• Journal of Wetlands Research
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• v.16 no.3
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• pp.431-440
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• 2014

To propose the improvement and management plans to strengthen the pollutant removal efficiency of dam reservoir's constructed wetlands(CWs), the operation status and configuration of CWs (including water depth, operational flow, water flow distribution, residence time, and pollutant removal efficiency, aspect ratio, open water/vegetation ratio etc.) were analyzed in 10 major wetlands constructed in dam reservoirs. The pollutant concentrations in the inflows of the studied CWs were lower than those of American and European constructed wetlands. Especially, organic matter concentrations in all of inflows were below 3 mg/L(as BOD) due to advanced treatment of sewage disposal plant and an intake of low concentration water during dry and normal seasons. The average removal efficiency of total nitrogen(TN) and total phosphorus(TP) for 10 CWs ranged from 7.6~67.6%(mean 24.9%) and -4.9~74.5%(mean 23.7%), respectively, showing high in wetlands treating municipal wastewater. On the other hand, the removal efficiency of BOD was generally low or negative with ranging from -133.3 to 41.7%. From the analysis of the operation status and configuration of CWs, it is suggested that the low removal efficiency of dam reservoir's CWs were caused by both structural (inappropriate aspect ratio, excessive open water area) and operational (neglecting water-level management, lack of facilities and operation for first flush treatment, lake of monitoring during rainy events) problems. Therefore, to enable to play a role as a reduction facility of non-point source(NPS) pollutants, an appropriate design and operation manuals for dam reservoir's CW is urgently needed. In addition, the monitoring during rainy events, when NPS runoff occur, must be included in operation manual of CW, and then the data obtained from the monitoring is considered in estimation of the pollutant removal efficiency by dam reservoir's CW.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.893-900
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• 2009

To estimate the contribution of epiphytic algae attached on reed to organic matter production in constructed wetland, primary productivity by epiphytic algae was investigated in two sub-wetlands (Banweol and Donhwa wetlands) of the Sihwa Constructed Wetland (CW) with different chemistry of inflows. Chlorophyll a concentration of epiphytic algae was higher in the Banweol wetland (range:37~3,581 mgChl.a/$m^2$surface stem, average:655 mgChl.a/$m^2$surface stem) than the Donhwa wetland (range:87~2,093 mgChl.a/$m^2$surface stem, average:527 mgChl.a/$m^2$surface stem). In contrast, assimilation number (AN) representing photosynthetic activity was higher in the Donhwa wetland with low TN/TP ratio than the Banweol wetland. A negative correlation (r=0.46) was observed between TN/TP ratios of inflows and AN in two wetlands, implying that high photosynthetic activity of epiphytic algae may be related with low TN/TP ratio. The areal primary productivity ranged from 307 to 2,473 mgC/$m^2$/day in the Banweol wetland and from 756 to 2,096 mgC/$m^2$/day in the Donghwa wetland, showing high productivity in summer. Average primary production was lower in the Banweol wetland (1,166 mgC/$m^2$/day) than the Donghwa wetland (1,467 mgC/$m^2$/day), although the standing crop (as chlorophyll a concentration) was high in the Banweol wetland. This result may be due to the low photosynthetic activity of epiphytic algae in the Banweol wetland with high TN/TP ratio. The annual primary production (300 tonC/year) of epiphytic algae contributed 33% of the total production in the Sihwa CW. An excessive organic matter production in constructed wetland can negatively affect the efficiency of water treatment. Therefore, the role of epiphytic algae should be considered in management of constructed wetland for water treatment.

• Geophysics and Geophysical Exploration
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• v.8 no.1
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• pp.50-58
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• 2005

Recently, the imaging of geological structures beneath water-covered areas has been in great demand because of numerous tunnel and bridge construction projects on river or lake sites. An electrical resistivity survey can be effective in such a situation because it provides a subsurface image of faults or weak zones beneath the water layer. Even though conventional resistivity surveys in water-covered areas, in which electrodes are installed on the water bottom, do give high-resolution subsurface images, much time and effort is required to install electrodes. Therefore, an easier and more convenient method is sought to find the strike direction of the main zones of weakness, especially for reconnaissance surveys. In this paper, we investigate the applicability of the streamer resistivity survey method, which uses electrodes in a streamer cable towed by ship or boat, for delineating a fault zone. We do this through numerical experiments with models of water-covered areas. We demonstrate that the fault zone can be imaged, not only by installing electrodes on the water bottom, but also by using floating electrodes, when the depth of water is less than twice the electrode spacing. In addition, we compare the signal-to-noise ratio and resolving power of four kinds of electrode arrays that can be adapted to the streamer resistivity method. Following this numerical study, we carried out both conventional and streamer resistivity surveys for the planned tunnel construction site located at the Han River in Seoul, Korea. To obtain high-resolution resistivity images we used the conventional method, and installed electrodes on the water bottom along the planned route of the tunnel beneath the river. Applying a two-dimensional inversion scheme to the measured data, we found three distinctive low-resistivity anomalies, which we interpreted as associated with fault zones. To determine the strike direction of these three fault zones, we used the quick and convenient streamer resistivity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.310-313
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• 2012

