Use of Well Hydrographs in Shallow Fractured Aquifers to Determine Specific Yields and Continuum Transmissivities

2000 ◽  
Author(s):  
Lisa Shevenell
Keyword(s):  
Fractured Aquifers

scholarly journals Hydrochemistry and environmental isotopes (18O, 2H, 3H, 3He/4He) of groundwater and floodwater in the great area of Hurghada, Eastern Desert of Egypt

2021 ◽  
Vol 80 (11) ◽  
Author(s):  
M. Wannous ◽  
C. Jahnke ◽  
U. Troeger ◽  
M. Falk ◽  
F. Bauer
Keyword(s):  
Environmental Isotopes ◽  
Eastern Desert ◽  
Hydrochemical Parameters ◽  
Deep Wells ◽  
Fractured Aquifers ◽  
He Isotopes ◽  
Shallow Wells ◽  
The Common ◽  
Faulted Zone

AbstractPorous and fractured aquifers exist in the area of Hurghada, Eastern Desert of Egypt, whose recharge processes through the common flash floods are not identified. Hydrochemical parameters, stable isotopes 18O, 2H and tritium in floodwater and groundwater were applied in the area subject to study. Additionally, He isotopes were investigated in the deep wells in the faulted zone at the Abu Shaar Plateau. 3H activity in all sampled points lies below the detection limit excluding a recent recharge component in groundwater. However, the hydrochemical ratios and the stable isotope signature confirm that the shallow wells and springs (Red Sea Hills group) are being recharged from modern precipitation. The hydrochemical parameters of the deep wells at the Abu Shaar Plateau (coastal plain group) confirm another origin for the ions rather than the modern precipitation. Together with the 18O and 2H values, the Br/Cl ratio of this group confirms the absence of seawater intrusion component and the role of the fault as a hydraulic barrier. These 18O and 2H values deviate from the GMWL confirming an evaporation effect and colder infiltration conditions and reveal strongly a possible mixing with the Nubian Sandstone in the region. The 3He/4He ratio confirms a mantle contribution of 2% from the total He components.

scholarly journals Depth–Sequential Investigation of Major Ions, δ18o, δ2h and δ13C in Fractured Aquifers of the St. Lawrence Lowlands (Quebec, Canada) Using Passive Samplers

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1806
Author(s):  
Guillaume Meyzonnat ◽  
Florent Barbecot ◽  
José Corcho Alvarado ◽  
Daniele Luigi Pinti ◽  
Jean-Marc Lauzon ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Major Ions ◽  
Anthropogenic Activities ◽  
Carbon Sources ◽  
Passive Samplers ◽  
Flow Paths ◽  
Aquifer Heterogeneity ◽  
Fractured Aquifers ◽  
Fractured Carbonate ◽  
Observation Wells

General and isotopic geochemistry of groundwater is an essential tool to decipher hydrogeological contexts and flow paths. Different hydrogeochemical patterns may result from the inherent physical aquifer heterogeneity, which may go unnoticed without detailed investigations gathered from multilevel or multiple observation wells. An alternative to overcome the frequent unavailability of multiple wellbores at sites is to perform a detailed investigation on the single wellbore available. In this perspective, the aim of this study is to use passive samplers to sequentially collect groundwater at depths in long–screened wellbores. Such investigation is carried out for major ions and stable isotopes compositions (δ2H, δ18O, δ13C) at ten sites in the context of fractured carbonate aquifers of the St. Lawrence Lowlands (Quebec, Canada). The information gathered from the calco–carbonic system, major ions and stable isotopes report poorly stratified and evolved groundwater bodies. Contribution of water impacted by anthropogenic activities, such as road salts pollution and carbon sources from C4 vegetation, when they occur, are even observed at the greatest depths. Such observations suggest quick flow paths and efficient mixing conditions, which leads to significant contributions of contemporary groundwater bodies in the fractured aquifers investigated down to depths of about 100 m. Although physical aquifer investigation reported few and heterogeneously distributed fractures per wellbore, hydrogeochemical findings point to at overall well interconnected fracture networks in the aquifer and high vulnerability of groundwater, even at significant depths.

scholarly journals Telegraphic double porosity models for head transient behavior in naturally fractured aquifers

2013 ◽  
Vol 49 (7) ◽  
pp. 4399-4408 ◽  
Author(s):  
D. Hernández ◽  
M. Núñez-López ◽  
J. X. Velasco-Hernández
Keyword(s):  
Transient Behavior ◽  
Double Porosity ◽  
Fractured Aquifers ◽  
Naturally Fractured

scholarly journals Temporal and spatial scaling of hydraulic response to recharge in fractured aquifers: Insights from a frequency domain analysis

2013 ◽  
Vol 49 (5) ◽  
pp. 3007-3023 ◽  
Author(s):  
Joaquín Jiménez-Martínez ◽  
Laurent Longuevergne ◽  
Tanguy Le Borgne ◽  
Philippe Davy ◽  
Anna Russian ◽  
...  
Keyword(s):  
Frequency Domain ◽  
Domain Analysis ◽  
Frequency Domain Analysis ◽  
Spatial Scaling ◽  
Fractured Aquifers ◽  
Temporal And Spatial ◽  
Hydraulic Response

scholarly journals The influence of bedrock hydrogeology on catchment-scale nitrate fate and transport in fractured aquifers

2016 ◽  
Vol 569-570 ◽  
pp. 1040-1052 ◽  
Author(s):  
Alison Orr ◽  
Janka Nitsche ◽  
Marie Archbold ◽  
Jenny Deakin ◽  
Ulrich Ofterdinger ◽  
...  
Keyword(s):  
Fate And Transport ◽  
Catchment Scale ◽  
Fractured Aquifers

scholarly journals Detecção de um aquífero fraturado por múltiplas sondagens elétricas verticais e por caminhamento elétrico multinível

