• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.225-228
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• 2003

For the purpose of finding out the distributions of groundwater uses, the effect of facilities on the parameter and the correlations among measurements, various statistical analysis were carried out with the data of groundwater quality measurements from January to December in 2002. 1. The rates of groundwater for drinking water were 10.5% in Yangcheon-Gu, 10.2% in Kangdong-Gu, and 9.9% in Eunpyung-Gu. The rates of other uses of groundwater were shown to be 58.1%(786 wells) for civil defense emergency, 22.1%(299 wells) for contamination-concerning, 9.8%(133 wells) for water quality monitoring, consisting of 90% of all groundwater. 2. The 52.6% of groundwater for drinking were demonstrated to be appropriate while 91.9% for tither uses-domestic, industrial, agricultural uses- were shown to be proper. 3. For drinking water, the average values of colar, turbidity, NH3-N, F, and Fe were 11.216 degree, 2.138 NTU, 2.458mg/l, 0.212mg/1 and 0.507mg/1 respectively. 4. In cases of drinking water wells for emergency, the results of statistical analysis showed that building year of the wells, depth and pumping rate didn't affect on whether it was proper for that use or not. It were shown that there were linear correlations between depth and NO$_3$-N(-0.171) and F￣(0.332) while the correlation coefficients were 0.381 and -0.169 between the building year of well and depth and pumping rate respectively.

• Journal of Korea Water Resources Association
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• v.33 no.1
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• pp.61-72
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• 2000

The purpose of this study is to improve the method of evaluating groundwater recharge by using grid-based soil moisture routing technique. A model which predicts temporal variation and spatial distribution of soil moisture on a daily time step was developed. The model uses ASCII-formatted map data supported by the irregular gridded map of the GRASS(Geographic Resources Analysis Support System)-GIS and can generate daily and monthly spatial distribution map of surface runoff, soil moisture content, evapotranspiration within the watershed. The model was applied to Ipyunggyo watershed($75.6\;\textrm{km}^2$) located in the upstream of Bocheongchun watershed. Seven maps; DEM(Digital Elevation Mode]), stream, flow path, soil, land use, Thiessen network and free groundwater level, were used for input data. Predicted streamflows resulting from two years (l995, 1996) daily data were compared with the observed values at the watershed outlet. The results of temporal variations and spatial distributions of soil moisture are presented by using GRASS GIS. As a final result, the monthly predicted groundwater recharge was presented.sented.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.308-311
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• 2005

[ $^{222}Rn\;and\;^{226}Ra$ ] in groundwater were determined simultaneously using a gamma-spectroscopy. A nitrogen flushing equipment has been used for elimination and stabilization of high and unstable background activity due to the radon and its progenies in counting shield and room. The aim of present work was to control the background activity for simultaneous measurement of radium$(^{226}Ra)$ and radon$(^{222}Rn)$ in groundwater using a gamma-spectrometry. Background activity was about 1.0dps and the standard deviation was about 50%, The background activity could be minimized using nitrogen flushing equipment in the range of 0.1 to 0.5 and the RSD was about 5% at the experimental condition. The detection limit of $^{222}Rn\;and\;^{226}Ra$ in groundwater was 0.5dps/L in the background control method. In most groundwater used in the work, radon activity was more than the detection limit. However, radium activity in some groundwater was less than the detection limit. If the low level radium in groundwater must be measured, preconcentration process such as concentration should be performed before measuring the groundwater.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.10a
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• pp.271-273
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• 2005

The ${\delta}^{15}N\;and\;{\delta}^{15}O$ data of nitrate indicates the sources of nitrate in oxic groundwater as a mixture of ammonia or urea-containing fertilizer and manure. The ${\delta}^{34}S_{sulfate}$ values indicate that sulfate Is mainly originated from fertilizers and soil S. In sub-oxic groundwater, the increased ${\delta}^{34}S_{sulfate}$ values evidently indicate that sulfate is gradually removed by microbial mediated sulfate reduction. However, iron reduction does not occur In this study area. Such a reversed redox sequence may occur In the presence of stable iron oxides such as hematite and goethite in alluvlal aquifer.

• Journal of Soil and Groundwater Environment
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• v.24 no.5
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• pp.17-30
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• 2019

Intensive agricultural development in Mexicali valley, Baja-California, Mexico, has induced tremendous strain on the limited water resources. Agricultural water consumption in the valley mainly relies on diversions of the Colorado River, but their water supply is far less than the demand. Hence, the use of groundwater for irrigation purposes has gained considerable attention. To account for these changes, it is important to evaluate surface water and groundwater conditions based on historical water use. This study identified the effects of agricultural activities on groundwater levels and groundwater recharge in the Mexicali valley (in irrigation unit 16) by a comprehensive MODFLOW Farm process (MF-FMP) numerical modeling. The MF-FMP modeling results showed that the water table in the study area is drawn downed, more in eastern areas. The inflow-outflow analysis demonstrated that recharge to the aquifer occurs in response to agricultural supplies. In general, the model provides MF-FMP simulations of natural and anthropogenic components of the hydrologic cycle, the distribution and dynamics of supply and demand in the study area.

