• Title/Summary/Keyword: Nakdong-river

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Development of Flow Interpolation Model Using Neural Network and its Application in Nakdong River Basin (유량 보간 신경망 모형의 개발 및 낙동강 유역에 적용)

  • Son, Ah Long;Han, Kun Yeon;Kim, Ji Eun
    • Journal of Environmental Impact Assessment
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    • v.18 no.5
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    • pp.271-280
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    • 2009
  • The objective of this study is to develop a reliable flow forecasting model based on neural network algorithm in order to provide flow rate at stream sections without flow measurement in Nakdong river. Stream flow rate measured at 8-days interval by Nakdong river environment research center, daily upper dam discharge and precipitation data connecting upstream stage gauge were used in this development. Back propagation neural network and multi-layer with hidden layer that exists between input and output layer are used in model learning and constructing, respectively. Model calibration and verification is conducted based on observed data from 3 station in Nakdong river.

Application of a Distribution Rainfall-Runoff Model on the Nakdong River Basin

  • Kim, Gwang-Seob;Sun, Mingdong
    • Proceedings of the Korea Water Resources Association Conference
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    • 2012.05a
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    • pp.976-976
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    • 2012
  • The applicability of a distributed rainfall-runoff model for large river basin flood forecasts is analyzed by applying the model to the Nakdong River basin. The spatially explicit hydrologic model was constructed and calibrated by the several storm events. The assimilation of the large scale Nakdong River basin were conducted by calibrating the sub-basin channel outflow, dam discharge in the basin rainfall-runoff model. The applicability of automatic and semi-automatic calibration methods was analyzed for real time calibrations. Further an ensemble distributed rainfall runoff model has been developed to measure the runoff hydrograph generated for any temporally-spatially varied rainfall events, also the runoff of basin can be forecast at any location as well. The results of distributed rainfall-runoff model are very useful for flood managements on the large scale basins. That offer facile, realistic management method for the avoiding the potential flooding impacts and provide a reference for the construct and developing of flood control facilities.

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Standing Crop Distribution of Aquatic Plants in the West Nakdong River and Riparian Wetlands in the Nakdong River (서낙동강 본류 및 낙동강 둔치 습지의 수생식물 생물량 분포)

  • Kim, Gu-Yeon;Kim, Ji Yoon
    • Korean Journal of Ecology and Environment
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    • v.47 no.1
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    • pp.62-69
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    • 2014
  • Standing crop distribution of aquatic plants in the West Nakdong River and riparian wetlands in the Nakdong River were surveyed in May, July and September, 2010. Total 25 aquatic macrophyte species (submerged: 9, leaf-floating: 3, free-floating: 5, emergent: 8) were observed during the survey periods. Distribution area of aquatic plants and proportion of submerged communities were highest in Garakchi-deung ($212,032m^2$, 72.7%). The distribution area of aquatic plants was highest in Phragmites australis community ($421,584m^2$), followed by Hydrilla verticillata-Vallisneria natans community ($181,511m^2$), Potamogeton wrightii-Vallisneria natans community ($61,604m^2$), and Hydrocharis dubia community ($49,709m^2$). Garakch-ideung (212,032 kg) also had the highest aquatic plant production, followed by Suanchi-deung (15,546 kg), Daedong (5,813 kg), Dunchi-do (3,963 kg), Maekdo (1,463 kg), Yeommak (571 kg), Jungsa-do (530 kg), and Shinan (300 kg). Average standing crop of the study area were $147.8{\pm}20.8g\;DW{\cdot}m^{-2}$ in 1988, $96.1{\pm}20.0g\;DW{\cdot}m^{-2}$ in 2000, and $172.6{\pm}76.1g\;DW{\cdot}m^{-2}$ in 2010. For a sustainable management of river habitat and food source, aquatic plant should concurrently be surveyed with river environmental variables (i.e. sediment, nutrient, flow).

Development and Application of Coliform Load Duration Curve for the Geumho River (금호강 유역의 대장균 부하지속곡선 개발 및 적용)

