• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2003.10a
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• pp.105-126
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• 2003

In Korea most of annual rainfall is concentrated in several episodic heavy rains during the season of summer monsoon and typhoon. Because of uneven rainfall distribution many dams have been constructed in order to secure water supply in dry seasons. The Han River system has the most dams among Korean rivers, and the river is a series of dams now. Reservoirs need different strategy of water quality control from river water. Autochthonous organic matter and phosphorus should be the major target to be controlled in lakes. In this Paper some problems are discussed that makes efforts of water quality improvement ineffective in lakes of Korea, even after the substantial investment to wastewater treatment facilities.1) Phosphorus is the key factor controlling eutrophication of lakes and the reduction ofphosphors should be the major target of water treatment. However, water quality management strategy in Korea is still stream-oriented, and focused on BOD removal from sewage. Phosphorus removal efficiency remains as low as 10-30%, because biological treatment is adopted for both secondary treatment and advanced treatment. The standard for TP concentration of the sewage treatment plant effluent is 6 mgP/l in most of regions, and 2 mg/l in enforced region near metropolitan water intake point. TP in the effluents of sewage treatment plants are usually 1-2 mg/1, and most of plants meet the effluent regulation without a further phosphorus removal process. The generous TP standard for effluents discourages further efforts to improve phosphorus removal efficiency of sewage treatment. Considering that TP standard for the effluent is below 0.1 mg/l in some countries, it should be amended to below 0.1 mg/l in Korea, especially in the watershed of large lakes.2) Urban runoff and combined sewer overflow are not treated, even though their total loading into lakes can be comparable to municipal sewage discharges on dry days. Chemical coagulation and rapid settling might be the solution to urban runoff in regard of intermittent operation on only rainy days.3) Aggregated precipitation in Korea that is concentrated on several episodic heavyrains per year causes a large amount of nonpoint source pollution loading into lakes. It makes the treatment of nonpoint source discharge by methods of other countries of even rain pattern, such as retention pond or artificial wetland, impractical in Korea.4) The application rate of fertilizers in Korea is ten times as high as the average ofOECD countries. The total manure discharge from animal farming is thought to be over the capacity of soil treatment in Korea. Even though large portion of manure is composted for organic fertilizer, a lot of nutrients and organic matter emanates from organic compost. The reduction of application rate and discharge rate of phosphorus from agricultural fields should be encouraged by incentives and regulations.5) There is a lot of vegetable fields with high slopes in the upstream region of the HanRiver. Soil erosion is severe due to high slopes, and fertilizer is discharged in the form of adsorbed phosphorus on clay surface. The reduction of soil erosion in the upland area should be the major preventive policy for eutrophication. Uplands of high slope must be recovered to forest, and eroded gullies should be reformed into grass-buffered natural streams which are wider and resistant to bank erosion.

• Journal of the Korean Geographical Society
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• v.39 no.2
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• pp.229-240
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• 2004

This article aimed to suggest a program for environmental protection and sustainable development in southwest Primorskii Krai of the Russian federation by analysis of Natural conditions, natural resources and current economic activities. Issues relating to protecting unique biodiversity toward economic development are examined. Special attention is given to functional zoning of the Russian part of lower Tumen River drainage. Functional zoning is key to protecting the unique biodiversity found in wet and marshlands of the lower Tumen River. Recommendations for acceptable economic activity are provided. The major components for a Sustainable Development Program in this area are: to define economically effective and ecologically acceptable types of regional activity (aquaculture; deer farming; recreation) and effective forms of territorial organization; to determine the restrictions on regional industrial and economic development; to organize rational regional land use by carrying out functional zoning and by coordinating this activity with all land users, including restructuring existing protected territories into a single system and include it into an international biospheric network.

