• Water for future
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• v.25 no.4
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• pp.61-73
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• 1992

There are needs to examine the consequences of a regulation in effect to control the migration of leachates from disposal sites. The main objective of this study is to illustrate the methodology to evaluate basic disposal designs for compliance with a certain regulation, The "100/100 rule" is selected for demonstration purpose which dictates that the time for the leachates to travel a horizontal distance of 100feet (30.5m) away from the property where the landfill or pond is located must exceed 100 years. The two primary methods for disposal of ash from coal-fired utility plants, landfill and pond, are studied, Numerical groundwater flow analysis resulted in pressure head distribution and flux information in the cross-section of the domain while path line analysis provided travel path and time of leachate migration to compliance zone.ance zone.

• Journal of the Speleological Society of Korea
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• no.62
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• pp.11-16
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• 2004

Uro cave is a livestone cave formed at the Cambrian period. Uro cave is situated in Urosil, HogyeMyen, Moonkyunssi, HyungBok province. The temperature of the Uro cave is about 12～$15^{\circ}C$, humidity 90～95%, pH 7～8, Water temperature 12～$15^{\circ}C$, Carbon dioxide 500～900ppmv, hardness 110mg/$\ell$ in Conclusion, Uro cave does not have values of topography, environment, and tourism resource.

• Journal of Plant Biology
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• v.25 no.3
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• pp.123-133
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• 1982

The tropic structure and the function of a small pone ecosystem under the tree stand were studied in terms of energy flow. About 28% of total solar radiation was intercepted by the tree canopy over the pond. Primary producers converted 1.1%(3,382 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$) of solar radiation (320,000 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$) into gross primary production. The amount of energy availble to the pond snail was 1,683 kcal.m-2.y-1 of the net production by primary producers and 1,033 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$ of the litter fallen into the pond. The amount of gross secondary production by the pond snail was 245 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$. Judging from these, supply of both net primary production and the litter was indispensable for the maintenance of the pond ecosystem. The total amont of energy as gross primary production plus litter was 4,415 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$(100%). Since the total respiration loss was calculated to be 1,917 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$(43.4%), the rate of energy accumulation in the pond estimated to 56.6%.

• Animal Systematics, Evolution and Diversity
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• v.2 no.1
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• pp.49-62
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• 1986

A taxonomic study was carried out on the freshwater copepods of Order Calanoida from Korean during the period from May, 1983 to November, 1984. Materials consist of both specimens deposited at the Department of Biology, Kangreung National University and the specimens collected from various freshwater regions (excluding the subterranean waters) such as rivers, lakes, ponds, bogs, ricefields, etc. during this period. As a result of examining the specimens collected at the 26 localities in South Korea, 8 species of 3 families were identified, of which 4 species are newly known from Korea ; Sinocalanus sinensis (Poppe, 1889) ; Tropodiaptomus oryzanus Kiefer , 1937 ; Sinodiaptomus sarsi (Rylov, 1923) ; Neodiaptomus schemackeri(Poppe et Richard, 1892).

• Animal Systematics, Evolution and Diversity
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• v.8 no.2
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• pp.211-222
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• 1992

The systematic study of freshwater rotifers was conducted with the materials collected from 205 sites in South Korea. As a result, 4 subspecies, 3 from of Family Brachionidae (Keratella, Notholca) was identified; of which, 1 from is new to the Korean fauna: Keratella quadrata f. testudo. Total 135 species, 15 subspecies, 9 varieties and 10 forms representing 14 families 40 genera are now recorded from Korea by adding the 1 from newly described in the present paper.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.14 no.4
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• pp.43-52
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• 2018

This paper presents the cooling performance analysis results of a ground-source heat pump (GSHP) system using hybrid ground heat exchanger (HGHE). In this paper, the HGHE refers to the ground heat exchanger (GHE) using both a vertical GHE and a surface water heat exchanger (SWHE). In order to evaluate the system performance, we installed monitoring sensors for measuring temperatures and power consumption, and then measured operation data with 4 different load burdened ratios of the hybrid GHE, Mode 1~Mode 4. The measurement results show that the system with HGHE mainly operates in Mode 1 and Mode 2 over the entire measurement period. The average cooling coefficient of performance (COP) for heat pump unit was 5.18, while the system was 2.79. In steady state, the heat pump COP was slightly decreased with an increase of entering source temperature. In addition, the parallel use of SWHE and VGHE was beneficial to the system performance; however, further research are needed to optimize the design data for various load ratios of the HGHE.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.3 no.2
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• pp.53-65
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• 2000

