• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.1
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• pp.65-77
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• 2022

Due to muddy water from the highland fields upstream of Soyangho Lake, the Mandae, Gaa, and Jawoon have been redesignated as NPS management areas. This study aims to evaluate the adequacy and supplementation points of the implementation plan by analyzing the operation status of muddy water generation and reduction facilities through on-site investigations by NPS management area to achieve the effective nonpoint pollution reduction goal in the implementation of the implementation plan established in 2020. The SS load calculated based on the survey results from July to October 2019 from 2017 showed a decreasen in 2019 compared to 2017. Both and the Jawoon were analyzed to have decreased. However, the amount of precipitation also decreased by about 27%, so it was judged that the effect of the reduction project was not significant. As a result of the detailed investigation of abatement facilities, about 86% of the 793 facilities installed in the management area were evaluated as 'good'. As a result of a detailed investigation by subwatersheds, subwatersheds 105 and 106 in the Mandae were analyzed as apprehensive subwatersheds. appeared to fall. In addition, it was analyzed that the effect of reducing muddy water in the Mandae district was insufficient due to the high ratio of leased farmers, lack of efforts to reduce turbid water in leased farmland, conversion to annual crops, and neglect of bare land. In the case of Gaa district, although the abatement facilities are concentrated in the upstream, muddy water was also found to be severe.

• Journal of Wetlands Research
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• v.17 no.1
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• pp.101-111
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• 2015

This study conducted a field experiment to estimate the characteristics of the rain garden installed at the site near Haman, also proposed a one-dimensional model to simulate the infiltration and runoff from the rain garden. This model was used to evaluate the rain garden using the rainfall data after the installation and during the last 10 years. Also, this model was applied to the annual maximum rainfall events to quantify the size of the impervious area that the rain garden can offset the adverse effect. The results are summarized below. (1) Hydraulic conductivity of the rain garden was estimated to be about 0.0188 m/hr by the variable-stage experiment. Also, the simulation experiment using the last 10 years rainfall data over the entire roof area showed that the infiltration amount is about 90.38% out of the total rainfall. (2) Infiltration simulation of the annual maximum rainfall events during last 10 years showed that the rain garden can offset the impervious area with its size about 30 times of the rain garden surface.

• Journal of Korean Society on Water Environment
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• v.31 no.1
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• pp.12-18
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• 2015

In this research, the hydrologic effects between a pre-existing urban landuse and low impact development (LID) applied conditions were compared and evaluated. The infiltration trench and tree box filter that were utilized in LID represent only 1% of the catchment area that they drain. Storm event monitoring were conducted from July 2010 to July 2014 on a total of 22 storm events in both LID sites. After LID, hydrological improvement was observed as the sites exhibited a delay (lag time) or reduction in the magnitude, frequency and duration of runoff and flow peaks as the rainfall progress. In addition, the maximum irreducible peak flow reduction for infiltration trench was found to be 61% and 33% for the tree box filter when rainfall was 40 mm and 30 mm, respectively. In designing LID, it is recommended to consider the storage capacity and catchment area, as well as the amount of rainfall and runoff on the site.

• Journal of Korean Society on Water Environment
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• v.32 no.1
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• pp.30-35
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• 2016

Urban areas generate large amounts of stormwater and non-point source (NPS) pollutants during rainfall events. These are caused by various land use runoffs, vehicular and human activities and increased impervious cover. The increased runoff and NPS pollutants cause water quality deterioration in the receiving waters and adversely affect the aqua-ecosystem. These environmental impacts could be reduced through the application of low impact development (LID) techniques. In Korea, more than 80% of the total rainfall occurs in summer and most of these were 10 mm or less. Therefore, if the LIDs developed were able to cope with rainfall of 10 mm and below, NPS management could be efficiently conducted. This research was performed to determine the effect of varying amounts of rainfall on the performance capability of an established infiltration and filtration facility (IF facility) that can be applied to Korea's common rainfall ranges. The IF facility area was 1.75% of the catchment area, however the facility treated more than 40% and 60% runoff volume and pollutant reduction respectively for a 10 mm rainfall. Lastly, higher volume and pollutant reduction could be attained when the LID area was at least 2% of the entire catchment.

