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11.
Amit Bhardwaj Vasubandhu Misra Akhilesh Mishra Adrienne Wootten Ryan Boyles J. H. Bowden Adam J. Terando 《Climatic change》2018,147(1-2):133-147
We present results from 20-year “high-resolution” regional climate model simulations of precipitation change for the sub-tropical island of Puerto Rico. The Japanese Meteorological Agency Non-Hydrostatic Model (NHM) operating at a 2-km grid resolution is nested inside the Regional Spectral Model (RSM) at 10-km grid resolution, which in turn is forced at the lateral boundaries by the Community Climate System Model (CCSM4). At this resolution, the climate change experiment allows for deep convection in model integrations, which is an important consideration for sub-tropical regions in general, and on islands with steep precipitation gradients in particular that strongly influence local ecological processes and the provision of ecosystem services. Projected precipitation change for this region of the Caribbean is simulated for the mid-twenty-first century (2041–2060) under the RCP8.5 climate-forcing scenario relative to the late twentieth century (1986–2005). The results show that by the mid-twenty-first century, there is an overall rainfall reduction over the island for all seasons compared to the recent climate but with diminished mid-summer drought (MSD) in the northwestern parts of the island. Importantly, extreme rainfall events on sub-daily and daily time scales also become slightly less frequent in the projected mid-twenty-first-century climate over most regions of the island. 相似文献
12.
Sumira Malik Shristi Kishore Jutishna Bora Vishal Chaudhary Anjali Kumari Preeti Kumari Lamha Kumar Abhaya Bhardwaj 《洁净——土壤、空气、水》2023,51(3):2200044
In the past few years, microalgae have gained huge recognition from the scientific community due to their potential applications in the production of a broad array of bio-based products varying from biofuels to nanoparticles. Due to their elevated growth rate, high tolerance to various types of abiotic stresses, and complex metabolic capacity, microalgae can be used as promising tools for the attainment of a circular bioeconomy. Moreover, they can simply utilize nutrients from wastewater for biorefinery purposes, resulting in resource recovery coupled with wastewater treatment. However, due to their sub-optimal yields and high production costs, microalgae-based bio-products have not yet been commercialized. This review provides insights into the employment of microalgae as an efficient bioresource for the treatment of wastewater with simultaneous enactment as a biorefinery to produce biofuels, biochar, bioplastic, fertilizers, and other high-value bioproducts. Furthermore, the application of microalgal nanoparticles in wastewater treatment and prospects for genetic modification of microalgae for enhanced biorefinery capabilities have also been briefly highlighted. 相似文献
13.
N. K. Sharma S. Bhardwaj P. K. Srivastava Y. J. Thanki P. K. Gadhia M. Gadhia 《International Journal of Environmental Science and Technology》2012,9(2):361-370
Irrigating food crops with treated wastewater is a popular management option in India. This study evaluated the impacts of land application of treated petrochemical effluent on soil chemical properties. Soil samples were collected from different depths from sites irrigated with petrochemical effluent for 2?years and from control sites. The effluent collected was analysed for different physic?Cchemical properties and its impact on Lagenaria siceraria (Bottle gourd) growth. 100% concentrated effluent was used for the study and compared with the control. It was observed that application of effluent significantly increased the major cations and anions in the field. On the basis of the study, it may be suggested that treated petrochemical effluent can be used as an alternate source for irrigating crops as it increases the nutrient content of the soil. The overall application indicates a lavishing growth of L. siceraria crop in petrochemical irrigated soil than control sites. This study provides information for better understanding of changes in soil properties due to land application of petrochemical effluent. These changes must be considered in developing possible criteria for preserving delicate ecosystems. 相似文献
14.
