This study presents the data analysis results of groundwater chemistry and the occurrence of fluoride in groundwater obtained from the groundwater quality monitoring network of Korea. The groundwater data were collected from the National Groundwater Information Center and censored for erratic values and charge balance (±10%). From the geochemical graphs and various ionic ratios, it was observed that the Ca-HCO3 type was predominant in Korean groundwater. In addition, water-rock interaction was identified as a key chemical process controlling groundwater chemistry, while precipitation and evaporation were found to be less important. According to a non-parametric trend test, at p=0.05, the concentration of fluoride in groundwater did not increase significantly and only 4.3% of the total groundwater exceeded the Korean drinking water standard of 1.5 mg/L. However, student t-tests revealed that the fluoride concentrations were closely associated with the lithologies of tuff, granite porphyry, and metamorphic rocks showing distinctively high levels. This study enhances our understanding of groundwater chemical composition and major controlling factors of fluoride occurrence and distribution in Korean groundwater.

기존에 국내에서 지하수에 대한 해수의 영향 연구가 거의 이루어지지 않았던 다도해상의 도서 지역인 전라남도 신안군의 지하수 수질 특성을 평가하였다. 지하수에 대한 해수의 영향을 평가하기 위해 지하수의 현장 수질 측정과 주요 용존성분 등을 포함한 수리지구 화학적 인자를 조사하였다. 총 4회에 걸친 현장 수질 측정 결과, 500 μS/cm 이상의 높은 전기전도도 값을 나타내는 관정은 163개 중 74개로 나타났으며, 용존이온 분석을 통한 Cl−/HCO3− 몰 비로 지하수의 해수 영향을 분석한 결과 심한 영향 및 매우 심한 영향을 의미하는 2.8 이상의 값을 갖는 시료가 74개 중 40개에 해당하였다. 지하수 수질유형의 경우, 직접적인 해수의 영향을 받는 것으로 판단되는 Na-Cl 유형과 해수침투에 의한 지하수 진화단계에서 Na-Cl 이전 유형인 Ca-Cl 유형은 암반지하수의 경우 각각 35.3, 44.1%, 충적층/풍화대 지하수의 경우 52.5, 45%를 차지하였다. 이러한 대수층별 해수의 영향 특성은 각 관정의 해안에서의 거리, 양수량, 조석 등의 영향을 받을 것으로 판단된다.

본 연구에서는 결정질 기반암에 위치하는 12개 시추공의 지하수 수질을 분석하여, 다변량 통계 분석법을 활용하여 지하수 수질 진화 특성 및 성분 기원을 평가하였다. 지하수 수질 유형은 Na(Ca)-HCO3형과 Ca-HCO3형이 가장 우세하여, 물-암석 반 응에 의한 직접적인 양이온 교환 반응(Ca2+ → Na+)을 지시하며, 현장 지하수 특성과 실내 지하수 분석 결과에 기초한 연구 지역의 지하수 수질 진화는 초기 내지 중간 정도의 단계를 지시하는 것으로 사료된다. 다변량 분석 결과, 인위적인 기원인 NO3 -와 다른 성분들 간의 상관성을 살펴보면, Na+, Cl-와 양의 상관성을 나타난다. 염무의 기원인 Cl-와는 Na+, SO4 2-, Mg2+, K+ 와 양의 상관성을 나타낸다. 그러나 다른 성분들(Ca2+, Fe2+, HCO3 -, F-, SiO2)과는 상관성이 나타나지 않는다. Cl- 농도가 일반 적인 지하수 수질 범위에 포함되고 NO3 - 농도는 먹는물 수질기준치 이하로서 농도가 매우 낮으며, 대부분의 광물에 대해서 지하수 화학성분들은 불포화상태를 지시한다. 따라서, 연구지역의 수질 성분들은 대부분 물-암석 반응을 통한 자연적인 기 원을 지시하고 부분적으로는 자연적인 염무와 농업과 관련된 인위적인 오염으로부터 기인된다.

For introducing the groundwater quality assessment using background concentration of groundwater, several methods had been studied to estimate the background concentration of groundwater and to suggest the background concentration of study area. Some methods such as Box whisker plot, Percentile and Cumulative probability distribution had been adopted to estimate background concentration, and it was evaluated that the Cumulative probability distribution method presents more reasonable background concentration because it can consider the data distribution. So we estimated the background concentration of study area using cumulative probability distribution method. We suggested the background concentration for each hydrogeology respectively in case hydrogeological water quality similarity is very low.