2019 ◽  
Vol 37 (4) ◽  
pp. 368
Author(s):  
Juliana Targino Batista ◽  
José Agnelo Soares
Keyword(s):  
Data Acquisition ◽  
Fracture Zone ◽  
Crystalline Basement ◽  
Electric Resistivity ◽  
Vertical Fracture ◽  
Vertical Electrical Soundings ◽  
Resistivity Method ◽  
Fractured Aquifers ◽  
Electrical Soundings ◽  
Schlumberger Array

RESUMO O presente trabalho analisa o efeito da adoção de diferentes configurações do método da eletrorresistividade para investigar a ocorrência de potenciais aquíferos fissurais. Em uma área onde reconhecidamente existe uma zona de fraturas subverticais no embasamento cristalino foram aplicadas as técnicas de múltiplas sondagens elétricas verticais (SEVs), utilizando o arranjo Schlumberger, e o caminhamento elétrico utilizando o arranjo gradiente multinível. Três diferentes configurações foram testadas em uma mesma linha cuja direção é aproximadamente perpendicular aos planos das fraturas. Os resultados obtidos mostram que o caminhamento elétrico multinível pelo arranjo gradiente apresentou maior clareza na detecção da zona de fraturas em relação às configurações utilizando sondagens elétricas verticais. No entanto, tais estruturas subverticais ainda poderiam ser detectadas por sondagem elétrica, desde que adotado um afastamento adequado entre os centros das SEVs. As seções geoelétricas obtidas pelas configurações testadas indicam a presença de uma estrutura acumuladora de água subterrânea do tipo riacho-fenda. Adicionalmente, o caminhamento elétrico pelo arranjo gradiente apresenta vantagens operacionais em relação às demais configurações, sendo mais prático e rápido nos trabalhos de aquisição de dados no campo.Palavras-Chaves: Hidrogeofísica, eletrorresistividade, embasamento cristalino. ABSTRACT This paper analyzes the effect of adoption of different configurations of electric resistivity method to investigate the occurrence of potential fractured aquifers. In an area where there is a sub vertical fracture zone in the crystalline basement the techniques of multiple vertical electrical soundings (VES), using the Schlumberger array, and electrical profiling using the multilevel gradient array, were applied. Three different configurations were tested in a same line whose direction is approximately perpendicular to the fracture plan. The results show that the multilevel gradient array presented better clarity in detecting fracture zone than the settings using vertical electrical soundings. However, such sub vertical structures could still be detected by VES, since it is adopted a proper separation between the VES centers. Obtained geoelectric sections indicate the presence of a groundwater accumulating structure composed by a crack-induced stream. Additionally, the electric gradient profiling presents operational advantages in relation to other arrays, being more practical and fast for data acquisition in the field.Keywords: Hydrogeophysics, electric resistivity, crystalline basement.

Fracture network connectivity devolution monitoring using transdimensional data assimilation

2021 ◽  
Author(s):  
Márk Somogyvári ◽  
Mohammadreza Jalali ◽  
Irina Engelhardt ◽  
Sebastian Reich
Keyword(s):  
Data Assimilation ◽  
Weather Forecasting ◽  
Fractured Reservoirs ◽  
Fracture Network ◽  
Model Parameters ◽  
Fractured Aquifer ◽  
Dynamic Changes ◽  
Transport Pathways ◽  
Fractured Aquifers ◽  
Rock Characterization

<p>In fractured aquifers, the permeability of open fractures could change over time due to precipitation effects and hydrothermal mineral growth. These processes could lead to the clogging of individual fractures and to the complete rearrangement of flow and transport pathways. Existing fractured rock characterization techniques often neglect this dynamicity and treat the reconstruction as a static inversion problem. The dynamic changes then later added to the model as an independent forward modeling task. In this research we provide a new data assimilation-based methodology to monitor and predict the dynamic changes of fractured aquifers due to mineralization in a quasi-real-time manner.</p><p>We formulate the inverse problem as a dynamic ‘hidden Markov process’ where the underlying model dynamicity is just partly known. Data assimilation methods are specifically designed to model such systems with strong uncertainties. A typical example for such problems is weather forecasting, where the combination of nonlinear processes and the partial observations make the forecasting challenging. To handle the strong random behavior, data assimilation approaches use stochastic algorithms. In this study we combine DFN-based stochastic aquifer reconstruction techniques with data assimilation algorithms to provide a dynamic inverse modelling framework for fractured reservoirs. We use the transdimensional DFN inversion of (Somogyvári et al., 2017) to initialize the data assimilation. This method uses a transdimensional MCMC approach to identify the most probable DFN geometries given the observations. Because the method is transdimensional it can adjust the number of model parameters, the number of fractures within the DFN. We developed this idea further by enhancing a particle filter algorithm with transdimensional model updates, allowing us to infer DFN models with changing fracture numbers.</p><p>We demonstrate the applicability of this new approach on outcrop-based synthetic fractured aquifer models. To create a dynamic DFN example, we simulate solute transport in a 2-D fracture network model using an advection-dispersion algorithm. We simulate fracture sealing in a stochastic way: we define a limit concentration above which the fractures could seal with a predefined probability at any timestep. At the initial timestep, a hydraulic tomography experiment is performed to capture the initial aquifer structure, which is then reconstructed by the transdimensional DFN inversion. At predefined timesteps hydraulic tests are performed at different parts of the aquifer, to obtain information about new state of the synthetic model. These observations are then processed by the data assimilation algorithm, which updates the underlying DFN models to better fit to the observations.</p>

Sign in / Sign up

Export Citation Format

Share Document