• Journal of The Korean Society of Agricultural Engineers
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• v.51 no.6
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• pp.105-114
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• 2009

With urbanization in many countries, many pervious areas are being converted into impervious areas. These land use changes cause many negative impacts on runoff and water quality in the areas. Especially runoff volume and peak runoff are increasing with urbanization. In addition to the increased runoff, more pollutant transports to the downstream areas. For these reasons, Low Impact Development (LID) are nowadays being introduced in urban planning. For environment-friendly and economical urban development, the LID Integrated Management Practices (IMPs) are applied in various urban development. However, exact effects on runoff and water quality of various LID IMPs are not assessed with proper LID evaluation technique. Thus, the SWMM (Storm Water Management Model) 5.0 model was slightly modified to simulate the effect of infiltration manhole on runoff and water quality. For comparison of runoff and TSS (Total Suspended Solids) from the study area (26.5 ha), three scenarios were made in this study. It was found that runoff volume, peak runoff, and TSS could be reduced with infiltration manholes and pervious pavements to some degree. Although, there are many limitations in the analysis of LID effects on runoff and TSS, similar trends shown in this study would be expected with site-specific LID IMPs. Thus, it is strongly recommended that various site-specific LID IMPs, such as infiltration facilities, should be applied as much as possible for environment-friendly urban planning.

• Journal of Korean Society on Water Environment
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• v.27 no.5
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• pp.670-679
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• 2011

Chlorophyll-a is a major water quality indicator for an algal bloom in streams and lakes. The purpose of the study is to estimate chlorophyll-a concentration in tributaries of the Seonakdonggang by an artificial neural network (ANN). As the tributaries are ungauged streams, a watershed runoff and quality model was used to simulate water quality parameters. The tributary watersheds include urban area and thus Storm Water Management Model (SWMM) was used to simulate TN, TP, BOD, COD, and SS. SWMM, however, can not simulate chlorophyll-a. The chlorophyll-a series data from the tributaries were estimated by the ANN and the simulation results of water quality parameters using SWMM. An assumption used is as follows: the relation between water quality parameters and chlorophyll-a in the tributaries of the Seonakdonggang would be similar to that in the mainstream of the Seonakdonggang. On the assumption, the measurement data of water quality and chlorophyll-a in the mainstream of the Seonakdonggang were used as the learning data of the ANN. Through the sensitivity analysis, the learning data combination of water quality parameters was determined. Finally, chlorophyll-a series were estimated for tributaries of the Seonakdonggang by the ANN and TN, TP, BOD, COD, and temperature data from those streams. The relative errors between the estimated and measured chlorophyll-a were approximately 40 ~ 50%. Though the errors are somewhat large, the estimation process for chlorophyll-a may be useful in ungauged streams.

• Journal of Korean Society on Water Environment
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• v.26 no.1
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• pp.61-70
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• 2010

The increase of impervious cover (IC) in a watershed is known as an important factor causing alteration of water cycle, deterioration of water quality and biological communities of urban streams. The study objective was to assess the impact of IC changes on the surface runoff characteristics of Kap Stream basin located in Geum river basin (Korea) using the Storm Water Management Model (SWMM). SWMM was calibrated and verified using the flow data observed at outlet of the watershed with 8 days interval in 2007 and 2008. According to the analysis of Landsat satellite imagery data every 5 years from 1975 to 2000, the IC of the watershed has linearly increased from 4.9% to 10.5% during last 25 years. The validated model was applied to simulate the runoff flow rates from the watershed with different IC rates every five years using the climate forcing data of 2007 and 2008. The simulation results indicated that the increase of IC area in the watershed has resulted in the increase of peak runoff and reduction of travel time during flood events. The flood flow ($Q_{95}$) and normal flow ($Q_{180}$) rates of Kap Stream increased with the IC rate. However, the low flow ($Q_{275}$) and drought flow ($Q_{355}$) rates showed no significant difference. Thus the subsurface flow simulation algorithm of the model needs to be revisited for better assessment of the impact of impervious cover on the long-term runoff process.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.26 no.2
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• pp.81-95
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• 2014

