• 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 The Korean Society of Agricultural Engineers
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• v.65 no.2
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• pp.1-11
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• 2023

This study analyzed the impact of greenhouse cultivation area and groundwater level changes due to the water curtain cultivation in the greenhouse complexes. The groundwater observation data in the Miryang study area were used and classified into greenhouse and field cultivation areas to compare the groundwater impact of water curtain cultivation in the greenhouse complex. We identified the characteristics of the groundwater time series data by the terrain of the study area and selected the optimal model through time series analysis. We analyzed the time series data for each terrain's two representative groundwater observation wells. The Seasonal ARIMA model was chosen as the optimal model for riverside well, and for plain and mountain well, the ARIMA model and Seasonal ARIMA model were selected as the optimal model. A suitable prediction model is not limited to one model due to a change in a groundwater level fluctuation pattern caused by a surrounding environment change but may change over time. Therefore, it is necessary to periodically check and revise the optimal model rather than continuously applying one selected ARIMA model. Groundwater forecasting results through time series analysis can be used for sustainable groundwater resource management.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.217-220
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• 2002

To investigate the conditions of groundwater resources In Jeonju, Wanju, and Goksung, a basic groundwater survey was performed. From the survey, various useful informations such as groundwater use, waterlevel distribution, water chemistry were obtained. This study focused on the analysis of the water levels, which were automatically monitored with pressure transducers or manually measured. The monitorings were conducted for both shallow wells completed in alluvial aquifers and deep wells in bedrock aquifers. The automatically monitored waterlevels for alluvial aquifer were also used for estimation of recharge in the study area. This study presents results of the investigation.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.447-450
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• 2004

This study was conducted to characterize groundwater and river-water fluctuations at a riverbank filtration site in Daesan-myeon adjacent to the Nakdong River, using time series analysis. Water levels from six observation wells from January 2003 to October 2003 were measured. The autocorrelation analysis indicates that the wells are divided into three groups: group 1 represents strong linearity and memory, group 2 intermediate linearity and memory, and group 3 weak linearity and memory. The analysis indicates that groundwater levels in different monitoring wells vary in response to river-water levels, groundwater withdrawal and seasonal rainfall. Cross-correlation was also divided into three groups. Group 1 shows the highest cross-correlation function (0.49 - 0.54) for a lag time of 0 hours, group 2 intermediate cross-correlation function (0.34 - 0.45), and group 3 the lowest cross-correlation function (0.23 - 0.25). Different cross-correlation functions among the 3 groups are interpreted as an effect of tile distance from the river to the pumping wells.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.9
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• pp.630-635
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• 2013

There is a need to establish systematic procedure of groundwater quality standards, however, there were no specified basis for establishing substances and values in Korean groundwater quality standards for non-drinking water. In this study, we reviewed basis for deriving groundwater quality standard in the developed countries, considering carcinogenic and non-carciongenic risk via inhalation and dermal contact exposure pathways. Also, we reviewed the prior systematic procedure of standards related to water quality (e.g. drinking water, surface water, and wastewater). USEPA RAGS, ASTM RBCA, and Massachusettes presented the formulas for deriving groundwater concentrations of chemicals and there were similarity and differences. We suggests systematic procedure of groundwater quality standards, as follows. (1) Selection of groundwater pollutants population, (2) Possibility of risk assessment, (3) Selection of monitoring priority substances, (4) Monitoring, (5) Risk assessment, (6) Selection of groundwater quality standard candidates, (7) Selection of new substances and values for groundwater quality standards. Especially, groundwater concentration of hazardous material were presented according to revised risk formulas via inhalation and dermal contact.

