• KIEAE Journal
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• 제5권3호
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• pp.17-24
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• 2005

Until today, rainwater management was processed without disposing the peak discharge, which was due to rainfall, to provide stability against flood damage. In this process, the natural hydrologic cycle changed quickly, and because of this, some problems that could harm human beings and the environment arose. These problems need to be addressed accordingly. One of the proposals was to carry out decentralized rainwater management through a natural hydrologic cycle on site, including utilization, infiltration, detention, and retention of rainwater. This study aims to set the direction of applicable decentralized rainwater management to housing complex in Korea. Therefore, spacial properties in urban housing complexes were analysed such as the impervious area-to-land ratio, the green area-to-land ratio, artificial land-to-land ratio etc. As the result of this study, when a housing complex was small and developed by reconstruction, the impervious area, artificial land, the green area in the artificial land-to-land ratio were high. So, direction of decentralized rainwater management of these housing complexes is available to utilize and detain rainwater. On the other hand, those of big housing complexes in land development district were low relatively. So, direction of decentralized rainwater management of these housing complexes is available to infiltrate and evaporate rainwater.

• KIEAE Journal
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• 제11권2호
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• pp.59-65
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• 2011

To analyze changes in the water-balance before and after using decentralized rainwater management facilities, this study carried out hydrologic modeling based on data including roof planting, rainwater use, infiltration and detention facilities applied to the sites. The results of the analysis are as follows: First, the total runoff quantity after facility installation was about 24% less than before. In particular, it showed that the surface runoff declined significantly. Second, the analysis of the effects of different decentralized rainwater management facilities revealed that the rooftop planting contributed to about a 3.5 times increase in actual evaporation than before. Third, the analysis of the effect of decentralized management facilities by different rainfall events showed that it turned to have about a 30% decreasing effect after facility installation for a monthly rainfall over 500mm or so and about 50% declining effect for a monthly rainfall about 200mm. As discussed above, the study confirmed that it is important to implement decentralized rainwater management facilities to improve inevitable changes in water-balance arising from development as it would be a significant alternative for sustainable urban development.

• KIEAE Journal
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• 제6권3호
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• pp.27-34
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• 2006

The recent emphasis on ecological urban development has led to the need to maintain a hydrologic cycle in urban areas. As such, this study proposes decentralized rainwater management, a concept of onsite rainwater management that involves the utilization, infiltration, detention, and retention of rainwater. The main objective of this research is to estimate the proportion of decentralized rainwater management that is needed. From the research that was conducted in this study, it was found that the total runoff quantity increases by 10-20% after district lands are developed, when the probable rate of precipitation every 10 years is within this range. Thus, the runoff rate can be reduced by 10~20% of the total runoff quantity through decentralization. On the other hand, in the scale of housing complex development, the total runoff quantity increases by as much as 10~40% due to the changes in the rate of the impervious surface area. If 10-40% of the total runoff quantity was processed through decentralized rainwater management, the rate of infiltration, detention, retention, and runoff in precipitation prior to development could be recovered.

• KIEAE Journal
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• 제10권4호
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• pp.9-17
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• 2010

The purpose of this study is to draw out objective bases for selecting various applicable facilities in case of the establishment of rainwater management strategies. To do so, sixteen facilities were selected from decentralized rainwater management systems that induce rainwater infiltration and detention as well as centralized end-of-pipe type infiltration and detention facilities in local areas. With these facilities, it attempted to evaluate them in terms of sustainability, pollutant elimination, flood control capacity and costs and subsequently analyzed correlations between each characteristic. The outcomes of the analysis were as follows: First was the analysis of characteristics between decentralized rainwater management systems and end-of-pipe rainwater management systems. From the decentralized rainwater management systems, the mulden-rigolen system and grass swale at street level had the highest in the total of the four items while the totals of the underground detention tank and temporary detention site were highest in end-of-pipe rainwater management systems. After analyzing the correlation between different types of facilities and each variable, it can be said that decentralized rainwater management systems have a higher correlation than end-of-pipe rainwater management systems in terms of sustainability whereas the latter are better in flood control capacity than the former. Second, the analysis of correlation in variables of each facility is as follows: first, there is a negative correlation between sustainability value and flood control capacity value; and there is a positive correlation between flood control capability and pollutants elimination. In addition, it revealed that the higher the flood control and pollutant elimination capability the higher the facility costs. Based on these assessments, it is possible to use them as objective selection criteria for facility application in case of site development project or complex plan.