In the present study, the statistical analysis on the storm waves in the East Sea have been carried out, and the several storm waves were reproduced by the modified WAM as a first step for the accurate and prompt forecasting and warning against the swell waves in East Sea. According to the present study, the occurrences of the storm waves from the North were the most probable, while the waves from the Northeast were most frequently observed. It was found that the significant wave heights of storm waves from the North and Northern northeast were larger than those of storm waves from the Northeast. But due to long fetch distance, the significant wave periods of storm waves from the Northesast were longer than those of North and Northern northeast. In addition to the wave analysis, the numerical experiments for the storm waves in East Sea were carried out using the modified WAM, and three periods of storm waves in 2013 were calculated. The numerical results were well agreed with wave measurements. However the numerical simulation results in shallow water region showed lower accuracies compared to deep water, which might be due to lower resolution of wind field and bottom topography caused by large grid size, 5 minute, adopted in the present study. Overall computational efficiency of the modified WAM found to be excellent compared to original WAM. It is because the modified WAM adopted the implicit scheme, thereby the present model performed 10 time faster than original WAM in computation time.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.536-542
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• 2000

The purpose of this study is to evaluate the effect of stream quality by the farmer＇s livestock wastes management in a typical small agricultural watershed. AGNPS model has the capability to adjust the level of pollutant load from farmstead and the fertilization level of upland field. A small agricultural watershed(4.12 $\textrm{km}^2$) which has as livestock farmhouses located in Gosan-myun, Ansung-gun was selected. AGNPS data were prepared by using Arc/info and Idrisi. 4 storm events in 1999 was used for runoff calibration, and 2 storm event which is measured in hourly-base at 4 locations along the stream were used for water quality(TN, TP) calibration. Model＇s behavior to stream quality for 3 cases was investigated. First, the variation of pollution produced from the cattle shed affected little to the stream quality because the cattle sheds were roofed. Second, the good management of ground in farmstead affected to stream quality with 11% and 17% decrease in TN and TP, respectively. Third, the reduction of fertilization level to upland field affected to stream quality with 27.2% and 38.5% decrease in TN and TP, respectively.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1880-1884
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• 2006

도시 지역 개발후 하류지역에 유출량의 증가로 인해, 첨두유량의 완화는 도시 호우 관리에서 가장 중요한 고려 대상중의 하나이다. 일반적으로 설계기준의 호우에 대해서 개발지역의 첨두유량이 개발전의 첨두유량을 넘지 않도록 설계한다. 유수지는 오리피스와 위어를 이용하여 높은첨두율을 개발전의 첨두유량으로 조절하는 역할을 한다. 그러나 비싼 토지비용 때문에 한국에서 도시지역의 유수지 사용은 그렇게 일반적이지 않다. 따라서, 많은 도시 지역이 개발로 인한 유량의 증가를 겪고 있다. 이 연구에서는 새로 개발된 한국의 울산 화봉지역의 11 ha 소유역에서 첨두유량을 조절하기 위하여 어떻게 유수지와 오리피스와 위어를 설계하는지 조사하였다. 이 지역은 새로 개발된 한국의 도시지역을 보여주는 전형적인 지역으로 고려됐으며, 유수지는 2년 빈도, 10년 빈도 그리고 100년 빈도의 설계 강우에 대한 첨두유량을 조절할 수 있도록 설계하였다. 설계 유수지 모의를 위하여 Storm Water Management Model (SWMM)의 윈도우 최신 버전인 5.006a를 사용하였다. 이 연구에서는 얼마만큼의 유수지 면적이 다목적으로 사용될 수 있는지 제시하려 하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.832-836
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• 2008

우리나라는 하절기에 강우가 집중되고 있으며, 집중호우에 대한 도시 호우 피해사례가 최근 빈번히 발생하고 있다. 도시지역의 홍수유출량 저감 방안연구의 중요성에 대한 인식과 그 필요성이 절실한 상태이며, 그에 따라 본 연구에서는 대상 유역에 BMP를 적용한 저류지를 설치하여 첨두유량과 첨두시간의 저감 및 지체효과를 분석하고, 그 결과를 효율적으로 활용하고자 한다. 대상의 모형은 SWMM 5.0(Storm Water Management Model 5.0)을 이용하여 모델링 하였으며, 강우자료는 건설교통부 관할 의정부관측소의 1975년에서 2004년까지의 시강우자료를 바탕으로 24시간 Huff분포형을 산정하여 모형에 적용하였다. 대상 유역에 저류지 설치 전과 BMP가 적용된 저류지 설치 후, 그리고 BMP가 적용되지 않은 저류지 설치 후를 상호 비교하여 BMP저류지의 효과를 분석하였다.

