• 제목/요약/키워드: near stream

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Estimating Groundwater Recharge using the Water-Table Fluctuation Method: Effect of Stream-aquifer Interactions (지하수위 변동법에 의한 함양량 산정: 하천-대수층 상호작용의 영향)

  • Koo, Min-Ho;Kim, Tae-Keun;Kim, Sung-Soo;Chung, Sung-Rae;Kang, In-Oak;Lee, Chan-Jin;Kim, Yongcheol
    • Journal of Soil and Groundwater Environment
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    • v.18 no.5
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    • pp.65-76
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    • 2013
  • The water-table fluctuation (WTF) method has been often used for estimating groundwater recharge by analysis of waterlevel measurements in observation wells. An important assumption inherent in the method is that the water level rise is solely caused by precipitation recharge. For the observation wells located near a stream, however, the water-level can be highly affected by the stream level fluctuations as well as precipitation recharge. Therefore, in applying the WTF method, there should be consideration regarding the effect of stream-aquifer interactions. Analysis of water-level hydrographs from the National Groundwater Monitoring Wells of Korea showed that they could be classified into three different types depending on their responses to either precipitation recharge or stream level fluctuations. A simple groundwater flow model was used to analyze the errors of the WTF method, which were associated with stream-aquifer interactions. Not surprisingly, the model showed that the WTF method could greatly overestimate recharge, when it was used for the observation wells of which the water-level was affected by streams. Therefore, in Korea, where most groundwater hydrographs are acquired from wells nearby a stream, more caution is demanded in applying the WTF method.

Hydrochemical Effects of Tributaries and Discharged Waters in the Yangjae Stream Flowing Peri-urban Area (하천유지용수와 지천 유입에 따른 도시하천 양재천의 수리화학적 변화 연구)

  • Kim, Youn-Tae;Chung, Euijin;Park, Jonghoon;Woo, Nam C.
    • Journal of Korean Society on Water Environment
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    • v.34 no.6
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    • pp.678-687
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    • 2018
  • The purpose of this study was to understand the unique and complicated feature of urban stream receiving various inflows. The Yangjae stream, the second tier of the Han River, runs through the southern parts of Seoul, Korea and its middle part flows on the boundary of Seoul where land use is actively changing. Stream flow was greatly influenced by rainfall. Other than rainfall events, effluent discharge from wastewater treatment plant (WWTP) comprised 51 % of stream flux. As a result, majority ions water chemistry was changed at the receiving zone of the discharged effluent (Zone A). Its contribution increased to 69.9 % at the second sampling period with low stream flow. In the middle zone, inflows from the northern area, recently developed to a residential district showed low $NO_3-N$ and high $HCO_3$, Ca, $SO_4$, and $SiO_2$ indicating the effects of groundwater and concrete. One inflow (T-8), with extremely high Na and Cl, median $SiO_2$, was assessed to have anthropogenic influence, however its contribution to main stream was under 1 %. Road construction near Y-13 also affected water chemistry leading to the highest Na and Cl concentration. These hydro chemical changes can be critically used to evaluate the changes in water budget and fate of chemicals in a peri-urban watershed occasioned by human activities on the Yangjae.

동위원소를 이용한 폐금속광산 지역 오염원 추적 연구

  • Yeom Seung-Jun;Lee Pyeong-Gu;Lee In-Gyeong;Lee Uk-Jong
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2006.04a
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    • pp.209-212
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    • 2006
  • Using sulfur sotope analysis of dissolved sulfate in surface water, we have investigated the source of sulfate in order to identify the abandoned metallic mines, which have the potential of heavy metal contamination within watershed. The range of the sulfur isotope values for dissolved sulfate in stream waters (DD-1 and 2) are similar to those of sulfides from the Dunjun mine, which suggests that oxidation of sulfides is the principal source of $SO_4^{2-}$ in these stream waters. Also, heavier sulfur isotopes in waters near Baekjun and Hamchang mines imply the possibility of contamination in waters by these metallic mines.

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Estimation on the Water Quality of the Ian Stream, a Tributary of the Nakdong River (낙동강 지류 이안천의 수질 평가)

