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101.
Auto-correlation analysis of wave heights in the Bay of Bengal 总被引:1,自引:0,他引:1
Time series observations of significant wave heights in the Bay of Bengal were subjected to auto-correlation analysis to determine
temporal variability scale. The analysis indicates an exponential fall of auto-correlation in the first few hours with a decorrelation
time scale of about six hours. A similar figure was found earlier for ocean surface winds. The nature of variation of auto-correlation
with time lags was also found to be similar for winds and wave heights 相似文献
102.
Dipak Sarkar S. K. Gangopadhyay A. K. Sahoo 《Journal of the Indian Society of Remote Sensing》2006,34(3):245-260
Visual interpretation of IRS ID LISS-III fused with PAN data (1:12,500 scale) ofPatloinala micro-watershed of Puruliya district, West Bengal was carried out for delineating the physiographic units based on the variations
in image characteristics. The major physiographic units identified were upland(Tanr), medium land(Baid), and low land(Bahal andKanali). The satellite remote sensing data coupled with ground truth were translated in terms of soils using composite interpretation
map as base. The abstraction level attained was phases of soil series based on Soil Taxonomy. On the basis of physiographic
variation and soil or soil site characteristics such as texture, depth, slope, erosion etc. the problem areas were identified
and land use plan has been suggested for the overall development of the micro-watershed. 相似文献
103.
A two-dimensional numerical model is employed to study the effect of the coastal urban heat island on the sea breeze front
and the thermal internal boundary layer height. The temperature at the land surface is determined by solving an energy budget
equation. The effect of the urban heat island is studied by varying the width of the region and its intensity. During the
early afternoon, the presence of the urban heat island enhances the strength of convergence of the sea breeze front and also
reduces its inland penetration. The presence of the urban heat island causes increased thermal internal boundary layer height.
Larger urban width causes larger vertical velocity and higher thermal internal boundary layer. Stronger convergence and higher
thermal internal boundary layer are also obtained in case of larger heat island intensity. 相似文献
104.
105.
In an experiment on methane-emission measurements from rice fields amended with urea, biogas spent slurry (BSS) + urea, and farm yard manure (FYM) + urea, three distinctive peaks in the methane emissions were observed at 15, 46, and 69 days after transplanting (DAT) due to the availability of readily degradable C-sources. In all cases, the highest peak was at 69 DAT. The steepest Eh drop to a minimum of -320 mV was reached within two weeks of submergence. pH ranged between 7.5 and 8.5. The combined fertilization (FYM + urea) plot showed the maximum emission rate of 4.86 mg m–2 h–1 with a total load of 49.44 kg ha–1 and was 2.3 times higher than (BSS + urea)-treated plot (22.08 kg ha–1). Grain yields in urea, (BSS + urea) and (FYM + urea) plots were 3.34, 2.94, and 2.85 t ha–1 respectively, suggesting that biogas slurry is a preferred source over FYM causing lesser environmental pollution without any significant reduction in grain yield. 相似文献
106.
107.
Geological studies of the area around Katta, in the southern part of the Ratnagiri District of Maharashtra, were carried out with the help of visual remote sensing techniques using LANDSAT imageries on 1:250,000 scale and aerial photographs on 1:60,000 scale. The major stratigraphic units represented in the area under study are the Archean Complex, Kaladgi Supergroup, Deccan Trap, Laterite and Alluvium. The Kaladgis unconformably overlie the Archean metasediments and also at places exhibit faulted contacts with the latter. The major part of the area is covered by a thick evergreen vegetation. The interpretation followed by field work and laboratory work revealed the following:
- The different lithologic units could be delineated on the aerial photographs.
- Different lineaments marked on the imagery were found to be due either to faults or fracture zones. Some of the older faults appear to have been rejuvenated after the formation of the laterites.
- Some of the lithologic horizons can be identified on the Landsat imagery by virtue of their spatial signatures.
108.
Irene Sarkar R. Chander K. N. Khattri V. K. Gaur 《Journal of Earth System Science》1987,96(3):229-238
The paper describes an algorithm for estimating the hypocentral coordinates and origin time of local earthquakes when the
wave speed model to be employed is a layered one with dipping interfaces. A constrained least-squared error problem has been
solved using the penalty function approach, in conjunction with the sequential unconstrained optimization technique of Fiacco
and McCormick. Joint confidence intervals for the computed parameters are estimated using the approach of Bard for nonlinear
problems. These results show that when a hypocentre lies outside the array of recording stations and head waves from a dipping
interface are involved, then its inclination must be taken into account for dip angles exceeding 5°. 相似文献
109.
110.
The plankton collected from three fish ponds shows a considerable variability within a pond, between the ponds and in the course of the year. The individual volumes or weights are (minimum—mean—maximum): Gleotrichia echinulata 41–252–879 μg3, Chlorella vulgaris 18–42–94 μm3, Oscillatoria amphigranulata 99–306–827 μm3, Brachionus plicatilis 1–4.918 μg, nauplia 0.5–1.25–2.35 μg, Mesocyclops hyalinus 4–45–369—μg, Heliodiaptomus viduus 41–202–288 μg, Daphnia carinata 186–1468–4578 μg. 相似文献