• The Journal of Engineering Geology
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• v.29 no.4
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• pp.469-481
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• 2019

In addition to structural stabilization measures such as the construction of Sand Dam, non-structural management measures such as reasonable water demand and supply volume management are needed to prevent limited water supply damage due to drought. In this study, water supply-demand monitoring system was established for drought response in Seosang-ri basin in Chuncheon, the main source of domestic water for small water facilities. The flow rate of the stream was measured for monitoring the supply volume, and the daily flow rate was calculated by using it to calibrate the parameters of the SWAT (Soil and Water Assessment Tool). To monitor demand, the daily usage was calculated by measuring the change in the water level of the water tank. The relationship between the finally calculated daily supply and demand amount was analyzed to identify the shortage of water.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.789-795
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• 2008

Slope stability is affected by various factors. For safety management of slopes, monitoring systems have been widely constructed along railway lines. The representative data from the systems are variations of ground profile such like ground water level and pore water pressure etc. and direct displacement measured by ground clinometer and tension wire sensor. Slopes are mainly effected by rainfall and rainfall causes the decrease of factor of safety(FOS). Because FOS varies linearly by the variation of ground water level and pore pressure, it has a weak point that could not define the time and proper warning sign to secure the safety of the train. In this study, alternative of FOS such as reliability index and probability of failure is applied to slope stability analysis introducing the reliability concept. FOS, reliability index, probability of failure and velocity of probability of failure of the slopes by variation of ground water level are investigated for setting up the specification of safety management of slopes. By executing case study of a slope(ILLO-IMSUNGLI), it is showed to be applied to specification of safety management.

• Proceedings of the Korea Water Resources Association Conference
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• 2003.05a
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• pp.62-65
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• 2003

Improvement of the efficiency of the agricultural water use is important for the sustainable water management because the agricultural water use occupied above 60% of the total water use in korea. For the analysis of agricultural water use the Yi-dong experimental site was selected. For the monitoring system of the experimental site, four rainfall gauging stations and twenty-six water level gauging stations are established and operated. Analyses of the measured data are processed for the irrigation efficiency of agricultural water on the eight irrigation areas.

• Geomechanics and Engineering
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• v.14 no.3
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• pp.241-246
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• 2018

The displacement monitoring data series reconstruction method was developed under equal water level effects based on displacement monitoring data of concrete dams. A dam displacement variation equation was set up under the action of temperature and aging factors by optimized analysis techniques and then the dam displacement hydraulic pressure components can be separated. Through the dynamic adjustment of temperature and aging effect factors, the aging component isolation method of dam displacement was developed. Utilizing the isolated dam displacement aging components, the dam stability model was established. Then, the dam stability criterion was put forward based on convergence and divergence of dam displacement aging components and catastrophe theory. The validity of the proposed method was finally verified combined with the case study.

• The Korean Journal of Ecology
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• v.21 no.6
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• pp.759-770
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• 1998

biotic indices scoring with the benthic macroinvertebrates were assessed as pollution monitoring tools in the north branch of the Han River system, Korea. We investigated the temporal variability of water quality at unpolluted, moderately polluted and heavily polluted sites using several biotic indices and assessed appropriate biological monitoring indices for lotic systems in Korea. The following biotic and chemical indices were employed in order to compare their applicability to the lotic systems : Trent Biotic Index (TBI), Chandler's Biotic Index-Average Score per Taxon (CBI-ASPT), Modified Biological Monitoring Working Party Score System-Average Score per Taxon (BMWP-ASPT), Hilsenhoff's biotic Index (BI) and Family-level Biotic Index (FBI) models for biotic analyses and National Sanitation foundation's Water Quality Index (NSFWQI) and comprehensive Chemical Pollution Index (Pb/n) for chemical analyses of water quality. Index and score values were compared with each other and with 24 water chemistry parameters. All biotic indices were significantly auto-correlated (p<0.001) and BI and FBI/ROK among them were highly correlated (r=0.84). BI and BMWP-ASPT models were also highly correlated with NSFWQI, while TBI values showed high correlation with the Pb/n. The BI and BMWP-ASPT were highly correlated with the most water chemistry parameters. We conclude that the BI model, which includes indicator species and abundance of taxa, is best suited for the bioassessment of lotic systems in Korea. For rapid field-based assessments, FBI/ROK and BMWP-ASPT models are also appropriate.

