• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.05a
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• pp.24-27
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• 2000

The development of land classification and soil productivity rating systems (SPR) are examined for their application to valuation of agricultural land in South Dakota, USA. The application of SPR data to land valuation work conducted by real estate appraisers, tax assessors, and economists are discussed along with an assessment of its benefits and limitations.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.279-281
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• 2003

This study is intended to give information on agricultural nonpoint source pollution and transport related to fertilizer application and irrigation practice. Field-simulated soil columns were set up and leaching studies on fertilizer components such as nitrogen and phosphorus were performed. Nitrogen and phosphorus in the leachate showed different trends in each column and nonpoint source pollution in agricultural areas may be expected to depend on planted crops, soil conditions, and climate as well as irrigation and fertilizing management.

• Journal of Environmental Science International
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• v.22 no.5
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• pp.609-623
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• 2013

Fluctuation patterns of groundwater level as a factor that reflects the characteristics of groundwater system can be categorized as the various types of aquifer with the time-series data. Time-series data on groundwater level obtained from 115 monitoring wells in Jeju Island were classified according to variation types, which were largely affected by rainfall(Dr), rainfall and pumping(Drp), and unknown cause(De). Analysis results indicate that 106 wells belong to Dr and Drp and the ratio of the wells with the wide range of fluctuation in the western and northern regions was higher than that in the eastern and southern regions. From the results that Drp is relatively higher than Dr in the western region which has the largest agricultural areas, groundwater level fluctuations may be affected significantly due to the intensive agricultural use. Non-parametric trend analysis results for 115 monitoring wells show that the increasing and decreasing trends as the ratio of groundwater levels were 14.8% and 22.6%, respectively, and groundwater levels revealed to be increased in the western, southern and northern regions excluding eastern region. Results of correlation analysis that cross-correlation coefficients and the time lags in the eastern and western regions are relatively high and short, respectively, indicate that the rainfall recharge effect in these regions is relatively larger due to the gentle slope of topography compared to that in the southern and northern regions.

• Journal of Korean Society of Rural Planning
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• v.22 no.1
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• pp.13-23
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• 2016

There is a need to analyze unconfined groundwater behavior since the demand of groundwater use has been increasing. While unconfined groundwater temperature is tend to be affected by air temperature, it is hard to find an empirical study in South Korea. In this research, we try to determine the relationship between daily average air temperature and daily average groundwater temperature by time-sequential analysis of groundwater monitoring wells in Galshin basin in Yesan-Gun, Chungcheongnam-Do. In addition, models to estimate groundwater temperature from air temperature were developed. In this research 101-day moving average method with measured air temperature is used to estimate groundwater temperature. To verify the developed model, estimated values of average groundwater temperature with 101 moving average are compared to the measured data from September 10 2007 to September 9 2008. And, Nash-Stucliff Efficiency and Coefficient of Determination were 0.970 and 0.976, therefore it was concluded that the model allowing groundwater temperature estimation from air temperature is with reasonable applicability.

• Journal of Korean Society of Rural Planning
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• v.25 no.4
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• pp.35-45
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• 2019

Korean agriculture experienced rapid changes in its production structure to respond fluctuations on external conditions, and these changes have increased the dependence between agricultural resources and negative environmental externalities from agricultural production. As a tool for managing agricultural resources and reducing negative environmental effects from agricultural production, this study employs water-energy-food nexus for integrated resource management. To show the necessity of an integrated approach, this study evaluated three policy scenarios including changes in capital interest, water capacity, and energy cost. The results show that three scenarios have unintended consequences for farmers' incomes and their use of resources. Also the unintended consequences of government policies also affected farms' vulnerability to environmental changes. In particular, the expansion of financing for the establishment of non-circulating water curtain facilities did not have a significant effect on the crop switching of farms. In addition, increasing the amount of available water through the aquifer recharge project leads to the installation of non-circulating water curtain facilities in zucchini farm. It raises dependence on groundwater in agricultural production, thereby increasing farmers' vulnerability to groundwater shortages. These results imply that the agricultural sector needs to consider the interrelationship between agricultural resources when designing or evaluating policies.

• 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.

