• Journal of Environmental Health Sciences
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• v.29 no.1
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• pp.19-27
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• 2003

Coliforms is currently being used as the standard of environmental water qualify to evaluate the level of source water quality especially condition of fecal contamination. However, not properly applied to water quality management. So in this study, in addition to Coliforms, fecal contamination indicator bacteria turk at Feral Coliforms(FC), E. coli, Fecal streptococci(FS), Clostridium and environmental parameters related with it's distribution were investigated on a monthly basis in 6 water intakes of Han River. The mean of BOD, DO, SS and pH, benchmarks of source water management were maintained the second grade of environmental water quality standard applied to Han River but Coliforms exceeded it. Distribution of Coliforms ranged from 1.0×10¹ to 2.7 10/sup 5/ CFU/ml, FC ranged from ND to 5.3×10¹ CFU/ml, E. coli ranged from ND to 9.2×10¹ CFU/ml, FS ranged from ND to 2.5×10¹CFU/ml, they were steepy rise on July and August in common when rainfalls was heavy and water temperature was high, but Clostridium perfringens ranged from 1.7×10¹to 1.7×10¹CFU/ml not fluctuate by month. Statistical analysis of sampling data showed that most significant correlations occurred among FC and Coliforms(r = 0.840), E. coli(r = 0.792), FS(r = 0.687) and environmental parameters(temperature, turbidity, SS, rotor were all r > 0.60) while no significant correlation was observed between ammonia generally recognized fecal contamination indicator and bacteria. Identification of the coliforms showed that Enterobacter, Klebsiella, Citrobacter were comprised of 32%, 24%, 16% respectively, and E. coli were 7% of it. while E. coli was made up 85.9% of FC. The mean value of FC/Coliforms ratio, 5.2(0.1-42) were higher in Amsa, Guui than Jayang. Fecal coliforms, as those are able to reflect more particularly the extent of the fecal contamination, were considered useful in deciding the level of water treatment while monitoring the fecal contamination from the source of water supply. Therefore, it is expected that the water quality is going to be managed more efficiently by using fecal coliforms supplementarily to total coliforms which are current standard item of water-quality environment.

• Journal of Soil and Groundwater Environment
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• v.19 no.3
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• pp.33-38
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• 2014

This study was performed to evaluate the applicability of pump and treat technology as well as to identify the changes of groundwater level by continuous pumping at the petroleum contaminated site. A total of 9 monitoring wells were installed at the site and the contaminant concentrations, TPH, benzene, toluene, ethylbenzene and xylene, of groundwater were measured. With the results of the groundwater monitoring, a total of 9 wells were set up for pumping contaminated groundwater in 3 locations. The waste water treatment facility with a capacity of $10m^3/hr$ was installed in the site and operated for about 1 year. The concentrations of the contaminated groundwater from the 3 pumping wells were exceeded groundwater regulation for benzene and TPH. However, the effluent concentration of benzene and TPH was under the regulation showing the maximum level of 0.011 mg/L and 1.2 mg/L during the operation periods. Groundwater levels were decreased by continuous pumping and those were not recovered during the operation period. Groundwater levels of PW-1,2, PW-3,4,5,6 and PW-7,8,9 were decreased about 5 m, 0.7 m, 2 m, respectively. The hydraulic conductivity (K) of the region of PW-1,2, PW-3,4,5,6 and PW-7,8,9 was estimated to be $6.143{\times}10^{-5}cm/sec$, $2.675{\times}10^{-5}cm/sec$, $1.198{\times}10^{-4}cm/sec$. Groundwater level was seemed to be affected not by hydraulic conductivity but by morphological effect. These results show that the pump and treat technology has high applicability for the restoration of petroleum contaminated groundwater but needs continuous monitoring to prevent rapid groundwater drawdown.

• Journal of Sensor Science and Technology
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• v.27 no.5
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• pp.352-356
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• 2018

This paper relates to a technology for monitoring a liquefied gas storage tank in the special gas field where demand is increasing owing to the continuous growth of related fields such as the semiconductor, display, and ICT convergence electronics industries. We have proposed a system for real - time monitoring using wireless sensor network technology, and implemented a system consisting of a sensor unit, transmitter module, and receiver module to be attached to a liquefied gas storage tank. The system was applied to LCO2 tanks among various liquefied gas storage tanks to verify the feasibility. The storage tanks employed in the experiments has capacities of 16,179 l and was 1,920 mm in inner diameter. Furthermore, the density was 1.03 g/l. The measured data were compared with reference data on the remaining gas level versus the $CO_2$ height of the surface, expressed using a conventional water meter, provided by an existing storage tank supplier. The experimental results show that the data is similar to the standard data provided by the tank supplier, and has a high accuracy and reliability within an error range of 0.03%.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.273-274
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• 2006

The sea is origin of all lift, and 90% of the all living organisms are in the sea. The biosynthesis is very different. Many organisms are kept on a lower or developed to another evolutionary level than on shore. Our society is increasing demand and need for marine food and this food has to product at onshore or offshore fish farming sites. Ocean fish farms have a special operation properties such as a good quality water, net cage, sheltered locations and feeding system. The farming site is controlled and monitored for fish welfare as ammonia($NH_3$), temperature, the speed of a running fluid. Specially, the fish farm is seriously influenced by ammonia. In this paper, $NH_3$ monitoring system for ocean fish farm is researched for the suitable fish farming sites, and test equipment is designed for achieving practical data. The equipment wit monitoring algorithm is expected to the useful system for ocean fish farm.

