scholarly journals Study of Groundwater Flow Properties in a Karst System by Coupled Analysis of Diverse Environmental Tracers and Discharge Dynamics

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2442
Author(s):  
Andrej Stroj ◽  
Maja Briški ◽  
Maja Oštrić
Keyword(s):  
Electrical Conductivity ◽  
Groundwater Flow ◽  
Oxygen Concentration ◽  
Spring Water ◽  
Coupled Analysis ◽  
High Temporal Resolution ◽  
Valuable Insight ◽  
Environmental Tracers ◽  
Karst System ◽  
Excess Air

Monitoring of various naturally present substances or physical properties of the water, commonly called environmental tracers, can provide valuable insight in characteristics of groundwater flow systems and intrinsic processes. Analysis of individual tracer data most often gives an ambiguous interpretation, but employment of multiple diverse tracers can greatly increase interpretation reliability. We monitored multiple natural tracers including spring water electrical conductivity, temperature, loads of major anions and cations, stable isotopes of water, and total organic carbon together with discharge dynamics on Krbavica springs located in the Croatian part of Dinaric Karst region. We also monitored dissolved oxygen concentration as an indicator of “excess air” dynamics in the spring water, which is a very rarely recognized and not properly understood phenomenon in the karst groundwater studies. Analysis of the monitoring data revealed main characteristics of the karst system, among which following can be emphasized: (1) oxygen concentration together with conductivity and temperature (parameters monitored with high temporal resolution) were strongly related to discharge dynamics, while seasonal patterns were absent; (2) supersaturation with oxygen confirmed presence of “excess air”, most pronounced in high water conditions following the hydrograph peaks, indicating prevalence of closed flow conditions within the system; (3) electrical conductivity showed “anomalous” gradual decrease during the hydrograph recessions, attributed both to CO2 dynamics and mobilization of water from tiny fissures during high recharge conditions; and (4) stable isotope measurements confirmed good mixing of water within the system with mean residence time of a few years. Simultaneous monitoring of diverse tracer dynamics enabled detailed characterization of the karst system without excessive ambiguity.

Separation of groundwater-flow components in a karstified aquifer using environmental tracers

2020 ◽  
pp. 269-272
Author(s):  
R. Nativ ◽  
G. Günay ◽  
L. Tezcan ◽  
H. Hötzl ◽  
B. Reichert ◽  
...  
Keyword(s):  
Groundwater Flow ◽  
Environmental Tracers ◽  
Flow Components

The use of simulation and multiple environmental tracers to quantify groundwater flow in a shallow aquifer

1994 ◽  
Vol 30 (2) ◽  
pp. 421-433 ◽  
Author(s):  
Thomas E. Reilly ◽  
L. Niel Plummer ◽  
Patrick J. Phillips ◽  
Eurybiades Busenberg
Keyword(s):  
Groundwater Flow ◽  
Shallow Aquifer ◽  
Environmental Tracers

scholarly journals A multi-environmental tracer study to determine groundwater residence times and recharge in a structurally complex multi-aquifer system

2020 ◽  
Vol 24 (1) ◽  
pp. 249-267 ◽  
Author(s):  
Cornelia Wilske ◽  
Axel Suckow ◽  
Ulf Mallast ◽  
Christiane Meier ◽  
Silke Merchel ◽  
...  
Keyword(s):  
Groundwater Flow ◽  
Groundwater Recharge ◽  
Groundwater Age ◽  
Age Distribution ◽  
Dead Sea ◽  
Artificial Sweetener ◽  
Environmental Tracers ◽  
Jordan Valley ◽  
Aquifer System ◽  
Lumped Parameter

Abstract. Despite being the main drinking water resource for over 5 million people, the water balance of the Eastern Mountain Aquifer system on the western side of the Dead Sea is poorly understood. The regional aquifer consists of fractured and karstified limestone – aquifers of Cretaceous age, and it can be separated into a Cenomanian aquifer (upper aquifer) and Albian aquifer (lower aquifer). Both aquifers are exposed along the mountain ridge around Jerusalem, which is the main recharge area. From here, the recharged groundwater flows in a highly karstified aquifer system towards the east and discharges in springs in the lower Jordan Valley and Dead Sea region. We investigated the Eastern Mountain Aquifer system for groundwater flow, groundwater age and potential mixtures, and groundwater recharge. We combined 36Cl ∕ Cl, tritium, and the anthropogenic gases SF6, CFC-12 (chlorofluorocarbon) and CFC-11, while using CFC-113 as “dating” tracers to estimate the young water components inside the Eastern Mountain Aquifer system. By application of lumped parameter models, we verified young groundwater components from the last 10 to 30 years and an admixture of a groundwater component older than about 70 years. Concentrations of nitrate, simazine (pesticide), acesulfame K (ACE-K; artificial sweetener) and naproxen (NAP; drug) in the groundwater were further indications of infiltration during the last 30 years. The combination of multiple environmental tracers and lumped parameter modelling helped to understand the groundwater age distribution and to estimate recharge despite scarce data in this very complex hydrogeological setting. Our groundwater recharge rates support groundwater management of this politically difficult area and can be used to inform and calibrate ongoing groundwater flow models.

