Rice-acreage estimation for Orrisa using remotely sensed data     

S. Panigrahy  J. S. Parihar  N. K. Patel  V. K. Dadhwal  T. T. Medhavy  B. K. Ghose  N. Ravi  K. C. Pani  B. K. Panigrahy  V. N. Sridhar  R. R. Mohanty  S. K. Nanda  D. P. Tripathy  P. K. Mishra  H. P. Bhatt  S. R. Oza  S. Sudhakar  K. S. Sudha  P. Kumar  N. K. Das 《Journal of the Indian Society of Remote Sensing》1991,19(1):17-26

Rice is one of the most important foodgrains grown in India. Attempts have been made to estimate kharif rice acreage of Orissa state since 1986 using digital remote sensing data from Landsat MSS/TM and/or IRS-1A. Accuracies of the estimates obtained have been evaluated against BES (Bureau of Economics and Statistics) estimate. This paper describes the methodology adopted for rice acreage estimation of Orissa state, the results obtained for three years, i.e. 1986–87, 1988–89 and 1989–90, and their accuracy.  相似文献   

The nature of horizontal anomalies and magnetotelluric impedance over southern India     

A. K. Agarwal  J. T. Weaver 《Journal of Earth System Science》1990,99(4):681-692

The nature of horizontal anomalies and anomalous current systems in the region of the southern Indian peninsula is theoretically calculated with the aid of a thin sheet algorithm for northward and westward polarizations of a uniform inducing magnetic Held of period 20 min. The numerical model of the geoelectric structure is the one devised by Agarwal and Weaver (1989). The model results indicate the correspondence between the general features of the computed horizontal anomalies and the observed anomalies both at temporary array stations and at two permanent magnetic observatories (ANN and TRD). On the basis of model estimates of apparent resistivity and phase it is suggested that a one-dimensional interpretation of the sub-surface conductivity structure is valid near two of the array stations, whereas at all other coastal and inland stations, two-or three-dimensional interpretations of magnetotelluric (MT) data are required.  相似文献   

Performance of image classification on hyperspectral imagery for lithological mapping   总被引：1，自引：0，他引：1  

Nisha Rani  Venkata Ravibabu Mandla  Tejpal Singh 《Journal of the Geological Society of India》2016,88(4):440-448

SVM and SAM classifiers for the lithological mapping using Hyperion data in parts of Gadag schist belt of western Dharwar craton, Karnataka, India were used. The main objective of the present study is to assess and compare the potential use of Hyperion data set for lithological mapping. Accuracy assessment of the derived thematic maps was based on the analysis of the confusion matrix statistics computed for each classification map. For consistency, the same set of validation points were used in evaluating the accuracy of the lithological thematic maps produced. On the basis of the accuracy assessment results, it appears that SVM generally outperformed the SAM classifier in both OA accuracy and individual classes’ accuracies. OA accuracy and Kc for SVM is 96.93% and 0.9655, whereas for SAM it is 74.02% and 0.7085 respectively. SVM classification is the best in describing the spatial distribution and the cover density of each lithology, as was also indicated from the statistics of the individual class results. The individual class accuracy were also analyzed for the SVM and the result show that PA ranges from 87% to 100% and UA ranges from 91% to 100%, whereas for SAM ranges from 15% to 95%, and from 31% to 100% respectively. The SVM method could effectively classify and improve on the existing geological map for the Gadag schist belt (GSB) using hyperspectral data. The results could be validated through field visits. Therefore, it is concluded that hyperspectral remote sensing data can be efficiently used to improve existing maps, especially in areas where same rock types show variable degree of alteration over smaller spatial scales.  相似文献   

Assessing village-level carbon balance due to greenhouse gas mitigation interventions using EX-ACT model     

Ch. Srinivasarao  Y. Sudha Rani  V. Girija Veni  K. L. Sharma  G. R. Maruthi Sankar  J. V. N. S. Prasad  Y. G. Prasad  K. L. Sahrawat 《International Journal of Environmental Science and Technology》2016,13(1):97-112

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Devaluation of female work participation with urbanization: a case of peri-urban Ahmedabad     

Sikarwar  Ankit  Chattopadhyay  Aparajita  Jaiswal  Ajit Kumar  Rani  Ritu 《GeoJournal》2022,87(1):319-331

GeoJournal - Urban expansion of the Indian metropolitan cities has reached the rural peripheries. There have been social, economic, and environmental consequences of this process of...  相似文献   

Influence of natural and anthropogenic activities on UV Index variations – a study over tropical urban region using ground based observations and satellite data     

K. V. S. Badarinath  Shailesh Kumar Kharol  V. Krishna Prasad  Anu Rani Sharma  E. U. B. Reddi  H. D. Kambezidis  D. G. Kaskaoutis 《Journal of Atmospheric Chemistry》2008,59(3):219-236

