• Title/Summary/Keyword: Urban watershed

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Study on Spatial Change of Urban Forest Considering Definition of Urban Area in South Korea (도시지역 정의에 따른 도시숲의 공간적 변화에 관한 연구)

  • Doo-Ahn, KWAK;So-Hee, PARK
    • Journal of the Korean Association of Geographic Information Studies
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    • v.25 no.4
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    • pp.19-31
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    • 2022
  • The definition of urban forest is described as all forest and trees except the Natural Parks throughout whole territory in Urban Forest Act. But the concept of urban forest in the law differs from general awareness by Korean citizen and from definitions of other countries. For discussing such differences of urban forest definition, it was tested how much urban forest area would be changed according to the various definition of urban area. The urban area was defined to be four scenarios in this study in consideration of "urban area" by National Land Planning and Utilization Act (NLPUA), 300m buffered boundary from the "urban area" proposed by World Health Organization (WHO) and forest watershed area. In the scenario 1, including forest watershed intersected with "urban area" by NLPUA, urban forest area was estimated at 1.83 million ha in which urban forest area per person was 386㎡. In the scenario 2, including forest watershed intersected with 300m buffered boundary from the "urban area" by NLPUA, urban forest area was estimated at 1.92 million ha in which urban forest area per person was 405㎡. In the scenario 3, including forest watershed intersected with "urban area" placed within administration boundary (Eup·Dong districts), urban forest area was estimated at 1.08 million ha in which urban forest area per person was 230㎡. In the scenario 4, including forest watershed intersected with 300m buffered boundary from "urban area" placed within administration boundary, urban forest area was estimated at 1.20 million ha in which urban forest area per person was 256㎡. Therefore, the boundary of urban area should be agreed clearly prior to defining the urban forest area for avoiding unclear area calculated according to different definitions.

Potential Effects of Urban Growth under Urban Containment Policy on Streamflow in the Gyungan River Watershed, Korea

  • Kim, Jinsoo;Park, Soyoung
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.33 no.3
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    • pp.163-172
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    • 2015
  • This study examined the potential effects of urban growth on streamflow in the Gyungan River watershed, Korea, using urban containment scenarios. First, two scenarios (conservation and development) were established, and SLEUTH model was adapted to predict urban growth into the year 2060 with 20 years interval under two scenarios in the study area. Urban growth was larger under scenario 2, focusing on development, than under scenario 1, focusing on conservation. Most urban growth was predicted to involve the conversion of farmland, forest, and grasslands to urban areas. Streamflow in future periods under these scenarios was simulated by the Soil and Water Assessment Tool (SWAT) model. Each scenario showed distinct seasonal variations in streamflow. Although urban growth had a small effect on streamflow, urban growth may heighten the problems of increased seasonal variability in streamflow caused by other factor, such as climate change. This results obtained in this study provide further insight into the availability of future water resource and can aid in urban containment planning to mitigate the negative effects of urban growth in the study area.

Integrated Approach for Watershed Management in an Urban Area (도시 유역 관리를 위한 통합적인 접근방법)

  • Lee, Kil-Seong;Chung, Eun-Sung;Kim, Young-Oh
    • Journal of Korea Water Resources Association
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    • v.39 no.2 s.163
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    • pp.161-178
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    • 2006
  • Heathcote (1998) identified a systematic, seven-step approach to general watershed planning and management. It consists of 1) understanding watershed components and processes, 2) identifying and ranking problems to be solved, 3) setting clear and specific goals, 4) developing a list of management options, 5) eliminating infeasible options 6) testing the effectiveness of remaining feasible options, and 7) developing the final options. In this study the first five steps of that process were applied to the Anyangcheon watershed in Korea, which experiences streamflow depletion, frequent flood damages, and poor water quality typical of highly urbanized watersheds. This study employed four indices: Potential Flood Damage(PFD), Potential Streamflow Depletion(PSD), Potential Water Quality Deterioration(PWQD) and Watershed Evaluation Index(WEI) to identify and quantify problems within the watershed. WEI is the integration index of the others. Composite programming which is a method of multi-criteria decision making is applied for the calculation of PSD, PWQD and WEI (Step 2). The primary goal of the study is to secure instreamflow in the Anyangcheon during dry seasons. The second management goals of flood damage mitigation and water quality enhancement are also set (Step 3). Management options include not only structural measures that can alter the existing conditions, but also nonstructural measures that rely on changes in human behavior or management practices (Step 4). Certain management options which are not technically, economically, and environmentally feasible, are eliminated (Step S). Therefore, this study addresses a Pre-feasibility study, which established a master plan using Steps 1 through 5.

