• 한국도로학회논문집
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• 제15권1호
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• pp.47-56
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• 2013

PURPOSES: This study is to evaluate a ground water level effect on frost heaving in road pavements. METHODS: The effects of water table on frost heaving in pavement systems were evaluated from the mechanical analysis using FROST program. The input parameters and boundary conditions were determined by considering climates, pavement sections, and material properties specially subgrade soil types in Korea. RESULTS: When the water table located above the freezing depth, amount of frost heaving caused by freezing the water in pavement itself was big enough to damage in pavement system, although pavement system consists of fully non-frost-susceptible materials with sufficient thickness of anti-freezing layer. The amount of frost heaving was decreased rapidly with increasing the distance between the water table and freezing depth. CONCLUSIONS: It was concluded that there is no engineering problems related with frost heaving in practical sense when the distance between freezing depth and water table is over 1.5m for having subgrade soils less than 50% of #200 sieve passing to meet specification on quality control in Korea.

• Advances in environmental research
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• 제9권2호
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• pp.123-133
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• 2020

A time series dataset was conducted to ascertain the effect of water table on the variability in and emission of CH₄ and CO₂ concentrations at a closed landfill site. An in-situ data of methane/carbon dioxide concentrations and environmental parameters were collected by means of an in-borehole gas monitor, the Gasclam (Ion Science, UK). Linear regression analysis was used to determine the strength of the correlation between ground-gas concentration and water table. The result shows CH₄ and CO₂ concentrations to be variable with strong negative correlations of approximately 0.5 each with water table over the entire monitoring period. The R² was slightly improved by considering their concentration over single periods of increasing and decreasing water table, single periods of increasing water table, and single periods of decreasing water table; their correlations increased significantly at 95% confidence level. The result revealed that fluctuations in groundwater level is the key driving force on the emission of and variability in groundgas concentration and neither barometric pressure nor temperature. This finding further validates the earlier finding that atmospheric pressure - the acclaimed major control on the variability/migration of CH₄ and CO₂ concentrations on contaminated sites, is not always so.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권3호
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• pp.17-27
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• 2011

Recently, a physically based model of water-table fluctuation due to precipitation is developed based on aquifer water balance model. In the model, it was assumed that the water infiltration into ground surface is advection dominant and immediately reaches to water-table. The assumption may be suited for the sites where the water-table is shallow and/or the permeability of the unsaturated zone is high. However, there are more cases where the model is not directly applicable due to thick and low permeable unsaturated zone. For the low permeability unsaturated zone, the pattern of water flux passing through unsaturated zone is diffusive as well as advective. In this study, to improve the previously developed water-table fluctuation model, we combined the delayed drainage model, which has long been used in well hydraulics, to the water-table fluctuation model. To test the validity of the development, we apply the developed model to 5 different domestic sites. The model parameters are calibrated based on the groundwater hydrograph and the precipitation time series, and the correlation analyses among the parameters are pursued. The overall analyses on the delineated model parameters indicate that the delayed drainage parameters or delay index used in the developed model are able to reveal drainage information in the unsaturated zones.

• 한국작물학회지
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• 제40권2호
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• pp.195-202
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• 1995

토성과 지하수위를 달리하여 맥류의 생육과 수량에 미치는 반응을 알아보고자 올보리와 그루 밀을 공시하여 1992년 10월∼1993년 6월에 걸쳐 550l의 대형 포트 시험을 수행하였다. 토성을 식양토와 사양토로 조성하여 전 생육기에 거쳐 지하수위가 20cm, 30cm, 40cm, 50cm, 70cm가 되도록 조절하고 비가림 재배를 실시한 결과를 다음과 같다. 1. 간장과 지상부건물중은 지하수위가 높아짐에 따라 감소하였으며 그 정도는 밀보다 보리에서 더욱 크게 나타났고 지하부중에 대한 지상부중 비율은 지하수위가 높아짐에 따라 증대하였는데 그 정도는 보리에서 더욱 뚜렷하였으며 지하수위의 상승은 지상부보다 지하부의 생장에 더욱 크게 영향하였다. 2. 생육후반기(93년 5월 18일)의 신선엽수와 신선엽면적는 보리와 밀 모두 지하수위 30∼40cm 이상에서 감소하였고 가장 많은 신선엽수와 신선엽면적은 사양토는 지하수위 50cm, 식양토는 지하 수위 70cm에서 나타났다. 3. 엽록소 함량은 지하수위가 높아짐에 따라 감소되었는데 보리가 밀보다 토성에 따른 영향이 크게 나타났으며 광합성 능력은 지하수위 20cm에서 뚜렷이 저하하였다. 4. 출수기는 지하수위가 높아지면서 촉진되어 지하수위 20cm의 경우에 사양토에서 보리의 경우 2∼3일, 밀의 경우 4일 정도 빨라졌고 식양토에서는 별로 차이가 없었으며 등숙기는 지하수위가 높아짐에 따라 촉진되어 지하수위 20cm에서 보리의 경우 5∼7일, 밀의 경우 10일 정도 빨라졌다. 5. 수량은 토성에 따라 지하수위 50∼70cm에서 가장 많았으며 지하수위가 높아짐에 따라 감소 되어 지하수위 20cm에서 가장 크게 떨어졌는데 그 감소 정도는 보리에서 71.1％(식양토)∼72.2％(사양토)였고 밀에서 41.0％(식양토)∼60.0％(사양토)이었다. 6. 수량구성요소 면에서 단위면적당 이삭수는 지하수위가 높아짐에 따라 보리와 밀 모두 줄었으나 이삭당립중은 보리에서는 증가했고 밀에서는 감소하였다. 7. 수량과 엽록소 함량간에 보리와 밀 모두 높은 상관관계를 나타내었으며 보리에서는 신선엽면적이, 밀에서는 지상부건물중, 지하부에 대한 지상부중량 비율이 수량과 높은 상관을 보였다. 이상의 결과로 보아 토성에 따라 지하수위 50∼70cm에서 맥류의 생육과 수량은 최대가 되며 비교적 안전한 지하수위는 사양토에서는 30cm, 식양토에서는 40cm라 하겠으며 지하수위 상승에 따른 수량감소비율은 보리에 비하여 밀에서 더욱 크게 나타났다.

