• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.1
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• pp.25-35
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• 2015

As livestock manure treatment is becoming a problem, manure application in forest plantation is recommended as an alternative. In this study, to investigate the impact due to liquid manure application in forest plantation, soil, soil water and shallow groundwater quality had been monitored in poplar experimental site where the liquid manure (LM) was applied. Water samples were collected weekly during growing season (April to October) from 2008 to 2011. From the monitoring results, phosphorus concentration in the soil and soil water had no significant difference between LM and control plots. $NO_3$-N concentration of soil water in LM, however, showed higher concentration (13.6 mg/l at 40 cm, 35.1 mg/l at 80 cm) than control plot (1.5 mg/l at 40 cm, 0.5 mg/l at 80 cm). In case of shallow groundwater quality, pH, heavy metal, etc. were satisfied to the national agricultural water quality standard of groundwater and there were no significant difference between upstream and downstream. The $NO_3$-N concentration of shallow groundwater was also not exceeded the national drinking water standard. However, $NO_3$-N concentration in soil water and downstream of shallow groundwater had increased in 2011 when non-composted LM was applied mostly in non-growing season of tree (September). From the results, it is important to control nitrogen source, application time and decomposed or not when LM is applied. In addition, to investigate nitrate source, further long-term monitoring and modelling could be necessary.

• The Journal of Engineering Geology
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• v.23 no.4
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• pp.467-476
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• 2013

With increasing interest in environmental issues and the quality of surface water becoming inadequate for water supply, the Korean government has launched a groundwater development policy to satisfy the demand for clean water. To drive this policy effectively, it is essential to guarantee the accuracy of sustainable groundwater yield and groundwater use amount. In this study, groundwater use was monitored over several years at various locations in Korea (32 cities/counties in 5 provinces) to obtain accurate groundwater use data. Statistical analysis of the results was performed as a method for estimating rational groundwater use. For the case of groundwater use for living purposes, we classified the cities/counties into three regional types (urban, rural, and urban-rural complex) and divided the groundwater facilities into five types (domestic use, apartment housing, small-scale water supply, schools, and businesses) according to use. For the case of agricultural use, we defined three regional types based on rainfall intensity (average rainfall, below-average rainfall, and above-average rainfall) and the facilities into six types (rice farming, dry-field farming, floriculture, livestock-cows, livestock-pigs, and livestock-chickens). Finally, we developed groundwater-use estimation equations for each region and use type, using cluster analysis and regression model analysis of the monitoring data. The results will enhance the reliability of national groundwater statistics.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.695-700
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• 1999

Stream and groundwater qualities of two rural watershes in the upper North Han river basin were monitored for 14months. Six to eight stream sampling sites and two to there groundwater monitoring wells were chosen and water samples were regularyl collected and analyzed with respect to total nitrogen(T-N), total phosphorus(T-P) and total suspended solids(TSS). Monitoring data were graphically analyzed with respect to time.Rainfall amout and intensity seemed to have an impact on stream T-N and T-P concentration changes. TSS concentrations were generally lower than the first class stream water quality standared, Both stream and groundwater qualities near livesstock feetlot areas were degraded indicating the feedlots have an impact on water quality.

• Journal of Soil and Groundwater Environment
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• v.18 no.2
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• pp.19-26
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• 2013

This study developed the classification of National Soil Quality Monitoring Network (NSQM) and its site selection criteria to meet the recently established purposes of the NSQM. The NSQM were suggested by this study to classify into the six-purposes site groups from the current classification of land uses. The six purposes site groups were 1) intensive observation sites, 2) contaminant loading sites, 3) human activity sites, 4) background sites, 5) river soil sites, and 6) sites near the groundwater quality monitoring wells. Furthermore, this study developed the site selection criteria of NSQM utilizing the accumulated NSQM data, road traffic data, chemical emission data, census, soil information, and the literature related to soil quality variation due to contaminant loads. For selecting suitable sites for NSQM, this study used road traffic, chemical emission, the distance from the contaminant sources, and population information as specific criteria. The suggested site classification and criteria were appled for the current 100 NSQM sites for evaluation. Forty sites were met to the criteria suggested by this study, but sixty sites were not met to the criteria. However, some of the sixty sites also included the obscure sites that their addresses were not apparent to find them.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1383-1385
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• 2003

Remote sensing has been widely used in the exploration of groundwater. In this paper, on the establishment of empirical function between ground water and soil moisture content 6S code is used to reduce uncertainties in the remote sensing of groundwater. Then ground water levels are calculated using 6S corrected and uncorrected ETM+ image along with isochronous meteorological information. Greater correspondence between field examined and satellite monitoring data is obtained from corrected image than from the uncorrected image.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.117-121
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• 2005