  • Jung, Kang-Young;Im, Tae-Hyo;Kim, Gyeong-Hoon;Lee, In-Jung;Yoon, Jong-Su;Heo, Seong-Nam
    • Journal of Korean Society on Water Environment
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    • v.28 no.6
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    • pp.890-895
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    • 2012
  • Duration curves describe the percentage of time that a certain water quality (total/fecal coliform (=TC/FC)) or discharge is exceeded. The curves methodology are usually based on daily records and are useful in estimating how many days per year and event will be exceeded. The technique was further applied to estimated TC/FC loading to the Geumho River, using the daily mean flow rate and TC/FC concentration data during January, 2001 and December, 2011 for the Geumhogang6 (=Seongseo water level station) where an automated monitoring station is located in Gangchang-bridge. Low flow of the Seongseo (=11.1 cms) was equivalent to 75.3% on an exceedance probability scale. Load Duration curve for TC/FC loading at the Seongseo was constructed. Standard load duration curve was constructed with the water quality criteria for class III (TC/FC concentration = 5000/1000 CFU/ 100 mL). By plotting TC/FC observed load duration curve with standard load duration curve, it could be revealed that water quality do not meet the desired water quality for 68.8/11.2% on an exceedance probability scale. IF linear correlation between flow rate and coliform concentration is assumed, it can be interpreted that water quality exceed desired criteria when daily average flow rate is over 11.9/109.9 cms.

Development and Application of Coupled System for River Flow Analysis with Multi-dimensional Models in Nakdong River (낙동강수계 하천 흐름연계분석 시스템 개발 및 적용)

  • Ahn, Jung Min;Im, Toe Hyo;Lee, In Jung;Cheon, Se Uk;Lyu, Siwan
    • Journal of Wetlands Research
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    • v.16 no.4
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    • pp.389-402
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    • 2014
  • In this study, simulation technique with multi-dimensional model(EFDC), coupled with COSFIM and FLDWAV, has been applied to the upstream and downstream of weirs for hydraulic characteristics analysis through development of system and was performed for 8 multi-function weirs on Nakdong river using developed system. COSFIM, FLDWAV and EFDC can utilize suitable model in situation because they have pros and cons according to practical use purpose. Developed technique can offers spatial and grid unit information as well as line and section unit information from 1-D modeling. It is considered that the coupling simulation technique can provide useful hydraulic information for river management and treatment.

Ecological and Genetic Biodiversity of Corbicula leana in the Nakdong River and the Nam River

  • Huh, Man-Kyu;Lee, Bok-Kyu;Kim, Byung-Kee;Heo, Youn-Seong;Lee, Hak-Young
    • The Korean Journal of Ecology
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    • v.28 no.2
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    • pp.63-67
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    • 2005
  • The eleven local samples of six species including Corbicula leana examined in this study were collected from the Nam River and the Nakdong River in Korea. Buzas's new formula was used to evaluate the ecological biodiversity among eleven populations and six species. In addition, enzyme electrophoresis was used to genetic diversity within and among populations of C. leana. The upper populations of the river have fewer species than the middle and low populations of this river. The genetic diversity trends to increase from the source of the main river to the mouth. It suggests that the population of downstream might be expanded toward upstream.

Analysis of the estuary outflow characteristics of floating debris in the downstream of Nakdong River using satellite location tracking buoys (위성 위치 추적 부이를 활용한 낙동강 하류 부유쓰레기의 하구 유출 특성 분석)

  • Jang, Seon-Woong;Yoon, Hong-Joo;Seo, Won-Chan
    • The Journal of the Korea institute of electronic communication sciences
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    • v.10 no.2
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    • pp.157-164
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    • 2015
  • The present study is to identify discharge characteristic from the mouth of floating debris in the Nakdong River through real time tracking of moving route and by analyzing hydrometeorologic environmental. To identify the path and route of outflow through the mouth of the river of floating debris, small-sized buoy equipped with satellite location transmitters was used. Moreover, to identify hydrometeorologic environmental, flux of the river, change of discharge of the River-Mouth Weir and wind direction of the mouth of the river area were analyzed. From now on, the present study is expected to be utilized as basic data to identify damage and flowing into nearby ocean of the floating debris of Nakdong River in time of severe rain storm.

Effects of Environmental Factors on Algal Communities in the Nakdong River (낙동강의 환경요인이 조류군집 구성에 미치는 영향)

