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41.
Bhardwaj Pandit G. L. Sivakumar Babu 《Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards》2018,12(2):152-168
Traditional reliability-based design methodologies often involve selection of design which is of lowest cost and satisfies safety requirements. But, this design is sensitive to variation in statistics of input parameters (noise parameters) and might become unsatisfactory if an underestimation of coefficient of variation of input parameters is made. A relatively new design methodology known as robust geotechnical design (RGD) is applied for the case of reinforcement of rock slope using end-anchored rock bolts. This ensures selection of a cost-effective and safe design for which probability of failure (Pf) of reinforced rock slope is least sensitive to the noise parameters. Reliability-based RGD approach involves evaluation of Pf for each design with different possible noise parameters. Finding Pf for the complex geotechnical structure is computationally expensive, and thus an augmented radial basis function-based response surface is used as a surrogate to the finite element model of rock slope. This response surface, being very efficient, also performs well for a range of values of noise parameters. Later, minimum distance algorithm is applied to obtain a cost-effective and robust design. Finally, a comparison is made in the costs between two robust designs obtained for different target probability of failure for the same rock slope. 相似文献
42.
Aitkenhead Isabella Kuleshov Yuriy Watkins Andrew B. Bhardwaj Jessica Asghari Atifa 《Natural Hazards》2021,109(2):1425-1455
Natural Hazards - The Northern Murray–Darling Basin (MDB) is a key Australian agricultural region requiring efficient Agricultural Drought Management (ADM), focused on resilience. Although a... 相似文献
43.
Meenu Rani Sufia Rehman Haroon Sajjad B. S. Chaudhary Jyoti Sharma Sandeep Bhardwaj Pavan Kumar 《Natural Hazards》2018,94(2):711-725
Vizianagaram–Srikakulam coastal shoreline consisting of beaches, mangrove swamps, tidal channel and mudflats is one of the vulnerable coasts in Andhra Pradesh, India. Five site-specific parameters, namely rate of geomorphology, coastal elevation, coastal slope, shoreline change and mean significant wave height, were chosen for constructing coastal vulnerability index and assessing coastal landscape vulnerability. The findings revealed a shift of 2.5 km in shoreline towards the land surface because of constant erosion and that of 1.82 km towards the sea due to accretion during 1997–2017. The rate of high erosion was found in zones IV and V, and high accretion was found in zones II and III. Coastal vulnerability index analysis revealed constant erosion along shoreline and sea level rise in the study area. Most of the coast in zone V has recorded very high vulnerability due to erosion, high slope, significant wave height and sea level rise. Erosion and accretion, significant wave height, sea level rise and slope are attributed to high vulnerability in zones III and IV. Zone II recorded moderate vulnerability. Relatively lower slope, mean sea wave height and sea level rise have made this zone moderately vulnerable. Very low vulnerability was found in zone I, and low vulnerability was recorded in zone II. Accretion, low slope and low sea level rise were found to be causative factors of lower vulnerability. Thus, zones III, IV and V should be accorded higher priorities for coastal management. The findings can be helpful in coastal land planning and management and preparing emergency plans of the coastal ecosystems. 相似文献
44.
Acta Geochimica - Paleoproterozoic Bijawars of the Sonrai basin consists of (a) Sonrai (mostly carbonate carbonaceous shale and phosphatic breccia) and (b) Solda Formations (commonly chloritic and... 相似文献
45.
Deforestation is recognized as one of the most significant components in LULCC and global changes scenario. It is imperative
to assess its trend and the rate at which it is occurring. The changes will have long-lasting impact on regional climate and
in turn on biodiversity. Present study was taken up in Kanakapura and surrounding areas located on the fringes of Western
Ghats biodiversity hot-spots. Temporal satellite data from Landsat was classified into forest cover maps. Drivers of forest
cover changes such as roads and settlements were used in order to create predicted map of the region using GEOMOD tool in
Idrisi Andes. The predicted map was then validated using actual land cover map of same year prepared from Landsat data. The
validated map was found to be 84.26 % accurate. The validation was also tested using ROC approach which was found to be 0.614.
