• Environmental Engineering Research
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• 제13권2호
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• pp.69-72
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• 2008

The movement of sediments in the stream crossing a large industrial complex to the mouth of Masan Bay was monitored for eight years. Sediment samples were seasonally collected in the period of $1992{\sim}1997$ and $2001{\sim}2002$. The heavy metal content of sediment was found to be higher at dry season with the peak on February and significantly decreased at rainy season. Metals content in stream sediments were rapidly decreased by large precipitation events in rainy season because the contaminants in the upstream sediments were transported to the dredged area of Masan Bay where is a typical enclosed bay in Korea. The increasing and decreasing tendency of heavy metals in sediment was repeatedly observed for six consecutive years. The heavy metals assessment of stream sediment provide us the information about the pollutant source, transport pattern and control strategy along the industrial complex. It was strongly suggested that the transportable stream sediments of an industrial area should be controlled as one of the important strategies to restore and manage the enclosed bay. Combined wastewaters have been collected and treated in a publicly owned treatment works (POTW) after industrial wastewater treatment at each location of industries since 1994. A field study was conducted to investigate the pollutant removal efficiency and performance of contact oxidation system installed and operated in two locations in the stream. The stream sediment quality was improved since then, and as a consequence the habitat of the estuary has been restored.

• 동굴
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• 제7호
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• pp.37-39
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• 1998

The Bullock Creek Caves are located adjacent to the usually dry river bed of Bullock Creek, which reaches the sea about a kilometer north of Punakaiki. The caves have been comprehensively written up by Rodgers(l972). Under conditions of normal water flow Bullock Creek submerges where the stream meets limestone on the west side of thier Punakaiki syncline. In flood conditions it overflows the first submergence and progressively floods a series of smaller submergences down valley until it comes to the caves shown on the map. All these with the exception of Wazpretti Cave and Dry Valley Cave are probably more or less flooded during and after heavy rain.(omitted)

• 동굴
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• 제8호
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• pp.19-42
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• 1998

The Bullock Creek Caves are located adjacent to the usually dry river bed of Bullock Creek, which reaches the sea about a kilometer north of Punakaiki. The caves have been comprehensively written up by Rodgers(972). Under conditions of normal water flow Bullock Creek submerges where the stream meets limestone on the west side of their Punakaiki syncline. In flood conditions it overflows the first submergence and progressively floods a series of smaller submergences down valley until it comes to the caves shown on the map. All these with the exception of Wazpretti Cave and Dry Valley Cave are probably more or less flooded during and after heavy rain.(omitted)

• 상하수도학회지
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• 제22권1호
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• pp.39-48
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• 2008

This study was carried out to investigate the characteristics of the pollutant discharge from non-point source and to estimate the unit loads of the pollutant discharge from the upper watershed of Seomjin Dam during rainy season. The upper watershed of Seomjin Dam is located in the middle of Jeonbuk province is formed two tributaries mainly. A sub-branch stream of those tributaries is Imsil stream of which flow rate is about 13% of the main stream of Seomjin reservoir normally. On the basis of measurement result in this study, the water quality of Imsil stream was fluctuated highly and the quantity of measured pollutant discharge was higher than the value calculated with the proportion of flow rate during dry season. On the contrary, during rainy season the mean values of flow rate and water quality were higher than the quartile according to the statistical analysis. That means rainfall can influence strongly on the water quality of the upper watershed of Seomjin reservoir. Among the several criteria of water quality, SS discharge was most sensitive to the flow rate variation of stream, which was fluctuated in proportion of rainfall, basically. It was evaluated the event mean concentration (EMC) of non-point source pollutants depending on rainfall events as well. Though the pollutant discharge unit of Imsil stream was lower than the main stream of Seomjin reservoir, the EMC value of Imsil stream was higher than the main stream of Seomjin reservoir.

• 한국산림과학회지
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• 제101권4호
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• pp.574-578
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• 2012

