Hydrogeology of Hard Rock Aquifers ..................................................................... Patrick Lachassagne, Benoît Dewandel, and Robert Wyns

2014 ◽  
pp. 297-326 ◽  
Keyword(s):  
Hard Rock ◽  
Hard Rock Aquifers

scholarly journals Estimation of recharge in mountain hard-rock aquifers based on discrete spring discharge monitoring during base-flow recession

2021 ◽  
Author(s):  
Stefano Segadelli ◽  
Maria Filippini ◽  
Anna Monti ◽  
Fulvio Celico ◽  
Alessandro Gargini
Keyword(s):  
Hard Rock ◽  
Monitoring Program ◽  
Base Flow ◽  
Low Flow ◽  
Reliable Estimate ◽  
Spring Discharge ◽  
Aquifer Recharge ◽  
Clear Cut ◽  
Groundwater Circulation ◽  
Hard Rock Aquifers

AbstractEstimation of aquifer recharge is key to effective groundwater management and protection. In mountain hard-rock aquifers, the average annual discharge of a spring generally reflects the vertical aquifer recharge over the spring catchment. However, the determination of average annual spring discharge requires expensive and challenging field monitoring. A power-law correlation was previously reported in the literature that would allow quantification of the average annual spring discharge starting from only a few discharge measurements in the low-flow season, in a dry summer climate. The correlation is based upon the Maillet model and was previously derived by a 10-year monitoring program of discharge from springs and streams in hard-rock aquifers composed of siliciclastic and calcareous turbidites that did not have well defined hydrogeologic boundaries. In this research, the same correlation was applied to two ophiolitic (peridotitic) hard-rock aquifers in the Northern Apennines (Northern Italy) with well-defined hydrogeologic boundaries and base-outflow springs. The correlation provided a reliable estimate of the average annual spring discharge thus confirming its effectiveness regardless of bedrock lithology. In the two aquifers studied, the measurable annual outputs (i.e. sum of average annual spring discharges) could be assumed equal to the annual inputs (i.e. vertical recharge) based on the clear-cut aquifer boundaries and a quick groundwater circulation inferable from spring water parameters. Thus, in such setting, the aforementioned correlation also provided an estimate of the annual aquifer recharge allowing the assessment of coefficients of infiltration (i.e. ratio between aquifer recharge and total precipitation) ranging between 10 and 20%.

A study on the status of fluoride ion in groundwater of coastal hard rock aquifers of south India

2012 ◽  
Vol 6 (11) ◽  
pp. 4167-4177 ◽  
Author(s):  
C. Singaraja ◽  
S. Chidambaram ◽  
P. Anandhan ◽  
M. V. Prasanna ◽  
C. Thivya ◽  
...  
Keyword(s):  
South India ◽  
Hard Rock ◽  
Fluoride Ion ◽  
The Status ◽  
Hard Rock Aquifers

Regional study of hard rock aquifers in Alentejo, South Portugal

2007 ◽  
pp. 73-93 ◽  
Author(s):  
Ant√≥nio Chambel ◽  
Jo√£o Nascimento ◽  
Jorge Duque
Keyword(s):  
Hard Rock ◽  
Regional Study ◽  
Hard Rock Aquifers ◽  
South Portugal

Preliminary conceptual models of groundwater and nutrient dynamics in typical agricultural river catchments underlain by hard-rock aquifers in Scotland and Northern Ireland: The River Ythan and Upper Bann River Catchments

2021 ◽  
Author(s):  
Hamish Johnson ◽  
Jean-Christophe Comte ◽  
Ulrich Ofterdinger ◽  
Rachel Cassidy ◽  
Mads Troldborg
Keyword(s):  
Northern Ireland ◽  
Nutrient Dynamics ◽  
Conceptual Models ◽  
Nutrient Management ◽  
Hard Rock ◽  
Fate And Transport ◽  
Hard Rock Aquifers ◽  
Groundwater Systems ◽  
River Catchments

