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Venkata Giri Raj Kumar Konda Venkatesh Reddy Chejarla Venkata Ravibabu Mandla Vani Voleti Nagaveni Chokkavarapu 《Arabian Journal of Geosciences》2018,11(2):35
Developing nations are abandoned against tropical cyclones because of climatic changeability; the atmosphere is probably going to expand the recurrence and extent of some outrageous climate and calamity occasions. Urban areas and towns arranged along the coastline front belt in Visakhapatnam region experienced serious harm because of Hudhud cyclone, which happened on October 12, 2014. The fundamental motivation behind this exploration was to distinguish the vegetation damage in Visakhapatnam and neighbouring towns. In this analysis, Landsat-8 satellite datasets procured prior and then afterward the cyclone have been utilized; image processing techniques have been completed to evaluate the progressions of pre- and post-disaster condition. Vegetation index strategy was utilized to assess the damage to vegetation. Arrangement results and land utilize land cover change investigation demonstrate that 13.25% of agriculture Kharif and 31.1% of vegetation was damaged. Normalized difference vegetation index (NDVI) maps were produced for the previously, then after the cyclone circumstance, and vegetation biomass damage was evaluated in Visakhapatnam and Bhimunipatanam. General loss of vegetation in both the spots was 30.67 and 43.37 km2. The result of this review can be utilized by decision makers for the post-disaster support for rebuilding of influenced regions. 相似文献
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Salles Lucas A. Vani Bruno C. Moraes Alison Costa Emanoel de Paula Eurico R. 《Surveys in Geophysics》2021,42(4):999-1025
Surveys in Geophysics - Over the last 15 years, the satellite constellation of the global positioning system (GPS) has been modernized for more precise applications, with the introduction... 相似文献
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The Lonar crater in India provides an ample opportunity to in-depth analysis of crater morphology. This paper focuses on the topographical mapping of Lonar crater with detailed study on slope, regional analysis and its rim signature. The slope of the crater (inner wall region) reveals that the northern part is steep and southern part is gentle, while, on the outer region, the northern part is flat and the later shows abrupt variations. On regional topographical mapping (~4 crater radii) around the Lonar crater, it was observed that the terrain descends from NE to SW. An elevation difference of ~20 m was observed between the N and S part, infers that the pre-impact terrain is a descending one. The crater northern rim was elevated ~10 m to ~15 m, whereas southern rim was elevated ~50 m above the average regional surface. We found that the topographically lower southern region was abruptly changed and the rim has been uplifted to an elevation of ~604 m above the average regional elevation (~555 m). This result infers that the post-impact topography was abruptly altered along the S side. The crater rim signature extracted from highest point all along the rim shows a near flat surface on north, whereas the V-shaped protrusion shows active erosion and degradation on the west. Thus, DEM based topographic study has opened a new insight about the Lonar crater, from differential rim uplift, alteration along the rim and finally revealed that the impact crater formed on a descending terrain. 相似文献
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Anto A. Micheal K. Vani S. Sanjeevi 《Journal of the Indian Society of Remote Sensing》2014,42(2):445-451
Lunar surface exploration is increasing rapidly with priority being given to precision of lunar soft landing. Lunar soft landing is achieved when craters and grabens are used as navigational landmarks. Grabens are formed from localized tensional stress fields or from near-surface dike emplacement. These tectonic features tend to have consistently straight or accurate parallel-striking walls bounded by steep, inward-dipping normal faults. Aiming at navigational application, a novel approach for automatic graben detection based on Hessian technique has been implemented on Digital Terrain Model (DTM) of lunar image. The Hessian technique uses gradient change as a key parameter to identify grabens. Adaptive Binarization using Otsu method is used to extract graben features from the Hessian image. Features such as small grabens and craters are removed using morphological operations, resulting in significant appearance of grabens. The experiment is conducted in different DTM images of lunar surface and the results indicate 90 % of the grabens are detected. The statistical results are evaluated based on visual interpretation, for both automatic and manual graben detection. It is observed that the proposed automatic graben detection technique gives better results than the manual detection. 相似文献
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Paolo Tomassetti Emma Persia Isabel Mercatali Danilo Vani Veronica Marussso Salvatore Porrello 《Marine pollution bulletin》2009,58(4):533-541
The effects of solid organic wastes from a marine fish farm on sediment was tested using macrobenthic fauna as biological indicators. Impact on benthic fauna was evaluated in the vicinity of a fish farm in the Tyrrhenian Sea (Western Mediterranean) between July 2001 and October 2002. Changes in benthic community structure were investigated using multivariate, distributional and univariate analyses (diversity indices, AMBI and M-AMBI). The results showed sharp disturbance of assemblages under the cages and no effects in the area more than 25 m from the cages. Sediment alterations were related to an increase in farmed biomass and its wastes, as well as to low current speed that allowed accumulation of organic matter on the sea floor. It was possible to follow the ecological succession from slightly altered assemblages to heavily polluted ones in the very short period of a single fish fattening cycle (15 months). 相似文献
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