Recently, Land reclamation created agricultural land which is farming. Agricultural land which is farming have accident with frequency it is damage to crop of from brine. So, desalinization is the first priority prerequisite task in using the in reclaimed farm land. Vibrant research and technical development is working for reclaimed of desaliaization. But, Current technology is impossible desalinization of reclaimed land. As fast almost of people don't worry about concentration of salt in using the land reclamation of agricultural land irrigation water and river mouth of fountainhead of efforting from freshwater lake also ebb and flow of the tide land reclamation of agricultural land influnce from an increase of salt concentration by weather conditions and a malfunction of sea dike sluice In this paper, current is increased salt concentration in real time graphs were implemented to utilize external servers in using the WCDMA module. Inaddition it have to operate alarm in increase of salt concentration. besides, this program have implemented realtime concentration of salt monitoring system which save date in realtime the user can check again.

• Spatial Information Research
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• v.4 no.1
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• pp.1-11
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• 1996

DRASTIC system developed by U.S.EPA, is widely used for assessing groundwater pollution potential The system can be applied to site selection of well or waste disposal, Ianduse planning for groundwater protection, and monitoring. In this study, GIS(Geographic Information System) was established hydrogeological database of DRASTIC system and cartographic modeling to asre:; regional groundwater pollution potential around Chungju Lake. Hydrogeological factors of the system were depth to water, net recharge, aquifer media, soil media, slope and hydraulic conductivity. Risk of groundwater pollution to non -point source pollution, was also analyzed by incorporation of actual pollution sources(N, P) and DRASTIC system. The GIS data could be very quickly analysed hydrogeological characteristics of the study area by graphic user interface programs devel¬oped with AML(ARC Macro Language) of ARC/INFO.

• Journal of Forest and Environmental Science
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• v.29 no.1
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• pp.15-28
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• 2013

Protected area based ecotourism is now the most interesting topic to the nature lover and policy maker throughout the world because of its linkage with economic benefits, protected area management and biodiversity conservation. Based on this premise our study explores the visitors' perception on the recreational potential of Kaptai National park and its potentiality in ecotourism development in Bangladesh. The field survey was carried out both in holidays and non-holidays of the week from the late winter season in 2009 to the spring season in 2010. A total of 118 visitors were interviewed with the help of a semi-structured questionnaire. Study findings revealed that about 62% male constitute the visitors group with the maximum number of visitors in the age of between 15-25 years (35.59%). The tourists were very much attracted by boat riding (93.22%) followed by scenic beauty of Rampahar-Sitapahar (85.59%). A major portion of about 57.14% tourists wished to visit the park within a year because they got a lot of pleasure from Natural and green environment (86.44%) followed by boating on Kaptai Lake (85.59%). Most of the visitors (36%) were happy about existing facilities but defined some problems such as tour guiding facility, food and drinking water supply, etc. About 71% and 66% respondents perceived that Kaptai National Park made them to be concerned and protective of nature and supports and sustains local ecosystem respectively and 43% respondents agreed that Kaptai National Park ensures the social equity and involve local people in ecotourism which are the most important elements of sustainable ecotourism. The present study results also predict that the park might be a good recreational area for enjoying with family members and group of friends through proper management and promoting the relationships among tourism, local people and biodiversity conservation.

• Analytical Science and Technology
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• v.14 no.2
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• pp.173-179
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• 2001

The study was carried out to analyze the pollutant Fe, Cu, Cr, Zn, Cd for sediments collected from lake in K river basin. Three analytical methods currently used in Korea, Japan, U.S.A, were compared. Pretreatment using microwave digestion showed higher analytical results for Fe, Cu, Cr, Zn, Cd than Korean Official Method(KOM) and American Toxicity Characteristic Leaching Procedure(TCLP) Method. Also, analytical results using microwave digestion, TCLP and KOM were as follows: 38.1-48.0 mgFe/kg, 10.2-15.9 mgFe/kg AND 3.5-12.6 mgFe/kg, 37.0-50.1 mgCu/kg, 0.06-0.24 mgCu/kg and 0.01-0.03 mgCu/kg, 137.0-152.0 mgZn/kg, 0.67-0.82 mgZn/kg and 0.3-0.5 mgZn/kg, respectively. From this result, a new analytical method for the determination of heavy metal in sediment should be developed for the accurate estimation of pollution degree in sediment.

