scholarly journals The Effect of River Valleys and the Upper Cretaceous Aquitard on Regional Flow in the Dakota Aquifer in the Central Great Plains of Kansas and Southeastern Colorado

1995 ◽  
pp. 11-30
Author(s):  
P. Allen Macfarlane
Keyword(s):  
Hydraulic Conductivity ◽  
Great Plains ◽  
Upper Cretaceous ◽  
Flow System ◽  
Arkansas River ◽  
Local Flow ◽  
Discharge Area ◽  
Regional Flow ◽  
Regional Hydrogeology ◽  
Vertical Hydraulic Conductivity

In his reports on the regional hydrogeology of the central Great Plains, in particular southeastern Colorado and southwestern and central Kansas, Darton considered the Dakota aquifer to be a classic example of an artesian system. Computer simulations of the flow system in this study, however, suggest that the Dakota is not a regional artesian aquifer in the classic sense. Sensitivity analysis of a steady-state vertical profile flow model demonstrates that the flow system in the upper Dakota in western Kansas is heavily influenced by the Upper Cretaceous aquitard, the Arkansas River in southeastern Colorado, and rivers in central Kansas, such as the Saline, that have eroded through the aquitard and into the Dakota to the west of the main outcrop area of the aquifer. The model shows that local flow systems and the vertical hydraulic conductivity of the Upper Cretaceous aquitard heavily influence the water budget and the flow patterns. The aquitard restricts recharge from the overlying water table to underlying aquifers in western Kansas because of its considerable thickness and low vertical hydraulic conductivity. The Arkansas River intercepts ground-water flow moving toward western Kansas from recharge areas south of the river and further isolates the upper Dakota from sources of freshwater recharge. In central Kansas, the Saline River has reduced the distance between confined portions of the aquifer and its discharge area. In essence, this has improved the hydraulic connection between the confined aquifer and its discharge area, thus helping to generate subhydrostatic conditions in the upper Dakota upgradient of the river.

The evolution and non-fickian flow of local stagnant zones in hierarchically nested groundwater flow system under different rainfall infiltration intensity

2021 ◽  
Author(s):  
Ronglin Sun ◽  
Liqun Jiang ◽  
Xing Liang ◽  
Menggui Jin
Keyword(s):  
Climate Change ◽  
Groundwater Flow ◽  
Flow System ◽  
Rainfall Infiltration ◽  
Stagnant Zone ◽  
Local Flow ◽  
Discharge Area ◽  
Directional Flow ◽  
Regional Flow ◽  
Flow Systems

<p>Groundwater plays an active role in certain geologic processes that has been recognized in numerous subdisciplines for a long time. According to Toth (1963, 2009), gravity-driven regional groundwater flow is induced by elevation differences in the water table and its pattern is self-organized into hierarchical sets of local, intermediate and regional flow systems.  Convergence of two flow systems results in a stagnant zone called hydraulic trap which is under the discharge area, and diverge of two flow systems results in a stagnant zone called quasi-stagnant zone which is under the water divide. These stagnant zones have been found to be critical to accumulation of transported mineral matter. Based on analytical and numerical solutions, some researchers reported that the local stagnant point or zone that are located under the local counter directional flow system. There is a question that whether hydraulic trap and quasi-stagnant zone is separate or integrate, and whether they are located under the discharge area or water divide or counter directional flow systems.</p><p>In this study, two-dimensional numerical cross-sectional model is used to investigate the effect of climate change on local stagnant zones and whether the hydraulic trap and quasi-stagnant zone is separate or integrate. Considering the climate change of basin and the change of rainfall infiltration intensity, a flux upper boundary is used to simulate the rainfall recharge. Then a synthetic homogeneous sandbox with three potential sinks is used to validate the evolution of the hierarchical nested groundwater flow systems considering different rainfall infiltration intensity. Salt tracer test is used to investigate the effect of stagnant zones on solute transport.</p><p>According to numerical results, we concluded that the hydraulic traps and quasi-stagnant are possible to be separate only for simple local systems and the two local stagnant zones are located on two sides of the counter directional flow system. When nested flow systems occur, such as local-intermediate, local-intermediate-local, local-regional, the local hydraulic traps and quasi-stagnant zones are always integrated under the local counter directional flow systems. Laboratory results show that when the rainfall infiltration intensity reduce, the groundwater flow pattern will change and the penetration depth and scope of counter directional local flow system will decrease. The corresponding local stagnant zone will slowly be closing to the discharge area of that counter directional local flow system. Salt tracer tests show that there are obvious non-fickian phenomenon in the local stagnant zones in hierarchically nested flow systems even in the homogeneous aquifer.</p>

