• Journal of Korea Water Resources Association
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• v.40 no.3
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• pp.223-236
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• 2007

Recently in urban area flood damages increase due to local concentrated heavy rainfall. Even in the cities where stormwater drainage systems are relatively well established flood damage still occurs because of the capacity limitations of the existing stormwater drainage systems. When the flood exceeds the capacity limitation of the urban storm sewer system, it yields huge property losses of public facilities involving roadway inundation to paralyze industrial and transportation system of the city. To prevent such flood damages in urban area, it is necessary to develop adequate inundation analysis model which can consider complicated geometry of urban area and artificial drainage system simultaneously. The Dual-Drainage model used in this study is the urban inundation analysis model which combines SWMM with DEM based 2-dimensional surface flood inundation model. In this study, the dual drainage model has been modified to consider the effect of complex buildings in urban area. Through the simulation of time variable inundation process, it is possible to identify inundation alert locations as well as to establish emergency action plan for the residencial area vulnerable to flood inundation.

• Water for future
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• v.26 no.3
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• pp.125-135
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• 1993

This study was conducted for two purposes. The first was the selection of the proper model for the urban runoff, and NPS(non-point source) loads and the second was the adjustment of the selected model through the calibration and the verification of the observed data on an urban drainage basin. The selected model for this study was the Storm Water Management Model(SWMM) developed and maintained by the US Environmental Protection Agency(EPA). In particular, the Runoff Block for the surface discharge and the Transport Block for the flow routing was used. The study basin is Youngdu basin, which is a typical developed urban drainage basin. The four rainfall events for the runoff and the two for the four NPS pollutants(SS, BOD, COD and TN) were used for the calibration and the estimation of the model parameters. This study performed the calibration with regard to the peak discharge, the time to peak discharge, the volume and the relative error for three items. It was shown that SWMM can successfully be used for the prediction of the runoff and the NPS pollutants discharge. The result of this study can be used as the basis for the analysis of the correlation between the runoff and the NPS pollutants discharges, and the analysis of the mass balance with the monthly and annual NPS loads in an urban drainage basin.

• Journal of Korean Society on Water Environment
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• v.22 no.6
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• pp.1068-1074
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• 2006

For receiving water quality protection a control systems of urban drainage for CSOs reduction is needed. Examples in combined sewer systems include downstream storage facilities that detain runoff during periods of high flow and allow the detained water to be conveyed by an interceptor sewer to a centralized treatment plant during periods of low flow. The design of such facilities as storm-water detention storage is highly dependant on the temporal variability of storage capacity available as well as the infiltration capacity of soil and recovery of depression storage. For the continuous long-term analysis of urban drainage system this study used analytical probabilistic model based on derived probability distribution theory. As an alternative to the modeling of urban drainage system for planning or screening level analysis of runoff control alternatives, this model has evolved that offers much ease and flexibility in terms of computation while considering long-term meteorology. This study presented rainfall and runoff characteristics of the subject area using analytical probabilistic model. Runoff characteristics manifested the unique characteristics of the subject area with the infiltration capacity of soil and recovery of depression storage and was examined appropriately by sensitivity analysis. This study presented the average annual CSOs, number of CSOs and event mean CSOs for the decision of storage volume.

• Journal of Soil and Groundwater Environment
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• v.16 no.6
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• pp.34-45
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• 2011

For the Hancheon drainage area in Jeju island, a groundwater flow model using Visual MODFLOW was developed to simulate artificial recharge through injection wells installed in the Hancheon reservoir. The model was used to analyze changes of the groundwater level and the water budget due to the artificial recharge. The model assumed that $2{\times}10^6m^3$ of storm water would recharge annually through the injection wells during the rainy season. The transient simulation results showed that the water level rose by 39.6 m at the nearest monitoring well and by 0.26 m at the well located 7 km downstream from the injection wells demonstrating a large extent of the affected area by the artificial recharge. It also shown that, at the time when the recharge ended in the 5th year, the water level increased by 81 m at the artificial reservoir and the radius of influence was about 2.1 km downstream toward the coast. The residence time of recharged groundwater was estimated to be no less than 5 years. The model also illustrated that 15 years of artificial recharge could increase the average linear velocity of groundwater up to 1540 m/yr, which showed 100 m/yr higher than before. Increase of groundwater storage due to artificial recharge was calculated to be $2.4{\times}10^6$ and $4.3{\times}10^6m^3$ at the end of the 5th and 10th years of artificial recharge, respectively. The rate of storage increase was gradually diminished afterwards, and storage increase of $5.0{\times}10^6m^3$ was retained after 15 years of artificial recharge. Conclusively, the artificial recharge system could augment $5.0{\times}10^6m^3$ of additional groundwater resources in the Hancheon area.

