• Journal of the Korean association of regional geographers
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• v.22 no.1
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• pp.240-250
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• 2016

Monitoring for water quantity and quality was conducted in this study for 2 years (2012~2013) in Oenam Stream which is a tributary of Seomjin River and upstream of Juam Lake. Suspended solid and total phosphorous(TP) were monitored and analyzed, then water quantity and quality as well as their relation with landuses were identified based on the previous study. Flow showed the similar pattern with precipitation but some discrepancies existed due to the distance between weather station(Gwangju) and study area. Watershed was modeled based on observed data using SWAT(Soil and Water Assessment Tool). Model calibration was conducted using data obtained in 2012 and validation was conducted using data in 2013. The coefficient of determination ($R^2$) between observed and modeled showed 0.6644 and 0.5176 for flow and TP, respectively for model calibration period. For validation period, $R^2$ was 0.7529 for flow and 0.7057 for TP, which were higher than calibration period. Hot spots were determined for watershed management by analyzing the amount of sediment and TP outcome from each sub-watershed. TP loading by landuse determined that cropland, of which the area takes only 5% from entire watershed, generated 53.6% of TP and residential and cowshed was responsible for 23.5% of TP loading.

• Journal of the Korean Geographical Society
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• v.52 no.1
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• pp.15-24
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• 2017

Management of non-point sources for water quality control practice is complicating but very important. Sediments mainly from croplands are prioritized in non-point source management due to the sediment attached phosphorous. In this study, flow and sediment yields are modeled in Oenam watershed located in Hwasun, Jeollanam-do, a upstream of Juam Lake. A spatially distributed model and GIS(Geographic Information System) data was used to find out hot spots of sediment yields, to analyze the effectiveness of filter strips, and to visualize the effectiveness. The impacts of filter strips was estimated on the reduction of flow and sediments at 17.2% and 46.4% respectively when the filter strips were installed in the sub-watersheds with the most serious sediment yields.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1234-1238
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• 2005

우리나라의 수질오염에 대한 규제는 주로 호소 및 하천의 수질을 향상시키기 위하여 하수 및 공장폐수 등 점오염원을 중심으로 관리되어 왔으나 강우와 함께 대량 유출된 비점오염원은 수용하천의 자정능력을 감소시키고 있고 이로 인해 하천과 호소의 수질은 향상되지 못하고 있다. 또한, 농촌지역에서 배출되는 비점오염원은 정확한 기작의 분석이 안 되고 있으며, 비료$\cdot$농약의 사용 증가에 따라 영양염 및 유해물질에 의한 수질오염의 영향이 증가되고 있는 실정이다. 본 연구는 농촌지역의 강우-유출로 인한 비점오염물질의 유출특성 및 배출부하량을 조사하기 위하여 영산강권역의 외남천을 대상으로 조사하였다. 대상 유역의 토지용도 구분은 (1)논지역, (2)밭지역, (3)산지지역, (4)농촌주거지역, (5)복합지역(논, 산지)으로 구분하였다. 시료의 채취는 강우시 5회에 걸쳐 조사하였으며, 2L 용량의 무균채수병에 채취한 후, 아이스박스에 $4^{\circ}C$이하로 보관하여 24시간 이내로 실험실에 운반하여 실험하였으며, 매회 시료 채취 주기는 강우유출이 발생하기 전부터 강우 종료 후 유출량 변화가 없을 때까지 $9\~12$단계로 세분하여 유출량과 pH, DO, BOD, COD, SS, T-N, T-P의 농도를 측정하였다. 본 연구에서 조사한 결과 토지이용별 비점오염원의 SMC를 살펴보면 BOD의 SMC는 $4.38\~11.02mg/{\ell}$, COD의 SMC는 $7.07\~23.99mg/{\ell}$, T-N은 $1.57\~5.20mg/{\ell}$, T-P는 $0.11\~0.274mg/{\ell}$의 범위를 갖는 것으로 나타났으며, 전반적으로 논 지역에서 비교적 높게 나타났는데 이는 농작물의 경작에 따른 시비법의 영향으로 판단된다. 또한, 비점오염원의 유출특성을 보면 전반적으로 초기 오염물질 유출특성 갖는 것으로 나타났다.

• Journal of Environmental Science International
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• v.21 no.1
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• pp.31-39
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• 2012

The objective of this study is to provide pollutant loads delivery ratio for flow duration in Oenam-cheon watershed, which is upstream watershed of Juam Lake. To calculate the delivery ratio by flow duration, rating curves and discharge-loads curves using measured data were established, then Flow Duration Curve(FDC) and pollutant loads delivery ratio curves were constructed. The results show that the delivery ratios for $BOD_5$ for abundant flow($Q_{95}$), ordinary flow($Q_{185}$), low flow($Q_{275}$), and drought flow($Q_{355}$) were 23.9, 12.7, 7.1, and 2.9%, respectively. The delivery ratios of same flow regime for T-N were 58.4, 31.2, 17.2 and 7.1%, respectively. While, the delivery ratios T-P were 17.3, 7.5, 3.4, and 1.1% respectively. In general, delivery ratio of high flow condition showed higher value due to the influence of nonpoint source pollution. Based on the study results, generalized equations were developed for delivery ratio and discharge per unit area, which could be used for ungaged watershed with similar pollution sources.

