Time filter

Source Type

Bangalore, India

Reddy A.G.S.,Central Ground Water Board
Journal of the Geological Society of India | Year: 2012

The study on water level conditions of fractured aquifer system in northeastern part of Anantapur district is of immense importance as the area is covered by varied geological formations and has different irrigation patterns. The monthly groundwater level data of 154 observation wells for five year period (2001-06) is analyzed to decipher the behavior of water levels in different seasons and geo-environments. The hydrographs of the average water level data of each Mandal (group of villages) indicate steady declining trend ranging from 0.50 to 2.91m/yr. Yellanuru Mandal has both the shallowest and the deepest water levels among eight Mandals, highly undulating terrain could be one of the reasons for this contrasting condition. The pre-monsoon water levels show decline of 8.22 m in one year from May 2002 to 2003. A negative seasonal fluctuation of -1.49m has occurred in the year 2002 during which the area received 32% less than normal rainfall. The mean water levels are deeper by 42% in areas covered by sedimentary formations than those of granite terrain. Raise in water levels is significant where monthly rainfall is more than 200 mm. Due to erratic rainfall in space and time, deeper water levels are noticed even in post-monsoon period and shallow in February month at some locations. The water levels in command areas are deep and exhibit falling trend as the area forms the tail end part of the Tunga Bhadra High Level Canal. The deeper water level conditions and its declining feature is directly related to groundwater development in the form of increased agriculture activity, reduced area under rain-fed crops, high horticulture development. Arid climatic conditions, low precipitation and continuous exploitation of groundwater resources could be other factors contributing for steady decline in water levels in the area. The wide variations in groundwater levels could be due to uneven topography, heterogeneous and anisotropic conditions of granites and poor porosity - permeability of shales, lack of vegetation, and increased groundwater extraction. © 2012 Geological Society of India. Source

Senthilkumar M.,Central Ground Water Board | Elango L.,Anna University
Hydrogeology Journal | Year: 2011

Groundwater modelling is widely used as a management tool to understand the behaviour of aquifer systems under different hydrological stresses, whether induced naturally or by humans. The objective of this study was to assess the effect of a subsurface barrier on groundwater flow in the Palar River basin, Tamil Nadu, southern India. Groundwater is supplied to a nearby nuclear power plant and groundwater also supplies irrigation, industrial and domestic needs. In order to meet the increasing demand for groundwater for the nuclear power station, a subsurface barrier/dam was proposed across Palar River to increase the groundwater heads and to minimise the subsurface discharge of groundwater into the sea. The groundwater model used in this study predicted that groundwater levels would increase by about 0.1-0.3 m extending out a distance of about 1.5-2 km from the upstream side of the barrier, while on the downstream side, the groundwater head would lower by about 0.1-0.2 m. The model also predicted that with the subsurface barrier in place the additional groundwater requirement of approximately 13,600 m3/day (3 million gallons (UK)/day) can be met with minimum decline in regional groundwater head. © 2011 Springer-Verlag. Source

Naik P.K.,Central Ground Water Board
International Journal of Water Resources Development | Year: 2016

Water is an issue that relates to all aspects of human development in Africa, including health, agriculture, education, economics, and even peace and stability. But the perception that Africa has perpetual water scarcity and is heading towards water crisis is challenged by a significant number of water professionals. Although most agree that Africa suffers from economic water scarcity, physical water scarcity could possibly be controlled with better water management. The large amount of international aid granted annually to Africa is a subject of criticism. This article examines the water crisis in Africa, whether it is a myth or reality, and reasons thereof, and suggests remedial measures. © 2016 Informa UK Limited, trading as Taylor & Francis Group Source

Reddy A.G.S.,Central Ground Water Board | Kumar K.N.,Kakatiya University
Environmental Monitoring and Assessment | Year: 2010

Hydrogeochemical studies were carried out in the Penna-Chitravathi river basins to identify and delineate the important geochemical processes which were responsible for the evolution of chemical composition of groundwater. The area is underlain by peninsular gneissic complex of Archaean age, Proterozoic meta-sediments, and strip of river alluvium. Groundwater samples were collected covering all the major hydrogeological environs in pre- and post-monsoon seasons. The samples were analyzed for major constituents such as Ca 2+, Mg2+, Na+, K+, CO3 -, HCO3 -, Cl-, SO2 -4, NO3 -, and F-. The groundwater in general is of Na+-Cl-, Na+-HCO3 -, Ca2+-Mg2+-HCO3 -, and Ca2+-Mg2+-Cl- types. Na+ among cations and Cl- and/or HCO3 - among anions dominate the water; Na+ and Ca2+ are in the transitional state with Na+ replacing Ca2+ and HCO3 - Cl- due to physiochemical changes in the aquifer and water-rock interactions. The Ca2+-Mg2+-Cl- HCO3 - type water in one third samples suggest that ion exchange and dissolution processes are responsible for its origin. Change in storage of aquifer in a season does not influence the major geochemical makeup of groundwater. Gibbs plots indicate that the evolution of water chemistry is influenced by water-rock interaction followed by evapotranspiration process. The aquifer material mineralogy together with semiarid climate, poor drainage system, and low precipitation factors played major role in controlling groundwater quality of the area. © 2009 Springer Science+Business Media B.V. Source

The assessment of hydrogeochemical processes that govern the water quality of inland freshwater aquifers in coastal environment, especially in Indian sub-continent, is occasionally attempted. To bridge the gap, a detail hydrochemical evaluation of groundwater occurring in coastal alluvium is attempted. Single set of high-density water sampling is done from a limited area to gain an in-depth knowledge of the processes that govern the water chemistry of the sandy aquifers. The water is of weak alkaline nature and less mineralized, EC being < 1,000 μS/cm in many samples. Major ion composition indicates that water is contaminated with excess concentration of nitrates. Ionic abundance is in the order of Cl- > Na+ > Ca2+ > HCO3- > SO42- > Mg2+ > NO3-. Na+ and Cl- are almost in similar proportions implying the influence of coastal climate on water quality. The water shows modest variation in their ionic assemblage among different sample points as evident from Schoeller scheme. Groundwater can be classified into three distinct facies viz. Cl--Ca2+-Mg2+, Na+-Cl- and Ca2+-Mg2+-HCO3- types. The ionic assemblages, their indices, ratios and cross-plots substantiate that multiple processes were involved in the evolution of the water chemistry. Among them, silicate weathering, halite dissolution, ion exchange and base exchange played prominent role in the ion enrichment of groundwater. The aquatic chemistry is further influenced and modified by marine environment, evapotranspiration and anthropogenic inputs which is authenticated by good correlation (r2 = 1) among the Na+-Cl-, EC-Mg2+, Na+ and Cl-. Gibbs plots established that evaporation is more responsible for contribution of minerals to the groundwater than aquifer material. Nitrate contamination can be attributed for poor sewerage disposal mechanism which is aggravated by fertilizer inputs, irrigation practices and agriculture activity. A contrasting correlation (r2 ≥90 to <0.40) among select pairs of ions reassures dissimilar source of those ions, involvement of multiple processes and limited interaction of formation water with aquifer material. © 2012 Springer-Verlag. Source

Discover hidden collaborations