scholarly journals Accelerated gravity testing of aquitard core permeability and implications at formation and regional scale

2015 ◽  
Vol 12 (3) ◽  
pp. 2799-2841
Author(s):  
W. A. Timms ◽  
R. Crane ◽  
D. J. Anderson ◽  
S. Bouzalakos ◽  
M. Whelan ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Preferential Flow ◽  
Fluid Velocity ◽  
Regional Scale ◽  
Geotechnical Centrifuge ◽  
Regional Flow ◽  
Clayey Silt ◽  
Vertical Hydraulic Conductivity ◽  
Core Permeability

Abstract. Evaluating the possibility of leakage through low permeability geological strata is critically important for sustainable water supplies, the extraction of fuels from strata such as coal beds, and the confinement of waste within the earth. The current work demonstrates that relatively rapid and reliable hydraulic conductivity (K) measurement of aquitard cores using accelerated gravity can inform and constrain larger scale assessments of hydraulic connectivity. Steady state fluid velocity through a low K porous sample is linearly related to accelerated gravity (g-level) in a centrifuge permeameter (CP) unless consolidation or geochemical reactions occur. The CP module was custom designed to fit a standard 2 m diameter geotechnical centrifuge (550 g maximum) with a capacity for sample dimensions of 30 to 100 mm diameter and 30 to 200 mm in length, and a maximum total stress of ~2 MPa at the base of the core. Formation fluids were used as influent to limit any shrink–swell phenomena which may alter the permeability. Vertical hydraulic conductivity (Kv) results from CP testing of cores from three sites within the same regional clayey silt formation varied (10−7 to 10−9 m s−1, n = 14). Results at one of these sites (1.1 × 10−10 to 3.5 × 10−9 m s−1, n = 5) that were obtained in < 24 h were similar to in situ Kv values (3 × 10−9 m s−1) from pore pressure responses over several weeks within a 30 m clayey sequence. Core scale and in situ Kv results were compared with vertical connectivity within a regional flow model, and considered in the context of heterogeneity and preferential flow paths at site and formation scale. More reliable assessments of leakage and solute transport though aquitards over multi-decadal timescales can be achieved by accelerated core testing together with advanced geostatistical and numerical methods.

Groundwater flow systems in the crystalline rocks of the Okanagan Highland, British Columbia

1968 ◽  
Vol 5 (4) ◽  
pp. 813-824 ◽  
Author(s):  
D. W. Lawson
Keyword(s):  
Hydraulic Conductivity ◽  
Groundwater Flow ◽  
Flow System ◽  
Crystalline Rock ◽  
Crystalline Rocks ◽  
Two Dimensional ◽  
Local Flow ◽  
Groundwater Flow Systems ◽  
Flow Systems ◽  
Two Dimensional Flow

An investigation of the groundwater flow systems associated with the most prominent topographic expression in the Okanagan Highland (a U-shaped valley) revealed that the hydraulic conductivity of the crystalline rock varies exponentially with depth, and that the local flow systems within the upper 125 to 150 ft of the crystalline rock conduct an estimated 10 to 17 Imperial gallons per day per foot thickness in a two-dimensional flow system. These local flow systems are quantitatively the most significant in the Okanagan Highland.