산지소유역의 밤나무림, 소나무림, 개벌조림지를 중심으로 강우특성에 따른 임분별 탁도 변화 특성을 조사하고 탁도 발생에 영향을 미치는 산림환경 인자를 분석한 결과를 요약하면 다음과 같다. 임분별 탁도와 관련인자간의 분석에서 색도, 부유물질, 소류토사량, 경사, 강우강도, 선행무강우일수, 유역면적, 유로길이는 1%의 유의수준에서 양의 상관관계를 나타내었고, 누적강우량은 5% 유의수준에서 양의 상관관계를 나타내었다. 또한 산지계류수의 탁도발생에 영향을 미치는 인자를 분석한 결과 선행무강우일수, 강우강도, 유로길이, 색도 및 부유물질의 순으로 나타났으며, 탁도 발생에 영향을 많이 미치는 다중회귀식은 Y(탁도)=-28.125+0.047x(부유물질)+0.058x(색도)+1.518x(강우강도)+0.264x(유로길이)+1.837x(선행무강우일수)로 추정할 수 있었다. 따라서, 산림의 개발과 이용으로 인해 교란된 토양은 강우와 함께 계류로 유출되어 하류의 하천 및 호소의 수질에 영향을 미치므로 산림지역의 산지계류에서는 탁도에 영향을 주는 부유물질 및 토사유출 등을 줄일 수 있도록 버트리스 사방댐이나 수질정화용 사방댐 등 사방구조물의 설치가 필요할 것으로 보인다.

• 한국물환경학회지
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• 제25권3호
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• pp.452-458
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• 2009

This study was carried out to assess the effect of discharge loading at sewage treatment plants (STP) on water quality in Kyoungan stream. The seasonal variations of water quality (BOD, COD, SS, TN, and chl.a) at site 1(Mesanribo) were similar with those at site 2(Sehabo). BOD, COD, SS, and chl.a concentration were also similar except for TN and TP concentration which were lower than those at site 1. The BOD, COD, TN, TP and chl.a concentration at site 2 in dry period were higher than that of wet period. The ratios of BOD, TP, COD, SS discharge loading at all STP in Kyoungan stream watershed to delivery loading at site 2 were 0.69, 0.54, 0.48, 0.31, and 0.26 on average, respectively. Both site 1 and site 2, the seasonal variations of discharge loading at STP did not showed any relationship with those of water quality. The mean ratios of inflow loading at site 1 to delivery loading at site 2 were relatively high that ranged from 0.43 to 0.61. In dry period, the ratios of discharge loading at STP in Sehabo watershed to delivery loading at site 2 were below 0.2 except for BOD (0.24), and decreased <0.1 in wet period. While, SS loading from watershed between site 1 and site 2 to delivery loading at site 2 ratios increased in wet period.

• 자원환경지질
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• 제42권4호
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• pp.315-333
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• 2009

이 연구에서는 대전지역 주요 도심하천인 갑천, 유등천, 대전천을 대상으로 하천수의 수리화학적 특성과 산소, 수소, 황, 탄소 동위원소 특성을 분석하였다. 하천수 시료는 풍수기와 갈수기 2차례 채취되었다. 하천의 수리화학적 특성은 상류에서는 Ca(Mg)-$HCO_3$ 유형을 보이다가 도심권을 통과하면서 Ca(Mg)-$SO_4(Cl)$유형으로 전이되고 하류에서는 Na(Ca)-$HCO_3$(Cl, $SO_4$) 유형으로 변하였다. 이와 같은 화학적 유형의 변화는 자연적 영향뿐만 아니라 하수처리장의 방류수와 인위적 오염물질의 유입에 의한 영향이 관여된 것으로 해석된다. 전반적으로 풍수기에 비해 갈수기에 하천수의 전기전도도 값이 높은 특성을 보여준다. 갑천하류는 하수종말처리장의 방류수가 합류되면서 수질이 급격하게 변화한다. 하천수의 pH는 상류에서 중성을 보이다가 도심권을 지나면서 최고 pH 9.8의 고알카리성을 보인다. 이는 현장조사결과 아파트의 우수관을 통한 세제 유입에 기인하는 것으로 보인다. 하천수의 산소-수소 동위원소 관계식은 ${\delta}D=6.45{\delta}^{18}O-7.4$으로 Craig의 순환수선보다 다소 하향 이동되어 도시된다. 이는 기단의 변화와 하천수의 표면 증발 효과에 의한 것으로 보인다. 뿐만 아니라, 상-하류사이에 고도효과를 반영하는 동위원소 조성 값의 차이를 보여준다. 하천수의 ${\delta}^{13}C$ 값은 $-19.5{\sim}-7.8%o$ 범위로 대기중 이산화탄소와 유기물 기원의 범위에 해당된다. 전반적으로 하천수의 상류에서 하류로 향할수록 ${\delta}^{13}C$값이 높아지므로 $CO_2$의 기원이 상류에서는 주로 유기물기원에서 도심권에서는 오염된 대기와 지하수의 기저유출로 인한 무기기원의 비율이 높아지기 때문으로 해석된다. ${\delta}^{34}S-SO_4$함량 관계도에서 하천수를 4개 그룹(갑천중 상류, 유등천, 대전천, 갑천하류)으로 구분하였다. 황산염의 농도는 갑천중상류<유등천<대전천<갑천하류의 순서로 높아지는 반면 ${\delta}^{34}S$값은 감소하는 경향을 보인다. 이는 하천별 황산염의 증가에 따른 공급원이 다르다는 것을 의미한다. 하천수내 황의 기원은 대기기원을 중심으로 황산염의 농도가 높아질수록 황철석의 영향이 큰 것으로 해석된다. 그러나 하천수에 유입되는 생활하수 등에 대한 황동위원소 자료가 없으므로 이에 대한 영향에 대해서는 향후 연구되어야할 과제이다.