• Membrane and Water Treatment
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• v.10 no.1
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• pp.91-97
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• 2019

Application of bioretention systems in Korea is highly considered due to its minimal space requirements, appropriateness as small landscape areas and good pollutant removal and peak hydraulic flow reduction efficiency. In this study, the efficiency of two lab-scale bioretention types having different physical properties, media configuration and planted with different shrubs and perennials was investigated in reducing heavy metal pollutants in stormwater runoff. Type A bioretention systems were planted with shrubs whereas type B were planted with perennials. Chrysanthemum zawadskii var. latilobum (A-CL) and Aquilegia flabellata var. pumila (A-AP) respectively were planted in each type A bioretention reactors while Rhododendron indicum linnaeus (B-RL) and Spiraea japonica (B-SJ), respectively were planted in each type B bioretention reactors. Results revealed that the four lab-scale bioretention reactors significantly reduced the influent total suspended load by about 89 to 94% (p<0.01). Type B-RL and B-SJ reactors reduced soluble Cr, Cu, Zn, and Pb by 28 to 45% that were 15 to 35% greater than the soluble metal reduction of type A-CL and A-AP reactors, respectively. Among the pollutants, total Cr attained the greatest discharged fraction of 0.52-0.81. Excluding the effect of soil media, total Pb attained the greatest retention fraction in the bioretention systems amounting to 0.15-0.34. Considering the least discharge fraction of heavy metal in the bioretention system, it was observed that the bioretention systems achieved effectual reduction in terms of total Cu, Zn and Pb. These findings were associated with the poor adsorption capacity of the soil used in each bioretention system. The results of this study may be used for estimating the maintenance requirements of bioretention systems.

• Journal of the Korean Geotechnical Society
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• v.38 no.6
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• pp.41-47
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• 2022

Permeable pavement technology allows the penetration of rainfall into the roadbed, thereby reducing surface runoff and enhancing water quality. The water quality can be improved by adding a filter layer to the permeable pavement. This study analyzes the permeability performance and particulate-matter removal efficiency of a bottom ash-silica sand filter. The performances of five filters with bottom ash and silica sand as the basic materials were evaluated on particulate matter sized 60 ㎛ or smaller. The pure silica sand sample and pure bottom ash sample delivered an average removal efficiency of around 70%. The removal efficiency of the mixed sample was approximately 90%, exceeding the recommended reduction rate (80%) at non-point pollution reduction facilities. In future work, the filter performance should be further verified on permeable pavement.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.247-247
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• 2016

최근 한국은 지구환경 변화에 따른 기후변화 영향으로 집중호우로 인한 도시홍수가 급증하고 있다. 기상변화에 의한 집중호우와 급증된 도시화로 인해 불투수면적이 증가하고, 이는 홍수시 유출량을 증가시켜 기존 하도 또는 내배수 시스템의 적정 소통량을 초과하여 홍수를 발생시킨다. 그리하여 홍수피해를 저감하기 위해 구조적 및 비구조적 홍수방어대책들이 마련되어 시행하고 있다. 하지만 내수배제시설의 경우, 기존의 치수계획이 빗물펌프장 등 일부 구조물에 한정되어 있기에 해당 홍수방어시설에 과도한 부담이 있는 실정이다. 따라서 유역 내에 투수면적을 최대한 확보하여 토양의 수문학적 특성을 유지 보전시켜 첨두유량, 도달시간, 직접유출량을 도시 개발 이전상태와 최대한 유사하도록 하는 홍수유출저감시설을 설치하여 빗물펌프장과 같은 홍수방어시설에 대한 과부하를 덜어준다. 이러한 홍수유출저감시설은 크게 저류시설과 침투시설로 구분된다. 홍수유출저감시설들은 해당 지역의 입지특성, 재해저감효과 및 제약조건에 따라 설치 위치 및 규모가 결정된다. 또한 저감효과는 CN 값의 변화로 정량화하여 시설의 적합성을 판단할 수 있다. 본 연구에서는 SWMM 모형을 이용하여 김천시의 평화배수분구지역을 대상으로 CN 저감을 기반으로 한홍수유출저감시설을 평가하고자 한다.

