• 한국농공학회지
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• 제8권1호
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• pp.1088-1096
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• 1966

The following is a method of synthetic unitgraph derivation based on the routing of a time area diagram through channel storage, studied by Clark-Jonstone and Laurenson. Unithy drograph (or unitgraph) is the hydrograph that would result from unit rainfall\ulcorner excess occuring uniformly with respect to both time and area over a catchment in unit time. By thus standarzing rainfall characteristics and ignoring loss, the unitgraph represents only the effects of catchment characteristics on the time distribution of runoff from a catchment The situation abten arises where it is desirable to derive a unitgraph for the design of dams, large bridge, and flood mitigation works such as levees, floodways and other flood control structures, and are also used in flood forecasting, and the necessary hydrologie records are not available. In such cases, if time and funds permit, it may be desirable to install the necessary raingauges, pruviometers, and stream gaging stations, and collect the necessary data over a period of years. On the otherhand, this procedure may be found either uneconomic or impossible on the grounds of time required, and it then becomes necessary to synthesise a unitgraph from a knowledge of the physical charcteristics of the catchment. In the preparing the approach to the solution of the problem we must select a number of catchment characteristic(shape, stream pattern, surface slope, and stream slope, etc.), a number of parameters that will define the magnitude and shape of the unit graph (e.g. peak discharge, time to peak, and base length, etc.), evaluate the catch-ment characteristics and unitgraph parameters selected, for a number of catchments having adequate rainfall and stream data and obtain Correlations between the two classes of data, and assume the relationships derived in just above question apply to other, ungaged, Catchments in the same region and, knowing the physical characteritics of these catchments, substitute for them in the relation\ulcorner ships to determine the corresponding unitgraph parameters. This method described in this note, based on the routing of a time area diagram through channel storage, appears to provide a logical line of research and they allow a readier correlation of unitgraph parameters with catchment characteristics. The main disadvantage of this method appears to be the error in routing all elements of rainfall excess through the same amount of storage. evertheless, it should be noted that the synthetic unitgraph method is more accurate than the rational method since it takes account of the shape and tophography of the catchment, channel storage, and temporal variation of rainfall excess, all of which are neglected in rational method.

• 한국수자원학회논문집
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• 제53권spc1호
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• pp.755-764
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• 2020

현재 우리나라는 수자원단위지도의 표준유역(850개) 및 KRF의 집수구역(7,807개) 등의 기준 도면이 수자원 정책 수립의 기본 도면으로 활용되고 있으나, 물관리 일원화 시점에 맞추어 지표수-지하수의 연계 관리 및 수량-수질 통합관리를 위해서는 보다 적절한 규모의 표준 도면 설정이 필요해 보인다. 지표수에 비하여 지하수는 느린 이동 속도를 보이고 3차원 흐름 특성을 갖고 있으므로 지표수-지하수 연계 평가를 위해서는 광역적 규모의 유역 보다는 준 유역 규모가 보다 효과적인데, 표준유역보다 평균 면적이 작은 KRF 집수구역은 1차 또는 2차 지류를 포함하는 준 유역 규모에 해당한다. 그러나, KRF는 지표수 수계를 기준으로 구역을 구분하였기 때문에 넓은 평지 또는 높은 산악지역에서는 지나치게 작거나 큰 면적을 갖고 있다. 따라서, 지표수-지하수 연계 통합 관리에 적합한 단위 유역은 기존 KRF 집수구역을 수정하여 설정하는 것이 필요하다. 이로부터 설정될 개소 당 약 5 ~ 15 ㎢ 면적의 단위 유역은 지류의 구성과 관정의 위치를 고려할 때 지방자치단체의 수자원 관리의 기본 단위가 될 수 있으며, 물수요-공급 평가, 수문 계측 시스템의 배치, 지하수 허가 총량 기준, 오염의 평가, 정책의 우선 순위 결정 등 실질적인 수자원 통합관리의 기본 수단으로 활용 가능할 것이다.

