• Title/Summary/Keyword: Catchment area

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Evaluation of Supply Adequacy of Park Service in Suwon-si by Urban Park Catchment Area Analysis (도시공원 이용권 분석을 통한 수원시 공원서비스의 적정성 평가)

  • Kim, Hyun;Kim, Yea Sung;Lee, Da-Som;Kim, Jee-Yeop
    • Journal of the Korean Institute of Landscape Architecture
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    • v.43 no.2
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    • pp.114-124
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    • 2015
  • In the city, the urban park contributes to the quality of citizen life in many ways, and the importance of the urban park as an urban planning facility is growing each day. In this study, evaluation of park service supply adequacy in Suwon-si, the difference in analysis methods, and the type of land use at urban park catchment area analysis were analyzed. As a result, there were remarkable differences between the two analysis methods. In Suwon-si, the catchment area by network analysis was only about 41% of catchment area by buffer analysis. However, when basic local authorities establish planning of parks and green areas, they use buffer analysis to calculate the park service area. It means that such calculations of urban park service areas may be wider than actually used. Also, because there were differences between urban park catchment areas by land use types, guidelines of planning parks and green areas will be adjusted. Although quantitative expansion of the park area is also important for the realization of green welfare, it is necessary to consider city characteristics such as the population size, population density, land use types, and so on.

The Quantitative Evaluation of Catchment Plan-Form Elongation (집수평면의 신장도에 대한 정량적 평가)

  • Kim, Joo-Cheol;Lee, Sang-Jin;Noh, Joon-Woo
    • Journal of Korea Spatial Information System Society
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    • v.11 no.3
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    • pp.1-8
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    • 2009
  • In this study the concepts on the elongation, compactness and equivalent ellipse of catchment plan-forms are applied to the real basins considering their theoretical frameworks. The catchment plan-forms and corresponding equivalent ellipses, obtained from GIS, are inspected on downstream directions. As a result the catchment plan-forms seem to be the population of the basin shapes which come from the random interaction between two conjectures on Hack's law being controversial recently. The ratio of the maximum and minimum inertia moments of the catchment plan-form Ri is more sensitive to evaluate the elongation of the basin shapes than the ratio of the main channel length and diameter of circle which has the same area as the catchment plan-form E. The catchment plan-forms compactness measures show distinct aspects according to their different definitions. These results are caused by the difficulties to quantification of the shapes and the composite consideration with more than two compactness measures and the fractal analysis are therefore required to recover them.

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A Characteristic Analysis of Critical Duration of Design Rainfall in Medium Sized Catchment (중규모 하천유역에서 임계지속기간 특성 분석)

  • Lee, Jung-Sik;Park, Jong-Young;Kim, Seok-Dong
    • Journal of the Korean Society of Hazard Mitigation
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    • v.9 no.1
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    • pp.135-144
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    • 2009
  • The objective of this study is to examine the effect of hydrological factors on critical durations, and to analyze the relationship between the watershed characteristics and the critical duration of design rainfall in the medium sized catchments. Hydrological factors are used to return period, probable intensity formula, hydrograph method, effective rainfall and temporal pattern of design rainfall. Hydrologic analysis has done over the 44 medium sized catchments with $50{\sim}5,000{\beta}{\yen}$. Watershed characteristics such as catchment area, channel length, channel slope, catchment slope, time to peak, concentration of time and curve number were used to simulate correlation analysis. All of hydrological factors except return period influence to the critical duration of design rainfall. Also, it is revealed that critical duration is influenced by the watershed characteristics such as area, channel length, channel slope and catchment slope. Multiple regression analysis using watershed characteristics is carried out for the estimation of relationship among these. And the 7 type equations are proposed by the multiple regression using watershed characteristics and critical duration of design rainfall. The determination coefficient of multiple regression equations shows $0.96{\sim}0.97$.

Relevance between Subway Commuting Travel Time and Spatial Extent of the Catchment Areas (지하철 통근통행시간이 역세권의 공간범위에 미치는 영향분석)

  • Lee, Seungil;Jang, Se Jin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.1D
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    • pp.119-127
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    • 2008
  • Nowaday, the local governments eager to change their transport system aiming for public transport oriented one. However, it is more important to change the land use system in the catchment areas of public transport in order to enhance its usage sustainably for the long run. This research aims to seek maximal spatial extent of the catchment areas of the Seoul Metropolitan Subway in consideration of its urban spatial structure in order to accommodate the potential users living around the subway stations. For this task the empirical data of the household travel survey for the Seoul Metropolitan Area conducted 2002 were analysed. It was founded that the walking access times to the subway stations, which can represent their spatial extents, are related to their travel times, but differently according to their given positions in the urban spatial structure. The characteristics of subway commuters also affect them with the conditions. It is to be expected that the results of this research can contribute to an enhancement of its usage by applying to land-use policies of the catchment areas.

