scholarly journals Preliminary potentiometric map and flow dynamic characteristics for the upper-basalt confined aquifer system

1993 ◽  
Author(s):  
F.A. Jr. Spane ◽  
R.G. Raymond
Keyword(s):  
Dynamic Characteristics ◽  
Confined Aquifer ◽  
Flow Dynamic ◽  
Aquifer System

scholarly journals Cl− as a Chemical Fingerprint of Solute Transport in the Aquitard-Aquifer System of the North Jiangsu Coastal Plain, China

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-16
Author(s):  
Qin Ge ◽  
Xing Liang ◽  
Menggui Jin ◽  
Jing Li ◽  
Yan Liu
Keyword(s):  
Solute Transport ◽  
Coastal Plain ◽  
Transport Mechanism ◽  
Shallow Groundwater ◽  
Confined Aquifer ◽  
Aquifer System ◽  
The North ◽  
System A ◽  
Tracer Migration ◽  
Natural Tracer

Detailed vertical profiles of Cl− in porewaters through the aquitard-aquifer system were used to yield solute transport mechanism and build a conceptual model regarding evolution processes and transport time of natural tracer migration in North Jiangsu coastal plain, China. One-dimensional vertical simulated models of Cl− profiles illustrate that diffusion appeared to be the dominant solute transport mechanism in the aquitard-aquifer system. A downward groundwater flow did not improve the fitness between simulated and measured values. Several simulated models were constructed and suggested that the evolution of the Cl− profiles is mainly ascribed to the introduction of seawater and freshwater of transgression-regression to the first confined aquifer and the upper boundary. Groundwater in the first confined aquifer recharged by the Late Pleistocene glacial meltwater (25–15 ka BP) was supported in response to the low Cl− concentrations. The shallow groundwater in the first confined aquifer and porewater with high salt were attributable to the Holocene seawater intrusion. These timeframes were also consistent favorably with the results of previous studies into the palaeohydrology of the study area.

scholarly journals Investigation of flow dynamic characteristics of inverse fluidized bed biofilm reactor for degrading pharmaceutical based biomedical wastewater

2020 ◽  
Author(s):  
Sabarunisha Begum S ◽  
Mohamed Yacin Sikkandar ◽  
Prakash NB ◽  
Mohsen Bakouri ◽  
Ahmed Bakhit Alanazi ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Dynamic Characteristics ◽  
Biofilm Reactor ◽  
Flow Dynamic ◽  
Inverse Fluidized Bed

scholarly journals Salinity and modelling of the Annaba aquifer system, North-East of Algeria

2018 ◽  
Vol 37 (1) ◽  
pp. 113-120
Author(s):  
Habiba Majour ◽  
Azzedine Hani ◽  
Larbi Djabri
Keyword(s):  
Steady State ◽  
Solute Transport ◽  
History Matching ◽  
Transport Model ◽  
Water Levels ◽  
Model Verification ◽  
Confined Aquifer ◽  
Deep Aquifer ◽  
Aquifer System ◽  
North East

Abstract The potentiometer area in the Annaba basin, covering an area of 264 km2, has declined considerably since 1995. The analysis of the chronological hydrographs (1991–2009) of the piezometric observations shows that this decline is related to about twenty years (20 years) drought that began in 1991. To synthesize hydrological data and study regional changes in aquifer interactions caused by changes in discharge, and determine the contamination of aquifers by salty intrusion in coastal areas, and making forecasts by the year 2023, a multi-layered transient model as well as a solute transport model has been developed. The groundwater flow was modelled using the finite difference method with a horizontal dimension of 500 × 500 m for the cells. The model consists of two layers, the first corresponding to the alluvial phreatic aquifer and the second to the deep confined aquifer, and is calibrated against the steady state groundwater heads recorded before 1996. Model verification was done by history matching over the period 1991–2009. Under steady-state conditions, the correspondence between simulated and observed water levels is generally good (average difference of 0.4 m). For the deep aquifer, the simulated time-series hydrographs closely match the recorded hydrographs for most of the observation wells. For the alluvial aquifer, the recorded hydrographs cover only a short time period, but they are reproduced. The model indicates that groundwater pumping induced a decrease in natural discharge, a downward leakage in most of the basin and a continual water-level decline. The model has also been applied to the analysis of recharge impact. Simulating the behaviour of the system over the period 1991–2009 without pumping indicated small changes in hydraulic head. These results show that the groundwater reservoir has a low recharge, but excellent hydraulic properties. A solute-transport model was used to study aquifer contamination from salty intrusion in coastal sectors; it was extended to the year 2023 by simulating an optimistic hypothesis that maintains present pumping until 2023. The model indicates that the head decrease of the alluvial phreatic and deep confined aquifers will be 4 m and 5 m respectively. The solute concentration in the deep confined aquifer will increase from 1 gꞏdm−3 (prior 2009) to 5 gꞏdm−3 in 2023.

scholarly journals Analytical Solution of Tidal Loading Effect in a Submarine Leaky Confined Aquifer System

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Zongzhong Song ◽  
Hailong Li ◽  
Qian Ma ◽  
Chunmiao Zheng ◽  
Jiu Jimmy Jiao ◽  
...  
Keyword(s):  
Analytical Solution ◽  
Confined Aquifer ◽  
One Dimensional ◽  
Aquifer System ◽  
Groundwater Level Fluctuations ◽  
Groundwater Head ◽  
Aquifer Systems ◽  
Groundwater Fluctuation ◽  
Loading Effects ◽  
Tidal Loading