• 한국지구과학회지
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• 제44권4호
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• pp.291-306
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• 2023

Shallow groundwater in rural areas is primarily polluted by agricultural activities. Nitrate-nitrogen is an indicator of artificial pollution. In this study, the hydrochemical characteristics and nitrate-nitrogen pollution of shallow groundwater were examined in two agricultural villages (Hyogyo-ri and Sinan-ri) in Chungcheongnam-do Province, Korea. Physicochemical quality analysis of shallow groundwater and stream water in the field, and chemical analysis in the laboratory were conducted from July 2020 to October 2021. In Hygyo-ri and Sinan-ri villages, shallow groundwater mainly belonged to the Ca-Cl, Ca-H CO₃, Na-HCO₃, and Na-Cl types, whereas stream water predominantly belonged to the Ca-HCO₃ type. The nitrate-nitrogen concentration in shallow groundwater varied depending on the season, displaying an increased concentration of nitrate-nitrogen in the dry season compared to the rainy season. Stream water may be influenced by runoff into villages from the surrounding area, although both shallow groundwater and stream water are affected by artificial pollution. In addition, the nitrate-nitrogen concentration in stream water was lower than that in shallow groundwater.

• 한국조경학회지
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• 제34권3호
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• pp.1-11
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• 2006

This study analyzed characteristics of natural and human environments in Chuncheon's Gongji stream, and suggested nature-friendly planning strategies for self-purification of water quality, biodiversity improvement and conservative waterfront recreation. The environmental analysis included streambed structures, floodplain soils, water quality, vegetation, wildlife, and human facilities. Natural colonization of vegetation for the middle section of the study stream was obstructed by a straightened concrete revetment of baseflow channel, and vehicle movement and concrete parking lots across the floodplain. These human disturbances also deteriorated the naturalness of the stream landscape and limited habitation of bird species. However, natural sedimented wetlands in half of the channel width for the lower section of the stream contributed to a desirable vegetational landscape and greater bird occurrence. Based on BOD measurements, water quality of the stream fell under class $II{\sim}III$ of the stream water-quality standard, but it was worse around sewage outlets due to incomplete sewage collection especially during the dry season. Dominant fish species included typical inhabitants of good water-quality streams that are tolerant of adverse habitat changes. Nature-friendly planning strategies were established based on analysis of the environmental characteristics. They focused on not merely spatial zoning and layout divided into four zones - preservation, partial preservation, conservation and use -, but close-to-nature channel revetment techniques, natural water-purification facilities, biotope diversification, and water-friendly recreation and circulation. Strategies pursued both renewal of stream naturalness and hydraulic stability of streamflow by minimizing transformation of natural channel micro-topography and biotope, and by reflecting natural traces of streambed structures such as revetment scour and sedimentation.

• 한국환경과학회지
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• 제22권5호
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• pp.571-580
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• 2013

In this study, compared with the result of water surface elevation and water velocity on the establishment of river maintenance basic plan and result of HEC-GeoRAS based GIS, and after use the result of water surface elevation and velocity were observed in the Han stream on Jeju island, analysis 2 dimensional stream flow. the lateral hydraulic characteristics and curved channel of the stream were analyzed by applying SMS-RMA2 a 2 dimensional model. The results of the analysis using HEC-RAS model and HEC-GeoRAS model indicated that the distribution ranges of water surface elevation and water velocity were similar, but the water surface elevation by section showed a difference of 0.7~2.18 EL.m and 0.63~1.16 EL.m respectively, and water velocity also showed differences of maximum 1.58m/sec and 2.67m/sec. SMS-RMA2 analysis was done with the sphere of Muifa the typhoon as a boundary condition, and as a result, water velocity distribution was found to be 1.19 through 3.91 m/sec, and the difference of lateral water velocity in No. 97 through 99 the curved channel of the stream was analyzed to be 1.59 through 2.36 m/sec. In conclusion it is anticipated that the flow analysis of 2 dimension model of stream can reflect the hydraulic characteristics of the stream curved channel or width and shape, and can be applied effectively in the establishment of river maintenance basic plan or management and designing of stream.