• KIEAE Journal
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• 제6권3호
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• pp.3-10
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• 2006

As environmental problems and water-shortage phenomenon become a global issue, many states look for the effective method to use water resources. So, decentralized rainwater management is recognized as a new water management system that rainwater can be infiltrated and used on-site. But it is little difficult to build a park, lake, and forest for evaporating rainwater in city because the land price of city is very high. In order to build an excellent infiltration system for a dwelling and a park in Korea, KICT has developed Linear infiltration system. This infiltration system is consist of first flush treatment, storage and infiltration, overflow control system. These elements are connected closely and working as a combined system. A storm sewer can be changed by the linear infiltration system. This study is to make design guideline using Linear infiltration system in apartment house. So ATV-DVWK-M13, FLL and present condition of Korean rainwater system were analyzed and the guidelines direction were set up. Through this study, a foundation is prepared to build the decentralized rainwater management of apartment house.

• KIEAE Journal
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• 제12권3호
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• pp.33-40
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• 2012

Since 2000 country region developmental policy has been to integrate not only the improvement of physical living environment but also various subjects on ecology, environment, scenery, local culture, and green tourism. This study has recently established a decentralized Rainwater Management plan in order to provide an hydrology cycle system to the eco-village being planned by Seocheon-gun as a part of the garden village development business promoted by the ministry of agriculture and forestry. Hydraulic conductivity of the subject area is measured at $10^{-7}{\sim}10^{-10}m/sec$, and a flowerbed-type rainwater Infiltration system capable of controlling a non-point pollution source that stems from the development-caused impermeable surface has been applied. In the case of rainwater flowing out from the main entrance way and parking lot within the complex being treated in the flowerbed-type rainwater infiltration system, natural purification effects via soil and plants as well as natural water cycling effects through evaportranspiration and infiltration are expected. The significance of this study, compared to conventional decentralized rainwater management being applied limited to the urban areas, is that it offers appropriate rainwater management planning based on the analysis of the current situation of the subject area. Decentralized Rainwater Management is a valuable measure both economically and ecologically that reduces the burdens on local underground water cultivation as well as rain water pipe lines or purification systems, and sewage pipes.

• KIEAE Journal
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• 제14권3호
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• pp.15-21
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• 2014

In this study, we developed a modular rainwater infiltration system that can be applied for general purposes in urban areas to prepare for localized heavy rain caused by climatic change. This study also analyzed the system's effects on reducing runoff. An analysis of the system's effects on reducing runoff based on rainfall data and monitoring data obtained between September 2012 and December 2013 after the system was installed showed that approximately 20~22% of the runoff overflowed from the infiltration facility. Also, an analysis of the runoff that occurred during the monsoon season showed that 25% of the runoff overflowed through the storm sewer system of the urban area. These results show that the rainwater overflows after infiltrating the detention facility installed in the area during high-intensity rainfall of 100mm or higher or when precipitation is 100mm for 3~4 days without the prior rainfall. According to precipitation forecasts, torrential rainfall is becoming increasingly prevalent in Korea which is increasing the risk of floods. Therefore, the standards for storm sewer systems should be raised when planning and redeveloping urban areas, and not only should centralized facilities including sewer systems and rainwater pump facilities be increased, but a comprehensive plan should also be established for the water cycle of urban areas. This study indicates that decentralized rainwater management can be effective in an urban area and also indicates that the extended application of rainwater infiltration systems can offer eco-friendly urban development.