The model was then further extended to predict forest cover losses for year 2015. The results highlight ongoing deforestation
in the areas adjoining Western Ghats. It also presents an application of the tool and the validation methods which can be
used in predictive modeling related studies. 相似文献
46.
Natural Hazards - Tropical cyclones (TCs) of the Bay of Bengal (BoB) cause catastrophic loss over the coasts at the time of landfall in India, Bangladesh, Myanmar and Sri Lanka. To strengthen... 相似文献
47.
Mixed layer depth (MLD) variability in the Eastern Equatorial Indian Ocean (EEIO) from a hindcast run of an Ocean General Circulation Model (OGCM) forced by daily winds and radiative fluxes from NCEP-NCAR reanalysis from 2004 to 2006 is investigated. Model MLD compares well with the ～20,000 observations from Argo floats and a TRITON buoy (1.5°S and 90°E) in the Indian Ocean. Tests with a one-dimensional upper ocean model were conducted to assess the impact on the MLD simulations that would result from the lack of the diurnal cycle in the forcing applied to the OGCM. The error was of the order of ～12 m. MLD at the TRITON buoy location shows a bimodal pattern with deep MLD during May–June and December–January. MLD pattern during fall 2006 was significantly different from the climatology and was rather shallow during December–January both in the model and observation. An examination of mixed layer heat and salt budget suggested salinity freshening caused by the advective and vertical diffusive mixing to be the cause of shallow MLD. 相似文献
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49.
Rashmi SrivastavaValentin A. Krassilov 《Cretaceous Research》2012,33(1):66-71
In India, potential sources of angiosperm macrofossils are the intertrappean cherts of Rajmahal Hills, palynologically and radiometrically dated as Barremian-Aptian. However, our revision of the previously reported flower-like and fruit-like fossils from the Rajmahal Formation does not confirm their angiosperm affinities. Instead they are related to bennettitalean and pentoxylean gymnosperms. At the same time, the underground storage organs and supposed feeding marks on Carnoconites seeds revealed in the course of this study suggest angiosperm-like habits in the Indian Pentoxylon plant. 相似文献
50.
Hydrograph separation and precipitation source identification using stable water isotopes and conductivity: River Ganga at Himalayan foothills 总被引：3，自引：0，他引：3
A. S. Maurya Miral Shah R. D. Deshpande R. M. Bhardwaj A. Prasad S. K. Gupta 《水文研究》2011,25(10):1521-1530
The observed retreat of several Himalayan glaciers and snow packs is a cause of concern for the huge population in southern Asia that is dependent on the glacial‐fed rivers emanating from Himalayas. There is considerable uncertainty about how cryospheric recession in the Himalayan region will respond to climate change, and how the water resource availability will be affected. As a first step towards quantifying the contribution of glacier‐melt water, hydrograph separation of River Ganga at Rishikesh into its constituent components, namely (i) surface runoff, (ii) glacial ice‐melt and (iii) groundwater discharge has been done in this paper. A three‐component mixing model has been employed using the values of δ18O and electrical conductivity (EC) of the river water, and its constituents, to estimate the time‐varying relative fraction of each component. The relative fraction of the surface runoff peaks (70–90%) during winter, due to the near‐zero contribution of glacial ice‐melt, essentially represents the melting of surface snow from the catchment. The contribution of glacial ice‐melt to the stream discharge peaks during summer and monsoon reaches a maximum value of ～40% with an average of 32%. The fraction of groundwater discharge varies within a narrow range (15 ± 5%) throughout the year. On the basis of the variation in the d‐excess values of river water, it is also suggested that the snow‐melt and ice‐melt component has a significant fraction derived from winter precipitation with moisture source from mid‐latitude westerlies (also known as western disturbances). Copyright © 2010 John Wiley & Sons, Ltd. 相似文献