The groundwater quality through livestock excreta survey based on “Act of the management and use of livestock excreta” was investigated by selecting sampling sites within 1 km of the farmland without considering hydrogeological units. However, these sites can be affected by various pollution sources such as chemical fertilizers and livestock excretions. Additionally, the effects of pollution sources on groundwater quality in the sites cannot be clearly distinguished from naturally occurring backgrounds. In this study, a method was developed to select the sampling sites for groundwater quality through livestock excreta survey in order to understand the effects of pollution sources especially livestock excreta. First, the concentrations of nitrate within the radius of 200 m, 300 m, 500 m and 750 m, respectively, from the farms regarded as pollution sources in hydrogeological units were compared in 2016-2017. All the nitrate concentrations at 200 - 500 m from the farms exceeded a background concentration, 13.3 mg/L. Those at 750 m and the background concentrations measured by the Ministry of Environment were comparable. Therefore, the appropriate radius was suggested as 500 m for livestock excretions survey. In this study, the areas within 500 m from the farms could be considered under the influence of livestock excretions, while those beyond 500 from the pollution sources as background in hydrogeological units. The developed method was validated by applying it to the sites selected based on both administrative divisions and watersheds for livestock excretion survey. The average densities for the developed method were 0.82 and 0.39 points/km2, respectively, which were considered as appropriate levels according to those of the European Environmental Agency.

A Cultivation method to minimize the damage caused by high temperatures was studied by investigating the effects of groundwater cooling treatment on the growth, yield, and quality of strawberries. In the groundwater cooling treatment, the daily average temperature of the rhizosphere was reduced from 26.9°C to 24.9°C . The root length increased by 0.3–9.2 cm, depending on the cultivar and growth period. The leaf number, leaf area, leaf length, leaf diameter, and plant height also increased, especially in the cultivars ‘Seolhyang’ and ‘Maehyang’, resulting in higher fresh and dry weights. The number of fruit per plant increased from 7.7 to 12.5 in ‘Seolhyang’, and the fruit weight increased by 0.3 g in ‘Seolhyang’ and 1.3 g in ‘Maehyang’. The fruit hardness increased, but no significant difference in fruit coloration was observed. The sugar content of the fruit was improved by 0.2–0.3 °Brix. Therefore, groundwater cooling of the rhizosphere was effective in improving the growth and productivity of strawberries under abnormally high temperature conditions and can be considered a cost-efficient cooling system.

가축매몰지 인근 지하수 수질은 지하수 이용과 관련하여 많은 관심이 집중되고 있다. 한국 환경부에서는 지하수 수질 감시를 위하여 지하수 수질을 직접 측정하는 방법을 제시하고 있다. 이 방법은 수질분석에 많은 시간과 비용이 소요되기 때문에 관측지점이 수백개 이상인 경우에는 효율적인 모니터링이 어려울 수 있다. 금회 연구에서는 지하수의 전기 전도도를 매몰지에서의 지하수 수질 지표로 사용하는 방안을 제안하였다. 지하수 수질 수준을 판별하기 위하여 가축 매물지 근방의 장기적인 지하수 수질 측정자료를 통계학적인 방법으로 분석하여 지하수 수질 지표와의 상관관계를 도출하였고, 무선 통신망을 이용한 원격 모니터링 기법을 이용하여 보다 신속하게 지하수 상태를 감시할 수 있는 가능성을 제시하였다.

This study characterized water quality of groundwater and purified water used for drinking water in 30 schools in Gyeongsangbukdo Province. The results of the study showed that 43% of groundwater and 45% of purified water were not suitable for drinking. Among them, microbial contaminations were the most serious problem. In raw groundwater, the exceeding rates of total colony counts was the highest in August (53.6%). Purified water samples showed higher rate of exceeding drinking water standard for total colony counts while showing lower rate of exceeding drinking water standard for total coliforms and fecal coliforms in March and August. Overall, proper managements for microbial contaminations are required for both groundwater and purified water. Furthermore, special attention should toward students not to drink water when groundwater or purified water exceeds the drinking water quality standard.