  • Yu, Jae Jeong;Lee, Hae Jin;Lee, Kyung-Lak;Lee, In Jeong;Jung, Gang Young;Cheon, Se Uk
    • Journal of Korean Society on Water Environment
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    • v.30 no.5
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    • pp.539-548
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    • 2014
  • This study was carried out to investigate algal community structures and their correlations with environmental factors on five weir areas in the Nakdong River, South Korea. Water qualities, hydrodynamics, meteorological conditions and algal species compositions were observed in studied sites from May 2010 to Dec. 2013. Results showed that average total phosphorus concentration of 2013 was decreased by 52.4% in comparing with that from 2010 to 2011. Chlorophyll.a concentrations were positive significant with water temperature, pH, total phosphorus and total nitrogen, but is not significant with turbidity and suspended solids. Seasonal successions of algae were observed that Stephanodiscus sp. was dominant species with 65.3% of dominant frequency in studied site. Large algal biomass of the low temperature-adapted diatoms were observed during temperature range of $4{\sim}9^{\circ}C$, but large cyanobacterial biomass mainly during high temperature period ranged from $22^{\circ}C$ to $32^{\circ}C$. Microcystis sp. dominated during high water temperature in summer. The yearly correlations of algal biomass with accumulated solar radiations were not significant but seasonal correlations of summer from June to August were significant with correlation coefficient 0.33 (p<0.05). There were not significant correlations between turbidities and algal biomass. Turbidity and suspended solids concentrations were not significant correlation with algal biomass. According to the results, algal communities had strong correlation with water temperature and had partially correlation with solar radiation. For an effective management of algal blooms, water managers should survey with more long-term monitoring of various environmental factors and algal communities.

Change in Distribution Characteristics of Surface Sediments of Weir Section in Nakdong River (낙동강 수계 보 구간 표층 퇴적물의 분포 변화)

  • Lee, Kwon Chul;Kim, Hyoung Geun;Lee, Hye Yun;Yang, Deuk Seok;Kim, Shin
    • Korean Journal of Ecology and Environment
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    • v.53 no.4
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    • pp.355-364
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    • 2020
  • This study was carried out to investigated changes in sediments in the eight weir sections of Nakdong River. Sediments were collected and analyzed for Grain Size, Ignition loss, Total Organic Carbon, Total Nitrogen, Total Phosphorus, and Meta. The upstream of the weir was found that fine-grained sediments have repeated increases and decreases. It was found that coarse-grained sediments were being maintained in the downstream part of the weir. The sediments Ignition Loss, Total Organic Carbon, Total Nitrogen, Total Phosphorus are strongly correlated with Grain Size, and these increased at the point where sediments are fine. In the case of metal, the concentration increased across the board, and the correlation with Grain Size, Ignition loss, Total Organic Carbon, Total Nitrogen, and Total Phosphorus was weak. Although there were some sections where fine-grained sediments, organic materials, nutrients, metals increased in the Nakdong River, the overall pollution level is considered weak.

Development of the Estimation Model on Daily Pollutant Loads for the Nakdong River Basin II. Application of the Model (낙동강 유역에 대한 일별 유달부하량 산정모델개발 II. 모델식의 활용)

  • Yoon, Young-Sam;Yu, Jae-Jeong;Kim, Moon-Soo;Lee, Hae-Jin;Lee, Jun-Bae;Yang, Sang-Yong
    • Journal of Environmental Science International
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    • v.16 no.3
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    • pp.333-345
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    • 2007
  • As analyzed the estimated values of the daily delivery loads from thirteen major side streams such as Naesung-river, Keumho-river, Hwang-river, Nam-river during five years (from 1999 to 2003), the daily BOD inflow into the main stream of Nakdong river in 2003 shows the highest quantity as 31.1 ton and the daily BOD inflows in 1999, 2000, 2001, and 2002 are 26.7 ton, 22.5 ton, 21.0 ton, 25.8 ton, respectively. The daily TN in-flow into the main stream of Nakdong river in 2003 shows also the highest quantity as 64.9 ton and the daily TN inflows in 1999, 2000, 2001, and 2002 are 55.19 ton, 46.27 ton, 39.5 ton, 53.38 ton, respectively. The daily TP inflow into the main stream of Nakdong river in 2003 shows the highest quantity as 2.70 ton likewise and the daily TP inflows in 1999, 2000, 2001, and 2002 are 2.17 ton, 1.87 ton, 1.60 ton, 2.10 ton, respectively The rate of BOD loads from each side main stream into the main stream of Nakdong river shows that the BOD loads of Keumho-river are the highest as the values range from 32.8 % (2002) ${\sim}$ 35.1 % (2003) and the BOD loads of Nam-river, Naesung-river, Hwang-river are high in the order named. The rate of TN loads to the main stream is also similar to the trend of BOD loads. The contribution of the TN loads of Geumho-river to the contamination of the main stream is also the highest having a range from 27.0 % (2002) to 28.8 % (1999) among the main side streams and the TN loads of Naesung-river, Nam-river, and Heachun-river are high in the order named. The rate of TP loads is quite different from the trend of BOD and TN loads. The TP rate of Keumho-river, however, is still the highest as ranging 58.6 % (2002) to 61.7 % (2003) and the river has the biggest portion (over 50%) of the entire pollution to the main stream of Nakdong river.