• 한국농공학회지
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• 제36권2호
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• pp.123-131
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• 1994

Experimental studies were conducted to make clear the soil moisture environment under the condition of paddy-upland rotational fields by investigating water-table depths and soil moisture contents during growing season of crops in two kinds of soil. The following results were obtained. 1.Although water-table depths fluctuated with the amount of rainfall in the experimental field, it seemed that the variation of vater4able depths in the paddy-upland rotational, field was strongly affected by the condition of locations on paddy fields. 2.It is recognized that the concept of sum of excess water depth(SEWxx) and sum of excess water day(SEDxx) can be used to represent the soil moisture stress index due to the fluctuation of water-table depths. 3.The results of this study clearly indicate that drainage in paddy-upland rotational field to maintain an optimum soil moisture content must be made by introducing the concept of block drainage which needs both subsurface drainage and intercept drainage around a field. 4.Soil moisture contents were affected by both the amount of rainfall and water-table depths, however, the moisture content for top soil showed higher correlation with the amount of rainfall while that for subsoil with water-table depths.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.299-299
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• 2017

Due to the climate changes in Korea, the numbers of both torrential rain events and drought periods have increased in frequency. Water management practice against water shortage and flooding is one of the key interesting for field crop cultivation, and groundwater often serves as an important and safe source of water to crops. Therefore, the objective of this study is to evaluate the effect of groundwater table levels on soil water content and soybean development under two different textured soils. The experiment was conducted using lysimeter located in Miryang, Korea. Two types of soils (sandy-loam and silty-loam) were used with three groundwater table levels (0.2, 0.4, 0.6m). Mean soil water content during the soybean growth period was significantly influenced by groundwater table levels. With the continuous groundwater level at 0.2m from the soil surface, soil water content was not statistically changed between vegetative and reproductive stage, but the 0.4 and 0.6m groundwater table level was significantly decreased. Lower chlorophyll content in soybean leaves was found in shallow water table treatment in earlier part of the growing season, but the chlorophyll contents were non-significant among water table treatments. Groundwater table level treatments were significantly influenced on plant available nitrogen content in surface soil. The highest N contents were observed in 0.6m groundwater table level. It is probably due to the nitrogen loss by denitrification as the result of high soil water content. The length and dry weight of primary root was influenced by groundwater level and thus the highest length and dry weight of root were observed in 0.6m water table level. This result showed that soybean root growth did not extend below the groundwater level and increased with the depth of groundwater table level. The results of this study show that the management of groundwater level can influence on soil characteristics, especially on soil water content, and it is an important practice of to reduce yield loss caused by the water stress during the crop growing season.

• 한국수자원학회논문집
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• 제36권6호
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• pp.1035-1046
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• 2003

TOPMODEL의 지하수면길이 분포에 대한 예측능력을 평가하기 위해 2개 기본가정과 지하수면깊이에 대한 지배방정식을 검증하였다. 검증에는 토양두께가 얇은 급경사 사면의 수문관측과 토양조사 자료를 이용하였다. 조사사면에서 지하수면반응과 토양의 수리적 특성은 지형경사와 평행하는 수리경사, 지하수면깊이에 지수함수적으로 감소하는 투수량계수 등과 같은 TOPMODEL의 기본가정과 일치하였다 토양의 투수량계수감소율(f)과 토성은 지표부터 깊이 0.3m까지 사면전체에서 공간적으로 균질하지만, 토성과 f의 수직적인 변화로 깊이 0.3m 아래부터 공간적으로 불균질한 특성을 보인다. 조사사면에서 TOPMODEL의 지배방정식은 f값이 공간적로 균질한 깊이의 지하수면깊이 분포를 예측하는데 적용할 수 있는 것으로 나타났다.