• Journal of Environmental Science International
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• v.7 no.4
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• pp.451-460
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• 1998

The objectives of this study Is to evaluate the total runoff yield, peak flow and peak flow travel time depending on the urbanization, return period and rainfall patterns at the downstream of Manchon urban watershed in TaeGu City. SWM(Storm Water Management Model) is used for runog analysis based on 5 different steps of urbanization and 4 different types of Hufrs quartile according to 8 return periods. It is analyzed that the order of total runoff yield according to raiun patterns is Huffs 4, Huffs 2. Huffs 3 and Huffs 1 quartile, that of peak flow magnitude is Huffs 2, Huffs 1, Huffs 4 and Huffs 3 quartile at present development ratio. under the 60, 70, 80 and 90ft of urbanization to the 50% of urbanization by means of the rainfall patterns, the mean Increasing ratio of total runoff yield for each case is 4.55, 11.43, 16.07 and 20.02%, that of peak flow is 5.82, 13.61, 17.15 and 18.83%, the mean decreasing ratio of peak flow travel time Is 0.00, 2.44, 5.07 and 6.26%, the mean increasing ratio of runoff depth Is 4.51, 11.42, 16.02 and 20.05% respectively. the mean increasing ratio of total runoff yield by means of each and 19.71%. Therefore, as the result of this study. it can be used for principal data as to storm sewage treatment and flood damage protection planning in urban small watershed.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.529-533
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• 2016

미국 환경청의 SWMM 5(storm water management model 5)는 유역의 홍수유출 모의 및 연속 유출 모의를 할 수 있는 모형으로서 국내뿐만 아니라 세계적으로 많이 사용되고 있는 모형이다. SWMM 5와 같은 유역 유출모형에서 결과의 적절성을 향상시키기 위해서는 모형에 사용되는 매개변수를 올바르게 추정할 필요가 있다. 하지만, 외국의 정교한 유역 유출모형들이 우리나라에서 제대로 적용되고 있지 못하는 이유 중 하나는 적절한 매개변수의 추정이 이루어지지 못하고 있는 점이다. 이러한 문제를 해결하고자 SWMM 5의 매개변수 추정 지원 시스템을 개발하였다. SWMM 5의 매개변수 추정지원 시스템은 민감도 분석, 최적화 기법에 의한 모형 자동보정, 매개변수 할당 및 도움 모듈로 이루어져 있다. SWMM 5의 매개변수 추정 지원 시스템에 사용되는 최적화 기법은 전역최적화 기법 중 하나인 SCE-UA(shuffled complex evolution-University of Arizona) 이다. SWMM 5의 매개변수 추정 지원 시스템의 개발은 국내 수자원 기술자들의 SWMM 5에 대한 이해 및 활용도를 더욱 향상시켜줄 것으로 기대한다.

• Water for future
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• v.26 no.4
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• pp.85-95
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• 1993

Three purposes of this study are as follows: The first was the development of the extention method for the limited data observed in an urban drainage basin. The second was the analysis of the correlation between storm water runoff and NPS(non-point source) pollutant discharge, The last was the calculation of the monthly and annual specific NPS loads using the established correlation. the selected model was the SWMM monthly and annual specific NPs loads using the established correlation. The selected model was the SWMM (Storm Water Management model) developed by the US EPA(environmental Protection Agency). As a result of this study, the best correlation between storm wate runoff and NPS pollutants discharge was produced by the non-linear correlation between runoff rate(mm/hr)and specific loads rate(g/ha/sec)for all pollutants studied ; SS, COD, BOD, and TN. The best correlation through the analysis based on evently total mass was made by the linear correlation between the specific accumulated runoff(mm) and the specific accumulated loads(kg/ha) for CASE 1., and by the non-linear correlation for CASE 2. The NPS annual specific loads for the urban basin studied were 4933 kg/ha/year for SS, 775kg/ha/year for BOD, 3094kg/ha /year for COD,257kg/ha/year for TN, respectively. And the proportion of the NPS annual specific loads to the total annual specific loads were 42 % for SS, 13 % for BOD, 29% for COD, and 21 % for TN.