• Journal of the Korean Society of Groundwater Environment
• /
• v.6 no.4
• /
• pp.188-193
• /
• 1999

Transport of pollutants in aquifer largely depends on groundwater flow which is governed by aquifer hydraulic parameters. Determination of these parameters and associated groundwater modeling become essential for adequate remediation of contaminate groundwater. The objective of this paper is to analyze groundwater flow and determine the optimum hydraulic parameters by performing groundwater modeling based on sensitivity analysis for unconfined sandy gavel aquifer constructed in a laboratory scale under various boundary condition. Results revealed that the simulated drawdown was lower than the observed drawdown irrespective of boundary conditions. and specific yield (S$_{y}$) had less effect on the grondwater flow than permeability (K) in the aquifer. Water balance analysis showed that the measured drawdown in neighboring observation wells during pumping was higher than either simulated or recovered water table. The indicated that a difference might exist in the water tables between aquifer and wells. The difference was investigated by time domain reflectometry (TDR) measurements on water contents in the region of water table and capillary fringe, and explained by a delayed response of water table during gravitational drainage as the water table was lowered as a result of pumping.g.

• The Journal of Engineering Geology
• /
• v.4 no.2
• /
• pp.219-229
• /
• 1994

Since groundwater flow in fractured rocks is controlled by the distribution of fractures irregu1arly developed in space, it is not possible to understand the hydraulic characteristics of fractured aquifers using Theis equation which is applicable only to homogeneous isotropic confined aquifer. This study deals with the theoretical background of the fractal groundwater flow model with leakage, the methodology of calculation of the hydraulic parameters, and the application of the developed model to field data. From the result of the application of the fractal model to two field data in Hongcheon and Yusung areas, we obtained a good match between theoretical curves and observed curves, with the same hydraulic parameters at the pumping well and the observation well. In the two pumping test analyses, we have determined 1.9 of the fractal dimension. This means that the dimension of groundwater flow at these two sites is slightly smaller than radial flow.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2004.04a
• /
• pp.459-462
• /
• 2004

This study assesses groundwater vulnerability to contaminants in 12 administrative districts of the city of Changwon, using DRASTIC technique. DRASTIC was originally applied to situations in which the contamination sources are at the ground surface, and the contaminants flow into the groundwater with infiltration of rainfall. However, groundwater contamination in urban areas can also be related to excessive pumping resulting in a lowering of the water level. The correlation coefficient between minimum DRASTIC indices and the degree of poor water quality for 10 districts is low as 0.40. The correlation coefficients between minimum DRASTIC indices and the groundwater discharge rate, and between minimum DRASTIC indices and well density per unit area are 0.70 and 0.87, respectively. Thus, to evaluate the potential of groundwater contamination in urban areas, it is necessary to consider other factors such as groundwater withdrawal rate and well density per unit area with ratings and weights as well as the existing six DRASTIC factors.

• Economic and Environmental Geology
• /
• v.40 no.6
• /
• pp.833-841
• /
• 2007

The groundwater heat pump system(GWHP) is one of the most efficient ground source heat pump system(GSHP) which uses low grade and shallow geothermal energy for cooling and heating purpose. The GWHP system shall be designed properly based on peak block load performance and optimum pumping rate of groundwater comparable to ground coupled heat pump system(GCHP). The optimum pumping rate depends on groundwater temperature at a specific site, size of plate heat exchanger, and total head loss occurred by whole system comprising pumps and pipings. The required optimum flow rates of the system per RT are ranged from 3.8 to 9.8lpm being less than the typical building loop flow of 9.5 to 11.4lpm.

• Economic and Environmental Geology
• /
• v.42 no.6
• /
• pp.561-574
• /
• 2009

Unsaturated/saturated groundwater flow and solute transport model, VSFRT2D(Variable Saturated Flow and Reactive Transport model) was developed considering effects of pumping, irrigation, and denitrification. VSFRT2D employed Richards equation as governing equation for groundwater flow and previously existing unsaturated models modified by including computational procedure of evapotranspiration at surface using Thornthwaite method when precipitation doesn't occur. Bioremediation processes based on monod kinetics are described using four nonlinear contaminant transport equations and three nonlinear microbes transport equations. The developed model was applied to field data in Hongsung area contaminated with nitrate. In order to identify the effect of precipitation, pumping, evapotranspiration, irrigation, fertilizer application, and various bioremediations on groundwater flow and contaminant transport, individual processes were separated and simulated. Then all results obtained from the individual processes are compared with each other. The simulation results show that bioremediation had a negligible effect on nitrate concentration change. However, pumping for irrigation, precipitation, and nitrogen fertilizer application showed profound influences on nitrate concentration change.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2003.09a
• /
• pp.565-569
• /
• 2003