• 한국환경복원기술학회지
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• 제14권3호
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• pp.57-69
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• 2011

This study examined the relationship between Phragmites australis' growth and sediment properties at mud tidal flat of Donggum-ri, Gilsang-myeon, Gangwha-gun, Incheon city. Field survey was carried out from May, 2010 to October, 2010. Water content, soil texture, electric conductivity and water table depth for sediment, density, height, dry weight and flowering for P. australis were examined at several plots from the starting point (the coastal embankment) to the end point of the two populations. The result was as follows. Firstly, the water table increased along distance from the embankment at one line (N-line) but was similar at the other line (S-line) in a P. asustralis population. Water tables were higher out of than within a P. australis population at two populations. Secondary, in N-line, the height and dry weight of P. australis decreased along the distance from embankment but, in S-line, those were similar in its population. P. australis' growth was dependent on electric conductivity at lower layer (water table level) rather than upper one (the surface). Thirdly, density of P. australis changed during growing season and was similar in a population, except for the end point of patch. In summary, the growth and distribution of P. australis were dependent on salt content of tidal flat's sediment (water table level) and this was affected by fresh water of the inland.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회 2차
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• pp.38-44
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• 2010

Shaking table tests were performed to reproduce the dynamic behavior of estuary barrage and its subbase soil which can be potentially damaged during earthquake loading. For understanding the vibration effect to the ground during earthquake, the model was formulated with 1/300 scale of prototype estuary barrage and subbase soil. Scott and Iai(1989) proposed the law of the similarity for similar experimental conditions. The laboratory model shaking table test was conducted under the vibration condition of simulated earthquake of 0.154g. The horizontal displacement on the structure was measured during the shaking table test. The pore water pressure was also monitored for the underground layers of soil. The field horizontal displacement and the pore water pressure can be predicted by using the results of the laboratory shaking table test.

• 한국작물학회지
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• 제40권3호
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• pp.278-284
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• 1995

본 연구는 토성별 지하수위가 밀, 보리의 생산물 종실의 품질 및 발아와 효소활성에 미치는 영향 등을 추구함으로서 적정지하수위와 지하수위에 따른 피해 정도를 구명 평가하고자 실시하였다. 올보리와 그루밀을 공시하여 1992년 10월 ~ 1993년 6월에 걸쳐 대형포트(550 liter) 시험을 수행하였다. 토성을 식양토와 사양토로 조성하여 전 생육기에 걸쳐 지하수위가 20, 30, 40, 50, 70cm가 되도록 조절하고 비가림 재배를 실시하였는데 그 결과를 요약하면 다음과 같다. 1. 정립비율과 종보비중은 토성과 지하수위에 따른 영향이 일정하지 않았으며 1,000립중은 보리와 밀 모두 지하수위가 낮아짐에 따라 증가하였고 토성에 따른 차이는 미미하였다. 2. 조단백 함량은 보리와 밀 모두 지하수위가 높아질수록 많아졌으며 특히 밀에서 뚜렷하게 나타났다. 토성에 따른 조단백 함량의 변화는 지하수위에 따른 영향보다 적었으며 사양토에서의 것이 식양토의 것보다 높은 경향이었으나 그 차이는 적었다. 3. 조지방 함량은 보리와 밀 모두 지하수위가 높아질수록 낮아졌으며 사양토에서의 조지방 함량이 높은 경향으로 나타났다. 4. 회분 함량은 보리와 밀 모두 지하수위가 높아질수록 낮아졌으며 특히 사양토에서 그 경향이 뚜렷하였다. 5. 밀의 제분율은 토성에 따른 차이는 없었으며 지하수위 20cm에서 종실 제분율이 65% 정도로 나타났고 지하수위 40cm 이하에서 제분율이 67% 이상으로 나타났다. 6. 2$0^{\circ}C$에서 3일 이내의 발아율에서 보면 보리와 밀 모두 모든 처리에서 95% 이상의 발아율을 보였으며 토성에 관계없이 지하수위 20cm에서 가장 낮은 발아율을 보였고 지하수위가 낮아질수록 발아율도 높아졌다. 7. 보리에서 24시간 이내의 발아율에서는 일정한 경향을 나타내지 않았으나 48시간 이내의 발아율에서는 사양토의 지하수위 20cm 처리를 제외하고는 89% 이상의 발아율로 나타나 48시간 이내에 대부분이 발아하는 발아세를 보였다. 8. 보리 맥아에서의 당화력(diastic power)은 지하수위 20cm 처리구에서 가장 낮게 나타났고 지하수위 30cm 이하 처리에서의 당화력의 차이는 현저하지 않았으며 토성에 따른 맥아 당화력의 차이는 나타나지 않았다.