• Journal of Urban Science
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• v.12 no.2
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• pp.1-6
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• 2023

Due to abnormal climate patteZns, recent extreme weather events such as floods, occurring more frequently than once in a century, have become a common occurrence. This has resulted in frequent urban flooding due to the inadequate capacity of sewage pipelines, originally designed to handle floods occurring once every 20 to 30 years. To tackle this situation, measures such as partial flow retention through reservoirs, flood control facilities, and underground tanks have been implemented. In this study, the Storm Water Management Model, a sewage pipeline model developed by the U.S. Environmental Protection Agency (U.S. EPA), was used to analyze the flow capacity of sewage pipelines on the campus of Daegu University and to conduct research on pollutant reduction through superior control facilities. When the allowable flow velocity, ranging from 0.8 m/s to 3.0 m/s, could not be met, the slope of the sewage pipeline was adjusted through step junctions. The simulation demonstrated a 20% reduction in peak flow, decreasing from 0.69 cm/s to 0.55 cm/s, through the implementation of flow regulation facilities. It is anticipated that the findings of this study can serve as valuable data for adjusting flow velocity and reducing peak flow within the pipelines.

• Journal of the Korean housing association
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• v.20 no.3
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• pp.69-76
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• 2009

The Storm Water Management Model(SWMM) by EPA is a dynamic rainwater-runoff simulation model used for single event or long-term simulation of runoff quantity and quality from primarily urban areas. The SWMM simulation program is operated by the site area, the weather date, conduit plan etc. on reference region. The purpose of this study was to analyze flood area, the duration of flooded and surcharged on the reference region. Without rainwater stored tank, the area of flooded and surcharged on reference area is similar to the area of reference region. But, With rainwater stored tank, the area of flooded and surcharged on reference area is much reduced compared to without rainwater stored tank. According to SWMM simulation results, the rainwater stored tank is located closer to site is more effective for reduction of duration of flooded and surcharged and flow rate.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.6
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• pp.711-717
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• 2009

In this study, SWMM model is used to reproduce the main storm sewer system located in the Nae-Hang drainage basin of the Mokpo city and keep track of flood discharge. Given the outlet of the reaches border the coastline, this paper has taken the dual-drainage approach to perform inundation simulation, considering both the overflows and inflows at the manholes of the sewer system, and at the same time, taking the impacts of tidal stage into consideration. The following conclusions are reached in this study: First, when planning lowland sewer system alongside the coastline or the riverside, the tidal stage or flood stage need to be considered in the planning and design processes. Second, an analysis that fails to consider overflow and inundation at the manholes may overestimate inundation depth of the flooded area. In other words, in order to estimate flood discharge and flood stage in a lowland storm sewer system, it is desirable to analyze the conveyance capacity of storm sewer system and simulate overflow and inundation at the manholes at the same time.

• Journal of Korea Water Resources Association
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• v.31 no.6
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• pp.695-708
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• 1998

Recently, it seems increasing trends that the design floods on the middle and small scale of urban regions and natural basins are evaluated with introducing to the concept of the critical storm duration. However the study of the critical storm duration is not sufficient and especially on the natural basins, it rarely performed. therefore in this study, estimated the critical storm duration and peak discharge according to the rainfall distribution type, the position of peak rainfall intensity, and the frequency on the natural basins were evaluated using Clark model and the influence of each factors on the design floods was analyzed with sensitivity analysis on the parameters of the model.

• Water for future
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• v.15 no.3
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• pp.37-47
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• 1982

In the past, the design flow of the urban storm drainage systems has been used largely on a basis of empirical and experience, and the rational formula one of empirical method has been widely used for our country, as well as world wide. But the empirical method has insufficient factor because minimal consideration is given to the relationship of the parameters in the equation to the processes being considered, and considerable use of experience and judgment in setting values to the coefficients in the equation is made. The postcomputer era of hydrology has brought an acceleration development of mathematical methods, thus mathematical models are methods which will greatly increase our understanding in hydrology. On this study, a simple mathematical model of urban presented by British Road Research Laboratory is tested on urban watersheds in Ju An Ju Gong Apartment. The basin is located in Kan Seog Dong, Inchon. The model produces a runoff hydrograph by applying rain all to only the directly connected impervious area of the basin. To apply this model the basin is divided into contributing areas or subbasins. With this information the time area for contributing is derived. The rainfall hyetograph to design storm for the basin flow has been obtained by determination of total rainfall and the temporal distribution of that rainfall determined on the basis of Huff's method form historical rainfall data of the basin. The inflows from several subbaisns are successively routed down the network of reaches from the upstream end to the outlet. A simple storage routing technique is used which involves the use of the Manning equation to compute the stage discharge curve for the cross-section in question. To apply the model to a basin, the pattern of impervious areas must be known in detail, as well as the slopes and sizes of all surface and subsurface drains.