• Journal of Soil and Groundwater Environment
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• v.26 no.6
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• pp.144-156
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• 2021

This study examined hydrogeological characteristics of groundwater and surface water interaction in the fresh-saline water mixed zone of East Coast lagoon area, Korea, using several technical approaches including hydrological, lithological, and isotopic methods. In addition, the fresh-saline water interface was evaluated using vertical electrical conductivity (EC) data. For this purpose, three monitoring wells (SJ-P1, SJ-P2, and SJ-P3) were installed across the Songji lagoon at depths of 7.4 to 9.0 m, and water level, EC, and temperature at the wells and in the lagoon (SJ-L1) were monitored using automatic transducers from August 1 to October 21, 2021. Isotopic composition of the groundwater, lagoon water, and sea water were also monitored in the mid-September, 2013. The mixing ratios calculated from oxygen and hydrogen isotopic composition decreased with increasing depth in the monitoring wells, indicating saline water intrusion. In the study area, the interaction of groundwater-surface water-sea water was evident, and residual salinity in the sedimentary layers created in the past marine environment showed disorderly characteristics. Moreover, the horizontal flow at the lagoon's edge was more dominant than the vertical flow.

• The Journal of Engineering Geology
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• v.14 no.3 s.40
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• pp.313-323
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• 2004

• Journal of Korea Water Resources Association
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• v.53 no.7
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• pp.507-519
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• 2020

This study developed the radon measurement system that can be used for crustal movement monitoring and seismic occurrence and prediction, and compared and analyzed the results of test-operated radon measurement system and observed seismic occurrence cases. First, the developed radon measurement system consists of an NB-IoT radon measurement device, data center, data analysis, and data supply server. Because the measured radon data can be remotely trasmitted by using NB-IoT, this system is very suitable for installation and operation in unmaaned groundwater station. Second, the developed radon measurement device was test-operated at two groundwater stations in Gimpo from May to July 2019. The measured radon data was compared with the groundwater-level and electrical conductivity measurement data, and it was confirmed that the radon measurement device developed in this study has some potential for commercialization. Finally, from November 2019 to February 2020, three observed seismic cases and daily measured radon, groundwater-level, electrical conductivity data by the NB-IoT radon measurement device installed at three groundwater stations in Pohang, which is a test-bed, were compared and analyzed. As a result of the analysis, it was confirmed that the seismic occurrence correlated with radon, groundwater level, and electrical conductivity and all of these measured data will be able to provide basic data to help in seismic monitoring and prediction in the future.

• Journal of the Geological Society of Korea
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• v.54 no.5
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• pp.557-566
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• 2018

Pohang earthquake (Main shock magnitude = 5.4) occurred in Southeastern region of South Korea in November 15, 2017. Groundwater levels of 6 monitoring wells with 5 minutes interval measurements located in that region and stream water levels of 4 stations located along the Hyeongsan-gang stream are used for the analysis of earthquake induced effects. Four groundwater monitoring wells show a short-term decrease of groundwater level after a main shock and one well does an increase and the maximum change is about 42.0 cm. Especially, groundwater levels at two monitoring wells near the epicenter are consistently maintained after a decrease. There is little relationship between earthquake magnitude or a distance to epicenter and changing amount of groundwater level and it may be due to the inhomogeneity of geologic material and unconsolidated sediments distribution. The changes in permeability of fractured zone and groundwater levels occasionally cause changes in stream flow rate, and water level of the Hyeongsan-gang stream in the study area decreases just after the earthquake and increases again up to the normal level and next shows an more gentle decreasing slope. Total increasing flow rates at S1 (upstream site) and S4 (downstream site) stations are about $12,096m^3$ and $116,640m^3$, respectively, during the increasing period.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.839-846
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• 2004

The objective of this study is the evaluation of the tunneling effect on the groundwater-surface water interaction. The designed tunnel line is laid beneath the Gapo-cheon, which runs throughout study area. And, the pre-evaluation of the tunnel-influence on the Gapo-cheon is urgently needed. However, it is very difficult to find out the similar domestic and/or foreign cases. In this study, we would exclude the numerical modeling technique with insufficient data. Instead of the evaluation of the tunneling effect on the groundwater-surface water interaction with the numerical modeling, we monitored the flow rate of surface water at various point. We measured the flow rate of surface water at 5 points. With the results of surface flow, we can conclude that 39% of flow rate in Gapo-cheon is contributed by the groundwater discharge, as baseflow.