• KIEAE Journal
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• 제7권4호
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• pp.9-15
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• 2007

As environmental problems and water-shortage phenomenon become a global issue, many states look for the effective method to use water resources. So, decentralized rainwater management is recognized as a new water management system that rainwater can be infiltrated and used on-site. But it is little difficult to build a park, lake, and forest for evaporating rainwater in city because the land price of city is very high. In order to build an excellent infiltration system for a dwelling and a park in Korea, KICT has developed Linear infiltration system. This infiltration system is consist of first flush treatment, storage and infiltration, overflow control system. These elements are connected closely and working as a combined system. A storm sewer can be changed by the linear infiltration system. This study is to show real application idea about Linear infiltration system with improving some detail in apartments. For this purpose, we devide application idea into the artificial ground and the natural ground and each ground type, suggest a method to cooperate with the other landscape and linear infiltration system. Through this study, we came to recognize a recognition difference of an expert and a commoner about decentralized rainwater management.

• KIEAE Journal
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• 제12권5호
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• pp.3-10
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• 2012

In this study, the influence of decentralized rainwater management over the changes in evapotranspiration was analyzed. The analysis method was obtained by establishing the decentralized rainwater management plan according to different scenarios, and subsequently examined evapotranspiration in the plan. Scenario 1 refers to the analysis of the existing situation, in which was 100% of a parking lot is asphalt pavement. In Scenario 2, the pavement of the parking surface in the parking lot is replaced with lawn blocks. In Scenario 3, some asphalt pavement was removed to establish a flower-bed type infiltration system to allow rainwater to permeate. In Scenario 4, infiltration and storage of rain water would be achieved by transforming the parking surface into lawn blocks, keeping the asphalt for the parking road while establishing a vegetation strip. The amount of evapotranspiration of the target site was analyzed with a water budget analysis program (CAT) using the 2001 meteorological data for each scenario According to the analysis values of S2 and S3, it was found that evapotranspiration is critically affected by the amount of area replaced with pervious area in the total target site. An energy equivalent to 680kWh is required for 1 ton of water to evaporate. Hence, it can be seen that the active inducement of evapotranspiration in urban area makes a positive contribution not only to heat island mitigation, but also to the small-scale water circulation process in a city.

• 한국수자원학회논문집
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• 제45권1호
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• pp.65-73
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• 2012

기후변화로 인한 집중호우와 도시화로 인한 불투수면의 증가는 많은 양의 비를 바로 하수관거로 유출시켜 관거 용량초과로 저지대침수 등의 피해를 일으킨다. 지금까지는 도시의 치수안전도를 높이기 위해 하수관거를 확장하고, 빗물펌프장의 용량을 증대하는 등의 방법을 주로 채택하고 있지만 많은 비용과 시간의 소비를 필요로 하여 현실적으로 불가능에 가깝다. 최근 소방방재청과 수원시는 기존 우수배수 시스템의 한계를 보완하고 대처하기 위한 새로운 대처방안으로 다목적 분산형 빗물관리를 제안하고 있다. 본 연구에서는 수원의 상습침수지역인 M마을을 연구 대상지로하여 XP-SWMM을 이용하여 분산형 빗물저류조 적용에 따른 첨두유출 저감 효과를 확인을 위해 설치 개수, 배치유형(설치위치)을 다르게 하여 집중호우시 치수 안전도에 미치는 영향을 모의하였다. 그 결과 3,000 용량의 빗물저류조 한 개를 설치할 경우 첨두유출이 15.5% 저감되었으며, 500$m^3$ 용량저류조를 6개설치하였을 때는첨두유출이 28%저감되었다. 빗물저류조 배치유형의경우 상류 지역에 가장 비중 있게 설치하고 중류, 하류 순으로 비중을 두어 설치한 형태가 가장 첨두유출 저감효과가 좋았다. 본 연구에서 얻어진 다목적 분산형 빗물관리 시스템의 해석방법은 기후변화에 대비하여 하수관거 용량을 증설하지 않고도 치수 안전도를 증가시킬 수 있는 시스템을 경제적으로 설계하고, 그 효과를 예측하는데 사용될 수 있다.