One-year-long groundwater-level data have been collected from 18 wells in Cheon-an area. The result of barometric efficiency, autocorrelation, cross-correlation and statistical distribution evaluated from the measurement data shows that groundwater-level measurements from observation wells are the principal source of information about aquifer characteristics. Data from WA-2 has high barometric efficiency as well as steady decreasing auto-correlation coefficient, which means nonleaky confined aquifer, Most aquifers in this study show the unconfined properties so that barometric efficiencies are mostly low and the coefficients of cross-correlation between groundwater-level and precipitation are commonly high. This study showed that the long-term groundwater-level monitoring data without artificial stress such as pumping would give accurate information about aquifer characteristics.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2004.04a
• /
• pp.468-471
• /
• 2004

Groundwater development as a means of acquiring subsidiary water resource is very important for the persistent security of water resource. Nowadays, pneumatic fracturing technology which was developed in the advanced countries is applied for increasing pumping rate and eliminating contaminants. From the results of this study, hydraulic aperture and permeability are presented.

• Journal of Korea Water Resources Association
• /
• v.41 no.1
• /
• pp.27-34
• /
• 2008

Groundwater development in coastal areas induces saltwater intrusion. In many cases amount of groundwater resources available for development is limited by a pre-specified limit of additional saltwater intrusion. In this paper a simple equation is developed to assess available groundwater resources which depends on the constraint of acceptable additional saltwater intrusion. Strack#s single-potential analytical solution is used to derive the equation. Available groundwater increases as more additional intrusion is allowed. However, critical points limit both the maximum pumping rate and the allowed saltwater intrusion limit. The equation is presented in the form of design curves from which the maximum pumping rate can be read off quickly. The equation and the design curves are suitable for preliminary estimation of available groundwater resources in coastal areas.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.1 no.1
• /
• pp.1-8
• /
• 2005

Aquifer Thermal Energy Storage (ATES) can be a cost-effective and renewable geothermal energy source, depending on site-specific and thermohydraulic conditions. To design an effective ATES system having the effect of groundwater movement, understanding of thermohydraulic processes is necessary. The heat transfer phenomena for an aquifer heat storage are simulated by using FEFLOW with the scenario of heat pump operation with pumping and waste water reinjection in a two layered confined aquifer model. Temperature distribution of the aquifer model is generated, and hydraulic heads and temperature variations are monitored at the both wells during 365 days. The average groundwater velocities are determined with two hydraulic gradient sets according to boundary conditions, and the effect of groundwater flow are shown at the generated thermal distributions of three different depth slices. The generated temperature contour lines at the hydraulic gradient of 0.001 are shaped circular, and the center is moved less than 5 m to the direction of groundwater flow in 365 days simulation period. However at the hydraulic gradient of 0.01, the contour center of the temperature are moved to the end of east boundary at each slice and the largest movement is at bottom slice. By the analysis of thermal interference data between two wells the efficiency of the heat pump system model is validated, and the variation of heads is monitored at injection, pumping and no operation mode.

• Journal of Energy Engineering
• /
• v.28 no.3
• /
• pp.55-64
• /
• 2019

This study identified key patents on U.S. underground water technology through patent network analysis. As a result, there were many technologies that used the technology to remove heavy metals to prevent contamination of groundwater. While patents between groundwater technology patents were in charge of intermediaries, the connectivity between groundwater technologies is not high. The patented technologies related to groundwater were largely distinguishable by pumping, monitoring, and decontamination. Monitoring includes techniques that enable identification of physical and biological properties, such as the type of contaminants, as well as geographic characteristics for analysis of groundwater flow, flow or water quality. Pollution purification technology refers to the process of physiochemical and biological purification for soil and groundwater. U.S. technology cases showed that the U.S. had high technology in water treatment area. And patent protection were also needed to cope with water shortages caused by climate change.