scholarly journals A Preliminary Study on a Pumping Well Capturing Groundwater in an Unconfined Aquifer with Mountain-Front Recharge from Segmental Inflow

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1243
Author(s):  
Haixiang Li ◽  
Xu-sheng Wang
Keyword(s):  
Water Supply ◽  
Unconfined Aquifer ◽  
Shape Factors ◽  
Unconfined Aquifers ◽  
Capture Zones ◽  
Pumping Wells ◽  
Travel Time Distribution ◽  
Mountain Front ◽  
Constant Head ◽  
A Site

Unconfined aquifers beneath piedmont pluvial fans are widely distributed in front of mountains and proper for water supply with pumping wells. However, the catchment zone and capture zones of a pumping well in such an unconfined aquifer is not well known. We develop a preliminary simplified model where groundwater flows between a segmental inflow boundary and a discharge boundary of constant head. The catchment zone is delineated from numerical simulation via MODFLOW and MODPATH. Results are expressed with dimensionless variables and lumped parameters to show general behaviors. Sensitive analyses indicate that there are 4 types of the catchment zone according to different connections to the boundaries. The shape of the catchment zone is quantitatively analyzed with typical shape factors. Capture zones with respect to special travel times are identified from travel time distribution in the catchment zone. The modeling results can be applied in the design of water supply wells and delineation of protection zones at a site with similar hydrogeological conditions.

An Iron Age A site on the Chilterns

1951 ◽  
Vol 31 (3-4) ◽  
pp. 132-148 ◽  
Author(s):  
K. M. Richardson ◽  
Alison Young
Keyword(s):  
Water Supply ◽  
Iron Age ◽  
The West ◽  
North West ◽  
The North ◽  
Roman Villa ◽  
Adjoining Area ◽  
Cursory Examination ◽  
A Site ◽  
The Hill

In 1946 a visit to the barrow, which lies on the edge of the western scarp of Chinnor Common, and a cursory examination of the adjoining area, cultivated during the war, resulted in finds of pottery and other objects indicating Iron Age occupation. The site lies on the saddleback of a Chiltern headland, at a height of about 800 ft. O.D. Two hollow ways traverse the western scarp, giving access to the area from the Upper Icknield Way, which contours the foot of the hill, then drops to cross the valley, passing some 600 yards to the north of the Iron Age site of Lodge Hill, Bledlow, and rising again continues northwards under Pulpit Hill camp and the Ellesborough Iron Age pits below Coombe Hill. The outlook across the Oxford plain to the west is extensive, embracing the hill-fort of Sinodun, clearly visible some fourteen miles distant on the farther bank of the Thames. The hollow way at the north-west end of the site leads down to a group of ‘rises’ hard by the remains of a Roman villa, and these springs are, at the present day, the nearest water-supply to the site.

scholarly journals Hydrogeological Conceptual Model in the Middle of Randublatung Groundwater Basin

2021 ◽  
Vol 926 (1) ◽  
pp. 012078
Author(s):  
D L Setyaningsih ◽  
K D Setyawan ◽  
D P E Putra ◽  
Salahuddin
Keyword(s):  
Groundwater Flow ◽  
Conceptual Model ◽  
Unconfined Aquifer ◽  
Primary Data ◽  
Essential Information ◽  
Aquifer System ◽  
The North ◽  
Shallow Wells ◽  
Groundwater Basin ◽  
Constant Head

