• Journal of Environmental Health Sciences
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• v.22 no.4
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• pp.33-42
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• 1996

This research is to show the application of runoff model and runoff analysis of urban storm drainage network. the runoff models that were used for this research were RRL, ILLUDAS, and SWMM applicative object basin were Geucknak-chun and Sangmu drainage basin located in Seo-Gu, Kwangju. The runoff analysis employed the design storm that distributed the rainfall intensity according to the return period after the huff's method. The result from the comparative analysis of the three runoff models was as follows The difference of peak runoff by return period was 20-30% at Sangmu drainage area of $3.17 Km^2$, while less than 10% at Geucknak-chun drainage area of $12.7 Km^2$. The peak runoff were similar to all models. At the runoff hydrograph the times between rising and descending points were in the sequence of RRL, ILLUDAS and SWMM, but the peak times were similar to all models. The conveyance coefficient to examine the conveyance of the existing drainage network was 0.94-1.37, which means insecure, in Geucknak-chun drainage basin and 0.69-1.16, which means secure, in sangmu drainage basin.

• Journal of Korea Water Resources Association
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• v.40 no.5
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• pp.373-382
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• 2007

The exact resolution of channel initiation points is not so easy because of the dynamic behaviors of water movement on the hillslope. To this end, Kim, Joocheol and Kim, Jaehan(2007) have represented the channel network in real world basins for slope-area regimes using DEM. This study is its sequential content and then proposes the reliabilities of the hypothetical channel networks identified from DEM, which are assessed based on the geometric characteristics of drainage density and source-basin. The resulting drainage structures on the natural basin can be found to be depicted remarkably depending on the hypothetical channel network applied by slop-area threshold criterion. In addition, it is shown that there is a wonderful geometric similarity between the shapes of source- basin in a geomorphologically homogeneous region. Area threshold criterion could have restricted the shape of source-basin, so that it might bring about the incorrect drainage structures. But the hypothetical channel networks identified from DEM deserves special emphasis on expressing the space-filling structures nonetheless.

• Journal of Environmental Impact Assessment
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• v.20 no.6
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• pp.857-866
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• 2011

This research categorized EIA target highways into following three types in order to minimize non-point source pollution from highway runoff. 1. Big drainage basin. 2. Small drainage basin. 3. Bridge section. The Natural, Filter and Swirl-Type devices were evaluated in terms of removal efficiency of TSS, BOD, COD, T-N, T-P, compatibility of site selection, economic feasibility, and maintenance convenience through which the final BMP was selected. According to the removal efficiency result, the area of Big and Small Drainage basin and bridge section had higher removal efficiency with natural facility than that of the Filter or Swirl-Type device. To make appropriate selection of highways'BMP for non-point source pollution, this study will aim to contribute to building more environmentally friendly highways by proposing the selection process that is made of 5 stages. 1. Selecting the target drainage basin. 2. Selecting the land for the mitigation facility. 3. Analysing the ease of maintenance. 4. Technically evaluating each installation. 5. Evaluating the effective implementation methods.

• Journal of Environmental Science International
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• v.9 no.3
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• pp.193-199
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• 2000

This study is carried out the analysis of the runoff characteristics for the design of the interior drainage systems by SWMM in urbanization basin. The basin analyzed in this study is Bumuh-chun basin which is located in Susung-gu of Taegu city. Huff method is used for rainfall distribution analysis. The optimal rainfall duration in Bumuh-chun basin is analyzed as about 90 minutes decided from comparison of arrival time and critical duration. Flood flow variation pattern is proposed through the comparison of the results of peak flow and peak time analyzed by SWMM about pre-urbanization and post-urbanization of Bumuh-chun basin. It is known that the variation of arrival time caused by the rapid increase of pavement rate in the upper area shows about 20∼25 minutes faster than pre- urbanization. Therefore, the management of surface water for design of water supply and drainage, and channel alteration has to considered the variation of geological factors according to urbanization.

• The Korean Journal of Quaternary Research
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• v.17 no.2
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• pp.79-84
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• 2003

This study revealed the differences in runoff processes of granite drainage basins in Korea and Mongolia by hydrological measurements in the field. The experimental drainage basins are chosen in Korea (K-basin) and Mongolia (M-basin). Occurrence of intermittent flow in K-basin possibly implies that very quick discharge dominates. The very high runoff coefficient implies that most of effective rainfall quickly discharge by throughflow or pipeflow. The Hortonian overlandflow is thought to almost not occur because of high infiltration capacity originated by coarse grain sized soils of K- basin. Very little baseflow and high runoff coefficient also suggest that rainfall almost does not infiltrate into bedrocks in K-basin. Flood runoff coefficient in M-basin shows less than 1 %. This means that most of rainfall infiltrates or evaporates in M-basin. Runoff characteristics of constant and gradually increasing discharge imply that most of rainfall infiltrates into joint planes of bedrock and flow out from spring very slowly. The hydrograph peaks are sharp and their recession limbs steep. Very short time flood with less than 1-hour lag time in M-basin means that overland flow occurs only associating with rainfall intensity of more than 10 mm/hr. When peak lag time shows less than 1 hour for the size of drainage area of 1 to 10 km2, Hortonian overland flow causes peak discharge (Jones, 1997). The results of electric conductivity suggest that residence time in soils or weathered mantles of M-basin is longer than that of K-basin. Qucik discharge caused by throughflow and pipeflow occurs dominantly in K-basin, whereas baseflow more dominantly occur than quick discharge in M-basin. Quick discharge caused by Hortonian overlandflow only associating with rainfall intensity of more than 10 mm/hr in M-basin.