<p>The environmental fate and transport of nitrogen and phosphorus nutrient species leached from agroecosystems are largely influenced by the hydrogeological setting, which dictates the distribution of groundwater flow pathways, residence times, and physio-chemical properties of the subsurface. Traditional conceptual models tend to oversimplify these relationships, and their application towards river catchment nutrient management promotes insufficient characterisation of hydrogeological heterogeneity, which is subsequently not accounted for. Until recently, very little hydrogeological information and conceptual understanding existed for groundwater systems within the postglacial basement terranes of Scotland and Northern Ireland, due to an abundance of surface water resources and prevalence of poorly productive bedrock aquifers. Recent research has demonstrated the role of geological heterogeneity in determining the contaminant transport behaviour of these hard-rock aquifers, where the presence of weathering and fracturing can potentially result in the rapid delivery of nutrients to rural water supplies and groundwater-dependent ecosystems.</p><p>We aim to further elucidate the role of hydrogeological setting in river catchment nutrient dynamics to improve agricultural sustainability in geologically heterogeneous agricultural regions. This will be achieved by developing conceptual models of nutrient fate and transport for two contrasting agricultural river catchments. Here, we present preliminary conceptual models based on a literature review of groundwater systems within the same geological terranes, analysis of hydrochemical monitoring data, and accounting for catchment-specific features through desk studies of geological and airborne geophysical surveys.</p><p>The River Ythan is a groundwater-dominated lowland catchment within Scotland’s arable belt, designated a Nitrate Vulnerable Zone due to the eutrophication of its estuary. This catchment is geologically complex, with a variably metamorphosed and sheared Precambrian basement with igneous intrusions ranging from ultrabasic rocks to granite. This complexity is enhanced by the significant preservation of Tertiary weathering profiles and an extensive but discontinuous cover of glacial deposits derived from the saprolites. The superficial deposits create a shallow aquifer system characterized by oxic, well-mixed groundwaters with high nitrate concentrations. The bedrock groundwater bodies feature lower nitrate concentrations with variable denitrification rates, resulting from the relationships between lithology, tectonics, and weathering.</p><p>Two upland headwater sub-catchments of the Upper Bann River (Co. Down, Northern Ireland) drain either side of the contact between a granodiorite laccolith and Lower Palaeozoic metasedimentary rocks within an elevated drumlinoid landscape. Here, diffuse phosphorus exports to surface waters have not experienced the same extent of decline observed in storm runoff phosphorus following the implementation of nutrient management policies. Anoxic groundwaters favourable for denitrification may result in the release of previously adsorbed (legacy) phosphorus following the reductive dissolution of Fe (hydr)oxides. These conditions are generated by (a) confinement by thick, drumlinised clayey tills; and (b) bedrock structures promoting deep groundwater flow.</p><p>The site-specific conceptual models will be further developed through multi-scale geophysical characterisation of hydrogeological heterogeneity and constrained by the catchment-scale distribution of residence times derived from stable (<sup>2</sup>H, <sup>18</sup>O) and radioactive (<sup>3</sup>H) isotope compositions of groundwaters. These refined conceptual models can guide the development of numerical groundwater models and spatially targeted nutrient management.</p>

scholarly journals Breaks in Resistivity Sounding Curves as Indicators of Hard Rock Aquifers

1983 ◽  
Vol 14 (1) ◽  
pp. 33-40 ◽  
Author(s):  
P. N. Ballukraya ◽  
R. Sakthivadivel ◽  
R. Baratan
Keyword(s):  
Empirical Study ◽  
Deep Water ◽  
Apparent Resistivity ◽  
Hard Rock ◽  
Fracture Zones ◽  
Resistivity Sounding ◽  
Resistivity Method ◽  
Hard Rock Aquifers

In a previous paper (Nordic Hydrology, Vol. 12, 1981), the authors have discussed the inadequacies in the technique of resistivity method for location of sites for constructing deep water walls in hard rock areas. It was pointed out that the water bearing fracture zones in the bed rock could not be identified by merely considering geoelectrical parameters such as layer resistivity. An empirical study based on the correlation of minor irregularities or deviations – “BREAKS” – in the normally smooth sounding curves with the actual driller's logs reveals that under normal geo-electric conditions these water bearing zones (hard rock aquifers) are indicated in the curve by a perceptible lowering of apparent resistivity and hence could be used as a guide for locating well sites. As such breaks may also be caused by other conditions such as lateral inhomogeneities, certain methods for distinguishing them are discussed.

Sign in / Sign up

Export Citation Format

Share Document