질산성질소와 염소이온은 지하수에서 흔히 나타나는 항목으로서 농약의 사용이나 도시화 등에 의하여 주로 발생한다. 일반적으로 동일 지점의 지하수 수질 자료는 관측망의 경우를 제외하고는 샘플의 수가 제한적이기 때문에 시계열 자료를 활용한 추세 평가에 한계가 있다. 본 연구에서는 제주도 수계의 분포 특성, 저지대의 낮은 지형 경사, 수리적 특성 및 다공질 지질 특성 등을 고려하여 간격의 격자를 작성하고 격자내에 포함된 수질검사 자료를 모두 취합하여 시계열 데

The characteristics of drinking groundwater quality at Chung Cheong Nam Do was analyzed by investigating the 3,086 groundwater data which were carried out the water quality inspection from Jan. 1998 to Dec. 1998. It was found that all the mean concentration of items was not over the drinking water quality standard except Zn at Yeongee area. The highest mean concentration of nitrate was 8.2 ㎎/ℓ at Hongsung area. And the mean concentrations of nitrate and ammonium at Sucheon, Yesan, Yeongee were relatively higher. It was considered that the groundwater of that area was contaminated by breeding livestock as farm pollutants. The mean concentrations of chloride, hardness and evaporation residual at coastal regions were higher than inland regions. Especially the mean concentration of chloride was 2.5 times higher. It was considered that the groundwater at coastal regions was affected by seawater. It was found that the correlation between Fe and Mn was relatively high(r=0.776) and the correlation between hardness and evaporation residual was very high(r=0.983). The rainfall series and detection rate of E-coli had the hydrologic persistence. The correlation between the detection rate and rainfall series over 150 mm was very high (r=0.9146). Therefore it is surely required to control the groundwater sanitation in the rainy season.

지하수 수질 감시를 위한 관측망의 설치는 지하수자원의 보호를 위해 매우 중요하다. 그러나 현재 지하수 수질 관측망의 설계는 합리적인 방법보다는 현장전문가의 경험과 직관에 의존하는 경우가 많다. 본 논문에서는 3차원 수질모의와 최적화를 이용하는 지하수질 관측망의 설계방법론을 제안하였다. 설계과정은 다음의 세 가지 경우로 정형화되었다. (Ⅰ) 평균농도를 감시하는 위치를 선정하되 관측정의 수기 제한되는 경우, (2) 최대농도를 감시하는 위치를 선정하되 관측정

The analysis of groundwater quality in Kyungnam Province was conducted using monitoring results obtained during 1994. According to the analysis, most heavy metals and pesticides listed in Korean drinking water standards were not detected in Kyungnam Province groundwater, but arsenic and volatile organics such as TCE and PCE were detected. Four inorganic contaminants were detected and frequency of violating the standards was in order of NO_3-N, F^+, As, NH_3-N. Of organics, TCE and PCE were the only contaminants detected. TCE more frequently violated the standards than PCE. Correlation was investigated among contaminants detected in Kyungnam Province groundwater. The correlation results showed that high correlation existed among dissolved solids, hardness, and SO_4^2-.

지하수질 감시를 위한 관측은 지하수를 사용하는 주변 인구의 보건은 물론이고 궁극적으로는 지하수자원 보전이라는 측면에서 매우 중요하다. 그러나 지하수 수질관측망은 설계부터 운영에 이르기까지 임의적이고, 체계적이기보다는 경험에 의존하거나 과학적이지 못한 방식으로 시행되고 있는 것이 사실이다. 본 연구는 지하수질 관측망의 효율적 배치를 위한 방법론의 현장적용성을 검토하기 위하여 대표적인 설계방법론을 대상으로 비교연구 하였다. 그 결과, 지하수질 관측망의 설계

In order to provide for the guidance on groundwater quality monitoring network design and also, to suggest the index to the solution of the contaminated groundwater remediation problems in the lake watershed, it is necessary to analyze the contaminant transport in the groundwater. The solute transport was analyzed in the lake watershed to investigate the behavior of the injected contaminant sources depend on the relationships between the point of contaminant sources and position of the lake. Three hypothetical groundwater flow systems, which is composed of a flow-through lake and two solute sources, were considered. The lakes located in the upper, middle, and lower portions of a watershed respectively. The transported contaminant was numerically simulated for five years by using MT3D contaminant transport model under the three-dimentional steady state conditions. From the above simulations, it can be concluded that the contaminant concentration was high as the contaminant source located at the upper position of a watershed, and the influence of the contaminant injection was large as the solute source located at the lower position. When the injection of contaminant was continued for one year without regard to the position of contaminant source and the lake, the influence of contaminant source was reached to bedrock.