• Journal of Korean Society on Water Environment
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• v.24 no.6
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• pp.806-816
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• 2008

In recent years, increases in impervious areas with rapid urbanization and land use changes are causing numerous hydrologic and environmental problems. In this study Low Impact Development (LID) was applied to investigate changes in runoff and peak runoff with LID plans. SWMM 5.0 was used to simulate LID Integrated Management Practices (IMPs) at study area. The SWMM estimated total runoff volume with conventional land use planning is (82.3%, 46.44 mm), (99%, 73.16 mm) greater than total runoff before urbanization, while total runoff with LID is (11.1%, 46.44 mm), (49%, 73.16 mm) greater than those before urbanization. With the LID adoption in land use planning, pervious area increases by 49.8% compared with that from the conventional urban land use planning, resulting in (32.7%, 46.44 mm), (23.6%, 73.16 mm) decrease in total runoff, and (32.6%, 46.44 mm), (18.5%, 73.16 mm) decreases in peak rate runoff. The results obtained from this study indicate that peak rate runoff, time to peak, and total runoff can be reduced with the LID in urban land use planning because the LID secures pervious areas with various LID IMPs. The SWMM simulated result using design storm data and the US EPA suggested CN values for various LID IMPs implies that how environment-friendly urban land use planning with the LID adoption is important for sustainable development at urbanizing watershed.

• Journal of Korean Society on Water Environment
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• v.22 no.1
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• pp.110-115
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• 2006

Flooding situation of Sutak basin was simulated and simulation seemed to be consistent with the real flooding situation in terms of high water levels and timings of flooding. The flood simulation model was used to evaluate alternatives to mitigate flooding problems in Sutak basin. From the evaluation of flood mitigation plans, it was found that combined operation of Sutak and Inchang pumping stations through partial diversion of inflow of Sutak pumping station to Inchang pumping station was the most effective one among the suggested mitigation plans. About 500 meter diversion channel will be needed to send 30% of Sutak pumping station inflow to Inchang pumping station. This will reduce overload of Sutak pumping station and the storage capacity of Inchang pumping station will be more efficiently utilized.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1802-1806
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• 2006

It is important to consider the effects of land-use changes on surface runoff, stream flow, and groundwater recharge. Expansion of urban areas significantly impacts the environment in terms of ground water recharge, water pollution, and storm water drainage. Increase of impervious area due to urbanization leads to an increase in surface runoff volume, contributes to downstream flooding and a net loss in groundwater recharge. Assessment of the hydrologic impacts or urban land-use change traditionally includes models that evaluate how land use change alters peak runoff rates, and these results are then used in the design of drainage systems. Such methods however do not address the long-term hydrologic impacts of urban land use change and often do not consider how pollutants that wash off from different land uses affect water quality. L-THIA (Long-Term Hydrologic Impact Assessment) is an analysis tool that provides site-specific estimates of changes in runoff, recharge and non point source pollution resulting from past or proposed land-use changes. It gives long-term average annual runoff for a land use configuration, based on climate data for that area. In this study, the environmental and hydrological impact from the urbanized basin had been examined with GIS L-THIA in Korea.

• Journal of Korea Water Resources Association
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• v.55 no.10
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• pp.707-721
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• 2022

In this study, a state-of-the-art review on urban inundation simulation technology was presented summarizing major achievements and limitations, and future research recommendations and challenges. More than 160 papers published in major domestic academic journals since the 2000s were analyzed. After analyzing the core themes and contents of the papers, the status of technological development was reviewed according to simulation methodologies such as physically-based and data-driven approaches. In addition, research trends for application purposes and advances in overseas and related fields were analyzed. Since more than 60% of urban inundation research used Storm Water Management Model (SWMM), developing new modeling techniques for detailed physical processes of dual drainage was encouraged. Data-based approaches have become a new status quo in urban inundation modeling. However, given that hydrological extreme data is rare, balanced research development of data and physically-based approaches was recommended. Urban inundation analysis technology, actively combined with new technologies in other fields such as artificial intelligence, IoT, and metaverse, would require continuous support from society and holistic approaches to solve challenges from climate risk and reduce disaster damage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.1
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• pp.110-115
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• 2007

The localized rainfall happens frequently in urban areas recently and then, he drain pipes of urban areas do not drain well when the localized rainfalls happen. Specially, the inundation by the backwater on the lowland should be solved certainly in urban planning and sewer rehabilitation. In this study, it was examined whether the carrying capacities of the drain pipe are satisfied about a current design standard of the rainfall considering the outflows of the urban areas by the rainfall analysis. Also, the backwater in the drain pipe and the inundation on the lowland were analyzed considering the water level of the discharged river and the propriety of the design standard was examined by the analysis about the rainfall frequency. Also, the results offered the basic data to decide whether the detention reservoir should be established and the scale of the pump station.