Flood monitoring using microwave remote sensing in a part of Nuna river basin,Odisha, India     

Sananda Kundu  S. P. Aggarwal  Nanette Kingma  Arun Mondal  Deepak Khare 《Natural Hazards》2015,76(1):123-138

  相似文献   

Rapid eco-physical impact assessment of tropical cyclones using geospatial technology: a case from severe cyclonic storms Amphan     

Mishra  Manoranjan  Kar  Dipika  Debnath  Manasi  Sahu  Netrananda  Goswami  Shreerup 《Natural Hazards》2022,110(3):2381-2395

The tropical cyclones are very destructive during landfall, generating high wind speeds, heavy intensive rainfall, and severe storm surges with huge coastal inundations that have massive socioeconomic and ecological catastrophic effects on human beings and the economic well-being. The sizable ecological effects of cyclonic storms cannot be ignored because of the uncertainty of impact, intensity induced by a warming ocean, and sea level rise. The Super Cyclonic Storm Amphan which falls under the category five classifications under the scheme of the India Meteorological Department (IMD), on the basis the maximum sustained wind speeds gusting up to 168 km/h affected parts of West Bengal and Odisha in India, and south-west Bangladesh between May 16 and 20, 2020. In this work, we have focused on the coastal districts of Kendrapada, Bhadrak, Balasore in Odisha, Purba Medinipur, and South Twenty-Four Parganas in West Bengal, India and, Khulna, Barisal division of Bangladesh that have been seriously affected by the Super Cyclonic Storm Amphan. The objective of the study is to analyze the eco-physical assessment of tropical cyclone Amphan using geospatial technology. Therefore, shoreline change detection and enhance vegetation index have been used in this research work to systematically analyze the eco-physical impact parameters of Cyclonic Storm Amphan using ortho-rectified Landsat 8/OLI imagery and MODIS dataset of USGS with high spatial resolutions of 30–500 m. The result highlights that about 60.33% of the total transects of the study area was eroded, but only 24.99% of the total transects experienced accretion, and 14.68% of the total transects depicted stability. The scientific study will benefit coastal managers and policymakers in formulating action plans for coastal zone management, natural resilience, and sustainable future development.

  相似文献   

A Size-Dependent Bonded-Particle Model for Transversely Isotropic Rock and its Application in Studying the Size Effect of Shale     

Zhao  Yun  Mishra  Brijes  Shi  Qingwen  Zhao  Gaobo 《Geotechnical and Geological Engineering》2022,40(11):5437-5453

Geotechnical and Geological Engineering - The bonded-particle model (BPM) method has been used to study the size effect and anisotropy of rock strength. This research proposes a new bonded-particle...  相似文献   

FEA of Urban Rock Tunnels Under Impact Loading at Targeted Velocity     

Mishra  Swapnil  Zaid  Mohammad  Rao  K. S.  Gupta  N. K. 《Geotechnical and Geological Engineering》2022,40(4):1693-1711

Geotechnical and Geological Engineering - This paper presents the effect of impact load and weathering of surrounding rockmass on the deformation behavior of urban underground structures. The FEM...  相似文献   

Ice Height and Backscattering Coefficient Variability over Greenland Ice Sheets Using SARAL Radar Altimeter     

S. Chander  S. K. Mishra  Prakash Chauhan  Ajai 《Marine Geodesy》2015,38(3):466-476

Ice sheets investigation is important with regard to climate change and contribution to the sea level rise or fall. Radar altimetry in complement with laser altimetry can serve as a suitable candidate for precise monitoring of ice sheet evaluations. SARAL due to higher observation into the polar region (up to 82.5°N) can cover nearly 100% of the Greenland ice sheet. Continuous ice tracking mode retracker can provide useful information about ice surfaces, that is, determining the snow coverage, ice sheet transaction margin, and the evolution of snow depth during winter more accurately. This study present the results obtained with SARAL satellite Altika radar altimeter over the Greenland ice sheet region. The altimeter high rate waveforms products are used for utilizing the full capability of the instrument. High resolution DEM (1 km) generated using ICESAT/GLAS altimeter has been used for selecting the good quality data over the study region. Four different retrackers—Ocean, ICE-1, ICE-2, and Sea-Ice—were tested on the SARAL altimeter data set and compared with the DEM extracted ice sheet elevations. Three different data analysis—region of interest (ROI), track analysis, and cross-over analysis—were performed for in-depth analysis of the ice height changes and back scattering coefficient variability. ROI's (1° × 0.5°) were selected based on accumulation dry snow zone, percolation zone, wet snow zone, and ablation zone. Finally to observe the effect of Ka band, SARAL results has been compared with the Envisat altimeter in terms of back scatter and error in the height retrieval due to penetration problem within the ice sheet layer. The new SARAL data set confirms the potential of ice altimetry and provides a new opportunity to monitor the ice sheet surface topography evolution.  相似文献   

Pressure anisotropy and dark energy models in scale invariant theory of gravitation     

B. Mishra  P. K. Sahoo  S. K. Tripathy 《Astrophysics and Space Science》2015,356(1):163-171

  相似文献   

Improving multimodel weather forecast of monsoon rain over China using FSU superensemble   总被引：3，自引：0，他引：3  