scholarly journals Modeling Groundwater Flow System of a Drainage Basin in the Basement Complex Environment of Southwestern Nigera

2018 ◽  
Vol 1 ◽  
pp. 1-7
Author(s):  
Akinola S. Akinwumiju ◽  
Martins O. Olorunfemi
Keyword(s):  
Groundwater Flow ◽  
Drainage Basin ◽  
Flow System ◽  
Subsurface Water ◽  
Complex Environment ◽  
Basement Complex ◽  
Local Flow ◽  
Groundwater Flow System ◽  
Regional Flow ◽  
Flow Directions

This study attempted to model the groundwater flow system of a drainage basin within the Basement Complex environment of Southwestern Nigeria. Four groundwater models were derived from Vertical Electrical Sounding (VES) Data, remotely sensed data, geological information (hydrolineaments and lithology) and borehole data. Subsequently, two sub-surface (local and regional) flow systems were delineated in the study area. While the local flow system is controlled by surface topography, the regional flow system is controlled by the networks of intermediate and deep seated faults/fractures. The local flow system is characterized by convergence, divergence, inflow and outflow in places, while the regional flow system is dominated by NNE-SSW and W-E flow directions. Minor flow directions include NNW-SSE and E-W with possible linkages to the main flow-paths. The NNE-SSW regional flow system is a double open ended flow system with possible linkage to the Niger Trough. The W-E regional flow system is a single open ended system that originates within the study area (with possible linkage to the NNE-SSW regional flow system) and extends to Ikogosi in the adjoining drainage basin. Thus, the groundwater drainage basin of the study area is much larger and extensive than its surface drainage basin. The all year round flowing (perennial) rivers are linked to groundwater outcrops from faults/fractures and contact zones. Consequently, larger percentage of annual rainwater usually leaves the basin in form of runoff and base flow. Therefore, the basin is categorized as a donor basin but with suspected subsurface water input at its northeastern axis.

scholarly journals Aquifer and Pond Relationship Under Potential Influence of Eucalyptus and Sugarcane

2021 ◽  
Author(s):  
Rafael Terada ◽  
Ricardo Hirata ◽  
Paulo Galvão ◽  
Fernando Saraiva ◽  
Norio Tasse ◽  
...  
Keyword(s):  
Major Ions ◽  
Flow System ◽  
Pond Water ◽  
Shallow Aquifer ◽  
Potential Influence ◽  
Local Flow ◽  
Discharge Area ◽  
Geophysical Surveys ◽  
Before And After ◽  
Flow Directions

Abstract A hydraulic interaction between a pond and shallow aquifer in a watershed surrounded by cultivations of sugarcane and eucalyptus trees was evaluated in Brazil. The pond, located in lower topographic levels, was prematurely interpreted as the local shallow aquifer's discharge area, suggesting the groundwater could flow towards the pond. However, water table gradients indicated opposite directions, bringing up questions about the eucalyptus root's potential to access groundwater, consequently lowering the water level and changing the groundwater flow directions. Physicochemical parameters, stable isotopes of δ18O and δ2H, major ions analysis were determined in samples of groundwater and pond water; and geophysical surveys and groundwater level measurements were performed before and after the eucalyptus cutting. The results showed 1) the eucalyptus does not have a significant influence on the groundwater dynamic; 2) the pond behaves as a recharge, not a discharge area; and 3) previously considered as a local flow, the interaction between groundwater and pond is determined by an intermediate flow system, controlled by a near spring, independently of the seasonal variation and land uses.