  • Choi Kwangsoon;Lee Hyekeun;Kim Hojoon;Kim Saewon
    • Proceedings of the Korea Water Resources Association Conference
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    • 2005.05b
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    • pp.1239-1243
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    • 2005
  • The water quality of the Ian Stream, a tributary of the Na14dong River, was estimated to provide an information in establishment of an ecological restoration plan for fan dam which will be constructed in near future. Seven stations were selected in upstream (3 stations) and downstream (4 stations) of Ian Stream, centering the construction site of Ian dam. Samples were collected at the surface water of 7 stations selected on May 1, June 16, and September 1 in 2004. The values of DO, pH, and BOD are satisfied Grade I for river water standard in nearly all sites. The concentrations of total nitrogen (TN) and total Phosphorus (TP) showed low level with ranges of $1.10\~2.25\;mgN/L,\;5\~14\;{\mu}gP/L$. However, the total and fecal conform bacteria were detected in nearly stations, especially high at the upstream stations. The number of fecal conform bacteria corresponds to the Grade III for river water standard. In addition, some metals (iron, manganese) were detected during dry season. As a consequence, general water quality of Ian Stream satisfied Grade I for river standard and it is expected that pollution loads from watershed is not significant. However, the detection of fecal conform, which is thought to be from livestock and residents, and some metals originating mimes watershed can have a potential health risk exists for aquatic organisms lived in Ian Stream. It needs to be solved by the construction of wastewater treatment plant to diminish the health risk from stream water polluted by fecal conform and metals, and to provide the safe ecological habitat for aquatic organisms.

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A Study on Hydraulic Analysis using GIS-based RMA-2 and HEC-1 - For Stream Reach between Gongdo and Pyeongtaek Water Level Gauge Stations - (GIS 기반의 하천흐름해석모형 RMA-2와 유역유출모형 HEC-1을 이용한 하천의 수리학적 특성 분석 연구 - 공도·평택 수위관측소 구간을 대상으로 -)

  • Park, Min-Ji;Park, Geun-Ae;Kim, Seong-Joon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.10 no.1
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    • pp.124-135
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    • 2007
  • The purpose of this study is to analyze the hydraulic behavior in a stream reach using SMS RMA-2 model with a series of dynamic boundary conditions of main stream and lateral flows simulated by WMS HEC-1 program. For the stream reach (10.5 km) between Gongdo and Pyeongtaek water level gauge stations of Anseongcheon, the model simulated two dimensional flow characteristics by applying dynamic flow conditions of rainfall frequencies of 50, 100, 500, and 1,000 years for the main stream and three tributaries. The temporal flow behavior successfully simulated and the results showed that the distribution of mean velocity and water level within the stream reach increased according to the increase of flow frequency. Especially, the flow velocity sensibly increased at the near downstream of lateral inflow as the width of main stream is narrower.

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O/H Stable Isotopic Composition and Groundwater-surface Water Connectivity: A Case Study for Wangjeon-ri Water Curtain Cultivation Area, Nonsan, Korea (산소/수소안정동위원소를이용한지하수-지표수연계성연구: 논산시왕전리수막 재배지역 사례)

  • Moon, Sang-Ho
    • Economic and Environmental Geology
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    • v.51 no.6
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    • pp.567-577
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    • 2018
  • One of problems related with water curtain cultivation (WCC) in Korea includes severe declination of groundwater levels during the peak season, and it is likely that the problem can be resolved efficiently when the connection characteristics between groundwater and stream are well understood. This study examined temperature, and oxygen/hydrogen stable isotopic compositions of the flowing groundwater to understand the connection between stream and ground water, and the influence of stream water on the nearby aquifer. This study was performed in Wangjeon-ri (Kwangseok-myon, Nonsan City), the well-known strawberry town using WCC technique. The sampling was done during February 2010 through June 2011 for both groundwaters and nearby streams. Temperature distribution pattern indicates that stream widely affected groundwater in the right part of WCC ara. In the left part, the influence of stream seems to occur narrowly near the stream. The similar phenomenon is reflected in the oxygen and hydrogen isotopic data.

Analysis of Road-to-Stream Linkage Characteristics in a Mountain Catchment using the Discriminant Analysis (판별분석을 이용한 산악지역 도로-하천 연결 특성 분석)

  • Park, Sang-Hyoung;Park, Changyeol;Yoo, Chulsang
    • Journal of Korean Society on Water Environment
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    • v.27 no.2
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    • pp.147-158
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    • 2011
  • This study analyzed the linkage characteristics between road runoff and the nearest streams in mountain regions using a discriminant analysis. The road-to-stream linkage is an important characteristic to evaluate whether the contaminant on road surface is transported directly into the nearby channel system. This study evaluated a total of 51 drainage outlets of mountain roads near the Soyanggang Dam. The linkage between road and stream, slope and width of road, and other information necessary for the discriminant analysis have been collected by in situ investigation and by analyzing the Digital Elevation Model. Finally, as independent variables in the discriminant analysis, the contributing road representing the road characteristics (similar to the runoff from the road drainage outlet) and the distance and slope of the connecting channel between road and nearest stream were selected. Among these three, the distance was found to have the highest discriminant power, the contributing road the lowest. Using the discriminant function derived, 40 out of 51 cases (78.4%) were correctly discriminated and the remaining 11 cases (21.6%) were wrongly discriminated. Reasons of wrongly discriminated cases were mainly due to change in drainage outlet direction, excessive runoff, change in road-to-stream path, etc. This result also indicates that the road-to-stream linkage can be introduced or prohibited by exactly the same way.

