A Hybrid Occam and Marquardt-Levenberg Inversion Approach to Time-lapse Transient Electromagnetic Monitoring of Water Infiltration at a Recharge Basin

2013 ◽  
Author(s):  
A. Swidinsky ◽  
H. El-Kaliouby
Keyword(s):  
Time Lapse ◽  
Water Infiltration ◽  
Recharge Basin ◽  
Transient Electromagnetic ◽  
Electromagnetic Monitoring

scholarly journals Quantifying aquifer properties and freshwater resource in coastal barriers: a hydrogeophysical approach applied at Sasihithlu (Karnataka state, India)

2012 ◽  
Vol 16 (11) ◽  
pp. 4387-4400 ◽  
Author(s):  
J.-M. Vouillamoz ◽  
J. Hoareau ◽  
M. Grammare ◽  
D. Caron ◽  
L. Nandagiri ◽  
...  
Keyword(s):  
Sea Level ◽  
Groundwater Resources ◽  
Time Lapse ◽  
Unconfined Aquifer ◽  
Spatial Knowledge ◽  
Western India ◽  
Transient Electromagnetic ◽  
Freshwater Resource ◽  
Aquifer Properties ◽  
Rainfall Patterns

Abstract. Many human communities living in coastal areas in Africa and Asia rely on thin freshwater lenses for their domestic supply. Population growth together with change in rainfall patterns and sea level will probably impact these vulnerable groundwater resources. Spatial knowledge of the aquifer properties and creation of a groundwater model are required for achieving a sustainable management of the resource. This paper presents a ready-to-use methodology for estimating the key aquifer properties and the freshwater resource based on the joint use of two non-invasive geophysical tools together with common hydrological measurements. We applied the proposed methodology in an unconfined aquifer of a coastal sandy barrier in South-Western India. We jointly used magnetic resonance and transient electromagnetic soundings and we monitored rainfall, groundwater level and groundwater electrical conductivity. The combined interpretation of geophysical and hydrological results allowed estimating the aquifer properties and mapping the freshwater lens. Depending on the location and season, we estimate the freshwater reserve to range between 400 and 700 L m−2 of surface area (± 50%). We also estimate the recharge using time lapse geophysical measurements with hydrological monitoring. After a rainy event close to 100% of the rain is reaching the water table, but the net recharge at the end of the monsoon is less than 10% of the rain. Thus, we conclude that a change in rainfall patterns will probably not impact the groundwater resource since most of the rain water recharging the aquifer is flowing towards the sea and the river. However, a change in sea level will impact both the groundwater reserve and net recharge.

scholarly journals Modelling time-lapse shear-wave velocity changes in an unsaturated soil embankment due to water infiltration and drainage

First Break ◽  
2017 ◽  
Vol 35 (8) ◽  
Author(s):  
Atsushi Suzaki ◽  
Shohei Minato ◽  
Ranajit Ghose ◽  
Chisato Konishi ◽  
Naoki Sakai
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Unsaturated Soil ◽  
Time Lapse ◽  
Water Infiltration ◽  
Velocity Changes

Ground-penetrating radar surveys for the detection of preferential flow into soils

2020 ◽  
Author(s):  
Simone Di Prima ◽  
Thierry Winiarski ◽  
Rafael Angulo-Jaramillo ◽  
Ryan D. Stewart ◽  
Mirko Castellini ◽  
...  
Keyword(s):  
Ground Penetrating Radar ◽  
Preferential Flow ◽  
Three Dimensional ◽  
Time Lapse ◽  
Water Infiltration ◽  
Single Ring ◽  
Before And After ◽  
Infiltration Tests ◽  
Ground Penetrating ◽  
Preferential Flows

<p>Preferential flow is more the rule than the exception, in particular during water infiltration experiments. In this study, we demonstrate the potential of GPR monitoring to detect preferential flows during water infiltration. We monitored time-lapse ground penetrating radar (GPR) surveys in the vicinity of single-ring infiltration experiments and created a three-dimensional (3D) representation of infiltrated water below the devices. For that purpose, radargrams were constructed from GPR transects conducted over two grids (1 m × 1 m) before and after the infiltration tests. The obtained signal was represented in 3D and a threshold was chosen to part the domain into wetted and non-wetted zones, allowing the determination of the infiltration bulb. That methodology was used to detect the infiltration below the devices and clearly pointed at nonuniform flows in correspondence with the heterogeneous soil structures. The protocol presented in this study represents a practical and valuable tool for detecting preferential flows at the scale of a single ring infiltration experiment.</p>

Feasibility of Monitoring Hydraulic Connections between Aquifers Using Time-lapse TEM: A Case History in Inner Mongolia, China

2019 ◽  
Vol 24 (3) ◽  
pp. 361-372
Author(s):  
Kang Chen ◽  
Junyan Zhang ◽  
Guoqiang Xue ◽  
Hao Huang ◽  
Weiying Chen ◽  
...  
Keyword(s):  
Case History ◽  
Inner Mongolia ◽  
Electromotive Force ◽  
Time Lapse ◽  
Pumping Test ◽  
Pumping Tests ◽  
Transient Electromagnetic ◽  
Successful Case ◽  
Aquifer Properties ◽  
Hydrogeological Data

