FOREST FIRE BURNT AREA EXTRACTION USING FUZZY INTEGRATION OF MULTI-SENSOR SATELLITE DATA FOR THE HIMALAYAN STATE

Burnt area assessment due to forest fires is an important aspect to estimate the extent of loss of biodiversity which has become feasible even in hilly and inaccessible areas with the help of geospatial technologies. But satellite data also has some limitations as it increases commission error by misclassifying non-burnt areas as burnt areas. To reduce this commission error, present study has attempted to integrate multi-sensor satellite data to characterize and extract forest fire burnt areas in Uttarakhand which is a fire prone hilly state in Western Himalaya. Landsat-8 and Sentinel-2 optical datasets have been used to calculate eleven vegetation/burn indices to identify burn patches for fire season of 2022 (February to June). These vegetation/burn indices have been calculated from Landsat-8 and Sentinel-2 datasets and integrated using Fuzzy Logic Modelling to get characterized forest fire burnt area maps. Accuracy assessment has been done using Moderate Resolution Imaging Spectroradiometer (MODIS) and Visible Infrared Imaging Radiometer Suite (VIIRS) active fire points for the characterized map of burnt area by Landsat-8, Sentinel-2 and combining indices from both sensors. The fuzzy map of burnt area using Landsat-8 showed the accuracy of 66.25%, while Sentinel-2 showed accuracy of 59.79% and the integration of fuzzy burnt area maps of both sensors showed the highest accuracy of 79.66%. This information of characterized burnt areas of a region can help forest managers to identify high vulnerable areas to focus on during the fire season to prevent the losses to natural resources, life and property in the region

LONG-TERM THERMAL ANOMALY DETECTION AND MAPPING AT PIXEL LEVEL USING A GOOGLE EARTH ENGINE TOOL

Frequency of extreme weather events such as cloudbursts, heatwaves etc. have increased as an outcome of changing climate. Identification of the pattern of extreme temperature events is important since it governs various events such as heatwaves, wildfires, droughts, storms, coldwaves etc. Moderate Resolution Imaging Spectroradiometer (MODIS) provides Land Surface Temperature (LST) data at 1 kilometre of spatial resolution at daily interval that can help in the identification and mapping of the anomalies in the temperature at pixel level. This study proposes a global-scale daily long-term thermal anomaly detection tool made using Google Earth Engine (GEE) App. This open source tool with the name of ‘Deviation from Mean’ uses the MODIS LST data available from 2000 till date to detect temperature anomaly based on the deviation of temperature of any day (chosen by the user) from the long-term climatological mean. It also generates a time-series plot of temperature values of any pixel for any date for last 24 years i.e. 2000–2023 in the graphical form to analyze the variation in the temperature over the time. A case study has also been done using the tool to highlight the thermal anomaly experienced over the Indian sub-continent during March-April, 2022 and 2023. This tool is capable of providing thermal anomaly information at global, regional as well as local level that can help in taking region-specific mitigation measures

Generalized Gravi-Electromagnetism

A self consistant and manifestly covariant theory for the dynamics of four charges (masses) (namely electric, magnetic, gravitational, Heavisidian) has been developed in simple, compact and consistent manner. Starting with an invariant Lagrangian density and its quaternionic representation, we have obtained the consistent field equation for the dynamics of four charges. It has been shown that the present reformulation reproduces the dynamics of individual charges (masses) in the absence of other charge (masses) as well as the generalized theory of dyons (gravito - dyons) in the absence gravito - dyons (dyons). key words: dyons, gravito - dyons, quaternion PACS NO: 14.80H

Geo-Informatics in India: Major Milestones and Present Scenario

Geo-informatics has emerged globally as a useful tool to address spatial problems with significant societal implications that require integrative and innovative approaches for analysis, modelling, managing, and archiving of extensive and diverse data sets. Breakneck technological development and availability of satellite based data and information services in public domain along with real time geo-data n through participatory approaches, in the two last decades have led to a sea-change in our know-how of our natural resources and their effective management at various levels. It has led to a realization that every phenomena and requirement in our day to day life has some spatial, or geographic component that can be predicted and governed more effectively through geoinformatics tool. India also has come a long way in effective utilization of geoinformatics for various applications. This quantum leap owes its foundation in a humble beginning about half century back and almost parallel developments in the country’s space programme to a current level where it touches almost all areas of life and living. Though geoinformatics technology (GIT) is believed to reach satisfactory level in the country, Indian geospatial community faces critical challenges with respect to research, education and training along with enhanced the access to the stakeholders and mobilization of the workforce, that are crucial in further penetration of this technology in context to India’s development. In this paper we have critically reviewed milestones of GI development and its current utilization status in Indian context

NATURE OF 4f ELECTRONS IN Tb OXIDES BY X-RAY ABSORPTION SPECTROSCOPY

On étudie l'évolution de la valence du Terbium dans les oxydes Tb2O3, Tb4O7 et TbO2 à partir des spectres MIV-V et LIII. Les spectres de Tb4O7 correspondent exactement à la somme pondérée (50%) des spectres de Tb2O3 et de TbO2. L'analyse des spectres de Tb2O3 indique que le dernier électron 4f reste localisé dans la couche 4f. Dans le cas de TbO2 on interprète les structures supplémentaires par la délocalisation de l'electron 4f. Ce comportement spécifique et son influence sur les liaisons dans ces oxydes font l'objet de la discussion.The MIV-V and LIII absorption spectra of Tb2O3, Tb4O7 and TbO2 reveal a clear evolution of Tb valence in these oxides. The Tb4O7 spectra are found to be 50% weighted sum of Tb2O3 and TbO2 individual spectra. These observations indicate that in Tb2O3 the last 4f electron remains localized in the 4f shell whereas it shows a specific behaviour in TbO2. The delocalization of the last 4f electron in TbO2 leads to the observation of complex spectral features. The nature of the 4f electron and its influence on the type of bonding in these oxide is discussed

In : inland fisheries management

Not AvailableNot AvailableNot Availabl

EXAFS AND NES STUDIES OF RARE EARTH AND TRANSITION METAL CATALYSTS

Une série de composés intermétalliques RNix (R = La, Ce ; x = 2 ou 5) et CeNiAl ainsi que les hydrures stables RNi2H4 et CeNiAlH3.3 ont été testés dans la réaction d'hydrogénation du monoxyde de carbone. Ces composés présentent une période d'activation qui a pu être reliée à la décomposition des composés initiaux en un système nickel sur oxyde de terre rare. Les conditions d'activation et l'activité catalytique dépendent fortement de la composition initiale et du taux de décomposition de l'intermétallique ou de l'hydrure, alors que la sélectivité ne varie pas.A series of RNix (R = La, Ce and x = 2 or 5) and CeNiAl intermetallics and stable RNi2H4 and CeNiAlH3.3 hydrides have been tested in CO hydrogenation. The observed increase of activity with time on stream has been correlated to the decomposition of the compounds into nickel supported on rare-earth oxide. Catalytic activity and time and temperature conditions of activation are related to the initial composition and the transformation of the compounds, whereas selectivity is unchanged