Urban Hydrologic Monitoring due to Internet Hydrologic Monitoring System (인터넷 수문관측시스템을 이용한 도시수문 모니터링)

  • Seo, Kyu Woo;Kim, Nam Gil;Na, Hyun Woo;Lee, In Rock
    • Proceedings of the Korea Water Resources Association Conference
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    • 2004.05b
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    • pp.1321-1325
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    • 2004
  • The continuous monitoring of the runoff in the small-scaled urban watershed and easily accessible experiment catchment is necessary to investigate the overall status of the development in the urban catchment and the varying aspects of the discharge characteristics due to the urbanization. However, the research on the management and the characteristics of the small-scaled model basin for discharge tests has not been actively performed up to now. This study selects the Dong-Eui university basin, which locates at Gaya-dong in Busan, as the experiment catchment to monitor the discharge rate in the urban watershed. EMS(DEMS, DATA-PCS EMS, mini rain gage & AWS(AWS-DEU, DATA-PCS AWS) monitoring system installed for the collection of hydrological data such as the rainfall and the waterlevel. This experiment catchment is the typical urban catchment and is under development, and it is possible to analyze the varying aspects of the discharge rate during and after the development.

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Sustainable Water Resources Planning to Prevent Streamflow Depletion in an Urban Watershed: 2. Application (도시유역의 건천화 방지를 위한 지속가능한 수자원 계획: 2. 적용)

  • Lee, Kil-Seong;Cung, Eun-Sung;Shin, Mun-Joo;Kim, Young-Oh
    • Journal of Korea Water Resources Association
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    • v.39 no.11 s.172
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    • pp.947-960
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    • 2006
  • This study shows the application of sustainable water resource planning procedure developed in the previous paper. Its goal is to prevent the streamflow depletion in upstream watershed of the Anyangcheon which is a typical urban stream. The pressure-state-response model which is the framework to reflect the sustainability was applied. The composite programming which is the multilevel multicriteria decision making technique is also used in the calculation of state and evaluation index. The feasible alternatives were proposed and hydrologically analyzed by SWAT(Soil and Water Assessment Tool) and the priority ranking of alternatives were proposed based on the results of SWAT.

L-THIA/NPS to Assess the Impacts of Urbanization on Estimated Runoff and NPS Pollution (도시화에 따른 유출과 비점원 오염 영향을 평가하기 위한 L-THIA/NPS)

  • Kyoung-Jae Lim;Bernard A. Engel;Young-Sug Kim;Joong-Dae Choi;Ki-Sung Kim
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.45 no.4
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    • pp.78-88
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    • 2003
  • The land use changes from non-urban areas to urban areas lead to the increased impervious areas, consequently increased direct runoff and higher peak runoff. Urban areas have also been recognized as significant sources of Nonpoint Source (NPS) pollution, while agricultural activities have been known as the primary sources of NPS pollution. Many features of the L-THIA/NPS GIS, L-THIA/NPS WWW system have been enhanced to provide easy-to-use system. The L-THIA model was applied to the Little Eagle Creek (LEC) watershed in Indiana to evaluate the accuracy of the model. The L-THIA/NPS GIS estimated yearly direct runoff values match the direct runoff separated from U.S. Geological Survey stream flow data reasonably. The $R^2$ and Nash-Sutcliffe values are 0.67 and 0.60, respectively. The L-THIA estimated runoff volume and total nitrogen loading for each land use classification in the LEC watershed were computed. The estimated runoff volume and total nitrogen loading in the LEC watershed increased by 180% and 270% for the 20 years. Urbanized areas -"Commercial", "High Density Residential", and "Low Density Residential"- of the LEC watershed made up around 68% of the 1991 total land areas, however contributed more than 92% of average annual runoff and 86% of total nitrogen loading. Therefore, it is essential to consider the impacts of land use change on hydrology and water quality in land use planning of urbanizing watershed.nning of urbanizing watershed.