• Water for future
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• v.14 no.4
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• pp.27-34
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• 1981

The design flow of the urban strom drainage systems has been assessed largely on a basis of empirical relations between rainfall and runoff, and the rational formula has been widely used for the cities in our country. In order to estimate it more accurately, the urban runoff simulation model based on the RRl method has been developed and applied to the sample basin in this study. The rainfall hyetograph of the design stromfor the design flow has been obtained by the determination of the total rainfall and the temporal distributions of that rainfall. The total rainfall has been assessed from the empirical formula of rainfall intensity and the temporal distribution of that rainfall determined on the basis of Huff's method from the historical rainfall data of the basin. The virtual inflow hydrograph to each inlet of the basin has been constructed by computing the series of discharges in each time increment, using design strom hyetograph and time-area diagram. The actual runoff hydrograph at the basin outlet has been computed from the virtual inflow hydrographs by developing a relations between discharge and storage for the watershed. The discharge data for verification of the simulated runoff hydrograph are not available in the sample basin and so the sensitivity analysis of the simulation model has not been possible. The peak discharge for the design of drainage systems has been estimated from the computed runoff hydrograph at the basin outlet and compared to thatl obtained form the rational formula.

• Journal of the Korean association of regional geographers
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• v.3 no.1
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• pp.51-62
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• 1997

In various places of drainage basins of major rivers in South Korea are distributed intermontane basins. Basin floor covered with fluvial deposits carried from the surrounding mountane area becomes alluvial plain. Its productivity is comparatively higher than anywhere else. Thus basin is a local administrative, economic, and cultural core area. Intermontane basin consists of backward mountane area, gentle hills, and alluvial lowland. The purpose of this paper is to elucidate the morpogenetic processes and development age of Angae Basin located in the sedimentary rock region. Hills with the height of a.s.l. $80{\sim}100m$ distributed in Angae Basin are residual landforms, which are the remnants of dissection of the etchplain that results from the denudation of bedrock deeply weathered along tectolineaments under the warm and moist climate, and reflect lithological differentiation of bedrock. Those hills have been comparatively higher ridges since the initial stage of the original etchplain, and they have been immune from fluvial processes. The etchplain appeared as $80{\sim}100m$ hills. the high terrace distributed in upstream reach of Nakdong River drainage basin and the old meander-cut at Seoburi in Wicheon drainage basin, are formed at the same stage when riverbed of Wicheon Stream functioned as a local base level according as the fluvial system of Wichoen arrived at dynamic equilibrium.

• Journal of the Korean Society of Hazard Mitigation
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• v.4 no.3 s.14
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• pp.51-60
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• 2004

Urban flood damage has been caused by drainage deficiency. One of the methods to solve this problem is to construct detention basin and Pumping station and to pump out the water to the river. However, because of rapid urbanization, the capacity of drainage pipelines is sometimes not sufficient enough during the rainy season. Therefore, even though we have enough pumping stations, the inflow of surface water never reaches to the detention area, causing floods in urban area. This research is to find improvement of urban drainage system, estimating drainage pipeline risk. Also, eight models for a computer program were developed for practical use. The models were verified changing precipitation duration, intensity, design period, time distribution model, and etc. This verification was processed focusing that the model can regulate the water level in the detention basin and minimize the effect downstream. As a result Fuzzy models were found to be efficient to lower the water level in detention basin, and decreased about 8 cm in water level of downstream.

• The Journal of Information Technology
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• v.10 no.2
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• pp.1-9
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• 2007

This study analyzed major cities of Chung-cheong area in Korea, -Daejeon($36^{\circ}11'{\sim}36^{\circ}30'\;N$, $127^{\circ}15'{\sim}127{\circ}34'\;E$), Chungju($36^{\circ}54'{\sim}37{\circ}02'\;N$, $127^{\circ}52'{\sim}128^{\circ}02'\;E$), and Cheongju($36^{\circ}34'{\sim}36^{\circ}44'\;N$, $127^{\circ}22'{\sim}127^{\circ}34'\;E$)- their characteristics as a Information Site. The geology map, a summit level map, and a drainage network map are created and analyzed the Site. The results are as follows : First, the geology of these cities are related with the shapes and the characteristics of the inner basins. The relief of inner basin determines by the characteristics of the bedrocks. Second, the major cities are close to rivers and the size of the granite & alluvium area influences the relief energy of the urban areas. Finally, the drainage networks explains the process involved in forming the basin and development of urban area.

• Water for future
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• v.9 no.2
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• pp.67-75
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• 1976

With 9 existng reservoirs selected in the Sab-Gyo River Basin, the sedimentation of the reservoirs has been calculated by comparing the present capacity with the original value, which revealed its reduced reservoirs capacity. The reservoirs has a total drainage area of 6,792 ha, with a total capacity of 1,204.09 ha-m, and are short of water supply due to reduction of reservoirs capacity. Annual sedimention in the reservcire is relation to the drainage area, the mean of annual rain fall, and the slop of drainage area. The results of obtained from the investigation are summarized as follow; (1) A sediment deposition rate is very high, being about $9.19{m}^3/ha$ of drainage area, and resulting in the average decrease of reservoir capacity by 19.1%. This high rate of deposition could be mainly attributed to the serve denvdation of forests due to disor derly cuttings of tree. (2) An average unit storage of 415.8mm as the time of initial construation is decreesed to 315.59mm at present, as resultting, we could'nt supply water at 566.24ha. (3) A sediment deposition rate as a relation to the capacity of unit drainage area is as follow; $Qs=1.43 (c/a)^{0.531}$ (4) A sediment deposition rate as a relation to the mean of annval rainfall is as follow; $Qs=672.61 p^{0.024}$ (5) A sediment deposition rate as a relation to the mean slop of drainage area is follow; $Qs=267.21 S^{0.597}$