• Economic and Environmental Geology
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• v.45 no.1
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• pp.23-30
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• 2012

Major ions and nitrogen isotopic analyses were performed to determine the geochemical characters and to identify the source of nitrate of the shallow groundwater around agricultural field in the Youngdong area. The pH value of groundwater ranges from 60. to 8.2 (pH 7.2, mean). The average of EC, Eh and DO is 369 ${\mu}S/cm$ (70~729 ${\mu}S/cm$), 165.6 mV (29~383.2 mV), 4.3 mg/L (1.8~8.0 mg/L) respectively. The ion concentraion of groundwater was in the order of $Ca^{2+}$>$Na^{2+}$>$Mg^{2+}$>$K^{2+}$ and ${HCO_3}^-$>${NO_3}^-$>${SO_4}^{2-}$>$Cl^-$>$F^-$. Most of groundwater is Ca-$HCO_3$ type. The groundwater was affected by water-rock interaction in the shallow depth. Some groundwater is Ca-Cl or Na-$HCO_3$ (2.5%) type that was due to agricultural activities. The $NO_3$_N concetration of grondwater range from 10.2 mg/l to 26.9 mg/l, which show that this area is under nitrate pollution. ${\delta}^{15}N-NO_3$ value of the groundwater is the origins of are a combination of animal wastes and man-made fertilizers.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.1
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• pp.8-13
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• 1999

This research was investigated to examine the status of goundwater contamination in Chung-Nam area over 2 years from 1996 May to 1998 May. The results show that the overall detection rates of VOCs (volatile organic compounds) by region were as followed: industrial region > agricultural & industrial complex region > gas station region > around industrial region > downtown region, and excess rates of those were as followed: industrial region > gas station region > agricultural & industrial region > around industrial region > downtown region. Benzene and TCE of VOCs examined in Chon-An industrial region exceeded drinking water standard. At the agricultural & industrial complex region, the observed mean concentration of TCE was 3.107 mg/L and TCE was also detected at 48.152 mg/L which is 100 times higher than drinking water standard, and other VOCs were also observed at higher concentrations as well. Based on our studies, It is concluded that appropriate remedial action should be performed to protect further groundwater contamination and to restore groundwater quality in Chung-Nam area.

• Journal of Environmental Science International
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• v.28 no.9
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• pp.737-749
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• 2019

In this study, the sensitivity analysis of hydraulic conductivity and separation distance (distance between injection well and pumping well) was analyzed by establishing a conceptual model considering the hydrogeologic characteristics of facility agricultural complex in Korea. In the conceptual model, natural characteristics (topography and geology, precipitation, hydraulic conductivity, etc.) and artificial characteristics (separation distance from injection well to pumping well, injection rate and pumping rate, etc.) is entered, and sensitivity analysis was performed 12 scenarios using a combination of hydraulic conductivity ($10^{-1}cm/sec$, $10^{-2}cm/sec$, $10^{-3}cm/sec$, $10^{-4}cm/sec$) and separation distance (10 m, 50 m, 100 m). Groundwater drawdown at the monitoring well was increased as the hydraulic conductivity decreased and the separation distance increased. From the regression analysis of groundwater drawdown as a hydraulic conductivity at the same separation distance, it was found that the groundwater level fluctuation of artificial recharge aquifer was dominantly influenced by hydraulic conductivity. In the condition that the hydraulic conductivity of artificial recharge aquifer was $10^{-2}cm/sec$ or more, the radius of influence of groundwater level was within 20 m, but In the condition that the hydraulic conductivity is $10^{-3}cm/sec$ or less, it is confirmed that the radius of influence of groundwater increases sharply as the separation distance increases.

• The Journal of Engineering Geology
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• v.24 no.2
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• pp.237-246
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• 2014

Seasonal variations of major contaminants in groundwater around livestock burial areas in Gyeonggi province, Korea, were examined. Seven typical contamination indicators ($NO_3$-N, $NH_3$-N, chloride, pH, DO, ORP, and EC) were monitored in groundwater samples collected from 84 wells located within 60 m of livestock burial sites for the leachate plume emanating from the livestock burial sites. The monitoring results of pH, DO, ORP, and EC revealed minimal seasonal variations, providing no evidence for leachate plumes. The $NO_3$-N concentrations were below 30 mg/L and exhibited minimal seasonal fluctuations, even in the wells located close to (< 20 m) the burial sites; the $NH_3$-N and chloride concentrations also showed similar results. The contamination indicators examined in this study indicate that the observed groundwater contamination is primarily from preexisting pervasive contamination due to agricultural activities and livestock farming, not leachates derived from nearby livestock burial sites.