• Journal of Korea Water Resources Association
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• v.42 no.11
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• pp.897-909
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• 2009

The relative contribution of between hillslope-flow and stream-flow by heterogeneity of drainage path are quantitatively assessed in the present study with GIUH model based on grid of GIS. Application watersheds are selected Pyeongchang, Bocheong and Wi river basin of IHP in Korea. The mean and variance of hillslope and stream length are estimated and analyzed in each watershed. And coupling with observation storm events, estimate hillslope and stream characteristic velocity which dynamic parameters of GIUH model. The mean and variance of distribution of travel time (i.e. IUH) calculate using estimated pass lengths and characteristic velocities. And the relative contributions are assessed by heterogeneity of drainage path. As a result, the effect of the variance that determine shape of IUH dominate with hillslope's effect in the small watershed area (within 500 $km^2$). Thus, GIUH in the small watershed area must consider hillslope-flow.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3726-3734
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• 2012

This study evaluated the behavior of pollutants based on the seasonal change by selecting the branch river's factors that influence the outflow of pollutants in Soyang lake basin. The analysis method was the factor analysis that classified the factors of the drainage area influencing the outflow of pollutants, and evaluated selected representative factors. As a result of the study, SS and T-P factors should be classified as similar factors to the storm water runoff, and the improvement of water must be strived through managing source of pollution at the time of no rain. Second, as the result of the influence from the factors, spring and winter seasons usually exert 36% influence and summer and fall exert over 90% significant influence that the improvement of water through managing source of water seems possible. At last, the prediction about delivery pollution load considering the outflow characteristic of pollutants at the drainage area based on seasonal change by regarding selected factors as independent variables is possible.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.3
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• pp.841-847
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• 2014

Urban runoff models have been continuously developing with concerns for urban flood. Recently, models that be able to quantitatively analyze surface inundation caused by overflowed water from storm sewer were also developed by coupling 1-dimensional sewer model and 2-dimensional surface flow model. However, only overflowed water from storm sewer can be analyzed by the models have been developed until now. They are limited to be not able to analyze surface inundation caused by surface runoff that could not flow into the storm sewer. In order to overcome the limitation, basin-overlap method was devised adding a dummy 1-dimensional sewer layer to the model, so it can consider the efficiency of inflow to the storm sewer system. XP-SWMM 2011 is applied for urban runoff model and the flood event occurred on July 27, 2011 in basin-shaped Sadangcheon watershed is chosen for study inundation event. According to simulation results basin-overlap method reappear the observed inundation event more precisely than traditional method. This results suggest that drainage system has to be improved for reducing inundation caused by surface runoff and would be used as considerations for planning an urban basin design magnitude.

• Water Engineering Research
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• v.1 no.1
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• pp.39-48
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• 2000

This work was completed in partial fulfillment of an on-going research ot descover the effective management of urban nonpoint sources. The current data was obtained from the area of Shingal, Kyunni-do. The investigation was are predominant soures of storm-runoff load and drainage. As a result of the investigation, the road was found to be most seriously contaminated and a significant potential source deteriorating the quality of streams and lakes in the vicinity of the town. Thus, in could be concluded that an effective and systematic cleaning technique must be developed as soon as possible and be frequently applied to the road.

• Journal of the Korean institute of surface engineering
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• v.27 no.6
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• pp.347-358
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• 1994

Estimation of durability for corrugated steel pipe(CSP) has been evaluated by using several analytical methods. This study, using a plain hot-dip galvanized CSP as the base line, addresses additional coatings such as polymers sand bituminous coatings that may be used to achieve a desired design life of at least 50years. The behavior of both the soil side and the effluent side of the pipe have been studied. It is estimated that CSP generally provides outstanding dura-bility with regard to soil side effects, and that virtually any required service life can be attained by selecting appropri-ate coatingss and/or thickness of steel substrate. This study is limited to storm drainage systemss carrying naturally oc-curring surface water only. The recommendation in this report do not apply to sanitary or industrial waste sewers or other conduits used to carry corrosive effluents.

• Journal of Korea Water Resources Association
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• v.55 no.1
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• pp.1-10
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• 2022

Irrigation water supplied to the paddy field is consumed in the amount of evapotranspiration, underground infiltration, and natural and artificial drainage from the paddy field. Irrigation return flow is defined as the excess of irrigation water that is not consumed by evapotranspiration and crop, and which returns to an aquifer by infiltration or drainage. The research on estimating the return flow play an important part in water circulation management of agricultural watershed. However, the return flow rate calculations are needs because the result of calculating return flow is different depending on irrigation channel water loss, analysis methods, and local characteristics. In this study, the irrigation return flow rate of agricultural watershed was estimated using the monitoring and SWMM (Storm Water Management Model) modeling from 2017 to 2020 for the Heungeop reservoir located in Wonju, Gangwon-do. SWMM modeling was performed by weather data and observation data, water of supply and drainage were estimated as the result of SWMM model analysis. The applicability of the SWMM model was verified using RMSE and R-square values. The result of analysis from 2017 to 2020, the average annual quick return flow rate was 53.1%. Based on these results, the analysis of water circulation characteristics can perform, it can be provided as basic data for integrated water management.