• Journal of Korea Water Resources Association
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• v.43 no.5
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• pp.455-469
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• 2010

Changes of geomorphology in alluvial river and vegetation recruitment on its floodplain downstream from dams are investigated both qualitatively and quantitatively focusing on the downstream of Andong dam and Imha dam on the Nakdong River. Results of the analyses of river morphology and bed material in the study site show a general trend of riverbed degradation with a max scour of 3 m and bed material coarsening from pre-dam value of 1.5 mm in D50 to post-dam value of 2.5 mm. Decrease in bed shear stress due to the decrease in flood discharge have caused vegetation recruitment on the once-naked sandbars. As result, the ratio of area of vegetated bars over total area of bars has drastically changed from only 7% in 1971 before the Andong dam (constructed in 1976) to 25% after it, and increased to 43% only three year after the Imha dam (constructed in 1992) and eventually to 74% by 2005. Analysis of the vegetation succession at Wicjeol subreach, one of the three subreaches selected in this study for detailed investigation, has clearly shown a succession of vegetation on once-naked sand bars to a pioneering stage, reed and grass stage, willow shrub and eventually to willow tree stages. At the second subreach selected, two large point bars in front of Hahoe Village seem to have maintained their sand surfaces without a signifiant vegetation recruitment until 2005. The sand bars, however, seem to have been invaded by vegetation recently, which warns river managers to have a countermeasure to protect the sand bars from vegetation invasion in order to conserve them for the historical village of Hahoe. On the other hand, recruitment and establishment of vegetation on the sand bars by artificial disturbance of the river, such as damming, can create an unique habitat of backmarsh in the sandy river, as shown in the case of Gudam Wetland, and may increase the biodiversity as compared with relatively monotonous sand bars. Last, the premise in this study that decrease in flood discharge due to upstream dams and decrease in bed shear stress can induce vegetation recruitment on the naked sand bars in the river has been verified with the analyses of the distribution of dimensionless bed shear stress along the selected cross section in each subreach.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.2132-2137
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• 2009

갈대(Phragmites communis Trin.)란 염분이 있는 곳에서 자라는 염생식물로서 우리나라 전역에 분포하고 있다. 지난 50년 동안 우리나라의 여러 습지에 걸쳐서 갈대는 우점종으로 자라왔고, 육지와 수중서식지에서 갈대의 확산범위는 증가하고 있다. 갈대의 확산은 다른 습지 식물의 서식지를 파괴하고, 갈대가 번식하면 동 식물들의 번식 자체가 어려울 뿐 아니라 갈대숲에 포식자가 늘어나 살아가기 어려운 환경으로 변하기때문에 갈대를 체계적으로 관리할 수 있는 방안이 마련되어야 한다. 본 연구는 우점종이 다른 두 습지에서 갈대군집의 성장률을 관찰하고, 토양의 화학적 분석과 식물의 생리적 분석을 통해 갈대군집 성장에 미치는 영양염류의 영향을 규명하였다. 연구 대상지는 한강하구에 위치한 장항습지와 성동습지로서 동일하게 갈대가 분포하며, 장항습지에는 줄 군락이 성동습지에는 새섬매자기 군락이 우점하고 있다. 분석 항목은 이화학적 항목을 비롯하여 용존유기탄소(DOC, dissolved organic carbon), 체외미생물효소활성도(Extracellular enzyme activities), 암모니아성 질소($NH_4^+$), 질산성 질소($NO_3^-$)을 분석하였다. 실험결과, 두 습지 갈대의 성장은 7월부터 9월에 증가하였고 성동습지의 토양성분이 점토질로 형성되어 높은 수분함량과 유기물함량을 유지하고 있기 때문에 갈대의 밀도가 높고 성장률이 활발한 것으로 나타났다. 또한 미생물활성과 환경인자간 양의 상관관계를 보아 환경인자들이 미생물 활성을 자극하고 미생물들은 식물의 성장을 촉진하여 영향을 주며, 반면 식물 뿌리는 enzyme을 생성하는 미생물에게 C 삼출물을 공급해 enzyme 활성에 영향을 미칠 것으로 사료된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1957-1961
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• 2008