Building an Integrated Governance Model and Finding Management Measures for Nonpoint Source Pollution in Watershed Management of Korea

  • Ban, Yong Un;Woo, Hye Mi;Han, Kyung Min;Baek, Jong In
    • Environmental Engineering Research
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    • v.18 no.3
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    • pp.199-208
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    • 2013
  • This study intended to develop an integrated governance model and find measures to manage nonpoint source (NPS) pollutions in watershed management. To reach this goal, this study has analyzed NPS pollution management policies in Korea and has employed statistical methods such as expert Delphi survey, analysis of variance, and factor analysis. As a result, this study has found that the favored basic organization form was a private-public cooperative council. The necessary governance-based NPS pollution management measures determined through this study are as follows: to build collaboration mechanisms including those related to motivation provision, trust building, capacity building, and making optimal regulations; to employ financial resources based on principles such as 'polluter-pays', 'recipient-pays', and 'general-tax-source'; and to develop several programs, including system improvement, pilot and management projects, and publicity.

A Landscape Ecological Classification based on Watershed Focusing Landcover Types (경관생태학적 유역관리를 위한 토지이용 유형 분류)

  • Oh, Jeong-Hak;Jung, Sung-Gwan;Kwon, Jino;Park, Kyung-Hun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.10 no.4
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    • pp.22-34
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    • 2007
  • The purpose of this study is to evaluate landscape characteristics of watersheds in the Nakdong River Basin for identifying the groups of watershed with similar landcover patterns by using Geographic Information System and statistical technique. According to the results based on the cluster analysis using cluster analysis tool in the ArcGIS 8.3 program, 22 sub-watersheds were classified into three types; "Forest watershed", "Agriculture watershed", and "Urban watershed". In the forest watershed that has the least potential of ecological disturbances by human, a forest management approach based on geographic conditions and coverage types, etc., should be developed to sustain the ecological and environmental functions of forest. For the agriculture watershed, environmental-friendly agricultural techniques should be performed in the particular enhancement of riparian buffer zone to the prevent direct inflow of soils, fertilizers, and other chemicals into the stream network. Finally, in the urban watershed, an environmental-friendly plan that may increase the ratio of pervious surface and amount of green-space to should be reserved.

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Relationship between Inundated Areas and Environmental Characteristics in Watershed for Natural Drainage Capacity Assessment in Urban Area (도시의 자연배수능력 평가를 위한 유역 내 환경특성과 침수피해면적의 관계)

  • Chung, Kyung-Jin;Kim, Min-Jung;Kim, Ok-Soo
    • 한국방재학회:학술대회논문집
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    • 2007.02a
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    • pp.211-214
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    • 2007
  • The purpose of this study was to establish the basic information for natural drainage capacity assessment in urban area. We sorted midium watershed of Han river and Nak-dong river, and selected 30 rainfall events during 1995 to 2000 according to high level of damage. The inundated area showed high watershed slope about 25% and it indicated the greatest damage around the watershed located in 200-300m of altitude. Besides, the great damage by inundation was occurred in the mountainous agriculture region, where the forest scale was high and the urbanization was being progressed gradually. However, inundated area was small in case of grassland, water tone such as riparian area, bare ground and wetland. Moreover, the inundated area was different according to river shape and characteristics of river distribution such as the density of the stream order, conservation constant of the river system, and the number of undulations in the watershed. Therefore, it showed that land use, river shape and distribution characteristics of stream influence on inundation.

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