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51.
Manish Yadav Nitin Kumar Singh Bhupendra Kumar Soni Kusum Soni Pawan Kumar Singh 《洁净——土壤、空气、水》2023,51(1):2200059
In this study, three approaches namely parallel, sequential, and multiple linear regression are applied to analyze the local air quality improvements during the COVID-19 lockdowns. In the present work, the authors have analyzed the monitoring data of the following primary air pollutants: particulate matter (PM10 and PM2.5), nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide (CO). During the lockdown period, the first phase has most noticeable impact on airquality evidenced by the parallel approach, and it has reflected a significant reduction in concentration levels of PM10 (27%), PM2.5 (19%), NO2 (74%), SO2 (36%), and CO (47%), respectively. In the sequential approach, a reduction in pollution levels is also observed for different pollutants, however, these results are biased due to rainfall in that period. In the multiple linear regression approach, the concentrations of primary air pollutants are selected, and set as target variables to predict their expected values during the city's lockdown period.The obtained results suggest that if a 21-days lockdown is implemented, then a reduction of 42 µg m−3 in PM10, 23 µg m−3 in PM2.5, 14 µg m−3 in NO2, 2 µg m−3 in SO2, and 0.7 mg m−3 in CO can be achieved. 相似文献
52.
Srinivas R. Singh Ajit Pratap Dhadse Kunal Magner Joe 《Stochastic Environmental Research and Risk Assessment (SERRA)》2020,34(2):381-396
Stochastic Environmental Research and Risk Assessment - Climatic changes have a significant impact on the hydrologic behavior of a river especially its discharge. Sustainable management of water... 相似文献
53.
For a better management of water resources, the information on water stored in a basin in the form of snow is of immense use. Changes in the snow water storage with time influence the recession characteristics of the hydrographs. Recession is found to be slower in a basin when it contains higher snow water storage and becomes faster as the volume of stored water reduces. In other words, the recession coefficient is not constant throughout the melt season, it changes with time. In the present study, the possibility of assessing snow water storage at any time during the melt season using recession coefficients is examined. The hydrograph analyses have been made for the Glatzbach watershed in the Hohe Tauern region of the Austrian Alps. For this purpose, a relationship between snow water storage and the recession coefficients is developed. This study suggests a simple and useful approach to assess the snow water storage in a basin at any time during the snowmelt season. The information on the snow water storage of a basin can be obtained using a readily derived single parameter, the recession coefficient. The results are based on limited data, but they are sufficient to illustrate how the changes in snow water storage control the recession characteristics of the hydrographs. These investigations set the pace for further research in this area. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
54.
P. K. Misra A. K. Jauhri R. P. Tiwari S. Kishore Ajay Pratap Singh S. K. Singh 《Journal of the Geological Society of India》2011,78(4):355-364
The present paper records nine species of coralline algae from the Prang Formation of middle-late Eocene age from the Jaintia
Hills, Meghalaya. The algae are associated with the larger foraminifera including Nummulites, Alveolina and Discocyclina throughout the succession. The temporal distribution of algal species indicates that seven species are known from the Eocene.
Of the remaining two, one ranges from the Palaeocene to Eocene and the other is Palaeocene in age. The coralline algae and
larger foraminifers are differentiated into two associations, the lower one indicating inner-ramp environment of high energy
and the upper one showing deposition in relatively calm waters of deeper ramp environment. 相似文献
55.
Geochemistry and petrogenesis of Proterozoic granitic rocks from northern margin of the Chotanagpur Gneissic Complex (CGC) 总被引:1,自引:0,他引:1
Bhupendra S Yadav Nishchal Wanjari Talat Ahmad Rajesh Chaturvedi 《Journal of Earth System Science》2016,125(5):1041-1060
This study presents the geochemical characteristics of granitic rocks located on the northern margin of Chotanagpur Gneissic Complex (CGC), exposed in parts of Gaya district, Bihar and discusses the possible petrogenetic process and source characteristics. These granites are associated with Barabar Anorthosite Complex and Neo-proterozoic Munger–Rajgir group of rocks. The granitic litho-units identified in the field are grey, pink and porphyritic granites. On the basis of geochemical and petrographic characteristics, the grey and pink granites were grouped together as GPG while the porphyritic granites were named as PG. Both GPG and PG are enriched in SiO2, K2O, Na2O, REE (except Eu), Rb, Ba, HFSE (Nb, Y, Zr), depleted in MgO, CaO, Sr and are characterised by high Fe* values, Ga/Al ratios and high Zr saturation temperatures (GPGavg~ 861 °C and PGavg~ 835 °C). The REE patterns for GPG are moderately fractionated with an average (La/Yb)N~ 4.55 and Eu/Eu* ~ 0.58, than PG which are strongly fractionated with an average (La/Yb)N~ 31.86 and Eu/Eu* ~ 0.75. These features indicate that the granites have an A-type character. On the basis of geochemical data, we conclude that the granites are probably derived from a predominant crustal source with variable mantle involvement in a post-collisional setting. 相似文献
56.
