• Journal of Korean Society of Water and Wastewater
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• v.24 no.4
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• pp.377-386
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• 2010

To identify operating parameters of the up-flow filtering system, which is available to discharge filtering residue after the rain, developed for treatment of urban storm runoff, lab scale test was carried out. Removal efficiency of SS was 68.7%, 62.2%, and 58.6% at the area roading rate of 2.46m/h, 4.68m/h, and 10m/h, respectively, filtering device is desirable to operate at the lower than 4.68m/h of area roading rate to get higher level of 60% SS removal efficiency. The removal efficiency of SS was 57.1% ~ 68.7% at the raw water SS of 100mg/L ~ 600mg/L, and the SS in treated water was maintained at the constant level through the elapsed time. It is indicate that filtering device can guarantee a certain level of effluent water quality at various raw water quality. The removal efficiency of SS to the depth of filter media was 68.3%, 78.6% at the filter depth of 10 cm, 20cm respectively. The final treated water quality was showed 30.2mg/L of CODMn, 1.60mg/L of TN and 0.25mg/L of TP. The average removal efficiencies by filtering device developed in this research were recorded slightly lower levels than other research. The main reason of these results were the first, the filter depth of the media used in this test was shallow, the second, the kind of filter media in discharge port of residue. More research to kind of filter media, filter packing rate, select of media for residue discharge port should be go on to produce optimum operating condition. The result of this study would be valuable for the application of filtration device to control of urban storm water.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2006.09a
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• pp.177-180
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• 2006

• Proceedings of the Korea Water Resources Association Conference
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• 1997.05a
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• pp.274-279
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• 1997

• Water for future
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• v.22 no.2
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• pp.201-211
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• 1989

Using the storm data which was augmented by the stochastic correlation with it's neighbors, the multiquadric equation of random surface of total storm depth is constructed. And to separate the local components from it's regionals and find the regional characteristics, a double Fourier analysis was applied to the total depths of storm data. The local components, storm residuals of each storm was assumed to be homogeneous random field and investigated with it's autocorrelation function. For the practical application, isotropic was assumed and that was identified with emprical data. Coefficients of normalized autocorrelation for all storms showed similar apperance. Using this emprical result, an example of the radial spectral distribution function which represints the spatial characteristics of rainfall over Han River Basin during 1975-1983 is presented.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.6
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• pp.681-690
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• 2014

It is known that sewer problems are the major causes of road cave-in. The objective of this study is to analyze the risk of road cave-in due to storm sewer laterals. We investigated 174 storm sewer laterals using a zoom camera at O-dong area in Seoul. The causes of road cave-in were classified into five cases: breakage of rigid pipe, deformation of flexible pipe, out of pipeline alignment, changing pipe material or changing pipe diameter, and a poor linkage between lateral and sewer. In addition, all defects were sorted into five grades based on the severity rating at storm sewer laterals. In this study, the most fragile pipe materials were found to be concrete pipe and polyethylene pipe, which recorded 2.3 and 1.69 defect rates. With regard to the causes of road cave-in, deformation of flexible pipe has a large influence on road cave-in at present. On a long-term basis, the two causes, out of pipeline alignment and a poor linkage between lateral and sewer, could have more influence on road cave-in.

• Journal of Korea Water Resources Association
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• v.31 no.3
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• pp.309-315
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• 1998

The grid-based KIneMatic wave STOrm Runoff Model (KIMSTORM) was applied to YoncheonDam watershed (1,875km2) located in the Imjin river basin of the Korea. Six maps which are DEM(Digital Elevation Model), stream, flow path, soil, land use and Thiessen network, were used for input data. The simulated streamflows resulting from two selected storm events agreed well with the observed flows at the watershed outlet. The results of temporal variations and spatial distributions are presented by using GRASS. Keyword : grid-based, storm-runoff model, GRASS-GIS, Yoncheon dam watershed.

• Journal of Korea Water Resources Association
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• v.37 no.10
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• pp.823-836
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• 2004

Using the simple geometry for the idealized catchment consisting of two plane surfaces and a stream between them, runoff was analysed for the moving storms based on the kinematic wave equation. The storm velocity applied in this study was 0.25∼2.0 m/s moving up, down and cross direction of catchment. Applied rainfall distribution types are uniform, advanced, delayed, intermediate type. The results indicate that the moving storms of cross direction generate the largest peak runoff, and the smallest runoff appears in the case of up stream direction. The sensitivity of runoff to rainfall distribution types decreases as storm velocity increases. It is clear that faster storm velocity generates faster peak time and becomes thin hydrographs rapidly.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.346-352
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• 2017

This study discusses application of the storm water management model (SWMM) to designing the sponge city facilities in the Athletes Village of Military World Games in Wuhan in October 2019. The SWMM was used to simulate the runoff processes and reduction efficiencies of the sponge city facilities. The runoffs of the sponge city facilities were compared with those of traditional drainage system for the design rainfall of 35.2mm and the rainfalls with different recurrence periods. The results show that the hign density sponge city facilities could meet the requirements for 80% of annual runoff control rate, SWMM can determine the scales of the sponge city facilities and effectively simulate the hydrological processes for different layout schemes. The simulation model is also helpful to making optimization of the sponge city facility layout.

• Journal of Korea Water Resources Association
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• v.40 no.7
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• pp.533-543
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• 2007

This study characterized and qualitatively analyzed the storm events recorded in the Annals of Chosun Dynasty. First of all, the storm events are retrieved using the like Keun-Bi (big rain), Keun-Mul (high water), Hong-Soo (flood), and Pok-Woo (torrential rain). The storm events cited as Keun-Bi do not include any in detail explanation about the storm and damages, but the storm events cited as Keun-Mul, Hong-Soo, and Pok-Woo generally include in detail information. That is, the Keun-Bi was named simply based on the amount of rainfall, but the other three were named considering the runoff with significant damages. Evaluation of effective rainfall derived by the simple SCS method showed that most storm events named Keun-Bi had small antecedent five day rainfall amount to be categorized into AMC-1, but the others mostly into AMC-III. As result, the effective rainfall of Keun-Mul, Hong-Soo, and Pok-Woo were estimated much higher than those of Keun-Bi. Most storm events with lengthy explanation belong to the events with lots of damages, which also includes Keun-Mul, Hong-Soo, and Pok-Woo.

• International Journal of Ocean System Engineering
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• v.2 no.1
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• pp.37-49
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• 2012

An analysis of potential flooding by storm surge and wave run-up and overtopping can be used to evaluate protection afforded by the existing storm protection system. The analysis procedure can also be used to evaluate various protection alternatives for providing typhoon flood protection. To determine risk, the storm surges for both historical and hypothetical are compiled with tide conditions to represent high, slack and low water for neap, spring and mid range tides to use with the statistical procedure known as the Empirical Simulations Technique (EST). The EST uses the historic and hypothetical events to generate a large population of life-cycle databases that are used to compute mean value maximum storm surge elevation frequency relationships. The frequency-of-occurrence relationship is determined for all relevant locations along the shoreline at appropriate locations to identify the effect using the Empirical Storm Simulation (EST). To assist with understanding the process, an example is presented for a study of storm surge analysis for Freeport, Texas. This location is in the Gulf of Mexico and is subject to hurricanes and other tropical storms that approach from the Atlantic Ocean.