Abstract Randublatung groundwater basin is one of the groundwaters basins with massive utilization of groundwater pumping. However, the knowledge of the comprehensive hydrogeological system in this groundwater basin is limited, so this research aims to determine a comprehensive hydrogeological conceptual model of the Randublatung groundwater basin. The methodology was conducted by collecting secondary and primary data of deep and shallow wells to evaluate boundaries of pattern and direction of groundwater flow and develop the aquifer system’s geometry. The result shows that the groundwater flow boundaries are Grogol River in the west, Wado River in the East, Bengawan Solo river in the South as a river boundary, and Rembang Mountains in the North as a constant head boundary. Therefore, groundwater flows from the hills area to the Bengawan Solo River and the north as the river’s flow. Based on the log bor evaluation, the aquifer system of the study area consist of an unconfined aquifer with a maximum thickness of 20 m and three layers of confined aquifers with thickness vary between 8 to 60 m. the hydraulic conductivity of the aquifers depends on the aquifer’s lithology range from sand, gravel, limestone, and sandstone. This hydrogeological conceptual model provides essential information for numerical groundwater models in the middle of the Randublatung groundwater basin.

scholarly journals Underground Barrier Wall Evaluation for Controlling Saltwater Intrusion in Sloping Unconfined Coastal Aquifers

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2403
Author(s):  
Asaad M. Armanuos ◽  
Nadhir Al-Ansari ◽  
Zaher Mundher Yaseen
Keyword(s):  
Saltwater Intrusion ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Unconfined Aquifer ◽  
Numerical Results ◽  
Unconfined Aquifers ◽  
Sloping Bed ◽  
Bed Slope ◽  
The Cost ◽  
Barrier Wall

Barrier walls are considered one of the most effective methods for facilitating the retreat of saltwater intrusion (SWI). This research plans to examine the effect of using barrier walls for controlling of SWI in sloped unconfined aquifers. The sloping unconfined aquifer is considered with three different bed slopes. The SEAWAT model is implemented to simulate the SWI. For model validation, the numerical results of the seawater wedge at steady state were compared with the analytical solution. Increasing the ratio of flow barrier depth (db/d) forced the saltwater interface to move seaward and increased the repulsion ratio (R). With a positive sloping bed, further embedding the barrier wall from 0.2 to 0.7 caused R to increase from 0.3% to 59%, while it increased from 1.8% to 41.7% and from 3.4% to 46.9% in the case of negative and horizontal slopes, respectively. Embedding the barrier wall to a db/d value of more than 0.4 achieved a greater R value in the three bed-sloping cases. Installing the barrier wall near the saltwater side with greater depth contributed to the retreat of the SWI. With a negative bed slope, moving the barrier wall from Xb/Lo = 1.0 toward the saltwater side (Xb/Lo = 0.2) increased R from 7.21% to 68.75%, whereas R increased from 5.3% to 67% for the horizontal sloping bed and from 5.1% to 64% for the positive sloping bed. The numerical results for the Akrotiri coastal aquifer confirm that the embedment of the barrier wall significantly affects the controlling of SWI by increasing the repulsion ratio (R) and decreasing the SWI length ratio (L/La). Cost-benefit analysis is recommended to determine the optimal design of barrier walls for increasing the cost-effectiveness of the application of barrier walls as a countermeasure for controlling and preventing SWI in sloped unconfined aquifers.

scholarly journals Infiltration and Anti-Filtration Recharge-Pumping Well and Laboratory Recharge Tests

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1834
Author(s):  
Yuxi Li ◽  
Wanglin Li ◽  
Jiapeng He ◽  
Xiaojiao Zhang ◽  
Xinyi Li
Keyword(s):  
Steady State ◽  
Flow Pattern ◽  
Theoretical Equation ◽  
Steady State Flow ◽  
Inlet Flow ◽  
State Flow ◽  
Unconfined Aquifers ◽  
Pumping Wells ◽  
Single Well