In this paper, impact of Indian Doppler Weather Radar (DWR) data, i.e., reflectivity (Z), radial velocity (Vr) data individually and in combination has been examined for simulation of mesoscale features of a land-falling
cyclone with Advance Regional Prediction System (ARPS) Model at 9-km horizontal resolution. The radial velocity and reflectivity
observations from DWR station, Chennai (lat. 13.0°N and long. 80.0°E), are assimilated using the ARPS Data Assimilation System
(ADAS) and cloud analysis scheme of the model. The case selected for this study is the Bay of Bengal tropical cyclone NISHA
of 27–28 November 2008. The study shows that the ARPS model with the assimilation of radial wind and reflectivity observations
of DWR, Chennai, could simulate mesoscale characteristics, such as number of cells, spiral rain band structure, location of
the center and strengthening of the lower tropospheric winds associated with the land-falling cyclone NISHA. The evolution
of 850 hPa wind field super-imposed vorticity reveals that the forecast is improved in terms of the magnitude and direction
of lower tropospheric wind, time, and location of cyclone in the experiment when both radial wind and reflectivity observations
are used. With the assimilation of both radial wind and reflectivity observations, model could reproduce the rainfall pattern
in a more realistic way. The results of this study are found to be very promising toward improving the short-range mesoscale
forecasts. 相似文献
15.
Trapped waves of the 27 November 1945 Makran tsunami: observations and numerical modeling 总被引：1，自引：1，他引：0
S. Neetu I. Suresh R. Shankar B. Nagarajan R. Sharma S. S. C. Shenoi A. S. Unnikrishnan D. Sundar 《Natural Hazards》2011,59(3):1609-1618
The 27 November 1945 earthquake in the Makran Subduction Zone triggered a destructive tsunami that has left important problems
unresolved. According to the available reports, high waves persisted along the Makran coast and at Karachi for several hours
after the arrival of the first wave. Long-duration sea-level oscillations were also reported from Port Victoria, Seychelles.
On the other hand, only one high wave was reported from Mumbai. Tide-gauge records of the tsunami from Karachi and Mumbai
confirm these reports. While the data from Mumbai shows a single high wave, Karachi data shows that high waves persisted for
more than 7 h, with maximum wave height occurring 2.8 h after the arrival of the first wave. In this paper, we analyze the
cause of these persistent high waves using a numerical model. The simulation reproduces the observed features reasonably well,
particularly the persistent high waves at Karachi and the single high wave at Mumbai. It further reveals that the persistent
high waves along the Makran coast and at Karachi were the result of trapping of the tsunami-wave energy on the continental
shelf off the Makran coast and that these coastally-trapped edge waves were trapped in the along-shore direction within a
∼300-km stretch of the continental shelf. Sensitivity experiments establish that this along-shore trapping of the tsunami
energy is due to variations in the shelf width. In addition, the model simulation indicates that the reported long duration
of sea-level oscillations at Port Victoria were mainly due to trapping of the tsunami energy over the large shallow region
surrounding the Seychelles archipelago. 相似文献
16.
Surface and groundwater quality characterization of Deoria District,Ganga Plain,India 总被引：5，自引：5，他引：0
A water quality investigation was carried out in the Deoria district, Ganga plain, to assess the suitability of surface and
groundwaters for domestic, agricultural, and industrial purposes. As much as 50 representative samples from river and groundwater
were collected from various stations to monitor the water chemistry of various ions, comprising Ca2+, Mg2+, Na+, K+, HCO3
−, SO4
2−, NO3
−, Cl−, F−, and trace metals, such as Fe, Cu, Mn, Zn, Cd, and Pb. The results showed that electrical conductance (EC), total dissolved
solids (TDS), HCO3
−, Mg2+, Na+, and total hardness (TH) are above the maximum desirable limit, and apart from Fe and Mn all other trace metals are within
the maximum permissible limit for drinking water. The calculated values for sodium absorption ratio (SAR), salinity, residual
sodium carbonate (RSC), and permeability index (PI) indicate well to permissible use of water for irrigation. High values
of Na%, RSC, and Mg-hazard (MH) at some stations restrict its use for agricultural purpose. Anthropogenic activities affect
the spatial variation of water quality. Economic and social developments of the study area is closely associated with the
characteristics of the hydrological network. 相似文献
17.