Although there are many existing analytical studies of tidal groundwater level fluctuations in coastal aquifer systems, few of them focus on an offshore submarine aquifer. Here, we consider tidal groundwater head fluctuations in a submarine leaky confined aquifer overlain by a semipermeable seabed. Both the seabed and the confined aquifer are assumed to extend horizontally infinitely. A one-dimensional mathematical model is established to describe the problem, and the analytical solution is derived. The impacts of the tidal loading efficiency, hydraulic conductivity and elastic storage of the semipermeable layer and aquifer on the groundwater head fluctuations in the aquifer system are analyzed and discussed. Solution analyses indicated that tidal loading effects tend to enhance the amplitude of the tidal groundwater fluctuation in the confined aquifer system and to reduce the phase shift between the groundwater head and the sea tide fluctuations.

scholarly journals A Coupled One-Dimensional Numerical Simulation of the Land Subsidence Process in a Multilayer Aquifer System due to Hydraulic Head Variation in the Pumped Layer

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Ye Wang ◽  
Mao-sheng Zhang ◽  
Fu-sheng Hu ◽  
Ying Dong ◽  
Kun Yu
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Land Subsidence ◽  
Transition Period ◽  
Pressure Head ◽  
Hydraulic Head ◽  
Confined Aquifer ◽  
One Dimensional ◽  
Aquifer System ◽  
Simulation Results

After exploitation of groundwater had been reduced and the groundwater level of the confined aquifer had risen, land subsidence was observed to continue rather than cease for several years according to the layer-wise mark monitoring data in Xi’an. To analyze the phenomena, a numerical model of a coupled one-dimensional multilayer aquifer system is developed to represent land subsidence due to hydraulic head variation in the pumped layer. The numerical simulation results show that the pressure head in other layers does not rise immediately when the hydraulic head in the pumped layer starts to recover after pumping ceases. In addition, after the pumping is stopped, a dividing point can be found in aquitards next to the pumped layer, with the aquitards being divided into two parts: a compressed part and a rebounding part. The dividing points move toward the side and away from the pumped layer with the transferring of pore pressure in the aquitard. The results of the simulation also show that there is a transition period between land subsidence and rebound. In this transition period, land could continue to subside even though the hydraulic head in the pumped layer begins to recover.

scholarly journals Pemodelan Intrusi Air Asin Pada Akuifer Pantai (Studi Kasus: DKI Jakarta)

2019 ◽  
Author(s):  
Alan Wijaya
Keyword(s):  
Water Management ◽  
Ground Water ◽  
Salt Water ◽  
Large Population ◽  
Policy Formulation ◽  
Salt Water Intrusion ◽  
Confined Aquifer ◽  
Literature Study ◽  
Groundwater Use ◽  
Aquifer System

Some main issues related to the management of ground water resources are frequently faced by communities living in coastal areas in Indonesia, especially in the city of Jakarta, such as large population, rapid industrial and business growth, availability of groundwater resource and limitation of PAM (water supply company) capability, and Jakarta's geographic position with its aquifer system bordered by to the coastal. Those fundamental issues caused the saltwater intrusion in Jakarta to fade further into the freshwater aquifers system. The purpose of this study was to analyze the extent of the distribution of saltwater contamination to coastal aquifers in Jakarta so that it could be utilized in the policy formulation of ground water management and clean water management. The method used in this research was literature study, the data used in the form of secondary data and modeling conducted by the open source program well known as FREEWAT.The modeling of salt water intrusion on coastal aquifer of Jakarta was conducted into five model scenarios, namely (1) reduction of 50% of ground-water use, (2) reduction of 50% of groundwater use, (3) existing groundwater use in 2012, (4) increase of 25% of groundwater use, and (5) increase of 50% of groundwater use. From the modeling results, they were obtained the distribution of saltwater contamination on each layer of the aquifer of Jakarta. In unconfined aquifer the existing condition is scenario 3 intrusion as far as 1,604 m, on scenario 1 there is an intrusion decrease of 38%, in scenario 2 there is an intrusion decrease of 13%, in scenario 4 there is an increase in intrusion by 17% and on scenario 5 increase intrusion by 25%. In upper confined aquifer, the existing condition, namely scenario 3, has occurred as much as 1.809 m intrusion, in scenario 1 there is an intrusion decrease of 23%, in scenario 2 there is an intrusion decrease of 8%, in scenario 4 there is an increase in intrusion by 19% and in scenario 5 in-crease intrusion by 26%. In middle confined aquifer, the existing condition is scenario 3, 1.927 m intrusion occurs, on the scenario 1 there is an intru-sion decrease of 23%, in scenario 2 there is an intrusion decrease of 9%, in scenario 4 there is an increase in intrusion by 16% and in the scenario 5 increase intrusion by 22%.

Using Groundwater Responses to Infer Recharge - Part 5

1998 ◽  
Author(s):  
D Armstrong ◽  
K Narayan
Keyword(s):  
Time Lag ◽  
Worked Examples ◽  
Unconfined Aquifer ◽  
Confined Aquifer ◽  
Case Histories ◽  
Cross Sectional ◽  
Aquifer System ◽  
Groundwater Levels ◽  
Unconfined Aquifers ◽  
Event Basis

Analytical methods of assessing the response of groundwater levels to a range of factors, including elastic (barometric and tidal) influences in confined aquifers and recharge to unconfined aquifers due to infiltration of rain and other surface water, are presented. Responses in a confined aquifer to distant recharge events and the associated time lag is discussed. Also covered are responses to changes in storage volume resulting from direct recharge at the outcrop of an unconfined aquifer system both seasonally and on a single recharge event basis. Worked examples and case histories are used to illustrate methods of estimating the amount of recharge at different sites within a catchment. The application of vertical cross-sectional flow nets to the estimation of recharge is presented in the context of recharge/discharge profiles.

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