Estimation Method of Small Hydro Power Potential Using a Resource Map (자원지도에 의한 소수력 잠재량 산출)

  • Park, Wan-Soon;Lee, Chul-Hyung
    • 한국태양에너지학회:학술대회논문집
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    • 2008.11a
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    • pp.322-326
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    • 2008
  • This paper presents an estimation method of small hydro power(SHP) potential using a SHP resource map. As a basic unit of SHP energy potential at a certain area, capacity and annual energy production of unit head was calculated from the catchment area given by a SHP resource map which was established by numerical hydrologic simulation so that a logical and relatively accurate potential estimation was possible comparing with the performance analysis model for SHP sites. The performance characteristics for Samok-Ri site were analyzed, using the SHP resource map and the developed model. It was found that the SHP resource map and the developed model is useful tool to estimate SHP potential.

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Size Determination Method of Bio-Retention Cells for Mimicking Natural Flow Duration Curves (자연상태 유황곡선 보전을 위한 생태저류지 용량결정방법)

  • Lee, Okjeong;Jang, Suhyung;Kim, Hongtae;Kim, Sangdan
    • Journal of Wetlands Research
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    • v.18 no.4
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    • pp.424-431
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    • 2016
  • LID facilities like bio-retention cells is applied to manage stormwater. LID concept becomes an important part in stormwater management, and the clear understanding of hydrologic performance and hydrologic impact on the corresponding catchment has been needed. In this study, the application of flow duration curves as design strategy is investigated. Bio-retention cells like many LID facilities are installed to reproduce natural hydrologic processes. In this study, the attempt to determine the size of a bio-retention cell is carried out to satisfy the flow duration criteria. From the results, it is shown that "5 mm * the area of a target catchment" which is the current facility design capacity is valid for the drainage area with 20-30% impervious rate. In the 100% impervious catchment where LID facilities are typically installed, the design capacity to intercept stormwater of approximately 47 mm depth is required to reproduce natural flow duration curves. This means that about 11% of the target catchment area should be allocated as a bio-retention cell. However, the criteria of the design capacity and facility surface area should be set at the possible implementation conditions in reality, and site-specific hydrologic characteristics of a target catchment should be considered.

Trends of Health Care Utilization and Relevance Index of Stroke Inpatients among The Self-Employed Insured and Their Dependents of National Health Insurance (1998-2005) (국민건강보험 지역가입자 중 뇌졸중 입원환자의 의료이용 양상 및 지역친화도 추이 (1998-2005))

  • Kim, Ji-Hyun;Cho, Byung-Mann;Hwang, In-Kyung;Son, Min-Jeong;Yoon, Tae-Ho
    • Health Policy and Management
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    • v.18 no.4
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    • pp.66-84
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    • 2008
  • Objectives: This study aimed to. offer some fundamental evidences for the stroke management policy by investigating the trends of medical care utilization and regionalization in stroke inpatients. Methods: We used the National Health Insurance claims and registry data for stroke inpatients from 1998 to 2005. Among all stroke inpatient claims data, self-employed insured and their dependents were only included in this study. The classification of stroke was based on ICD-10(I60-I69) and its subtype was divided by hemorrhage(I60-I62) and infarction(I63-I64) type. To evaluate regionalization of medical care utilization, relevance index was calculated by regions. The regions were classified 8 large catchment areas and 163 self authorized areas. Results: The overall medical care utilization rate of stroke inpatient has been increased, especially infarction subtype. Among medical care institutions, the utilization of hospital has been the most rapidly increased. Although considered annual rate of interest, total medical cost of stroke inpatients has been increased, Totally, more than 84% of stroke inpatient were admitted to medical care institutions in their own large catchment area during 1998-2005. The relevance indices in their own large catchment area (self sufficiency rates) were more than 70% in most areas regardless of stroke subtype except Chungbuk catchment area. Self sufficiency rates of stroke inpatients among 163 self authorized areas in 1998 and 2005 were 84.2% and 83.1% in metropolitan, 46.7% and 45.5% in urban, and 19.5% and 22.6% in rural areas, respectively. Conclusion: Stroke management policy for improvement of distribution at the district level, especially in rural areas, may be helpful for reducing regional inequality in stroke.