T. N. KRISHNAMURTI  A. D. SAGADEVAN  A. CHAKRABORTY  A. K. MISHRA  A. SIMON 《大气科学进展》2009,26(5):813-839

In this paper we present the current capabilities for numerical weather prediction of precipitation over China using a suite of ten multimodels and our superensemble based forecasts. Our suite of models includes the operational suite selected by NCARs TIGGE archives for the THORPEX Program. These are: ECMWF, UKMO, JMA, NCEP, CMA, CMC, BOM, MF, KMA and the CPTEC models. The superensemble strategy includes a training and a forecasts phase, for these the periods chosen for this study include the months February through September for the years 2007 and 2008. This paper addresses precipitation forecasts for the medium range i.e. Days 1 to 3 and extending out to Day 10 of forecasts using this suite of global models. For training and forecasts validations we have made use of an advanced TRMM satellite based rainfall product. We make use of standard metrics for forecast validations that include the RMS errors, spatial correlations and the equitable threat scores. The results of skill forecasts of precipitation clearly demonstrate that it is possible to obtain higher skills for precipitation forecasts for Days 1 through 3 of forecasts from the use of the multimodel superensemble as compared to the best model of this suite. Between Days 4 to 10 it is possible to have very high skills from the multimodel superensemble for the RMS error of precipitation. Those skills are shown for a global belt and especially over China. Phenomenologically this product was also found very useful for precipitation forecasts for the Onset of the South China Sea monsoon, the life cycle of the mei-yu rains and post typhoon landfall heavy rains and flood events. The higher skills of the multimodel superensemble make it a very useful product for such real time events.  相似文献   

Uplift Capacity of Single Bent Pile and Pile Group Considering Arching Effects in Sand     

Amit Shelke  Sudib Mishra 《Geotechnical and Geological Engineering》2010,28(4):337-347

In this paper an analytical method has been proposed to predict the net ultimate uplift capacity of the single bent pile and pile group with a bent embedded in sand considering arching effects. Arching develops due to relative compressibility of sand relative to pile which activates the soil-pile friction. The method takes into consideration the embedded length (L), diameter of the pile (d), bent angle, surface characteristics of pile, group configuration, spacing of the pile group and the soil properties. Log spiral failure surface with parabolic arch shape was assumed in the analysis. Theoretical investigation for uplift capacity was been carried out for the single bent pile and group of pile (2 × 1, 2 × 2) embedded in sand. The variable used in the analysis were embedded length to pile diameter (L/d = 15, 20 and 25), spacing in the group (3d, 4d and 6d) and angle of bent (6°, 14° and 20°). Typical charts for evaluation of net ultimate uplift capacity for pile groups are presented through the figures. Comparison of theoretical results shows good agreement with established experimental results.  相似文献   

On the upstream mobility scheme for two-phase flow in porous media     

Siddhartha Mishra  Jérôme Jaffré 《Computational Geosciences》2010,14(1):105-124

When neglecting capillarity, two-phase incompressible flow in porous media is modelled as a scalar nonlinear hyperbolic conservation law. A change in the rock type results in a change of the flux function. Discretising in one dimension with a finite volume method, we investigate two numerical fluxes, an extension of the Godunov flux and the upstream mobility flux, the latter being widely used in hydrogeology and petroleum engineering. Then, in the case of a changing rock type, one can give examples when the upstream mobility flux does not give the right answer.  相似文献   

The evolution of the Palim granite in the Bastar tin province, Central India   总被引：1，自引：0，他引：1  

N. Pal  D. C. Pal  B. Mishra  F. M. Meyer 《Mineralogy and Petrology》2001,72(4):281-304

Summary The Palim granite, hosted by the metasedimentary country rocks in the Bastar tin province, is a heterogeneous pluton that comprises hornblende granite, biotite granite and two-mica granite. Spherical inhomogeneous surmicaceous enclaves occur within the granites with coarse grained cores of muscovite mantled by finer muscovite-quartz-biotite (± sillimanite) rims. Geochemical features imply that the granites are highly evolved and geochemically distinct. Petrographic and geochemical considerations point towards a transition from metaluminous I-type hornblende-bearing granite in the south to peraluminous volatile-enriched S-type like lithologies (biotite and two-mica granites) towards north. Modeling of highly incompatible elements such as Nb and Cs, implies 31 to 33% assimilated fractional crystallization of a melt with an initial composition close to that of the hornblende granite to form the two-mica granite. Hornblende geobarometry, plagioclase-hornblende thermometry (in hornblende granite) and phengite barometry (in two-mica granite), yield P-T estimates of 5–7 kb/725°–760 °C, and 6 kb/700 °C, respectively. The study further implies that a genetic link exists between granite magmatism and the formation of tin pegmatites in the region. The preponderance of peripheral pegmatites to the north-east of the Palim granite is regarded a result of outward crystal-melt fractionation and tectonic tilting of the pluton. Received October 21, 1999; revised version accepted December 12, 2000  相似文献