• Tunnel and Underground Space
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• v.16 no.1 s.60
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• pp.73-84
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• 2006

Effects of railway tunnel excavation on water level at a national groundwater monitoring station in Mokpo were evaluated by field investigation and numerical groundwater modeling. The water level at the station has experienced a decline of about 5 m within 1 year since July 2002. From the field investigation, it was concluded that decrease of precipitation oo increase of grundwater use was not reason for the decline. The Mokpo tunnel of new Honam railway, 70 m apart from the national station, appeared most plausible cause and a period of the tunnel excavation generally well matches up that of the drawdown. To quantify the effects of the tunneling on the water level, a groundwater flow modeling was performed. Especially, a most probable conceptual model was optimized through multiple preliminary simulations of various scenarios because there were few hydrogeological data available for the study area. The optimized model was finally used for the quantification. Based on the field investigation and the numerical simulations, it was concluded that the tunnel excavation was one of the most probable reasons for the substantial water level decline but further hydrogeologic investigation and continuous monitoring are essentially required for the surrounding area.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.6
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• pp.735-739
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• 2010

This study investigated a method for monitoring fishes immigrating to upper streams from the sea in relation to water level with elapsed time, and measured fish behavior patterns and swimming speed in a fishing boat gateway using an acoustic camera system. This method was employed due to difficulties, linked to high turbidity, of using only underwater optical systems for monitoring fish migrating to brackish water. Results showed that fish length distribution showed high correlation between haul sampling and an automatic counting algorithm supported by the DIDSON software program. These results will help to maximize the effects of fish run management by increasing understanding of the amount of major fish species migrating in relation to durable water levels.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.3
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• pp.85-94
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• 2020

Since the salinity of irrigation water is a critical constraint to the production of certain vegetable crops, salinity was considered as one of the most important factors of irrigation water. The purpose of this study were to monitor and assess the effects of saline irrigation water on strawberry and red radish growth in protected cultivation. One control and three treatments, which were differentiated according to the level of salinity in irrigated water, were employed for each vegetable to assess the effects of the irrigation with saline water. Monitoring has shown that using irrigation water with salinity above a certain level causes excessive accumulation of sodium (Na⁺) in both strawberry and red radish. Increased Na+ content was analyzed to be able to decrease the sugar content in strawberry. In addition, the salinity higher than the threshold level of irrigation water was found to reduce the growth and yield of strawberry and red radish. This study could contribute to suggest criteria for safe use of saline water in protected cultivation, although long-term monitoring is needed to get more representative results.

• Journal of Soil and Groundwater Environment
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• v.7 no.3
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• pp.45-59
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• 2002

This study is objected to demonstrate the spatial variability of the ground-water recharge by classifying the types of ground-water hydrographs and assessing the recharge ratio(the ratio of the rise of ground-water level to cumulative precipitation) of each type using the National Ground-water Monitoring network data. A total of 5 types were identified by factor analysis on the ground-water hydrographs nationwide. The recharge ratio of each type were estimated to be 6.5% (TYPE I), 4.1 % (TYPE II), 9.2%(TYPE III), 5.8 %(TYPE IV), 15.3 %(TYPE V) in the confidence level of 95.44% and 6% variation was estimated site by site even in the same type. The recharges of Han, Nakdong, Keum, Youngsan·Seomjin river basins were estimated as 10.0 %, 6.1 %, 8.3 %. and 6.6 % respectively. These results were consistent with the results of the existing baseflow method.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.3
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• pp.505-512
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• 2019

We propose a new method to monitor the water level of spent fuel pool in a nuclear power plant without electric power. We also analyze the performance and limitation of the proposed method. Our method is based on the reflected optical power at the end of optical fiber through a $1{\times}N$ optical coupler. We reveal that there is no problem to monitor the water level when using a $1{\times}8$ optical coupler. However, when a $1{\times}16$ optical coupler is used, only 15 out of 16 output ports can be used due to Rayleigh back-scattering. When a $1{\times}32$ optical coupler is used, only 25 out of 32 output ports can be used to monitor the water level.