• Title/Summary/Keyword: Watersheds

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The Influence on the Runoff Characteristics by the Land Use in Small Watersheds (소유역의 토지이용이 유출 특성에 미치는 영향)

  • Choi, Ye-Hwan;Choi, Joong-Dae
    • Proceedings of the Korea Water Resources Association Conference
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    • 2004.05b
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    • pp.204-208
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    • 2004
  • In the forthcoming 21C, the barometer of cultural lives depends on that the water demand will increase or not. On the opposite site of that, the small watersheds will influence directly on how to cover the surface of watersheds with land use, no planning developing watersheds, and the rearrangement of small rivers. Espacially as the exordinary climatic phenomena, water resources and water content of the small watersheds will be confused oil exactly not to make a plan of water resources. This study area has four small watersheds groups in Gangwon-Do Province, that is, group I five small river watersheds including Changchoncheon etc., group II fiver rivers watersheds including to Hwalsanmogicheon etc., group III five small river watersheds including Singicheon etc., group IV including to Sabulanggolcheon etc. According to the land use such as dry field(or farm), ice field, forest land, building lot arid others, in small watersheds, the amount of runoff will be impacted by precipitation. The comparison between the runoff was getting from Kajiyama Formular and calculated runoff from multi-linear regressed equations by land use percentage was performed. Its correlation which was estimated by coefficient of correlation will be accepted or not, as approched 1.00000 values. As the monthly water resources amount is estimated by multi-linear regressed equations, we make a plan to demand and supply the water quantity from small river watersheds during any return periods.

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The Influence on the Runoff Charateristics by the Land Use in Small Watersheds (II) (소유역의 토지이용이 유출특성에 미치는 영향 (II))

  • Choi, Ye-Hwan;Choi, Joong-Dae
    • Proceedings of the Korea Water Resources Association Conference
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    • 2005.05b
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    • pp.178-182
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    • 2005
  • In the forthcoming 21C, the development of cultural lives depends on that the water demand will increase or not. On the opposite site of that circumstance, many factors of the small watersheds will influence directly on how to cover the surface of watersheds with land use, no planning developing watersheds, and the rearrangement of small rivers. Especially as the extraordinary climatic Phenomena, exhaust of $CO_2$ and destruction of 03 layer, water resource and water foresting content of the small watersheds will be decreased by confusing on the malting a plan of water resources. For example, those are Typhoon Rusa in 2002, Typhoon Maemi in 2003 and heavy storms in 2004. This study area has three group and one of them having three small watersheds, total five small watersheds. That is, Sabukmyeon small watersheds in Chuncheon, Three small watersheds in Wonju(Jeoncheon, Jupocheon and Hasunamcheon), and Suipcheon in Yanggu-Gun which are located far away each other three group and different precipitation data. According to the land use such as dry field(or farm), rice field, forest land. building site and others in small watersheds, the amount of runoff will be impacted by monthly precipitation. The comparison between the runoff was getting from Kajiyama Formula and calculated runoff from multi-linear regressed equations by land use Percentage was performed with different precipitation data and different small watersheds. Its correlations which are estimated by coefficient of correlation will be accepted or not, as approached 1.0000 values. As the monthly water resources amount is estimated by multi-linear regressed equations with different precipitation data and different small watersheds having no gauging station, we make a plan in order to demand and supply the water quantity from small river watersheds during return periods.

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Development of Long Term Flow Duration Curves in 4 River Basins for the Management of Total Maximum Daily Loads (수질오염총량관리를 위한 4대강수계 장기유황곡선 작성방안)

  • Park, Jun Dae;Oh, Seung Young
    • Journal of Korean Society on Water Environment
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    • v.29 no.3
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    • pp.343-353
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    • 2013
  • Flow duration curve (FDC) can be developed by linking the daily flow data of stream flow monitoring network to 8-day interval flow data of the unit watersheds for the management of Total Maximum Daily Loads. This study investigated the applicable method for the development of long term FDC with the selection of the stream flow reference sites, and suggested the development of the FDC in 4 river basins. Out of 142 unit watersheds in 4 river basins, 107 unit watersheds were shown to estimate daily flow data for the unit watersheds from 2006 to 2010. Short term FDC could be developed in 64 unit watersheds (45%) and long term FDC in 43 unit watersheds (30%), while other 35 unit watersheds (25%) were revealed to have difficulties in the development of FDC itself. Limits in the development of the long term FDC includes no stream monitoring sites in certain unit watersheds, short duration of stream flow data set and missing data by abnormal water level measurements on the stream flow monitoring sites. To improve these limits, it is necessary to install new monitoring sites in the required areas, to keep up continuous monitoring and make normal water level observations on the stream flow monitoring sites, and to build up a special management system to enhance data reliability. The development of long term FDC for the unit watersheds can be established appropriately with the normal and durable measurement on the selected reference sites in the stream flow monitoring network.