Infiltration and anti-filtration recharge-pumping wells (hereinafter, referred to as IAF recharge-pumping wells) can enable rain-flood flowing in rivers or channel recharge to aquifers, in flood periods, and pump groundwater to be utilized in non-flood periods. In this study, a round IAF recharge-pumping well and a square IAF recharge-pumping well were developed, the structure and characteristic were introduced, the calculation equations of single-well recharge quantity of IAF recharge-pumping wells, in unconfined aquifers were deduced, and the steady-state flow recharge test was conducted in the laboratory. The conclusions were as follows. The theoretical equation of the single-well recharge quantity was reasonable. Compared to existing anti-filtration recharge wells, the new IAF recharge-pumping well had stronger anti-deposit and anti-scour abilities and the single-well recharge quantity increased by 400%. Compared to the square IAF recharge-pumping well, the round IAF recharge-pumping well had a better inlet flow pattern and a larger single-well recharge quantity. With an increase in the test times, the single-well recharge quantity gradually decreased and tended to be stable. The existence of the pumping pipe had a little influence on the single-well recharge quantity.

scholarly journals Improved Solutions to the Linearized Boussinesq Equation with Temporally Varied Rainfall Recharge for a Sloping Aquifer

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 826 ◽  
Author(s):  
Wu ◽  
Hsieh
Keyword(s):  
Groundwater Level ◽  
Boussinesq Equation ◽  
Integral Transformation ◽  
Transformation Method ◽  
Unconfined Aquifer ◽  
Convergence Criterion ◽  
Unconfined Aquifers ◽  
Linearized Boussinesq Equation ◽  
Sloping Aquifer ◽  
Rainfall Recharge

Sloping unconfined aquifers are commonly seen and well investigated in the literature. In this study, we propose a generalized integral transformation method to solve the linearized Boussinesq equation that governs the groundwater level in a sloping unconfined aquifer with an impermeable bottom. The groundwater level responses of this unconfined aquifer under temporally uniform recharge or nonuniform recharge events are discussed. After comparing with a numerical solution to the nonlinear Boussinesq equation, the proposed solution appears better than that proposed in a previous study. Besides, we found that the proposed solutions reached the convergence criterion much faster than the Laplace transform solution did. Moreover, the application of the proposed solution to temporally changing rainfall recharge is also proposed to improve on the previous quasi-steady state treatment of an unsteady recharge rate.

scholarly journals Fractional governing equations of transient groundwater flow in unconfined aquifers with multi-fractional dimensions in fractional time

2020 ◽  
Vol 11 (1) ◽  
pp. 1-12 ◽  
Author(s):  
M. Levent Kavvas ◽  
Tongbi Tu ◽  
Ali Ercan ◽  
James Polsinelli
Keyword(s):  
Groundwater Flow ◽  
Governing Equation ◽  
Water Flux ◽  
Unconfined Aquifer ◽  
Saturated Porous Media ◽  
Unconfined Aquifers ◽  
Heavy Tailed ◽  
Consistent Equation ◽  
Fractional Dimensions ◽  
Fractional Space

Abstract. In this study, a dimensionally consistent governing equation of transient unconfined groundwater flow in fractional time and multi-fractional space is developed. First, a fractional continuity equation for transient unconfined groundwater flow is developed in fractional time and space. For the equation of groundwater motion within a multi-fractional multidimensional unconfined aquifer, a previously developed dimensionally consistent equation for water flux in unsaturated/saturated porous media is combined with the Dupuit approximation to obtain an equation for groundwater motion in multi-fractional space in unconfined aquifers. Combining the fractional continuity and groundwater motion equations, the fractional governing equation of transient unconfined aquifer flow is then obtained. Finally, two numerical applications to unconfined aquifer groundwater flow are presented to show the skills of the proposed fractional governing equation. As shown in one of the numerical applications, the newly developed governing equation can produce heavy-tailed recession behavior in unconfined aquifer discharges.

Transient solution for radial two-zone flow in unconfined aquifers under constant-head tests

2010 ◽  
Vol 24 (11) ◽  
pp. 1496-1503 ◽  
Author(s):  
Y. C. Chang ◽  
H. D. Yeh ◽  
G. Y. Chen
Keyword(s):  
Transient Solution ◽  
Unconfined Aquifers ◽  
Constant Head
Sign in / Sign up

Export Citation Format

Share Document