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Sharma R.,Robertson College, Jabalpur | Bajpai J.,Robertson College, Jabalpur | Bajpai A.K.,Robertson College, Jabalpur | Acharya S.,Defence Institute of High Altitude Research | And 2 more authors.
Carbohydrate Polymers | Year: 2014

In this study, water absorbing Ca2+ ion cross-linked alginate nanoparticles were prepared and their water holding capacity was assessed. The prepared nanoparticles were characterized by Fourier transform infra red (FTIR) and X-ray diffraction (XRD) spectroscopy, field emission scanning electron microscopy (FESEM), and Zeta potential measurements to gain insights into their structural and morphological features and to see if the nanoparticles carried a charge over them. The swelling experiments were performed for different compositions of prepared nanoparticles at varied pH and temperatures. The capacity of the nanoparticles to retain imbibed water was evaluated by conducting deswelling studies of the pre-swollen nanoparticles. These particles were mixed with soil and soil-pot experiments were conducted. In order to assess the sustained water release potential of nanoparticles in agricultural fields, the seeds were planted in both native and nanoparticle-mixed soil pots, and moisture content of the soil was measured periodically and growth of the plants was observed. © 2013 Elsevier Ltd. All rights reserved. Source

Maurya A.S.,Physical Research Laboratory | Shah M.,Physical Research Laboratory | Deshpande R.D.,Physical Research Laboratory | Bhardwaj R.M.,Central Pollution Control Board | And 2 more authors.
Hydrological Processes | Year: 2011

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). © 2010 John Wiley & Sons, Ltd. Source

Gupta U.P.,Central Water Commission | Ojha C.S.P.,Indian Institute of Technology Roorkee | Sharma N.,Indian Institute of Technology Roorkee
Journal of Hydraulic Engineering | Year: 2010

Submerged vanes are submerged foils of low height and larger length, constructed in a river at an angle of attack α to the flow to modify the near-bed flow pattern and redistribute flow and sediment transport within the channel cross section. At a Froude number (F) of 0.13, the local scour development around the submerged vane without a collar was not enough to dislodge the vane whereas at F=0.25, there was a significant local scour hole around the vane and the vane was dislodged. With the introduction of a collar at the leading edge of a submerged vane, the scour depth at the leading edge of the vane was reduced to zero. A collar of circular shape was found more suitable for a rectangular vane. Recommendations for sizing collars at two values of F are given. The optimal α for a rectangular vane with a collar was found close to 40°. The study clearly indicates the advantages of using collars in case of submerged vanes and provides insight into selection of appropriate collar shapes. © 2010 ASCE. Source

Kumar M.D.,Institute for Resource Analysis and Policy | Pandit C.M.,Central Water Commission
International Journal of Water Resources Development | Year: 2016

This article discusses the bias of the growing constituency of civil society activists in India against conventional water management solutions implemented by the government, and the ‘alternatives’ they champion, which force the government to enter into an endless debate with these groups. The article goes into the fundamental reasons for this bias, and identifies four types of civil society activist: ‘professional’, ‘ideologue’, ‘romantic’ and ‘doomsday prophet’. The article also argues that water bureaucracies in India should adopt evidence-based policy making, subjecting the ‘alternatives’ to the same degree of scrutiny as the conventional ones, to end the policy dilemma, while enhancing the overall quality of design, execution and management of projects for better outcomes. © 2016 Informa UK Limited, trading as Taylor & Francis Group Source

Singh B.,Central Water Commission | Rai N.N.,Central Water Commission
Water and Energy International | Year: 2015

National Water Policy (2012) duly recognizes the ecological needs of the river setting aside a portion of river flows on the pattern of natural flow regime and environmental management plan is an integral part of planning of any water resources development project. The detailed environmental studies are required to be carried out including requirement of e-flows while planning any water resources project. However, the estimation of environmental flows is still a challenge primarily due to lack of both the understanding of and quantitative data on relationships between river flows and ecological characteristics of river. The assessment of environmental flows rationally keeping in view of limited water resources and dependence of livelihood of large population is still at infancy stage. Various studies show wide variations in the assessment of E-flows. The main challenge is to meet the e-flow requirement during lean period. There is claimer from various groups to reserve the majority of river flows for e-flows during lean period. However, the allocation of water for environmental needs should not be decided in isolation. The water requirements of other demands of food, energy, livelihoods etc in the basin should also be taken into account while allocating scares water resources to various competing users including environmental needs. The paper discusses the developments in field and views of CWC on the issue. © 2015, Central Board of Irrigation and Power. All rights reserved. Source

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