Pollutant Flux Releases During Summer Monsoon Period based on Hydrological Modeling in Two Forested Watersheds, Soyang Lake

  • Kang, S.H.
    • Environmental Engineering Research
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    • v.14 no.1
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    • pp.13-18
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    • 2009
  • In this study, specific pollutant releases during the Asian monsoon season were estimated and the information was applied to the non-point pollutant sources management from two forested watersheds of the Soyang Lake. The two watersheds are part of the 2,703 km2 Soyang Lake watershed in the northern region of the Han River. The outlets of the two watersheds were respectively analyzed for continuous water quality concentration and for discharge during various single rainfall events. Statistical power function methods are utilized to compare stream discharge and pollutant flux release during the study period. Based on the monitoring data during the study period, the specific load flux method using simulated discharge was conducted and validated in the two watersheds. The model predictions corresponded well with the measured and calculated pollutant releases. The modeling approach taken in this study was found to be applicable for the two forested watersheds.

The Algorithm of Protein Spots Segmentation using Watersheds-based Hierarchical Threshold (Watersheds 기반 계층적 이진화를 이용한 단백질 반점 분할 알고리즘)

  • Kim Youngho;Kim JungJa;Kim Daehyun;Won Yonggwan
    • The KIPS Transactions:PartB
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    • v.12B no.3 s.99
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    • pp.239-246
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    • 2005
  • Biologist must have to do 2DGE biological experiment for Protein Search and Analysis. This experiment coming into being 2 dimensional image. 2DGE (2D Gel Electrophoresis : two dimensional gel electrophoresis) image is the most widely used method for isolating of the objective protein by comparative analysis of the protein spot pattern in the gel plane. The process of protein spot analysis, firstly segment protein spots that are spread in 2D gel plane by image processing and can find important protein spots through comparative analysis with protein pattern of contrast group. In the algorithm which detect protein spots, previous 2DGE image analysis is applies gaussian fitting, however recently Watersheds region based segmentation algorithm, which is based on morphological segmentation is applied. Watersheds has the benefit that segment rapidly needed field in big sized image, however has under-segmentation and over-segmentation of spot area when gray level is continuous. The drawback was somewhat solved by marker point institution, but needs the split and merge process. This paper introduces a novel marker search of protein spots by watersheds-based hierarchical threshold, which can resolve the problem of marker-driven watersheds.

Necessity of Refractory Organic Matters Management in Total Maximum Daily Loads (TMDLs) (수질오염총량관리제에서 난분해성 유기물질 관리 필요성 및 개선방안)

  • Park, Jae Hong;Park, Bae Kyoung;Lee, Jae Kwan;Rhew, Doug Hee
    • Journal of Korean Society on Water Environment
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    • v.29 no.3
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    • pp.393-399
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    • 2013
  • To control organic matters, it needs to manage not only biodegradable organic matters but also refractory organic matters. Refractory organic matters from municipal wastewater, industrial wastewater, non-point sources and etc., have been continuously discharged to the near watersheds. It is estimated that the refractory organic matter ratios are continuously increased in waterbody. In watersheds of the Total Maximum Daily Loads (TMDLs), it was investigated that COD/BOD ratios increased in many unit watersheds of the 4 major river basins. The portions COD/BOD ratios increased were found to be a 97% of Geum River unit watersheds, a 81% of Yeongsan/Seumjin River unit watersheds, a 78% of Nakdong River unit watersheds, a 70% of Han River unit watersheds, respectively. Therefore, it has become important for establishment of effective management strategies to control refractory organic matter in watersheds of the Total Maximum Daily Loads (TMDLs). In order to properly manage organic matters including refractory organic matters, the present organic indicator (BOD) has to be converted to TOC (or COD). Compared to COD and BOD, TOC, as a organic matter indicator, is evaluated more appropriate.