• Parasites, Hosts and Diseases
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• v.56 no.5
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• pp.509-513
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• 2018

Present study was performed to survey infection status of digenetic trematode metacercariae in 2 alien fish species, Micropterus salmoides (largemouth bass) and Lepomis macrochirus (bluegill), in 2 rivers draining Chungcheongbuk-do, Republic of Korea. A total of 107 largemouth bass and 244 bluegills were caught in Daecheong-ho (ho=lake) and Musim-cheon (a branch of Geum-gang), in Chungcheongbuk-do April-July 2015. Additionally, 68 native fish of 5 species, i.e., Zacco platypus, Hemibarbus longirostris, Carassius auratus, Pseudogobio esocinus and Puntungia herzi, were caught from the same water bodies. All of the fish collected were examined by artificial digestion method. The metacercariae of Centrocestus armatus, Clinostomum complanatum, Metagonimus sp. and Diplostomum spp. were detected from 4 out of 5 native fish species in Daecheong-ho. However, any metacercariae were not found from 87 M. salmoides and 177 L. macrochirus in Daecheong-ho. In Musim-cheon, metacercariae of Exorchis oviformis and Metacercaria hasegawai were detected from 78% Z. platypus and 34% L. macrochirus, but any metacercariae not found in M. salmoides. We report here that the 2 alien fish species were less infected with the metacercariae than the native ones. Surveys on the metacercariae in the alien fish species in geographically various rivers should be undertaken for better understanding on the role of alien fish species in the trematode infections in Republic of Korea.

• Journal of Environmental Health Sciences
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• v.23 no.1
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• pp.18-27
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• 1997

The isolation, morphological study and growth characteristics of the algae were investigated from Lake Chuam. The isolated algae were applied the Agal Growth Potential test. The method of isolation and purification of the algae were used to Agar plating(AP), nutrient enrichment(NE), dilution(DI) and micro capillary technique(MC). Total isolated algae were 21 species. They were composed of Cyanophyceae, Dinophyceae, Bacillariophyceae, Euglenophyceae and Chlorophyceae. The numbers of algal strain by isolation technique were highest in dilution(21 species), and those of the rests were showed in order of NE > MC > AP. The sizes of isolated Selenastrum and Scenedesmus were $1.8\pm 1.4 \mu m$, $3.3\pm 0.9 \mu m$ in diameter and $6.4\pm 2.3 \mu m$, $13.6\pm 1.9 \mu m$ in length respectively. The morphology of isolated algae and NIES-collection strain was very similar each other, but the size was smaller isolated algae than that of NIES-collection. The optimum culture condition of isolated Selenastrum and Scenedesmus was about 30$\circ$C(25$\circ$C-35$\circ$C) in temperature and the maximum growth was appeared between 7,000 lux and 8,000 lux in the light intensity. The comparison of $\mu$(specific growth rate) on the concentration of nutrients such as nitrate and phosphate, isolated Selenastrum was appeared maximum it at 1.0 mg $NO_3-N/l$ but NIES-collection strain was showed 95% of maximum it at same nitrate concentration. Maximum g of isolated algae and NIES-collection strain in Scenedesmus onto nitrate concentration were very similar with the result of selenastrum. The specific growth rates of isolated algae and NIES-collection strain on the gradient concentration of phosphate were showed 0.72/day and 0.70/day at 0.02 mg $PO_4-P/l$ in Selenastrum but those of Scenedesmus were appeared 0.61/day and 0.57/day at same concentration $PO_4-P$.

• Ocean and Polar Research
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• v.30 no.4
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• pp.475-484
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• 2008

The word 'Saemangeum' indicates an estuarine tidal flat in the southwestern part of the Korean peninsula. The Saemangeum Reclamation Project was launched as a national project in 1991 to reclaim a large coastal area of $401\;km^2$ by constructing a 33-km long dyke. The final dyke enclosure in April 2006 has transformed the tidal flat into lake and land. An integrated oceanographic study has been conducted since 2002 as a part of the Government Action Plan to monitor and assess changes in the marine environment. Prior to the dyke enclosure, the coastal environment in the Saemangeum was a complex system governed by tidal motion, estuarine processes, and coastal circulation of the Yellow Sea. The dyke construction has radically changed not only the estuarine tidal system inside the dyke, but also the coastal marine environment outside the dyke. Post to the dyke enclosure, subsequent changes such as red tide, hypoxia, and coastal erosion/deposition occur successively. Red tides appear almost the year round in the inner area. Even under the condition that the sluice gates are fully open, the water quality does not improve as much as the developers would expect, mainly due to the critical reduction of the hydrodynamic stirring power. We will introduce details of our monitoring program and significant changes in the Saemangeum marine environment, based on observations and model results.