Evaluating cut slope failure by numerical analysis—a case study 总被引：3，自引：3，他引：0
Slope failure is very common phenomenon in hilly regions, especially in young techno active mountainous like Himalayas. It
is hazardous because of the accompanying progressive movement of the slope-forming material. In order to minimize the landslide
effects, slope failure analysis and stabilization requires in depth understanding of the process that governs the behavior
of the slope. The present article mainly deals with the analysis of the stability of road cut slopes of Rudraprayag Area,
Uttarakhand, India. The area experiences local as well as regional slides every year. Extensive field study was carried out
along the road cut slopes. Laboratory experiments were conducted to determine the various Physio-mechanical properties of
rock mass. These properties have been used as input parameters for the numerical simulation of slope using FLAC3D (Fast Lagrangian
Analysis of Continua) including geological discontinuities. The computed deformations and the stress distribution along the
failure surface are compared with the field observations. The study indicates that the overall slope is unstable except at
the location E where slope is critically stable. The effects of instability have been thoroughly considered and remedial measures
have been recommended. 相似文献
18.
A coupled chemistry–transport model is developed to study the production and loss of neutral atomic carbon and oxygen in the inner coma (≤104km) of Comet Halley. Subsequently, the generation of OI 1304 Å and OI 1356 Å and CI 1561 Å and CI 1657 Å emissions is studied. Calculations are performed utilizing solar EUV, utilizing photoelectrons, and assuming the precipitation of high energy “auroral” electrons of solar wind origin, the evidence for which has been inferred from many observations, as the sources for the production of these atoms and emissions, including only the gas phase species in the cometary coma. It is revealed that the electron impact dissociation of parent species could be a potentially important source of C and O production and their emissions in the inner cometary coma. Our calculated O density profile is in agreement with that calculated by R. R. Hodges, Jr. (1990,Icarus83, 410–433). The present study has demonstrated the importance of contributions from sources other than the solar fluorescence for deriving the O and C production rates from their emission line brightness. It is found that the electron impact and solar fluorescence contribute 34 and 66%, respectively, to the OI 1304 Å emission. However, when the auroral electrons are also included, the relative contributions of electron impact and solar fluorescence are 72 and 28%, respectively. In the case of CI 1657 Å the electron impact contribution amounts to 24 (18)% with (without) inclusion of auroral electrons. 相似文献
19.
Natural Hazards - Fatal landslides cause severe disasters to human lives and socioeconomic costs in China. In this study, the data non-seismically fatal landslides were collected between 2004 and... 相似文献
20.
Awdhesh Kumar Choudhary Bhardwaj Pandit G. L. Sivakumar Babu 《Geomechanics and Geoengineering》2020,15(1):1-9
ABSTRACTVertical anchor plates are often provided to increase the performance of various geotechnical engineering structures such as sheet pile walls, bulkheads, bridge abutments and offshore structures. Hence, the safe design of such structures needs a better understanding of the 3D behaviour of the anchor plate. This paper presents and discusses the results obtained from a series of 3D finite-difference analyses of vertical square anchor plate embedded in cohesionless soil. The 3D model is found to closely predict experimental pullout load–displacement relationship. The failure mechanism observed in the numerical model is found to be very similar to the failure reported in experimental studies. For a given embedment depth, the stiffness of the breakout factor–displacement response substantially reduces with increase in anchor plate size. However, the ultimate reduction in anchor capacity is found to approximately 8% with an increase in anchor size from 0.1 to 1 m. Numerical analysis reveals that at deeper embedment depth, the friction angle of sand is the critical parameter in enhancing the performance of anchor plate. The obtained 3D model results are then compared with the published results and are found to be reasonably in good agreement with each other. 相似文献