scholarly journals ESTIMATION OF RESIDENCE TIME AND CATCHMENT AREA OF SPRING WATER USING GEOCHEMICAL APPROACH BY 222Rn TRITIUM AND GROUNDWATER FLOW MODEL

2005 ◽  
Vol 49 ◽  
pp. 127-132
Author(s):  
Masataka MATSUMOTO ◽  
Yoshinari HIROSHIRO ◽  
Atsushi TSUTSUMI ◽  
Kenji JINNO ◽  
Hiroshi NIIDA
Keyword(s):  
Groundwater Flow ◽  
Residence Time ◽  
Catchment Area ◽  
Flow Model ◽  
Spring Water ◽  
Groundwater Flow Model ◽  
Geochemical Approach

scholarly journals CONTRIBUTION OF SEASONAL STOCHASTIC MODELS SARIMA TO THE RATIONAL WATER RESOURCES MANAGEMENT. THE CASE OF THE KRANIA ELASSONA KARST SYSTEM, THESSALY, GREECE

2004 ◽  
Vol 36 (4) ◽  
pp. 2012
Author(s):  
A. Μανάκος ◽  
Γ. Δημόπουλος
Keyword(s):  
Time Series ◽  
Stochastic Model ◽  
Groundwater Flow ◽  
Stochastic Models ◽  
Groundwater Resources ◽  
Spring Discharge ◽  
Karst System ◽  
Flow Conditions ◽  
Discharge Time ◽  
Monthly Discharge

Several stochastic models, known as Box and Jenkins or SARIMA (Seasonal Autoregressive Integrated Moving Average) have been used in the past for forecasting hydrological time series in general and stream flow or spring discharge time series in particular. SARIMA models became very popular because of their simple mathematical structure, convenient representation of data in terms of a relatively small number of parameters and their applicability to stationary as well as nonstationary process.Application of the seasonal stochastic model SARIMA to the spring's monthly discharge time series for the period 1974-1993 in Krania Elassona karst system yielded the following results. Logarithms of the monthly spring discharge time series can be simulated on a SARIMA (4,1,1)(1,1,1)12 type model. This type of model is suitable for the Krania Elassona karst system simulation and can be utilised as a tool to predict monthly discharge values at Kafalovriso spring for at least a 2 year period. Seasonal stochastic models SARIMA seem to be capable of simulating both runoff and groundwater flow conditions on a karst system and also easily adapt to their natural conditions.Adapting the proper stochastic model to the karst groundwater flow conditions offers the possibility to obtain accurate short term predictions, thus contributing to rational groundwater resources exploitation and management planning

scholarly journals Finite element analysis of freezing effect on soil nail wall

2021 ◽  
Author(s):  
Milad Babaei
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Earth Pressure ◽  
Field Measurements ◽  
Coupled Analysis ◽  
Valuable Insight ◽  
Freezing And Thawing ◽  
Element Analysis ◽  
Cold Regions ◽  
Soil Nail

This study presents a finite element analysis on the behavior of soil nail walls subjected to different freezing and thawing conditions. Thermo-mechanical coupled analysis has become increasingly important due to the increasing number of geotechnical structures built in cold regions. Soil nailing is a relatively new technique of reinforcing existing slopes or supporting new excavations. Its performance has been proven through decades of successful applications throughout the world. However, its applications in cold regions are still very limited due to sparse research available on its behavior in cold regions. In addition, soil may dramatically change its properties after experiencing freezing and thawing cycles. A two-dimensional finite element analysis using ABAQUS software is conducted to investigate the frost penetration depth in the soil and the resulting influence on the performance of the soil nail walls in Northern Ontario. The numerical model is verified against the field measurements obtained from a research program done in Brunswick, Maine, U.S. (Duchesne, 2003). The change of thermally induced stress along soil nails as well as the increase of displacements and earth pressure on the facing of the walls is investigated under freezing conditions. A parametric study is also conducted to probe the effect of thermal insulation systems on the wall facing and nails. This study provides valuable insight into the behavior of soil nailed structures in cold regions.