Measurements of total ozone column and solar UV radiation under different atmospheric conditions are needed to define variations of both UV and ozone and to study the impact of ozone depletion at the Earth’s surface. In this study, spectral and broadband measurements of UV-B irradiance were obtained along with total ozone observations and aerosol optical depth measurements in the tropical urban region of Hyderabad, south India. We specifically used an Ultra-Violet Multifilter Rotating Shadow band Radiometer (UVMFR-SR), to measure UV irradiance in time and space. To assess the aerosol and O₃ effects on ground-reaching UV irradiance, we used measurements from a Microtops II sun photometer in addition to the Tropospheric Ultraviolet Visible radiation (TUV) model. We also assessed the Defense Meteorological Satellite Program – Operational Line Scanner (DMSP-OLS) night time satellite data for inferring biomass burning fires during the study period. Results clearly suggested a negative correlation between the DMSP-OLS satellite derived fire count data and UVMFR-SR data suggesting that aerosols from biomass burning are directly attenuating UV irradiance in the study region. Also, correlation analysis between UV index and ozone measurements from sun photometer and TOMS-Ozone Mapping Instrument (OMI) indicated a clear decrease in ground reaching UV-B irradiance during higher ozone conditions. The higher levels are attributed to photochemical production of O₃ during the oxidation of trace gases emitted from biomass burning. Results also suggested a relatively high attenuation in UV irradiance (~6% higher) from smoke particles than dust. We also found a relatively good agreement between the modeled (TUV) and measured UV irradiance spectra for different atmospheric conditions. Our results highlight the factors affecting UV irradiance in a tropical urban environment, south India.  相似文献   

Variations in CO,O<Subscript>3</Subscript> and black carbon aerosol mass concentrations associated with planetary boundary layer (PBL) over tropical urban environment in India     

K. V. S. Badarinath  Anu Rani Sharma  Shailesh Kumar Kharol  V. Krishna Prasad 《Journal of Atmospheric Chemistry》2009,62(1):73-86

Carbon monoxide (CO), Ozone (O₃) and Black Carbon (BC) aerosol mass concentrations in relation to planetary boundary layer (PBL) height measurements were analyzed from January–December, 2008 over tropical urban environment of Hyderabad, India. DMSP-OLS night-time satellite data were analyzed for fire occurrence over the region and its correlation with pollution concentrations over the urban region. Results of the study suggested considerable increase in CO and BC concentrations during early morning hours. Higher concentration of BC, CO and ozone was observed during pre-monsoon, post-monsoon and winter and lowest concentrations exhibited during monsoon season. NCEP/NCAR reanalysis winds suggested long range transport of aerosols and trace gases from forest fires are enhancing the pollutant concentrations over the study area.  相似文献   

Modification of fold geometry in Almora Crystalline Shear Zone,Lesser Himalaya,India     

K. K. Agarwal  Nigar Jahan  Amar Agarwal 《Journal of the Geological Society of India》2010,75(2):411-414

The folds generally initiate at several discrete points along a layer or multilayer undergoing compressional forces. These compressional forces often lead to rotation of fold segments and in all such regimes, folds are strongly asymmetrical and are in complete agreement with the direction in which the force is applied and also with the related thrust sheet movement. This paper illustrates the progressive change in fold geometry with increasing compression and ductile shearing using natural example as studied in the Almora Crystalline Zone (ACZ).  相似文献   

Determination of structure parameters using sodar     

S. P. Singal  B. S. Gera  S. K. Agarwal 《Boundary-Layer Meteorology》1982,23(1):105-114

The temperature structure parameter at Delhi has been determined from intensity information of sodar observations for a period of one year at a height of 200 m in the planetary boundary layer applying the moisture correction due to Wesely. It is found that mean monthly values of the temperature structure parameter for stable and unstable conditions are quite different during the monsoon months (July to October) but are rather similar during the other months.The refractive index structure parameter values have been calculated for the dry atmosphere (optical) as well as by applying the moisture correction (radio) due to the Sirkis and Ottersten et al. models. It is found that the dry atmospheric values of the parameter are generally lower than the humidity-corrected values. The sodar-measured values of the parameter under dry atmospheric conditions have been examined in relation to the Hufnagel and Tsvang models.  相似文献   

A generalized method for various data processing techniques in gravity interpretation     

B. N. P. Agarwal  Jagdeo Singh 《Pure and Applied Geophysics》1976,114(6):975-982

Summary The various data processing techniques (downward continuation, first and second derivatives and their downward continuation) used in gravity interpretation, are analogous to different types of linear filtering operations whose theoretical filter (amplitude) responses can be derived from by suitably choosingN andd, whereu andv are angular frequencies in two perpendicular directions,d the height or depth of continuation in unit of grid interval; andN denotes the order of the vertical derivative. By incorporating a mathematical smoothing function, ( being the smoothing parameter) in the theoretical filter response function, it has been possible, by selecting a suitable value of smoothing parameter, to establish an approximate equivalence of the effect of the mathematical smoothing with the inherent smoothing introduced, because of the numerical approximation (approximation error) for practically all data-processing techniques. This approximate equivalence leads to a generalized method of computing sets of weight coefficients for various data-processing techniques from filter response matching method. Several sets of weight coefficients thus have been computed with different smoothing parameter. The amplitude response curves of the various existing sets of weight coefficients have also been calculated for assessing the quality of the approximation in achieving the desired filtering operation.  相似文献