• 한국지하수토양환경학회지:지하수토양환경
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• 제20권2호
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• pp.1-9
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• 2015

Groundwater has been a very precious resource for human life and economic development in the world. With increasing population and food demand, the groundwater use especially for agriculture is largely elevated worldwide. The very much large groundwater use results in depletion of major aquifers, land subsidences in many large cities, anthropogenic groundwater contamination, seawater intrusion in coastal areas and accompanying severe conflicts for water security. Furthermore, with the advent of changing climate, securing freshwater supply including groundwater becomes a pressing and critical issue for sustainable societal development in every country because prediction of precipitation is more difficult, its uneven distribution is aggravating, weather extremes are more frequent, and rising sea level is also threatening the freshwater resource. Under these difficulties, can groundwater be sustaining its role as essential element for human and society in the near future? We have to focus our efforts and wisdom on answering the question. Korean government should increase its investment in securing groundwater resources for changing climate.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권3호
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• pp.23-32
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• 2013

Korean groundwater quality standards were established in 1994, and revised in 2003 and 2010. The substances for which standards have been developed are classified into two groups, general pollutants, 4, and specific pollutants, 15. The standards have been applied to household water use, agriculture, aquaculture, and industrial use. However, there is no systematic methodology for either selecting candidate substances or establishing groundwater standards. We investigated various derivation methodologies for groundwater standards used by the European Commission and 27 member states and compared their methods for determining threshold values. The European Commission presented to their member states groundwater standards for two substances and a list of required substances for derivation of threshold values along with the member states. Interestingly, they first considered national background levels and then considered other criteria for water protection, such as drinking water standards, environmental quality standards, and irrigation standards. We suggest that Korean background levels in groundwater should be included in the methodology for establishing groundwater quality standards. These results may be useful in developing a systematic methodology for establishing Korean groundwater quality standards.

• 한국환경과학회지
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• 제33권7호
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• pp.511-522
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• 2024

The optimal yield is defined as the amount of groundwater that maintains a dynamic equilibrium state of the groundwater system over a long period. We examined the current problems, improvements, and methods for estimating the optimal groundwater yield in Korea, considering sustainable groundwater development. The optimal yield for individual wells and the sustainable yield for the entire groundwater basin were reviewed. Generally, the optimal yield for individual wells can be determined using long-term pumping and step drawdown tests. The optimal yield can be determined by groundwater quantity and quality, economic, and water use rights factors. The optimal yield of individual wells in the groundwater basin must be determined within the total sustainable amount of the entire groundwater basin, such that the optimal yield of a new well must be less than the remaining total sustainable amount, exempting the total optimal yield of the existing wells. Therefore, the optimal yield may be determined based on the estimated optimal yield at least twice per year. In addition, if groundwater level and pumping quantity data for at least one year are available, it may be effective to use the Hill, Harding, and zero groundwater-level change methods to re-estimate the optimal yield.

• 지구물리
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• 제8권3호
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• pp.145-152
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• 2005

울산 도시지역 지하수의 수질 특성을 파악하기 위하여 216개의 일반 수질분석과 168개의 VOCs 분석이 이루어졌으며, 이를 주거․상업지역, 공업지역, 농업지역, 산림지역으로 구분하여 토지이용과 지하수 수질과의 관계를 분석하였다. 전반적으로 보아서 남구 태화강 저지대 일대 주거․상업지역 지하수에서 과거 해수의 영향에 의해서 Na와 Cl의 함량이 높다. NO3는 농업지역, VOCs는 공업지역 지하수에서 높은 함량을 보이기도 하지만, 토지용도별 지하수의 수질오염 특성 구분은 어렵다. 아직까지 연구지역 지하수의 오염은 우려할만한 수준은 아니나, 도시화가 계속 진행되고 있기 때문에 계속적인 관찰이 요구된다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.122-126
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• 2005

Groundwater monitoring wells (about 70 wells) were extensively installed in 28 sites surrounding Lake Texoma, located on the border of Oklahoma and Texas, to assess the impact of geochemical stressors to shallow groundwater quality. The monitoring wells were classified into three groups (residential area, agricultural area, and oil field area) depending on their land uses. During a two-year period from 1999 to 2001 the monitoring wells were sampled every three months on a seasonal basis. Water quality assay consisted of 25 parameters including field parameters, nutrients, major ions, and trace elements. Occurrence and level of inorganics in groundwater samples were related to the land-use and temporal change.