scholarly journals Quantification of anthropogenic impact on groundwater dependent terrestrial ecosystem using geochemical and isotope tools combined with 3-D flow and transport modeling

2014 ◽  
Vol 11 (8) ◽  
pp. 9671-9713
Author(s):  
A. J. Zurek ◽  
S. Witczak ◽  
M. Dulinski ◽  
P. Wachniew ◽  
K. Rozanski ◽  
...  
Keyword(s):  
Groundwater Flow ◽  
Terrestrial Ecosystem ◽  
Transport Modeling ◽  
Environmental Tracers ◽  
Groundwater Abstraction ◽  
Flow And Transport ◽  
Wide Range ◽  
The Status ◽  
Water Ph ◽  
Stable Isotopes Of Water

Abstract. A dedicated study was launched in 2010 with the main aim to better understand the functioning of groundwater dependent terrestrial ecosystem (GDTE) located in southern Poland. The GDTE consists of a valuable forest stand (Niepolomice Forest) and associated wetland (Wielkie Bloto fen). A wide range of tools (environmental tracers, geochemistry, geophysics, 3-D flow and transport modeling) was used. The research was conducted along three major directions: (i) quantification of the dynamics of groundwater flow in various parts of the aquifer associated with GDTE, (ii) quantification of the degree of interaction between the GDTE and the aquifer, and (iii) 3-D modeling of groundwater flow in the vicinity of the studied GDTE and quantification of possible impact of enhanced exploitation of the aquifer on the status of GDTE. Environmental tracer data (tritium, stable isotopes of water) strongly suggest that upward leakage of the aquifer contributes significantly to the present water balance of the studied wetland and associated forest. Physico-chemical parameters of water (pH, conductivity, Na / Cl ratio) confirm this notion. Model runs indicate that prolonged groundwater abstraction through the newly-established network of water supply wells, conducted at maximum permitted capacity (ca. 10 000 m3 d−1), may trigger drastic changes in the ecosystem functioning, eventually leading to its degradation.

scholarly journals Using <sup>14</sup>C and <sup>3</sup>H to understand groundwater flow and recharge in an aquifer window

2014 ◽  
Vol 18 (12) ◽  
pp. 4951-4964 ◽  
Author(s):  
A. P. Atkinson ◽  
I. Cartwright ◽  
B. S. Gilfedder ◽  
D. I. Cendón ◽  
N. P. Unland ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Groundwater Flow ◽  
Groundwater Resources ◽  
Environmental Isotopes ◽  
Discharge Zone ◽  
Order Estimate ◽  
Residence Times ◽  
Abstract Knowledge ◽  
Lower Chloride ◽  
Recharge Rates

Abstract. Knowledge of groundwater residence times and recharge locations is vital to the sustainable management of groundwater resources. Here we investigate groundwater residence times and patterns of recharge in the Gellibrand Valley, southeast Australia, where outcropping aquifer sediments of the Eastern View Formation form an "aquifer window" that may receive diffuse recharge from rainfall and recharge from the Gellibrand River. To determine recharge patterns and groundwater flow paths, environmental isotopes (3H, 14C, δ13C, δ18O, δ2H) are used in conjunction with groundwater geochemistry and continuous monitoring of groundwater elevation and electrical conductivity. The water table fluctuates by 0.9 to 3.7 m annually, implying recharge rates of 90 and 372 mm yr−1. However, residence times of shallow (11 to 29 m) groundwater determined by 14C are between 100 and 10 000 years, 3H activities are negligible in most of the groundwater, and groundwater electrical conductivity remains constant over the period of study. Deeper groundwater with older 14C ages has lower δ18O values than younger, shallower groundwater, which is consistent with it being derived from greater altitudes. The combined geochemistry data indicate that local recharge from precipitation within the valley occurs through the aquifer window, however much of the groundwater in the Gellibrand Valley predominantly originates from the regional recharge zone, the Barongarook High. The Gellibrand Valley is a regional discharge zone with upward head gradients that limits local recharge to the upper 10 m of the aquifer. Additionally, the groundwater head gradients adjacent to the Gellibrand River are generally upwards, implying that it does not recharge the surrounding groundwater and has limited bank storage. 14C ages and Cl concentrations are well correlated and Cl concentrations may be used to provide a first-order estimate of groundwater residence times. Progressively lower chloride concentrations from 10 000 years BP to the present day are interpreted to indicate an increase in recharge rates on the Barongarook High.

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