• Nuclear Engineering and Technology
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• v.51 no.6
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• pp.1626-1632
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• 2019

Monitoring of environmental radioactivity is essential for ensuring the radiological safety of residents who live near nuclear power plants. Ulsan, South Korea, is surrounded by 16 nuclear power plants, the highest density in the country. In addition, the city contains facilities for conducting radiological nondestructive testing and using radioisotopes for medical purposes. It makes the confirmation of radiological safety particularly necessary. In this study, sampling points were selected based on regional characteristics, and surface water samples were pretreated and analyzed for gross beta and gamma radiation levels. In addition, the distribution of the city's gamma dose rate was determined using a mobile monitoring system and distribution visualization program. The results showed that there is no effect on the gross beta and gamma nuclides of artificial radionuclides, and the gamma dose rate of the entire region did not exceed the environmental radiation level in South Korea overall, confirming the radiological safety of the city.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.641-646
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• 2009

This study examines the effects of water shortage on agricultural wages in Northwest Bangladesh. For this study, meteorological data including information on the monthly temperature, precipitation, wind speed, hour of sunshine and humidity of six weather stations have been utilized during the monitoring period from 1985 to 2005. With the objective to analyze water surplus and water deficiency, a simple soil-water balance model and the modified Penman formula were applied to the Northwest Bangladesh. The seasonality of Mann-Kendell trend statistics has been used to identify the spatial variation of water surplus and deficiency throughout the region. For micro level verification of the result, a detailed field survey has been conducted within the study area. The results showed that the values of the potential evapotranspiration estimated by the modified Penmen equation were negative for certain periods. In this instance, the water deficiency of the district of Rajshahi was observed significantly in the period of pre-monsoon and post-monsoon. The field study also verified that because of such deficiency in water, the agricultural scenario of the area was widely influenced which lead to less agricultural production and less economic benefits.

• Journal of Korea Water Resources Association
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• v.48 no.4
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• pp.269-279
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• 2015

Nowadays, the world has suffered by natural disaster of climate change due to global warming. Korea has also faced with similar situation. To prevent these natural disaster, Four Major River Management has conducted. One of conducted content in Four Major River Management is the levee maintenance which classified into fill-up the inland, levee of reinforcement and so on. These maintenances may make the characteristics of groundwater flow change and affect to the levee safety (piping phenomenon). Therefore, analysis on groundwater fluctuation according to level of riverside and inland should be required. This study focus on levee of Hoe stream, which is connected to Nakdong river, and piping safety factor in the levee analyzed by using pore water pressure. Besides, groundwater fluctuation, which is depended on level of riverside and inland, is simulated by using the SEEP/W (2D ground water model). This simulation considered steady flow and unsteady flow. As a result, piping safety factor increased due to rising the inland level. Piping safety factor of riverside was effected by only river water level. Therefore, external levee factor considering inland level raising and suitable control of river water level is need to increase piping safety factor.

• The Journal of Engineering Geology
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• v.13 no.4
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• pp.457-474
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• 2003

This study aims to elucidate characteristics of groundwater level fluctuation at riverbank filtration sites in Daesan-myeon, Changwon City. Groundwater level fluctuation, river water level change and stream-aquifer interaction are very important to estimate optimal discharge rate of the pumping well. Water level contours from February 2003 to October 2003 show normal decreasing trend toward the Nakdong river with the hydraulic gradient of 0.008. However, flow reversion occurs when groundwater is discharged at the pumping wells or rise of the Nakdong river by rainfall. The fluctuation of the Nakdong river ranges 0 - 10 m msl. Autocorrelation analysis was conducted to the groundwater levels measured on the six monitoring wells (DS1, DS2, DS3, DS4, DS6 and DS7). The analyzed waterlevel data can be grouped into three: group 1 (DS1 and DS3) represents strong linearity and long memory effect, group 2 (DS1 and DS6) intermediate linearity and memory, and group 3 (DS4 and DS7) weak linearity and memory. Waterlevels of group 1 wells are relatively closely related to the change of river-water level. Those of group 2 wells are largely affected by the pumping and the river-water level, and those of group 3 wells are strongly linked to pumping.

• Journal of Soil and Groundwater Environment
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• v.6 no.1
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• pp.33-43
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• 2001

A calculation technique which estimates natural recharge using groundwater level change was proposed and prepared with the existing techniques using groundwater recession curve during dry days. As a part of estimating natural groundwater recharge nation wide, the reliable data from the national groundwater monitoring network were used and the methodology was applied to the three sites which have enough data (Chungju, Jinju and Kwangju). For this study, seasonal variation of groundwater level change, an analysis of lagging time on groundwater level and cumulative precipitation, and a comparative study for groundwater recharge were conducted.

• The Journal of Engineering Geology
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• v.16 no.2 s.48
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• pp.135-143
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• 2006

This study presents the results of a series of laboratory scale slope failure experiments aimed at clarifying the process and the condition leading to the initiation of rainfall-induced slope failures. For the evaluation of hydrologic response of the model slopes in relation the process of failure initiation, measurements were focused on the changes in volumetric water content during the initiation process. The process leading to failure initiation commences by the development of a seepage face. It appears reasonable to conclude that slope failures are a consequence of the instability of seepage area formed at the slope surface during rainfall period. Therefore, this demonstrates the importance of monitoring the development seepage area for useful prediction about the timing of a particular failure event. The hydrologic response of soil slopes leading to failure initiation is characterized by three phases (phase I, II and III) of significant increase in volumetric water content in association with the ingress of wetting front and the rise of groundwater level within the slope. The period of phase III increase in volumetric water content can be used to initiate advance warning towards a failure initiation event. Therefore, for the concept outlined above, direct and continuous monitoring of the change in volumetric water content is likely to provide the possibility for the development of a reliable and effective means of predicting the occurrence of rainfall-induced slope failures.