The objectives of this study are to develop a stormwater management system that would contribute to improving water circulation, recycling storm water and promoting biodiversity in urban areas, to apply the system in an actual site, and to verify its effectiveness in order to generate a stormwater management system applicable in Korea. This study reviewed former researches and case studies, categorized stormwater management system into pre-treatment, retention and infiltration phases, and analyzed the strength and weakness of the techniques by synthesizing unit techniques of each stage. As a result, the process of the stormwater management system includes the following phases: 1) a rubble filtration layer; 2) a retention pond; 3) a infiltration pond; and 4) a stormwater retention pool (recirculation and recycling). Then, an empirical study to design and create the generated system according to the features of a site and to verify its effectiveness was conducted. The future study direction is to verify the effectiveness of the developed stormwater retention and infiltration ponds. To this end, it is planned to perform hydrological monitoring using automatic measuring equipment and monitoring on habitat bases and the biota living on the base. Based on its outcome, the applied model would be refined and improved to develop an alternative stormwater management system that would allow to achieve the improvement of urban water circulation, increase of biodiversity and efficient use of water resources.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.6
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• pp.24-29
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• 2002

Nitrate removal rate in three cattail wetland cells was investigated. They were a part of a pond-wetland system for stream water treatment demonstration. The system was composed of two ponds and six wetland cells. The acreage of each cell was approximately $150m^2$. The earth works for the system were finished from April 2000 to May 2000 and cattails were planted in the three cells in June 2000. Waters of Sinyang Stream flowing into Kohung Estuarine Lake were pumped into a primary pond, whose effluent was discharged into a secondary pond. The reservoir was formed by a tidal marsh reclamation project and located in southern coastal area of Korean Peninsula. Effluents from the secondary pond were funneled into the three cells. Volumes and water quality of inflow and outflow were analyzed from July 2000 through January 2001. Inflow and outflow averaged $20.2m^3/day$ and $19.8m^3/day$, respectively. Hydraulic retention time was about 1.6 days. Average influent and effluent nitrate concentration was $1.98mg/{\ell}$, $1.38mg/{\ell}$, respectively. Nitrate removal rate averaged $82.6mg\;m^{-2}\;day^{-1}$. Seasonal changes of nitrate retention rates were closely related to those of wetland cell temperatures. The average nitrate removal rate in the cells was a little lower, compared with that of $125.0mg\;m^{-2}\;day^{-1}$ for the wetlands operating in North America. This could be attributed to the initial stage of the cells and inclusion of three cold months into the seven-month study period. Root rhizosphere in wetland soils and litter-soil layers on cell bottoms could not developed. Increase of standing density of cattails within a few years will establish both root zones suitable for the nitrification of ammonia to nitrates and substrates beneficial to the denitrification of nitrates into nitrogen gases, which may lead to increase of the nitrate retention rate.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.6
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• pp.316-326
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• 2017

Commercial buildings and institutions are predominantly cooled, thereby dissipating excess heat to a vertical ground heat exchanger (VGHE), than heat extracted over an annual cycle. Surface waters, such as lakes and ponds, provide a cost-effective means of reducing the VGHE length, and in balancing the thermal loads to the ground. This paper presents the measurement and analysis of the cooling performance of ground-coupled heat pump (GCHP) system, using surface water heat exchanger (SWHE) submerged in an artificial pond. In order to measure the performance of the system, we installed monitoring equipment, including sensors, for assessing the temperature and power consumption, after which the operation parameters were determined. The results from the thermal performance test for the SWHE indicate that the temperatures at the outlet of the SWHE and within the pond were affected by outdoor air temperature. In addition, the results reveal similar variation trends on temperatures; however, the peak temperatures of the SWHE were somewhat greater than those of outdoor air, due to the thermal capacity of the pond. Analyzing the cooling performance over the measurement period, the average coefficient of performance (COP) of heat pump was found to be 5.71, while that for the entire system was 2.99.

• Korean Journal of Weed Science
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• v.11 no.1
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• pp.19-25
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• 1991

This studies were conducted to get the basic information for the control of Scirpus planiculmis F. Schmidt in polder land. S. planiculmis was found to be the dorminant species all over the polder land of southwest seashore in Korea, while S. fluviatilis A. Gray was observed alone or with S. planiculmis at pond, waterway, and riverside. The degree of appearance of S. planiculmis was gradually increased with time and showed the peak at 4th and 5th year after cultivation. The density of S. planiculmis were higher in higher salinity area than in lower area. The control of S. planiculmis has been practised by herbicides and hand weeding together.