Hydraulic connections between aquifers is usually studied through hydrochemical analysis or by pumping tests. However, hydrochemical analyses are usually conducted in areas of variable lithology. In addition, the hydrogeological data obtained by drilling and pumping tests are typically insufficient to get 3D distributions of hydraulic head. In this paper, the time-lapse transient electromagnetic method (TEM) is used to image groundwater migration between aquifers in Inner Mongolia, China. First, 1D geophysical models of aquifers are generalized according to the hydrogeological conditions of the region, and the feasibility of detecting the multiple aquifers by TEM is analyzed and discussed. Then, the 2D models of aquifers pre- and post- pumping test are established based on the distribution of groundwater in the aquifers, and the variation law of induced electromotive force measured on the surface is analyzed. The simulation results show that significant time-lapse electromagnetic anomalies can be observed between pre- and post- pumping test and the variation in the induced electromotive force reaches a distinguishable level between 0.7 ms and 100 ms due to the vertical change in the aquifer properties. Furthermore, the electromagnetic variation generated by hydraulic connection between aquifers is greater than 30% within the range of 3/4 of the transmitting loop. Finally, a successful case history to map hydraulic connections between aquifers is conducted using a time-lapse TEM pre- and post- a pumping experiment. This simulation and field experiment shows that time-lapse TEM could characterize and monitor the groundwater migration more effectively than pump tests or hydrogeochemical methods alone.

scholarly journals 3D crosshole ERT for aquifer characterization and monitoring of infiltrating river water

Geophysics ◽  
2011 ◽  
Vol 76 (2) ◽  
pp. G49-G59 ◽  
Author(s):  
Ilaria Coscia ◽  
Stewart A. Greenhalgh ◽  
Niklas Linde ◽  
Joseph Doetsch ◽  
Laurent Marescot ◽  
...  
Keyword(s):  
River Water ◽  
Preferential Flow ◽  
Time Lapse ◽  
Water Infiltration ◽  
High Resistivity ◽  
River Flooding ◽  
Main Challenge ◽  
Acquisition Scheme ◽  
Definition Of ◽  
Natural Tracer

The hydrogeological properties and responses of a productive aquifer in northeastern Switzerland are investigated. For this purpose, 3D crosshole electrical resistivity tomography (ERT) is used to define the main lithological structures within the aquifer (through static inversion) and to monitor the water infiltration from an adjacent river. During precipitation events and subsequent river flooding, the river water resistivity increases. As a consequence, the electrical characteristics of the infiltrating water can be used as a natural tracer to delineate preferential flow paths and flow velocities. The focus is primarily on the experiment installation, data collection strategy, and the structural characterization of the site and a brief overview of the ERT monitoring results. The monitoring system comprises 18 boreholes each equipped with 10 electrodes straddling the entire thickness of the gravel aquifer. A multichannel resistivity system programmed to cycle through various four-point electrode configurations of the 180 electrodes in a rolling sequence allows for the measurement of approximately 15,500 apparent resistivity values every 7 h on a continuous basis. The 3D static ERT inversion of data acquired under stable hydrological conditions provides a base model for future time-lapse inversion studies and the means to investigate the resolving capability of our acquisition scheme. In particular, it enables definition of the main lithological structures within the aquifer. The final ERT static model delineates a relatively high-resistivity, low-porosity, intermediate-depth layer throughout the investigated aquifer volume that is consistent with results from well logging and seismic and radar tomography models. The next step will be to define and implement an appropriate time-lapse ERT inversion scheme using the river water as a natural tracer. The main challenge will be to separate the superposed time-varying effects of water table height, temperature, and salinity variations associated with the infiltrating water.

scholarly journals Water infiltration in an aquifer recharge basin affected by temperature and air entrapment

2017 ◽  
Vol 65 (3) ◽  
pp. 222-233 ◽  
Author(s):  
Sébastien Loizeau ◽  
Yvan Rossier ◽  
Jean-Paul Gaudet ◽  
Aurore Refloch ◽  
Katia Besnard ◽  
...  
Keyword(s):  
Water Temperature ◽  
Temperature Change ◽  
Cold Water ◽  
Infiltration Rate ◽  
Water Infiltration ◽  
Effect Of Temperature ◽  
Strong Increase ◽  
Air Entrapment ◽  
Recharge Basin ◽  
Basin Scale

AbstractArtificial basins are used to recharge groundwater and protect water pumping fields. In these basins, infiltration rates are monitored to detect any decrease in water infiltration in relation with clogging. However, miss-estimations of infiltration rate may result from neglecting the effects of water temperature change and air-entrapment. This study aims to investigate the effect of temperature and air entrapment on water infiltration at the basin scale by conducting successive infiltration cycles in an experimental basin of 11869 m2in a pumping field at Crepieux-Charmy (Lyon, France). A first experiment, conducted in summer 2011, showed a strong increase in infiltration rate; which was linked to a potential increase in ground water temperature or a potential dissolution of air entrapped at the beginning of the infiltration. A second experiment was conducted in summer, to inject cold water instead of warm water, and also revealed an increase in infiltration rate. This increase was linked to air dissolution in the soil. A final experiment was conducted in spring with no temperature contrast and no entrapped air (soil initially water-saturated), revealing a constant infiltration rate. Modeling and analysis of experiments revealed that air entrapment and cold water temperature in the soil could substantially reduce infiltration rate over the first infiltration cycles, with respective effects of similar magnitude. Clearly, both water temperature change and air entrapment must be considered for an accurate assessment of the infiltration rate in basins.

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