105 research outputs found
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No full textNot AvailableThis study evaluates an over-exploited aquifer (Balasor, India) and also explores the possibilities of sustainable management using several statistical approaches. First, bootstrap analysis indicates that groundwater pumping has resulted in the reduction of mean cultivated area as the average irrigation capacity per bore well dropped from 3.74 ha to 1.5 ha within a period of 10 years of operation. However, modelling the groundwater levels using the seasonal auto regressive integrated moving average (SARIMA) procedure showed no evidence of
large-scale groundwater withdrawals. The derived models can be used for water table forecasting and also for
infilling the missing observations. The empirical relationship among pumping test results indicated that well depth and aquifer thickness significantly influence the discharge from the aquifer. This discharge may have encouraged the resource-rich farmers to exploit the lower aquifer. Based on a contour plot, the zone of groundwater exploitation was estimated to vary from 25 to 60 m below the surface. Therefore, a uniform aquifer exploitation policy needs to be implemented to curb the vertical competition in exploiting the aquifer and to develop sustainable management of the groundwater.Not Availabl
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No full textNot AvailableThis study examines the changes in monsoon rainfall of India using a suite of extreme indices defined by the Expert Team on Climate Change Detection Monitoring and Indices (ETCCDMI) to make the Indian results comparable internationally, in addition to the use of some relevant indices particularly developed for the Indian climate. To this end, the recently developed high resolution daily gridded (0.5◦ ×0.5◦) rainfall dataset for the period 1971–2005 has been analysed using robust nonparametric techniques. Despite the high interannual variability and spatial diversity of the Indian climatology, the results reveal signal of changes for several extreme rainfall indices, generally consistent with the simulated outcome of an intensified Indian monsoon rainfall in the context of global warming. A predominant decrease in wet days, moderate and total rainfall is observed in the high rainfall regions of northeast, central and southwest India. In the active monsoon months of July and August, the dry spells defined by the maximum length of consecutive dry days (CDD) have increased significantly over the north and central regions of India, suggesting a serious threat to the Indian agriculture.
Simultaneously, the extreme rainfall indices, based on the percentile and absolute values, show increasing trends over large parts of the country. The probability density function (PDF) of several indices show noticeable changes since the 1990s over the homogeneous central and northeast parts of India. The indices representing the total monsoon rainfall and dry spells are better correlated with the El Ni˜no–Southern Oscillation (NINO3.4), compared to that of the Indian Ocean Dipole Mode Index (IODMI). The mapping of the observed rainfall trends and their correspondence to the large scale circulation modes is expected to assist the policy makers to prioritize the mitigation and adaptation strategies.Not Availabl
Colloidal silver nanoparticles prepared by UV-light induced citrate reduction technique for the quantitative detection of uric acid
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No full textNot AvailableThe tropical river basins of India are important because of the coastal ecosystem that they sustain and the densely populated economic zones that they serve. This study examines the recent trends in sediment load
and also explores the influence of the climatic and human forcing mechanisms on the land–ocean fluvial
systems. A large dataset comprised of the sediment time series of different timescale during the period 1986–
87 to 2005–06 from 133 gauging stations spreading across tropical river basins of India was analyzed. Results
indicate dramatic reductions in sediment load in the tropical river basins, which is beyond the fold of assignable natural variability. Around 88% (62%) of the total 133 gauging stations showed decline in sediment loads in the monsoon (non-monsoon) season. The significant downward trends outnumbered the corresponding upward trends in high proportions for both the seasons. Striking spatial coherence was observed among the significant trends, suggesting the presence of the cross-correlation among the sediment records. The regional trends, which account the spatial correlation, also indicated the widespread nature of the sediment declines. The rainfall, which is characterized by the non-significant decreasing trends and also frequent drought years, is the primary controller of the sediment loads for most of the river basins. It may be inferred that a little change in rainfall towards the deficit side leads to a significant reduction in sediment load.This is due to the diversion and storage of runoff to meet the manifold increases in water requirements for the agriculture and industry. Among the tropical rivers, the maximum reduction in sediment flux has taken place for the Normada River (−2.07×106 t/yr) due to the construction of dam. Although the sea level is rising, we speculate that the significant reduction in sediment loads may also have influenced the coastal erosion in recent years. The results of this study can be utilized for the sustainable management of the tropical river basins in the backdrop of a predicted erratic monsoon rainfall and the growing anthropogenic stresses.Not Availabl
Voltage Stability improvement based on firing angle control of SVCs in wind integrated system with ANN
No full textThe widening gap between energy generation and demand on a global scale, coupled with the imperative to reduce emissions, has necessitated the development of largescale sustainable energy solutions. Among the various renewable energy options, Wind Power stands out as a viable source capable of generating substantial amounts of electricity. However, the unpredictable nature of wind availability and its fluctuations pose challenges for grid operators in effectively harnessing and distributing the generated wind power. This issue becomes more pronounced when transmitting wind power through local grids to distant load centers. Voltage instability at local buses emerges as a significant concern in wind-integrated power systems. To address these challenges, dynamic compensation at multiple locations has proven to be an effective solution. Various alternative approach to controlling the firing of Static Var Compensators (SVCs) connected to the network is proposed in the present work. The traditional method, which relies on a classical control approach, is computationally intensive and time-consuming. To overcome this limitation, we propose the utilization of a trained Neural Network for simultaneous control of the firing angles of all SVCs, accommodating various system conditions such as change in load and wind generation fluctuations. Porposed method has been evaluated on both a modified IEEE-30 bus system and a 28-bus Indian system.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electrical Sustainable EnergyIntelligent Electrical Power Grid
Groundwater depletion in northern India: Impacts of the sub‐regional anthropogenic land‐use, socio‐politics and changing climate
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No full textNot AvailableRecent heat waves have been a matter of serious concern for India because of potential impacts on agriculture, food security, and socioeconomic progress. This study examines the trends and variability in frequency, duration, and intensity of hot episodes during three time periods (1951–2013,1981–2013 and 1998–2013) by defining heat waves based on the percentile of maximum, minimum, and mean temperatures. The study also explores heat waves and their relationships with hydroclimatic variables, such as rainfall, terrestrial water storage, Palmer drought severity index, and sea surface temperature. Results reveal that the number, frequency, and duration of daytime heat waves increased considerably during the post-1980 dry and hot phase over a large area. The densely populated and agriculturally dominated northern half of India stands out as a key region where the nighttime heat wave metrics reflected the most pronounced amplifications. Despite the recent warming hiatus in India and other parts of the world, we find that both daytime and nighttime extreme measures have undergone substantial changes during or in the year following a dry year since 2002, with the probability distribution functions manifesting a hotter-than-normal climate during 1998–2013. This study shows that a few months preceding the 2010 record-breaking heat wave in Russia, India experienced the largest hot
episode in the country’s history. Interestingly, both these mega events are comparable in terms of their evolution and amplification. These findings emphasize the importance of planning for strategies in the context of the rising cooccurrence of dry and hot events.Not Availabl
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