• 한국조경학회지
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• 제19권3호
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• pp.98-127
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• 1991

This study has purposes of not only establishing urban community park systems and index for designing the parks, which were reviewed from Korean urban community parks, but also finding the relation and the enticing area according to the catchment of urban community parks. This paper suggested two hypotheses. a. The strength of the catchment force of urban community parks can be represented to the usetimes or visitors of the parks, related with the distance for reaching the parks. b. The strength of the catchment force of the parks can be found to express the idiosyncratic one according to the qualitative differences between the parks. The suggested hypotheses were testified from Korean 9 urban community parks in Seoul., Suwon, Chongju, and Chonan, conforming the multiregressions of the variables, distance and usetime in the case of the first hypothesis, scale, the ratio of green space, population, the budget for the park, facilities and the function of the city in the case of the second hypothesis. All the correlation coefficients of usetime with distance except one were over about 0.8. The second hypothesis was testified with multiregressions for the variables. Therefore, the enticing area could be divided into three zones ; a closed aone to parks, a good used aone for parks, a possible zone for using parks.

• 한국수자원학회논문집
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• 제36권1호
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• pp.87-104
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• 2003

지표면 유출과 하천 유출 통으로 구성된 동일한 홍수유출모형 SIRG-RS를 소유역과 대유역에 적용하였다. 지표면 유출로부터의 유입 방법, 하천 접합부에서의 계산방법, 급경사 산지하천에서의 에너지손실 계산 등에서 개선책을 강구하였다. 마찰력 산정을 위하여 레이놀즈수와 조고비의 함수인 지수형 마찰계수 산정식을 도입하였다. 또한 지수형 마찰계수 산정식은 실험자료뿐 아니라 최근 입수한 현장 관측자료를 사용하여 개선하였다. 개선된 모형은 대규모의 유역과 아주 작은 크기의 소유역에도 적용하였는데, 두 가지 경우 모두 관측자료와 비교하여 양호한 계산 결과를 얻었다.

• 인간식물환경학회지
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• 제24권1호
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• pp.39-51
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• 2021

Background and objective: Urban topology can be characterized as impervious, which changes the hydrologic features of an area, increasing surface water flow during local heavy rain events. The pluvial flooding is also influenced by the vertical structures of the urban area. This study suggested a modified digital elevation model (DEM) to identify changes in urban hydrological conditions and segmentalized urban micro catchment areas using a geographical information system (GIS). Methods: This study suggests using a modified DEM creation process based on Rolling Ball Method concepts along with a GIS program. This method proposes adding realized urban vertical data to normal DEM data and simulating hydrological analyses based on RBM concepts. The most important aspect is the combination of the DEM with polygon data, which includes urban vertical data in three datasets: the contour polyline, the locations of buildings and roads, and the elevation point data from the DEM. DEM without vertical data (DCA) were compared with the DEM including vertical data (VCA) to analyze catchment areas in Shin-wol district, Seoul, Korea. Results: The DCA had 136 catchments, and the area of each catchment ranged from 3,406 m² to 423,449 m². The VCA had 2,963 catchments, with the area of each ranging from 50 m² to 16,209 m². The most important finding is that in the overlapped VCA; the boundary of areas directly affected by flooding and the direction of surface water flow could be identified. Flooding data from September 21, 2010 and July 27, 2011 in the Shin-wol district were applied as ground reference data. The finding is that in the overlapped VCA; the boundary of areas directly affected by flooding and the direction of surface water flow could be identified. Conclusion: The analysis of the area vulnerable to surface water flooding (SWF) was more accurately determined using the VCA than using the DCA.

• 한국농공학회지
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• 제20권3호
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• pp.4724-4731
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• 1978

Using hydrometric data from an upland river in North Wales, a relationship between rate of river flow and water stored within the catchment area (catchment storage) is assumed to exist, and is evaluated from an analysis of winter recession curves. This storage/river flow relationship, when combined with water balance equations, produces a set of equations which may be used for "routing" input of rainfall through a storage with defined outflow characteristics, providing a straightforward method of flood prediction and analysis from rainfall data. Recorded and predicted flood hydrographs are compared, and the effectiveness and limitations of the method are considered. The development of a complete mathematical model, embodying the storage/river flow relationship, and suitable for generation of continuous run-off records from rainfall and evaporation data, is also considered.

• 한국조경학회지
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• 제21권2호
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• pp.1-7
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• 1993

This study suggests one hypothesis: The strength between the catchment foreces of urban community parks can be represented to a gravity model. The gravity model is derived from the related of two subjects, witch is related with their distance. A grvity model for the catchments between parks is represented as followed formula: Iij=${\alpha}$${\times}$ $\frac{Pi$.$Pj}{${\beta}$r}$(formula) Here, Iij is a total number of the vistors of park i and j in a year. Pi is population of the catchment area of park i. Pj is population of the catchment area of park j. ${\alpha}$and, ${\beta}$ are parameters. This formula is testified in the case of Chong-ju community parks.