TRANSIENT GROUNDWATER FLOW SURROUNDING A RECHARGE SLOUGH IN A TILL PLAIN

1986 ◽  
Vol 66 (1) ◽  
pp. 121-134 ◽  
Author(s):  
J. G. MILLS ◽  
M. A. ZWARICH
Keyword(s):  
Hydraulic Conductivity ◽  
Groundwater Flow ◽  
Transient Flow ◽  
Flow System ◽  
Water Levels ◽  
Local Flow ◽  
Wide Range ◽  
Conductivity Water ◽  
Surface Saturation ◽  
The One

Knowledge of the groundwater flow system around a slough aids in the resolution of conflicting opinions on slough drainage. This study reports on the flow system around a typical temporary slough in a low relief till plain landscape. The site is located in a regional groundwater recharge area, with till of low hydraulic conductivity overlying a shale aquifer. The distribution of soil profile types in the landscape reflects a wide range of soil water regimes. Instrumentation at the site revealed an annual cycle of water levels and transient flow that was related to spring ponding of water in the slough. Numerical simulation of the flow system, under conditions of ponding, surface saturation, and evapotranspiration, helped to clarify and extend the field observations. Each depression in the landscape has a local flow system that is superimposed on the regional system. Hydraulic conductivity, water supply to the slough, and the amount and timing of infiltration and exfiltration all affect the local flow system. Temporary sloughs, such as the one studied, do not benefit agriculture, but drainage of these sloughs raises other concerns. Key words: Groundwater, transient flow, recharge, slough, pothole, simulation

Spatial and depth variability of streambed vertical hydraulic conductivity under the regional flow regimes

2018 ◽  
Vol 32 (19) ◽  
pp. 3006-3018 ◽  
Author(s):  
Jinxi Song ◽  
Liping Wang ◽  
Xinyi Dou ◽  
Fangjian Wang ◽  
Hongtao Guo ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Flow Regimes ◽  
Regional Flow ◽  
Vertical Hydraulic Conductivity ◽  
Streambed Vertical Hydraulic Conductivity

Saturated Hydraulic Conductivity of Clayey Tills and the Role of Fractures

1990 ◽  
Vol 21 (2) ◽  
pp. 119-132 ◽  
Author(s):  
Johnny Fredericia
Keyword(s):  
Hydraulic Conductivity ◽  
American Studies ◽  
Field Measurements ◽  
Present Knowledge ◽  
Saturated Hydraulic Conductivity ◽  
Field Observations ◽  
Laboratory Measurements ◽  
Vertical Hydraulic Conductivity ◽  
Data Field

The background for the present knowledge about hydraulic conductivity of clayey till in Denmark is summarized. The data show a difference of 1-2 orders of magnitude in the vertical hydraulic conductivity between values from laboratory measurements and field measurements. This difference is discussed and based on new data, field observations and comparison with North American studies, it is concluded to be primarily due to fractures in the till.

Effect of temperature on streambed vertical hydraulic conductivity

2013 ◽  
Vol 45 (1) ◽  
pp. 89-98 ◽  
Author(s):  
Weihong Dong ◽  
Gengxin Ou ◽  
Xunhong Chen ◽  
Zhaowei Wang
Keyword(s):  
Hydraulic Conductivity ◽  
Water Temperature ◽  
Sediment Cores ◽  
Effect Of Temperature ◽  
In Situ Tests ◽  
Effect Of Water ◽  
Vertical Hydraulic Conductivity ◽  
Increasing Trend ◽  
Streambed Vertical Hydraulic Conductivity

In this study, in situ and on-site permeameter tests were conducted in Clear Creek, Nebraska, USA to evaluate the effect of water temperature on streambed vertical hydraulic conductivity Kv. Fifty-two sediment cores were tested. Five of them were transferred to the laboratory for a series of experiments to evaluate the effect of water temperature on Kv. Compared with in situ tests, 42 out of the 52 tests have higher Kv values for on-site tests. The distribution of water temperature at the approximately 50 cm depth of streambed along the sand bar was investigated in the field. These temperatures had values in the range 14–19 °C with an average of 16 °C and had an increasing trend along the stream flow. On average, Kv values of the streambed sediments in the laboratory tests increase by 1.8% per 1 °C increase in water temperature. The coarser sandy sediments show a greater increase extent of the Kv value per 1 °C increase in water temperature. However, there is no distinct increasing trend of Kv value for sediment containing silt and clay layers.

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