대전광역시는 대전시의 3대 하천 살리기 사업 중 하나로 갑천을 2009년까지 수영이 가능한 하천으로 개선하는 '갑천 수질개선 기본계획'을 추진하고 있다. 이러한 계획이 성공적으로 수행되기 위해서는 오염물질을 포함하는 지류의 수질을 개선하는 것이 우선되어야 한다. 대전의 탄동천은 상류에 군부대 시설이 밀집해 있고 하수처리장이 운영되고 있는 관계로 하천 수질은 일반적인 하천에 비하여 높은 오염도를 나태내고 있다. 또한 중류지역의 주거시설에서 하수시스템으로 완벽하게 연결되지 못한 부분에서 오염물질이 유출되는 것으로 추정되며, 연구단지등에서 강우시 유출되는 비점오염물질 등이 하천의 수질에 영향을 미치고 있다. 본 연구에서는 탄동천의 상류 자운동의 자운1교부터 갑천과 합류되기 전의 국립중앙과학관 앞까지의 7.4km 구간의 6개 지점과 하수처리장 방류수, 우수 관거 및 지류인 삼성천 등 6개 점오염원 지점의 총 12개 지점에 대하여 현장조사 및 수질측정 을 진행하였다. 본 연구에서는 하수처리장으로 더 이상 제어하기 어려운 오염물질 농도를 추가로 저감하기 위하여 지표형 인공습지 운영 및 설계방안을 연구하였다. 인공습지를 합리적으로 설계하는 경우 결과 탄동천의 수질을 개선할 수 있을 뿐만 아니라 하천 환경을 개선하고 경관을 개선하는 효과가 있을 것으로 기대되며 도시형 소하천들의 수질 개선에 긍정적인 영향을 미칠 것으로 기대된다.

• Journal of Environmental Science International
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• v.28 no.12
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• pp.1123-1131
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• 2019

In this study, we investigated the spatial range, distribution pattern, temporal appearance, sex ratio, seasonal pattern, and size of the population of Leptalina unicolor locally inhabiting the wetland protection area in the Jaeyaksan Mountain. We found that the butterfly was distributed across four areas at 750 m above sea level and in an area of 96,000 ㎡. in the southeastern slope of the mountain. The discontinuous distribution of the butterflies in the meadow. According to our survey conducted from 2012 to 2014, L. unicolor occurred in May (spring) and July (summer) each year, with the male population more than three times higher than that of the female population. The population size estimated using the mark and recapture method on the back of the hind wing in the two years was as follows: 877±502 and 1243±800 individuals in the spring and summer of 2012, respectively, and 783±429 and 506±365 individuals in the spring and summer of 2014, respectively, suggesting no specific seasonal pattern. The findings of this study are expected to be useful for the conservation of the populations and habitats of L. unicolor, which are currently distributed locally due to a decrease in population size.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.2
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• pp.85-102
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• 2012

The purpose of this study is to offer the raw data for conserving the biodiversity of urban ecosystem by objective surveying and analysing the vascular plants distributed in major sites of Yangsan-si, Gyeongsangnam-do. The results are as follows. The numbers of vascular plants were summarized as 522 taxa including 110 families, 314 genera, 459 species, 4 subspecies, 46 varieties and 13 forms. The rare plants were 5 taxa including Aristolochia contorta, Drosera rotundifolia, Potentilla discolor, Viola albida and Hydrocharis dubia. The endemic plants were 13 taxa including Salix koriyanagi, Carpinus laxiflora, Stewartia pseudocamellia, Weigela subsessilis and so forth. The specific plants by floristic region were 30 taxa including Caltha palustris, Caryopteris incana, Ilex macropoda, Monochoria korsakowii and so forth. The naturalized plants were 44 taxa including Phytolacca americana, Lepidium virginicum, Solanum americanum, Aster subulatus var. sandwicensis, Panicum dichotomiflorum and so forth. The invasive alien plants were 5 taxa including Sicyos angulatus, Ambrosia artemisiifolia, Ambrosia trifida, Aster pilosus and Paspalum distichum.