• Journal of Korean Society on Water Environment
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• v.27 no.4
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• pp.467-474
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• 2011

In an effort to investigate water pollution characteristics of Juam lake, water samples were collected from three sites (Sites A, B, and C) of Oenam stream which is a typical tributary of rural watershed in the lake and analyzed for N concentration and the corresponding isotope ratio (${\delta}^{15}N$) of ${NO_3}^-$. Concentrations of ${NO_3}^-$ were not dramatically different among the sites; $0.8{\pm}0.2mgNL^{-1}$ (range: $0.0{\sim}4.3mgNL^{-1}$) for Site A, $1.1{\pm}0.2mgNL^{-1}$ ($0.0{\sim}4.3mgNL^{-1}$) for Site B, and $1.1{\pm}0.1mgNL^{-1}$ ($0.1{\sim}2.6mgNL^{-1}$) for Site C. Meanwhile, ${\delta}^{15}N$ tended to decrease with river flow; it was highest for Site A ($45.5{\pm}5.3$‰) followed by Site B ($19.7{\pm}2.0$‰) and Site C ($8.7{\pm}1.5$‰). Such high ${\delta}^{15}N$ values of ${NO_3}^-$ in Site A suggested that ${NO_3}^-$ derived from livestock feedlot (specifically livestock excrete of which ${\delta}^{15}N$ is higher than 10‰) is the predominant pollution sources despite mountainous area occupied the most of land-use in the watershed. Using the two-sources isotope mixing model, it was estimated that the contribution of cropping activities (i.e. fertilization) became greater in down-stream area (Sites B and C) due to the higher agricultural land-use than the up-stream area (Site A). Particularly, during the active cropping season, the low contribution of organic pollution sources indicated that domestic sewage was not the predominant pollution source. Therefore, it was suggested that agricultural sources such as livestock farming and cropping rather than mountainous and residential are the dominant sources of water pollution in the study area. These results could be effectively utilized in elucidating water pollution sources in rural areas and selecting water management practices.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.4
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• pp.14-26
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• 2011

Imdaejeong Wonlim is located on the verge of Sangsa Village in Sapyeong-ri, Daepyeong-myeon, Hwasun-gun Gyeongsangnam-do toward Northwest. It was planned by Sa-ae, Minjuhyeon in 1862 on the basis of Gobanwon built by Nam Eongi in 16th century against the backdrop of Mt. Bongjeong and facing Sapyeong Stream. As water flows from west to east in the shape of crane, this area is a propitious site standing for prosperity and happiness. This area shows a distinct feature of Wonlim surrounding the Imdaejeong with multi layers as consisting of 5 districts - front yard where landmark stone with engraved letters of 'Janggujiso of Master Sa-ea' and junipers are harmoniously arranged, internal garden of upper pavilion ranging from a pavilion to square pond with a little island in the middle, Sugyeongwon of under pavilionu consisting of 2 ponds with a painting of three taoist hermits, forest of Mt. Bonggeong and external garden including Sapyeong Stream and farmland. According to documentation and the results of on-site investigation, it is certainly proved that Imdaejeong Wonlim was motivated by Byeoseo Wonlim which realized the idea of 'going back to hometown after resignation' following the motives of Janggujiso, a hideout aimed to accomplish the ideology, 'training mind and fostering innate nature,' on the peaceful site surrounded by water and mountain, as well as motives of Sesimcheo(洗心處) to be unified with morality of Mother Nature, etc. In addition, it implies various imaginary landscapes such as Pihangji, Eupcheongdang, square pond with an island and painting of three Taoist hermits based on a notion that 'the further scent flies away, the fresher it becomes,' which is originated from Aelyeonseol(愛蓮說). In terms of technique of natural landscape treatment, divers techniques are found in Imdaejeong Wonlim such as distant view of Mt. Bongjeong, pulling view with an intention of transparent beauty of moonlight, circle view of natural and cultural sceneries on every side, borrowed scenary of pastoral rural life adopted as an opposite view, looked view of Sulyundaero, over looked view of pond, static view in pavilion and paths, close view of water space such as stream and pond, mushroom-and-umbrella like view of Imdaejeong, vista of pond surrounded by willows, imaginary view of engraved letters meaning 'widen knowledge by studying objectives' and selected view to comprise sunrise and sunset at the same time. In the beginning of construction, various plants seemed to be planted, albeit different from now, such as Ginkgo biloba, Phyllostachys spp., Salix spp., Pinus densiflora, Abies holophylla, Morus bombycis, Juglans mandschurica, Paulownia coreana, Prunus mume, Nelumbo nucifera, etc. Generally, it reflected dignity of Confucianism or beared aspect of semantic landscape implying Taoist taste and idea of Phoenix wishing a prosperity in the future. Furthermore, a diversity of planting methods were pursued for such as liner planting for the periphery of pond, bosquet planting and circle planting adopted around the pavilion, spot planting using green trees, solitary planting of monumentally planted Paulownia coreana and opposite planting presenting the Abies holophylla into yin and yang.