• 한국농공학회지
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• 제15권3호
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• pp.3096-3106
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• 1973

As a link in the chain of antidrought measure, our attempt is made to obtain basic informations on the construction of an infiltration gallary which can be supplied with irrigation water by catching of underground water in small river beds, which is economical, permanent and efficient. The experiment was made, concerning the structure of catchment conduits, by constructing a model sand tank $1.5m{\times}5m{\times}1.5m$ in dimension made of reinforced concrete. Various kinds of measuring equipment were attached to the model tank which contains a set of catchment conduits, each of them was made 30cm in diameter and 60cm in length with the ratio of sectional area to total area of influx holes 10:1, 20:1, 30:1. The average size of influx holes was fixed from 0mm to 10mm, 20mm and 30mm in diameter respectively. Obtained results are as follow; (a) In view of the water catchment capacity, manufacturing cost and the antipressure strength of the catchment conduits, it is the best method to decide the total number of influx holes 20 per sq. meter of each tile surface, and the size of influx holes 20mm in diameter, when the conduits have diameter less than 1m. (b) The greatest factor of safety against external load is to arrange the influx holes in a zigzag manner on the tile surface. The most effective formula of arrangement is $S{\geqq}\sqrt{2gd}$ where: s : spacing of opening row. g : spacing of opening line. d : diameter of influs hole.

• 한국제4기학회지
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• 제19권1호
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• pp.41-46
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• 2005

This study discusses the soil erosion on hillslopes and sediment deposition in lakes within catchments in South Korea. In order to determine seasonal variations of sedimentation in Yeongcheon and Seondong lakes, the sediment traps were set in the deep part of both lakes and lake sediments have been sampledmonthly from July 2004 to August 2005. Some properties such as highmineral content, fine particle size and high particle density in the Yeongcheon Lake indicate intensive soil erosion, sediment transportation and deposition throughout the catchment for a long time. The high sediment yield in the Seondong Lake is related with higher weathering intensity and extreme soil erosion by running water due to higher seasonal rainfall amount. Rates of erosion and sedimentation in the Seondong Lake are estimated to be higher than those of the Yeongcheon Lake, suggesting that the Seondong Lake is associated with higher precipitation, smaller catchment area, and extreme soil vulnerability to ephemeral erosion by overland flow during the heavy rainfall event. Consequently, both catchments are characterized by different erosion and sedimentation processes, as well as different geomorphic factors (bedrock, soil structure, rainfall intensity and catchment area).

• 대한토목학회논문집
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• 제43권4호
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• pp.421-431
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• 2023

하수관로 열화모델은 하수관망을 관리하는 의사결정자에게 자산의 미래 상태 예측에 대한 중요한 정보를 제공할 수 있다. 본 연구에서는 CCTV 조사를 통해서 확보한 구조적 상태평가 이력자료를 기반으로 마르코프 연쇄 모델을 이용하여 하수관로의 노후도를 추정하였다. A시의 3개 배수분구에서 1998-1999년과 2010-2011년에 CCTV 조사에 의해 수집된 관경 450 mm와 600 mm의 흄관 자료를 이용하여 분석하였다. EM 배수분구의 450 mm 관로와 600 mm 관로에서 주요 결함 발생이 다른 두 배수분구보다 빠르게 발생하는 것으로 나타났다. 관로 설치 이후 35년이 지난 시점에는 450 mm 관로의 약 29%, 600 mm 관로의 약 38%가 주요 결함이 발생했으며, 100년 후에는 각각 62%와 74%의 관로가 주요 결함으로 관로 기능을 상실하는 수준으로 나타났다. 관로설치 35년 후, SN 배수분구는 450 mm 관로의 약 26%, 600 mm 관로에서 약 35%, HK 배수분구에서는 450 mm 관로의 약 27%, 600 mm 관로에서 약 37%의 주요 결함이 발생한 것으로 예측되었다. 또한 600 mm 관로가 450 mm 관로보다 평균 12년 정도 빨리 기능 저하가 일어나는 것으로 나타났다. 한편, 관로의 주요 결함등급 비율을 40%로 설정하여 관로의 유효사용수명으로 적용할 경우, 450 mm 관로는 SN배수분구에서 60년, EM배수분구에서 42년, HK배수분구 59년이며, 600 mm 관로에서는 각각 43년, 34년 39년으로 나타났다.