• Journal of Wetlands Research
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• v.4 no.2
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• pp.1-11
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• 2002

The morphology, seed germination, and life history of Salix nipponica were investigated in the wetland of the Nam-River, Jinju, Gyeongsangnam-do, Korea from 2000 to 2001 to provide the basic data necessary for riverine ecosystem restoration through understanding the growth characteristics of Salix nipponica. Salix nipponica had stomata on only lower side and stomata type was paracytic. Salix nipponica produced many small and light seeds. The seed number per mature ament was 1599.4, seed mass of 0.04 mg, and fertilization rate of 66.1%. Seed germination was little affected by light. Germination rate was high and mean germination time was short Under flooding condition, seeds were germinated normally and were viable after as much as 14 days of flooding. But there were no differences under various water depths on germination rates. Tree age was closely correlated with more stem diameter than tree height and there was no difference of growth rate between male and female tree. Growth rate was most rapid for 2 to 3 years after germination, and length growth was almost stopped for more than 11 years even though mass growth was done. Besides even a second-year indivisual was flowered.

• Korean Journal of Ecology and Environment
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• v.43 no.1
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• pp.44-54
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• 2010

In this study, a comprehensive exploration and evaluation of washland candidate locations by means of field monitoring as well as spatial analysis in six major river system (Han, Nakdong, Nam, Geum, Youngsan, and Seomjin Rivers). Washland(in other words, river detention basin) is an artificial wetland system which is connected to streams or rivers likely to riverine wetlands. Major purpose of washland creation is to control floodings, water supply and purification, providence of eco-cultural space to human and natural populations. Characteristics and functions of riverine wetlands can be expected as well, thus it is believed to be an efficient multi-purpose water body that is artificially created, in terms of hydrology and ecology. Geographical information and field monitoring results for the washland candidate locations were evaluated in 2009, with respect to optimal location exploration, ecosystem connectivity and educational-cultural circumstances. A total of $269\;km^2$ washland candidate locations were found from spatial analysis (main channel of Rivers South Han, 71.5; Nakdong 54.1; Nam, 2.3; Geum, 79.0; Youngsan 46.4; Seomjin 15.7), and they tended to be distributed in mid- to lower part of the rivers to which tributaries are confluent. Field monitoring at 106 sites revealed that some sites located in the Rivers Nam and Geum is appropriate for restoration or artificial creation as riverine wetlands. Several sites in the Nakdong and Seomjin Rivers were close to riverine wetlands (e.g., Upo), habitats of endangered species (e.g., otters), or adjacent to educational facility (e.g., museums) or cultural heritages (e.g., temples). Those sites can be utilized in hydrological, ecological, educational, and cultural ways when evidence of detailed hydrological evaluation is provided. In conclusion, determination of washland locations in the major river basins has to consider habitat expansion as well as hydrological function (i.e. flood control) basically, and further utility (e.g. educational function) will increase the values of washland establishment.

• Korean Journal of Ecology and Environment
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• v.39 no.4 s.118
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• pp.498-507
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• 2006

The main objective of present study was to evaluate how seasonal rainfall influenced natural habitat conditions of 10 metric habitat variables along with ionic conditions and suspended solids in the Woopo Wetland during August 2002-July 2003. Largest spatial variabilities in total suspended solids (TSS) occurred during the summer monsoon and the inorganic suspended solids (ISS), expressed as a inorganic proportion of total solids, showed linearly increasing trend from the upstream to downstream. This phenomenon was mainly attributed to counter flow of turbid water from the main Nakdong-River. During the flooding, ISS : TSS ratio showed large increases (92%) in the downstream than the upstream (43%). For this reason, transparency declined (mean=0.13 m, range=0.08-0.21 m) largely in the downstream reach and thus, chlorophyll-a concentration showed low values (range: $4.2-8.6\;{\mu}g\;L^{-1}$), indicating a direct influence on primary productivity or algal growth by inorganic turbidity. In the 2nd survey, ISS averaged 4.0 mg $L^{-1}$ (3.3-4.8 mg $L^{-1}$), thus the ISS decreased by 14 fold, compared to the ISS in the 1st survey during the flooding, while organic suspended solids (OSS) values were greater than those of ISS, indicating a dominance of organic solids. This condition was similar to solid contents in the 3rd survey, but showed a large difference compared to the 4th survey during the growing season. Habitat health assessments, based on 10 metric habitat variables, showed that QHEI values were greatest in the growing season (May) than any other seasons and largest spatial variations occurred in the 2nd survey. Overall, dataset suggest that seasonal episodic flooding during the monsoon may largely contribute nutrient cycling and sediment contents in the Woopo Wetland and Topyung Stream.