• Journal of Soil and Groundwater Environment
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• v.20 no.2
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• pp.32-40
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• 2015

Laboratory column experiments were conducted to evaluate the feasibility of injectable apatite method for the sequestration of Sr-90 in groundwater. The columns were tested to evaluate the rate of citrate biodegradation, the amounts of apatite formed, and the treatability of strontium by the sediment and apatite. The results showed the decreases in citrate, calcium, and phosphate concentrations and the increases in alkalinity and citrate degradation products (acetate and formate) in the columns, suggesting that the citrate degradation and formation of calcium phosphate are occurring. Although the calcium and phosphate were not completely consumed within the columns, some amounts of apatite were formed and it showed an ability to treat strontium in groundwater. This study provides a fundamental understanding of reaction mechanisms for the injectable apatite sequestration method for Sr-90 removal.

• Journal of Soil and Groundwater Environment
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• v.29 no.3
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• pp.23-36
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• 2024

Miryang City, the study area, has a water supply rate of 87.4%, which is 12% lower than the national water supply rate of 99.4%, but has a high dependence on groundwater due to the high ratio of farms. In agricultural areas, contamination becomes relatively more critical, requiring significant attention to the management and conservation of groundwater resources. This study aims at estimate groundwater vulnerability of Miryang City using the DRASTIC index map, Piper diagram, and water quality data to correlated with the DRASTIC index. The results from DRASTIC map were divided into five classes: very high, high, moderate, low, and very low. The areas in central and southern part of study area, which are characterize by a very high index with [Ca-Cl] and [Na-Cl] water types, covering a large alluvium with the Miryang River and Nakdonggang River. In addition, a correlation analysis between groundwater quality parameters and the DRASTIC index was carried out. Chloride, sodium, and sulfate ions showed a weak relationship with DRASTIC index, with correlation coefficient was 0.507, 0.487 and 0.344, respectively. These results suggest that aquifer media, soil media, hydraulic conductivity, and chloride ion are important factors for groundwater vulnerability.

• Journal of Soil and Groundwater Environment
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• v.15 no.1
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• pp.66-72
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• 2010

The partitioning tracer method is to estimate the residual saturation of nonaqueous phase liquid (NAPL) in soils by analyzing tracer's retardation induced by the reversible partitioning of tracer with NAPL. This study is to estimate the residual diesel saturation in soils using the partitioning tracer method. Two-dimensional soil box was used to represent the 2-dimensional flows of groundwater and tracer solution in the saturated aquifer, and the soil box was filled with soil and then saturated with water. The residual diesel saturation was induced in saturated soil, and the partitioning tracer method was applied. The results from batch-partitioning experiment indicated that the diesel-water partitioning was linear with respect to tracer's concentration, and the partition coefficient of tracer between diesel and water was measured by their linearities. The groundwater flow in the saturated aquifer was simulated in the 2-dimensional soil box, and the residual diesel contamination was visually identified. The results from the partitioning tracer method with or without diesel in soils confirmed that 4-methyl-2-pentanol, 2-ethyl-1-butanol and 1-hexanol, can be used as a detecting method for diesel contamination. By the accuracies of estimations for diesel contamination using the partitioning tracer method, 2-ethyl-1- butanol showed the highest accuracy with 83%.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.270-274
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• 2000

We have developed the computer system with MOCT which is called "The Integrated National Groundwater Information system" since 1995 and now begin to supply the database and related informations for ground water by internet homepage. The integrated system is composed of four sub systems which are "Groundwater Information System", "DUREBAK", "Hydrogeologic Map Management System" and "Groundwater World Homepage". The local government offices use the "DUREBAK" program to manage the well development and maintenance. About 1,000,000 wells are managed in "DUREBAK" program and they submit the well database to MOCT every year. And now everyone can obtain the well data and other informations through internet homepage. We have set the standard process of data acquisition and management for ground water last four years.s of data acquisition and management for ground water last four years.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1999.10a
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• pp.57-60
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• 1999

Geochemical study was carried out to find out soil contamination at the heaped soil, moved from bottom of the storage pond in Pohang industrial complex, in Moondug, Chemical analysis showed that contents of heavy metals in the soil were higher than those of the ordinary soil. Contents of Cu and Cd in the soil exceeded Korean standard of soil contamination. Especially content of Cu exceeded Korean standard of soil contamination(50ppm) at the six points and at one point content of Cu was 113.3ppm. Contents of Be were so higher than U.S RCRA standard(0.2ppm) that they can affect soil environment. The followed research about relation between pollutant and soil and proper measures are required to prevent soil contamination from affecting environment of Moondug.