Implementation of Forest Canopy Density Model to Monitor Tropical Deforestation   总被引：1，自引：0，他引：1  

Jyotishman Deka  Om Prakash Tripathi  Mohamed Latif Khan 《Journal of the Indian Society of Remote Sensing》2013,41(2):469-475

  相似文献   

Soil erosion assessment in Rangit catchment,India through a process-based model in the geospatial environment     

Hari Venkata Durga Rao Korada  Venkateshwar Rao Vala 《国际地球制图》2013,28(5):507-519

The accurate assessment of soil erosion in the spatial environment can give valuable input in designing reservoirs and for preparing watershed management action plans. Rangit River in northeastern India is affected by severe soil erosion, causing reduction in its reservoir capacity. The main aim of the paper is to estimate the soil erosion in the Rangit catchment, India through a process-based soil erosion model that integrates remote sensing and field data in the geospatial domain, and also to identify the problem areas for further watershed management action plans. Various topographic parameters that were derived from land use, soil texture and a digital elevation model were used for the estimation of soil erosion. The Morgan, Morgan and Finny model was used to compute soil erosion. Based on the drainage pattern, the catchment was divided into eight sub-catchments for detailed study. Annual soil erosion was estimated for four years from 2002 to 2005 using the corresponding year’s meteorological data. Estimated soil erosion was compared with the field data in each year and found very good correlation.  相似文献   

Accuracy assessment of MODIS/Terra snow cover product for parts of Indian Himalayas     

Hari Prasad Chelamallu  G. Venkataraman  M.V.R. Murti 《国际地球制图》2013,28(6):592-608

Snow cover mapping is important for snow and glacier-related research. The spatial and temporal distribution of snow cover area is a fundamental input to the atmospheric models, snowmelt runoff models and climate models, as well as other applications. Daily snow cover maps from Moderate Resolution Imaging Spectroradiometer (MODIS) Terra satellite were retrieved for the period between 2004 and 2007, and pixels in these images were classified as cloud, snow or snow-free. These images have then been compared with ground snow depth (SD) measurements from the four observatories located at different parts of Himalayas. Comparison of snow maps with in situ data showed good agreement with overall accuracies in between 78.15 and 95.60%. When snow cover was less, MODIS data were found to be less accurate in mapping snow cover region. As the SD increases, the accuracy of MODIS snow cover maps also increases.  相似文献   

Sensitivity Analysis of Atmospheric Dispersion Simulations by FLEXPART to the WRF-Simulated Meteorological Predictions in a Coastal Environment     

C. V. Srinivas  K. B. R. R. Hari Prasad  C. V. Naidu  R. Baskaran  B. Venkatraman 《Pure and Applied Geophysics》2016,173(2):675-700

  相似文献   

Geochemistry of Mesoproterozoic Deonar Pyroclastics from Vindhyan Supergroup of Central India: Evidences of felsic magmatism in the Son valley     

Meenal Mishra  Vaibhava Srivastava  P. K. Sinha  Hari B. Srivastava 《Journal of the Geological Society of India》2017,89(4):375-385

Deonar Pyroclastics of Semri Group in the Vindhyan Supergroup originated as a result of violent and explosive intrabasinal submarine volcanism during the Mesoproterozoic period. These pyroclastics are rhyolitic to rhyodacitic in composition, comprised of banded, massive, pumiceous flow, breccia, vitric tuff, lapilli and volcanic bomb. The pyroclastic deposits represent welded and non-welded ignimbrites, exhibit typical eutaxitic texture. Mantle normalized multi-element patterns show enrichment in LILs and depletion in HFSFs. Ti, Nb and REE contents show close correlation with Zr, indicating their immobile character. HFSEs and Th/Nb, La/Nb and Zr/Nb values indicate contamination and these signatures represent mixing between mantle-derived rocks and the average continental crust. Deonar Pyroclastics reflect continental rift environment. Felsic magma plausibly generated by underplating of the mature Proterozoic crust of the Indian craton (which acted like a ‘heating lens’) resulted in extensive melting of metabasalt in the lower crustal levels. The high heat flow beneath the Indian shield accentuated heat generation which led to extensive partial melting of metabasalts. Thus, generation of rhyolitic magma occurred along the reactivated deep seated fractures and rifting of the craton, resulting in the explosive intra-basinal felsic vulcanicity in the Vindhyan basin.  相似文献   