Abhishek?Banerjee Prafull?SinghEmail author Kamleshwar?Pratap 《Arabian Journal of Geosciences》2016,9(18):711
Groundwater management is of fundamental importance to meet the rapidly expanding urban, industrial and agricultural water requirements in semi-arid areas. To assess the current rate of groundwater withdrawal and possibility of recharge of potential aquifer in the semi-arid regions is essential for water management. The present study aimed to identify potential area for groundwater recharge structure in the Gwalior area based on land use, rainfall variation, hydrological component and statistical analysis. In this work, a stream survival approach was used for the assessment of water channel by using triangulated network and regression analysis to find out the correlation of individual component with reference to water management. Land use/land cover (LULC) map prepared from multispectral satellite images of the study area and used to validate the hydrological component and the results observed through the regression model shows good correlation. Therefore, immediate and effective water management schemes are required for sustainable water resource development and management in the area. 相似文献
57.
Himalayan basins have considerable snow‐ and glacier‐covered areas, which are an important source of water, particularly during summer season. In the Himalayan region, in general, the glacier melt season is considered to be from May to October. Changes in hydrological characteristics of the runoff over the melt season can be understood by studying the variation in time to peak and time lag between melt generation and its emergence as runoff. In the present study, the runoff‐delaying characteristics of Gangotri Glacier, one of the largest glaciers in the Indian Himalayas, have been studied. For this purpose, hourly discharge and temperature data were collected near the snout of the glacier (4000 m) for three ablation seasons (2004–2006). The diurnal variations in discharge and temperature provided useful information on water storage and runoff characteristics of the glacier. In the early stages of the ablation period, poor drainage network and stronger storage characteristics of the glaciers due to the presence of seasonal snow cover resulted in a much delayed response of melt water, providing a higher time lag and time to peak as compared to the peak melt season. A comparison of runoff‐delaying parameters with the discharge ratio clearly indicated that changes in time lag and time to peak are inversely correlated with variations in discharge. Impact of such meltwater storage and delaying characteristics of glaciers on hydropower projects being planned/developed on glacier‐fed streams in India has been discussed. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
58.
Nagendra Pratap Singh Mitsuru Utsugi Tsuneomi Kagiyama 《Pure and Applied Geophysics》2009,166(12):2037-2058
In the present research, an attempt is made to derive the generalized expressions for the transient electromagnetic response of a large loop source over the surface of a homogeneous earth model for arbitrary receiver positions inside or outside the source loop. Expressions are derived for the impulse as well as step excitations of the source loop. As a cross check for validity of expressions, the step response expression is obtained from the impulse response expression and vice versa. Computations are performed for the TEM response over a homogeneous earth model for source-receiver offset (r = 0) pertinent to the central loop configuration and the results are compared with the published results for the central loop TEM responses. The results are in well coincidence with each other and thus provide the check for the authenticity of the expressions. To exemplify the nature of TEM response at various source receiver offsets, results are presented for the TEM response at source receiver offsets r = 0, r = a/2, r = a and r = 2a, 6a, 12a pertaining to the central loop, in-loop, on-loop and offset loop configurations, respectively. The results depict their characteristic variations. At receiver positions inside the loop source, both the impulse as well as step responses are of same sign, whereas at the receiver positions outside the loop source, both the curves exhibit a change of sign that shifts towards the later times with increase in the offset distances. The change of sign in impulse response occurs at a relatively later time than that in the step response. This is the initial presentation of TEM response expressions for the large loop source over a homogeneous earth model for arbitrary receiver position inside and/ or outside the loop source except for the case of receiver at the center of the loop and at the coincident loop point. This research would be of immense use in the development and use of the large loop TEM method in its various configurations and thus would enhance the applicability and cost effectiveness of the large loop source TEM method. 相似文献
59.
Bhupendra K. Mishra Chandra S. Dubey Dericks P. Shukla Prosun Bhattacharya Arnold L. Usham 《Environmental Earth Sciences》2014,72(9):3281-3291
High Arsenic (As) concentrations have been reported in superficial water in the Yamuna flood plains (YFP), Delhi, which is being extensively used for agriculture. The concentration of As in some common vegetables such as Solanum lycopersicum (tomato), Abelmoschus esculentus (lady’s finger), Solanum melongena (brinjal), Lagenaria siceraria (bottle gourd), Raphanus sativus (radish), Zea mays (corn), and Luffa acutangula (ridge gourd) has been studied in this work. The range of As concentrations (dry weight) varies from 0.6 to 2.52 mg/kg with the highest accumulation of 2.52 mg/kg in radish followed by tomato (2.36 mg/kg). The order of As concentration in the decreasing order is R. sativus > S. lycopersicum > Z. mays > L. acutangula > L. siceraria > S. melongena > A. esculentus. Thus, As accumulation is the highest in roots and the lowest in least juicy fruits. The daily dietary intake of As through the consumption of various vegetables was also calculated. Though the mean As concentration was the highest in radish (2.52 mg/kg) but the highest amount of As is being consumed through tomato (0.383 mg/day), which is nearly three times the World Health Organization’s provisional maximum tolerable daily intake limit of 0.126 mg/day for a 60 kg person. High concentration of As in vegetables grown in YFP, Delhi is being reported here. This high contamination is primarily due to the presence of As in irrigation water having its source from coal-based thermal power plants in the vicinity of the area. If not checked properly, it will pose a serious health risk to people living in these densely populated areas surrounding YFP. 相似文献