• 지구물리
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• 제7권2호
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• pp.121-134
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• 2004

This study has tried to develop the modified DRASTIC Model by supplying the parameters, such as structural lineament density and land-use, into conventional DRASTIC model, and to predict the potential of groundwater contamination using GIS in Hwanam 2 District, Gyeonggi Province, Korea. Since the aquifers in Korea is generally through the joints of rock-mass in hydrogeological environment, lineament density affects to the behavior of groundwater and contaminated plumes directly, and land-use reflect the effect of point or non-point source of contamination indirectly. For the statistical analysis, lattice-layers of each parameter were generated, and then level of confidence was assessed by analyzing each correlation coefficient. Groundwater contamination potential map was achieved as a final result by comparing modified DRASTIC potential and the amount of pollutant load logically. The result suggest the predictability of contamination potential in a specified area in the respects of hydrogeological aspect and water quality.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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• pp.113-114
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• 2004

In order to classify the groundwater recharge characteristics in an urban area, a time series analysis of groundwater level data was performed. For this study, the daily groundwater level data from 35 monitoring wells were collected for 3 years (Fig. 1). The use of the cross-correlation function (CCF), one of the time series analysis, showed both the close relationship between rainfall and groundwater level change and the lag time (delay time) of groundwater level fluctuation after a rainfall event. Based on the result of CCF, monitored wells were classified into two major groups. Group I wells (n=10) showed a fast response of groundwater level change to rainfall event, with a delay time of maximum correlation between rainfall and groundwater level near 1 to 7 days. On the other hand, the delay time of 17-68 days was observed from Group II wells (n=25) (Fig. 1). The fast response in Group I wells is possibly caused by the change of hydraulic pressure of bedrock aquifer due to the rainfall recharge, rather than the direct response to rainfall recharge.

• 지질공학
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• 제4권3호
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• pp.297-309
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• 1994

전국 210개 시군을 대상으로 지역별 지하수 이용량을 예측하는 기법을 개발하였다. 우선 210개 대상지역은 각 지역 지하수 이용 특성에 따라 생활형, 공업형, 농업형 지역으로 대분하고, 이들로부터 각 지역별 특성을 잘 나타내는 표본(생활형 22개 : 공업형 8개 : 농업형 32개)지역을 선정하였다. 이 지역에서 지하수 이용에 연관 가능한 인자들로 1) 농지면적, 2) 공업부지 면적, 3) 행정단위 면적, 4) 인구, 5) 지하수원 상수도 시설용량, 6) 1인 1일 평균수량, 7) 농업용수 사용량, 8) 공업용수 사용량, 9) 생활용수 사용량, 10) 상수도 보급률 등을 선정하고 이들의 자료를 수집 분석하였다. 이들과 지역별 지하수 이용량과의 관계를 분석한 결과 얻어진 상관계수를 t-test 방법으로 신뢰도 95%와 99%에서 그 관계의 중요성을 검증하였고, 이로부터 영향인자를 도출하였다. 이와 같이 도출된 영향인자들을 사용하여, 다중 회기분석법으로 생공형 지역과 농업형 지역에서의 지하수 이용량을 추정하는 관계식을 두출하였고, 이 식으로부터 얻어진 예측치를 실제 이용량과 비교하여 그 오차의 RMS를 최소화하도록 보정하였다. 이 모델은 미래 자료에 의하여 타당성이 검증된 후, 지역별 지하수자원의 개발 계획 수립시 최대 수요량의 예측에 사용될 수 있다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 추계학술발표회
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• pp.35-37
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• 2001

This study has investigated the chemical characteristics and the contamination of groundwater in relation to land use in Daejeon Metropolitan City. An attempt was made to distinguish anthrophogenic inputs from the influence of natural chemical weathering on the chemical composition of groundwater at Taejon. Groundwater samples collected at 170 locations in the Taejon area show very variable chemical composition of groundwater, e.9. electrical conductance ranges from 65 to 1,290 S/cm. Most groundwater is weakly acidic and the groundwater chemistry is more influenced by land use and urbanization than by aquifer rock type. Most of groundwater from green areas and new town residential districts has low electrical conductance, and is of Ca-HC $O_3$ type, whereas the chemical composition of groundwater from the old downtown and industrial district is shifted towards a Ca-Cl (N $O_3$+S $O_4$) type with high electrical conductance. A number of groundwater samples in the urbanized area are contaminated by high nitrate and chlorine, and exhibit high hardness. The Ep$CO_2$, that is the $CO_2$ content of a water sample relative to pure water, was computed to obtain more insight into the origin of $CO_2$ and bicarbonate in the groundwater. Factor analysis of the chemical data shows that the HC $O_3$ and N $O_3$ concentrations have the highest factor loadings on factor 1 and factor 2, respectively. Factors 1 and 2 represent major contributions from natural processes and human activities, respectively. The results of the factor analysis indicate that the levels of $Ca^{2+}$, $Mg^{2+}$, N $a^{+}$, Cl and SO4$^2$ derive from both pollution sources and natural weathering reactions.ons.

• 농촌계획
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• 제22권1호
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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.