In order to monitor the levels and seasonal variations of EDCs, samples of the discharged effluent from sewage & wastewater treatment plants and river waters were collected. The target EDCs including bisphenol A and alkylphenols were determined by Laser-induced fluorescence(LIF) as in-situ monitoring technique. The category of EDCs showed similar fluorescence spectra and nearly equal decay time. This point makes it hard to distinguish each EBCs from the EDCs mixture by LIF and LIF results were expressed only by the total EDCs. However, LIF monitoring results and GC-MS results was comparable. The correlation coefficient between EDCs concentration acquired from GC-MS and fluorescence intensity from LIF was significant. This study supports the feasibility of the application of LIF into EDCs monitoring In aquatic system.

• Journal of Soil and Groundwater Environment
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• v.12 no.5
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• pp.64-72
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• 2007

Nationwide occurrence of arsenic in groundwater of Korea was investigated with the data from the groundwater quality monitoring stations. During 2001-2006, As has been quantitatively detected in 3.0 % of the total wells $(5.0{\sim}188{\mu}g/L)$, and its geographical distribution suggests 3 groups: an urbanized and industrialized area (Seoul and its neighbouring province), and two naturally occurring areas (Chungbuk and Gyeongnam provinces). Natural occurrence of As appears to be geologically related with Ogcheon metasedimentary rocks and Cretaceous volcanic rocks. Based on the results of the previous studies in the high As sites, the oxidation of sulfides can be a major control on As concentrations in groundwater in the mineralized and altered zone within the area of Cretaceous volcanic rocks. Desorption process under slightly high pH conditions may also be responsible for high As in groundwater in areas of Ogcheon metasedimentary rocks.

• Journal of the Korean GEO-environmental Society
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• v.16 no.6
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• pp.39-43
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• 2015

This study extends the Distributed Temperature Sensing (DTS) application to delineate the saturated zones in shallow sediment and evaluate the groundwater flow in both downward and upward directions. Dry, partially and fully saturated zones and water level in the subsurface can be recognized from this study. High resolution seepage velocity in vertical direction was estimated from the temperature data in the fully saturated zone. By a single profile, water level can be detected and seepage velocity in saturated zone can be estimated. Furthermore, thermal gradient analysis serves as a new technique to verify unsaturated and saturated zones in the subsurface. The vertical seepage velocity distribution in the recognized saturated zone is then analyzed with improvement of Bredehoeft and Papaopulos' model. This new approach provides promising potential in real-time monitoring of groundwater movement.

• Journal of the Korean GEO-environmental Society
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• v.9 no.7
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• pp.73-85
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• 2008

320 national groundwater monitoring stations have been constructed since 1995 and groundwater levels are measured automatically 4 times a day at each well. It has a difficulty to estimate an average recharge rate of watershed using the recharge rate of the monitoring site because of the lack of its representative on converting a point recharge rate into a spatial one. In this study, the relations between site characteristics (topography, hydraulics, geology, facilities, etc.) and recharge rates of 223 monitoring sites, which were selected using cluster analysis, were analyzed using statistical methods, and finally, regression models were constructed for a recharge rate estimation of non-measured areas. The independent variables for these simple regression models, 1) width of adjacent stream, 2) distance to the nearest stream, 3) topographic slope, and 4) rock type, are proposed using analysis of variance. These models have lots of advantages such as an easy data collection from topographic and geologic maps, a few input variables, and also simplicity in use. Suitability analysis from the comparison between estimation values and original ones at monitoring sites shows that these models are useful for a groundwater recharge estimation.

• Journal of Korea Water Resources Association
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• v.31 no.6
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• pp.685-694
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• 1998

Protection of groundwater resources from contamination has been of increasing concern throughout the past decades. In practice, however, groundwater monitoring is performed based on the experience and intuition of experts or on the convenience. In dealing with groundwater contamination, we need to know what contaminants have the potential to threat the water quality and the distribution and concentration of the plumes. Monitoring of the subsurface environment through remote geophysical techniques or direct sampling from wells can provide such information. Once known, the plume can be properly managed. Evaluation of existing methodologies for groundwater monitoring network design revealed that one should select an appropriate design method based on the purpose of the network and the availability of field information. Integer programming approach, one of the general purpose network design tools, and a cost to-go function evaluation approach for special purpose network design were tested for field applicability. For the sam contaminated aquifer, two approaches resulted in different well locations. The amount of information, however, was about the same.