RUNOFF ESTIMATION FROM TWO MID-SIZE WATERSHEDS USING SWAT MODEL

  • Kim, Chulg-yum;Kim, Hyeon-jun;Jang, Cheol-hee;Kim, Nam-won
    • Water Engineering Research
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    • v.4 no.4
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    • pp.193-202
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    • 2003
  • SWAT model was applied to estimate daily stream flow for Yongdam and Bocheong watersheds in Korea. The model was calibrated and validated for the two watersheds and a new routine was added to analyze runoff process in paddy fields. The model efficiencies for two watersheds were 0.77 and 0.65 for the calibration period, and 0.76 and 0.50 for the validation period, respectively. It showed that water balance method simulated the runoff from paddy fields more precisely than CN method in SWAT. As results, the SWAT model is applicable to Korean watersheds, and more accurate estimation is possible using daily water balance method in paddy fields.

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An Integrated Watershed Environmental Assessment and Classification of the Mid-Nakdong River Region (낙동강 중류 지역의 통합적 유역환경평가 및 유형화)

  • Jung, Sung-Gwan;Park, Kyung-Hun
    • Journal of Environmental Impact Assessment
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    • v.13 no.3
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    • pp.137-151
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    • 2004
  • Many of today's environmental problems are regional in scope and their effects overlap and interact. The purpose of this paper is to developed a simple method for an integrated assessment of environmental conditions across the Mid-Nakdong River Region, by combining data on land use, impervious cover, roads, streams, riparian areas, forest patches, population, pollutant loadings, soil erosion and topography. A cluster analysis was used to identify groups of sub-watersheds with similar environmental characteristics. The mean value for each group was used to find watershed that may be more vulnerable to future environmental degradation. Watersheds in cluster I and II had high amount of forest, but the amount of riparian vegetation was low. Watersheds in cluster III, which located in the middle Geumho River and the main course of Nakdong River, had a greater proportion of their agriculture, a greater proportion of agriculture on steep slopes, and less forest adjacent to streams. Watersheds in cluster IV and V were in the most urbanized areas of the region. The principal adverse impacts for watersheds in this group were high scores for urban area, impervious cover, pollutant loadings, population density, forest fragmentation, and low amounts of forest and riparian forest cover. Notwithstanding the exploratory nature of cluster analysis, it appears to be a useful tool for grouping watersheds with similar environmental characteristics.

Generalization of the Extreme Floods for Various Sizes of Ungauged Watersheds Using Generated Streamflow Data (생성된 유량자료를 활용한 미계측유역 극한 홍수 범위 일반화)

  • Yang, Zhipeng;Jung, Yong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.42 no.5
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    • pp.627-637
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    • 2022
  • To know the magnitudes of extreme floods for various sizes of watersheds, massive streamflow data is fundamentally required. However, small/medium-size watersheds missed streamflow data because of the lack of gauge stations. In this study, the Streamflow Propagation Method (SPM) was applied to generate streamflow data for small/medium size watersheds with no measurements. Based on the generated streamflow data for ungauged watersheds at three different locations (i.e., Chungju Dam (CJD), Seomjin Dam (SJD), and Andong Dam (ADD) watersheds), the scale ranges of extreme floods were evaluated for different sizes of ungauged watersheds by using the specific flood distribution analysis. As a general result, a range of specific floods decreases with increasing watershed size. The distribution of the specific flood in the same size of a watershed possibly depends on the size and topography of the watershed area. The delivered equations were compared to show the relations between the specific flood and sizes of watersheds. In the comparisons of equations, the Creager envelope curve has the higher potential to represent the maximum flood distribution for each watershed. For the generalization of the maximum flood distribution for three watersheds, optimized envelop curves are obtained with lower RMSE than that of Creager envelope curve.

Utilization of Thematic Mappers Data for the Comparison of Methods to Create Watersheds

  • Chang, Eun-Mi;Park, Kyeong;Kim, Young-Soo;Lee, Bok-Ho
    • Proceedings of the KSRS Conference
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    • 1999.11a
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    • pp.343-348
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    • 1999
  • Delineation of watersheds is one of the most basic steps for water resource management and National Park management. The purpose of this study is to investigate how to utilize Thematic Mappers scenes to compare watersheds created by running a model with those produced by digitizing topographic maps of Keum River basin. A methodology is designed and tested using Geographic Information Systems (GIS) and remote sensing to map areas with various thematic maps. A CAD data on watersheds from the Decision Support system for Water Quality is converted into GIS format. The digital elevation model with 100-meter resolution is used to create watershed by cumulative watershed method. TM scenes are also classified by new procedures including stacking method, NDVI, NDWI, and unsupervised classification methods. To evaluate the relative correctness Kyerongsan National Park was studied intensively whose area was divided into 6 watersheds in both cases. The boundaries of watershed from the model are less correct than those of the topographic maps. This result shows that automated watershed creating system needs higher-resolution digital elevation model than 100-meters.

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