show that the oscillations in Ca II H exhibit more power compared to that of the G band. We also relate the power in intensity oscillations with different components of the photospheric vector magnetic field using near simultaneous spectro-polarimetric observations of the sunspot from the Hinode spectropolarimeter. The photospheric umbral power is strongly anti-correlated with the magnetic field strength and its line-of-sight component but there is a good correlation with the transverse component. A reversal of this trend is observed in the chromosphere except at low frequencies(ν≤ 1.5 mHz). The power in sunspot penumbrae is anti-correlated with the magnetic field parameters at all frequencies(1.0 ≤ν≤ 8.0 mHz) in both the photosphere and chromosphere, except that the chromospheric power shows a strong correlation in the frequency range 3–3.5 mHz. 相似文献
75.
The Franck-Condon factors and r-centroids, which are very closely related to vibrational transition probabilities, have been evaluated by the more reliable
numerical integration procedure for the bands of B
2 Σ+ - X
2 Σ+, C
2Σ+ - X
2 Σ+ andC
2 Σ+ - A
2 Πr systems of the astrophysical molecule BeF, using a suitable potential.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
76.
B. Karthikeyan V. Raja N. Rajamanickam S. P. Bagare 《Astrophysics and Space Science》2006,306(4):231-234
For molecular identification in astrophysical sources, an astrophysicist needs some spectroscopic parameters such as dissociation
energy, vibrational or rotational temperature of the source, band or line wavelengths, transition probability parameters,
etc. The Franck-Condon(FC) factors are proportional to the transition probabilities. In this study, the FC factors and r-centroids for the vibronic (vibration-electronic) transitions C
1 Σ + → X
1 Σ + of aluminium hydride (AlH), b
3 Σ ( −) → a
3 Π, C
1 Σ + → A
1 Π & C
′1 Δ → Δ 1 Π of boron hydride (BH) have been evaluated and the results are presented in tables which include band origin/head wavelengths.
The physical & astrophysical significances of our evaluated FC factors & r-centroids have been discussed and the possible presence of AlH in sunspot umbral spectra is also predicted.
PACS: 33 · 70 · Ca 相似文献
77.
本文通过约束大地测量研究来探索掸邦高原及其周围地区现今的地壳变形和长期块体运动,以期提供该地区地球动力学和相关地震危险状况的最新状态。掸邦高原在横向上由西侧的萨干(Sagaing)断裂和东侧的红河断裂这两条主要断裂包围。其中,青藏高原地壳的韧性流挤压被认为是该夹层变形单元变形的主要因素。大地测量清楚地表明,萨干断裂和红河断裂段分别具有约18 mm/a和约45 mm/a右旋运动走滑速率。此外,掸邦高原内部断层体系大地滑移累积表现为1213 mm/a的整体左旋运动速率。我们认为相对于刚性巽他古陆,研究区域的形变分布和长期块体运动主要受区域书架型断层作用控制,其原因是掸邦高原两侧的主断裂(萨干断裂和红河断裂)存在差异性断裂活动。 相似文献
78.
Sequential cumulative moment release data of macroearthquakes (Mw≥4.3) of seventeen seismic zones (A to Q) belonging to NE-Himalaya, Burmese-Andaman arc and West- Sunda arc are analysed by Hurst analysis, a non-parametric statistical procedure to identify clustering of low and high values in a time series. The moment release in a zone occurs in alternate positive, negative and positive sloping segments forming a wave like pattern with intervening small horizontal segment. The negative sloping segments indicate decelerated moment release pattern or temporal slackening of elastic strain release with high b–value (>0.95). The horizontal segment indicates temporal clustering of moderate magnitude events/seismic moments with moderate b-values (0.8–0.95). The positive segment is characterised by accelerated moment release within a short span of time indicating temporal clustering of larger magnitude earthquakes/seismic moments and exhibit lowest b–value (<0.7). All zones attest moderate to high Hurst K values, range 0.7-0.86. The pattern in Hurst plots, specially a reversal of trend after prolong negative slope is used for earthquake prognostication in the seismic zones. Our analysis shows that most of the zones register a notable reversal of Hurst clustering trend after a prolonged negative slope which is accompanied by a major earthquake near its end. However, South Burma region (Zone-I) and Tripura fold belt and Bangladesh Plain (Zone-K) do not show any moderate or large shock around the end of the negative sloping trend in Hurst plot. Hence, these two zones can be considered more prone to produce moderate to larger earthquakes in future. 相似文献
79.
Diptansu Sengupta Basab Mukhopadhyay Om Prakash Mishra 《Journal of the Geological Society of India》2018,92(6):661-670
The annual b-value fluctuation patterns in Burmese subduction zone and Andaman–Sumatra subduction zone are evaluated from earthquake data (January 1990 to June 2016; Mw ³ 4.3) to identify seismic cycles with sequential dynamic phases as described in the ‘elastic failure model’ of Main et al. (1989). Two seismic cycles have been identified in Andaman–Sumatra subduction zone, one started in 1990 and ended on 2004 with occurrence of great Sumatra earthquake (Mw 9.0) and the other started in 2005 and continuing till date with the phase of crack coalescence and fluid diffusion (3A&B). Similarly, the subduction zone of Burma shows evidence of one incomplete seismic cycle within 1990–2016 and presently undergoing the crack coalescence and fluid diffusion (3A&B) phase. The analysis has prompted to subdivide the area into thirteen smaller seismic blocks (A to M) to analyse area specific seismic trend and vulnerability analysis employing Hurst Statistics. Hurst plots with the dynamic phases of ‘elastic failure model’ of earthquake generation is compared to assess the blocks with high seismic vulnerability. The analysis suggest that north Andaman zone (block G) and north Burma fold belt (block M) are seismically most vulnerable. Moreover, the seismic vulnerability of Tripura fold belt and Bangladesh plain (block K) is equally high. 相似文献
80.
Maitrayee Chakraborty Sayan Biswas Pulak Sengupta 《International Geology Review》2015,57(11-12):1619-1632
The Arcuate Singhbhum Shear Zone (SSZ) forms an integral part and occurs at the southern fringe of the Palaeoproterozoic North Singhbhum Fold Belt (NSFB) of the East Indian Shield. Repeated folding, ductile shearing, and accompanying hydrothermal activities in the SSZ during the late Palaeoproterozoic (ca. 1.66–1.60 Ga) orogeny resulted in a highly tectonized ensemble of rocks including a suite of peraluminous kyanite-rich quartzite (KQR). Near Kanyaluka village, the KQR shows millimetre- to decimetre-thick alternation of kyanite- and quartz-rich bands. The banded rock is intensely sheared and is cross-cut by weakly deformed to undeformed kyanite-quartz veins. In many places, kyanite-rich bands show sea-green coloured pods rich in lazulite. Textural studies reveal that deformed kyanite and quartz grains are sequentially replaced by augelite and lazulite (XMg > 0.97) at the terminal phase of shearing in the SSZ. Modelling of observed textures and mineral compositions with the C-Space program shows the following augelite- and lazulite-forming reactions:
1.829Kyanite + 0.998P + 1.5H2O + 0.001Ca = 1Augelite + 1.666Al + 0.001 Mg + 1.822SiO2 + 0.002Fe + 0.0002Na
1.778Kyanite + 0.667Augelite + 1.294P + 1.011 Mg + 0.011Fe + 0.0001Na = 1Lazulite + 2.833Al + 1.78SiO2 + 0.001 Ca