Endwall Heat (Mass) Transfer in a Turbine Cascade Under Combustor-Level High Free-Stream Turbulence (연소기 출구 난류 상태에서의 터빈 익열 끝벽 열(물질)전달 특성)

  • Jun, Sang-Bae;Lee, Sang-Woo;Park, Byung-Kyu
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.759-764
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    • 2001
  • Heat (mass) transfer characteristics have been investigated on the endwall of a large-scale linear turbine cascade passage under a combustor-level high free-stream turbulence with a large length scale. Local heat (mass) transfer coefficients are measured by using the naphthalene sublimation technique. The result shows that local heat (mass) transfer on the endwall is greatly enhanced in the central region of the turbine passage, but there is no noticeable change in the local heat (mass) transfer in the region suffering severe heat load. Under the high free-stream turbulence, the local heat (mass) transfer coefficient shows more uniform distribution and its average value across the whole endwall region is increased by 26% of that at low turbulence condition. The heat (mass) transfer data on the endwall strongly supports that well-organized vortices near the endwall tends to suffer an suppression by the high free-stream turbulence.

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A Study on The Bed Scour at Stream Bridge during Flood - In the case of Jeongjang Bridge in Gurye - (홍수시 소하천 교량에서의 하상세굴 연구 - 구례 정장교를 중심으로 -)

  • Jung, Jae-Sung;Chung, Mahn;Kim, Min-Hwan
    • Journal of Environmental Science International
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    • v.11 no.10
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    • pp.1075-1080
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    • 2002
  • The hydrological frequency of the flood in July 2000 at Seosi stream basin in Gurye and the bed scour of the stream channel were estimated to investigate the bed scour related with Jeongjang bridge collapse. The storm over the basin in July 2000, 303mm/day was 103year frequency rainfall and the equivalent flood was 2580cms. As the results of 100year and 30year flood application, flood level 30.78~31.38m and mean velocity 3.79~4.03m/s were appeared. And the purification project of Seosi stream increased the velocity of the section near to Jeongjang bridge by the improvement of conveyance at the downstream. The local scour at pier was the major factor of bed scour at Jeongjang bridge site and the total scour at pier No.6 was increased from 2.32m to 2.45m by the purification project.

Analysis of Environmental Odor Factors for Dorim Stream in Gwanak-gu, Seoul (서울시 관악구 도림천 복개 정도에 따른 환경 악취 요인 분석)

  • Soyoung Park;Gokce Nur Ayaz;Heewon Kim;Hyungkee Yoon;Taehong Kwon;Sungkyoon Kim
    • Journal of Environmental Health Sciences
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    • v.50 no.2
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    • pp.83-92
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    • 2024
  • Background: In this study, we investigate the rapid increase in environmental odors and notable rise in civil complaints near Dorim Stream in the Gwanak-gu area of Seoul. Objectives: This study aims to identify the causal compounds responsible for environmental odors in the Dorim Stream and investigate the structural characteristics of the stream that influence odor generation. Methods: The research methodology involved setting up 41 sampling points, selecting panels for direct sensory evaluation to assess odor intensity, measuring dissolved oxygen and hydrogen sulfide concentrations, and using all-in-one low-temperature desorption gas chromatography (ATD-GC) and thermal desorption-gas chromatography-mass spectrometry (TD-GC/MS) analysis to identify odor-causing compounds. Results: The evaluation of Dorim Stream revealed that in areas with complete meandering, there were lower dissolved oxygen levels (4.5±2.67 mg/L) and higher odor intensity (4.0±0.92), while in partially meandering sections, higher dissolved oxygen levels (7.8±1.15 mg/L) and lower odor intensity (2.8±1.06) were observed. Hydrogen sulfide levels measured with sensors increased with higher temperatures, especially in the afternoon hours (12:00~14:00). Acetaldehyde was the dominant odor compound detected in both the Bonglim Bridge (0.4 ppm) area and Guro Bridge area (0.867 ppm), with concentrations more than twice as high near Guro Bridge. Odor-causing compounds identified by TD-GC/MS indicated a pungent, sulfurous odor in the Guro Bridge area and a musty odor in the Bonglim Bridge area. Conclusions: This study categorizes and analyzes the sources of odor in Dorim Stream in Seoul based on meandering patterns and the distribution of sewage facilities, highlighting the potential odor issues associated with combined sewage systems and sewer junctions and suggesting policy improvements.