• Journal of Korean Society of Rural Planning
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• v.30 no.2
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• pp.69-77
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• 2024

As impervious area increases due to urbanization, rainfall on the impervious area does not infiltrate into the ground, and stormwater drains quickly. Low impact development (LID) practices have been suggested as alternatives to infiltrate and store water in soil layers. The practices in South Korea is applied to urban development projects, urban renewal projects, urban regeneration projects, etc., it is required to perform literature research, watershed survey, soil quality, etc. for the LID practices implementation. Prior to the LID implementation at fields, there is a need to simulate its' effect on watershed hydrology, and Storm Water Management Model (SWMM) provides an opportunity to simulate LID practices. The LIDs applied in South Korea are infiltration-based practices, vegetation-based practices, rainwater-harvesting practices, etc. Vegetation-based practices includes bio-retention cell and rain garden, bio-retention cells are mostly employed in the model, adjusting the model parameters to simulate various practices. The bio-retention cell requires inputs regarding surface layer, soil layer, and drain layer, but the inputs for the drain layer are applied without sufficient examination, while the model parameters or inputs are somewhat influential to the practice effects. Thus, the approach to simulate vegetation-based LID practices in SWMM uses was explored and suggested for better LID simulation in South Korea.

• Journal of Wetlands Research
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• v.22 no.3
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• pp.187-193
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• 2020

The increase in the area of impervious water due to the recent abnormal weather conditions and rapid urbanization led to a decrease in the amount of low current, resulting in an increase in the amount of surface runoff. Increased surface runoff is causing erosion, destruction of underwater ecosystems, human and property damage in urban areas due to flooding of urban river. The damage has been increasing in Korea recently due to localized heavy rains, typhoons and floods. As a countermeasure, the Busan Metropolitan Government will proceed with the creation of the Eco-Delta City waterfront zone in Busan with the aim of creating a future-oriented waterfront city from 2012 to 2023. Therefore, the current urban river conditions and precipitation data were collected by utilizing SWMM developed by the Environment Protection Agency, and the target basin was selected to simulate flood damage. Measures to reduce flood damage in various cases were proposed using simulated data. It is a method to establish a disaster prevention plan for each case by establishing scenario for measures to reduce flood damage. Considering structural and non-structural measures by performing an analysis of the drainage door with a 30-year frequency of 80 minutes duration, the expansion effect of the drainage pump station is considered to be greater than that of the expansion of the drainage door, and 8 scenarios and corresponding alternatives were planned in combination with the pre-excluding method, which is a non-structural disaster prevention measure. As a result of the evaluation of each alternative, it was determined that 100㎥/s of the pump station expansion and the pre-excluding EL.(-)1.5m were the best alternatives.

• Journal of Wetlands Research
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• v.23 no.1
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• pp.67-73
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• 2021

As the impermeable area increases due to urbanization and industrialization, the influence of non-point pollutants caused by rainfall runoff on the water system is increasing. In the past, the best management practices(BMP) were used a lot to manage non-point pollutants, but recently, technology that naturally treats them through LID (Low Impact Development) technology is widely used. In this study, various rainfall events were simulated through the SWMM model based on the data of rainfall monitoring in bioretention among natural facilities. The characteristic of LID modeling research is that it is difficult to build accurate modeling data with short-term data because real data is the result obtained through natural facilities, and it is difficult to implement an accurate model. In this study, the data monitored for 3 years It is significant in that it has built a precise model. The actual data monitored a total of 18 times was simulated, and the inflow and outflow and the removal efficiency of five pollutants were simulated. As a result of performing the performance evaluation, most of the 7 items showed excellent indicators, and the TN and TP showed relatively low simulation performance. In the future, it is expected that Korea will introduce an integrated water management system in which the water supply system and the sewage system are substantially integrated and operated. Therefore, the results of this study are considered to play an important role in the initial stage of rainfall management in the future integrated water management system, and the extent of rainfall runoff reduction and pollutant reduction in the expected installation area can be predicted in advance. This is expected to prevent overdesign of bioretention.