Modeling of turbulent dissipation and its validation in periodically stratified region in the Liverpool Bay and in the North Sea     

Kaushik Sasmal  Subhendu Maity  Hari V. Warrior 《Ocean Dynamics》2015,65(7):969-988

  相似文献   

Brazilian Solar Spectroscope (bss)     

Sawant  H.S.  Subramanian  K.R.  Faria  C.  Fernandes  F.C.R.  Sobral  J.H.A.  Cecatto  J.R.  Rosa  R.R.  Vats  H.O.  Neri  J.A.C.F.  Alonso  E.M.B.  Mesquita  F.P.V.  Portezani  V.A.  Martinon  A.R.F. 《Solar physics》2001,200(1-2):167-176

Digital, decimetric (200–2500 MHz) Brazilian Solar Spectroscope (BSS) with high time (10–1000 ms) and frequency (1–10 MHz) resolution is in regular operation since April, 1998, at National Space Research Institute (INPE) at São José dos Campos, Brazil. BSS operates in conjunction with a 9-m diameter polar mounted antenna. It allows to select suitable observing frequency range, frequency and time resolutions and data can be digitized up to 100 channels. BSS has capabilities of quasi-real time display of the ongoing dynamic spectra of the solar activity that enables the observer to modify observational parameters so as to suit a specific type of activity such as spikes and improve the quality of data acquisition and storage. Minimum detectable flux density of the spectroscope, for different combinations of the observational parameters, is 3 s.f.u. Observations are carried out routinely from 11 UT to 19 UT. Necessary software for data acquisition and reductions has been developed in IDL 5.3 environment. Data are available in FITS and ASCII formats. Absolute timing accuracy of the station is less than 3 ms. Here, we present examples of the bursts which have been recorded by BSS and available display facilities.  相似文献   

Short-Term Periodicities in the Time Series of Solar Radio Emissions at Different Solar Altitudes   总被引：1，自引：0，他引：1  

R.P. Kane  Hari Om Vats  H.S. Sawant 《Solar physics》2001,201(1):181-190

A spectral analysis of the time series of daily values of 12 parameters, namely, ten solar radio emissions in the range 275–1755 MHz, 2800 MHz solar radio flux, and sunspot numbers for six continuous intervals of 132 values each during June 1997–July 1999 showed considerable differences from one interval to the next, indicating a nonstationary nature. A 27-day periodicity was noticed in Interval 2 (26.8 days), 3 (27.0 days), 5 (25.5 days), 6 (27.0 days). Other periodicities were near 11.4, 12.3, 13.3, 14.5, 15.5, 16.5, 35, 40, 50–70 days. Periodicities were very similar in a large vertical span of the coronal region corresponding to 670–1755 MHz. Above this region, the homogeneity disappeared. Below this region, there were complications and distortions due to localized solar surface phenomena.  相似文献   

Lightning-generated waves escaping out through plasma holes in the nightside Venus ionosphere     

R. N. Singh  Hari Om Upadhyay 《Journal of Earth System Science》1991,100(4):321-330

The plasma waves in the Venus ionosphere measured by OEFD aboard PVO are analysed. It is shown that these waves are generated by lightning like cloud-to-cloud discharges anywhere in the Venus ionosphere-surface waveguide. The theoretical minimum attenuation for waveguide mode propagation at 5.4 kHz is consistent with the maximum occurrence rate at this frequency. The lightning-generated and globally-propagating signals when encountered with plasma holes or ion-trough structures escape out partially and are detected by the OEFD aboard PVO. The 100 Hz signals can propagate upwards in whistler mode. Even the localized electrostatic mode waves would be converted into electromagnetic waves in the plasma holes and ion-trough regions.  相似文献   

Analyses of fission track etching and annealing phenomena in muscovite     

Hari S. Saini  O. P. Sharma  K. K. Nagpaul 《Pure and Applied Geophysics》1977,115(4):951-959

Variation of fission track density with etching time has been analysed to standardize the etching conditions. The relations between the etching parameters (i.e., temperature, concentration and time) have been established. The differences in unheated samples and samples heated for different times at a constant temperature have been studied Graphs of thermal annealing vs. optimum etching time and of density reduction vs. length shrinkage have been constructed for applications in fission track geochronology.  相似文献