• Journal of Korea Water Resources Association
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• v.43 no.8
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• pp.681-694
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• 2010

In this study, methodology to determine optimal location of washlands based on economic analysis is presented. Install costs of washlands are calculated by construction cost and land compensatory cost and benefits of washlands are calculated from flood damage reduction and befit from using washland as wetland. Indirect approach for runoff-flood damage relationship is suggested and benefit-cost analysis is used for economic analysis. Economic analysis is added to existing models that used only flood reduction effect to determine optimal location of washlands. Suggested methodology is applied to 13 potential washlands in Anseong River basin to examine its applicability. Applied result of new methodology is compared with that of existing model. As the application results, it is possible to determine the optimal combinations of washlands can provide more economic benefit compared to existing studies. It is determined that considering economic analysis can be better option for decision making problem searching for optimal location of washlands.

• Journal of Korea Water Resources Association
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• v.42 no.7
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• pp.559-569
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• 2009

Due to environmental, economical and the other limitations, it has been more difficult to construct new large hydraulic structure such as dam. For this reason, it has been tried to use small hydraulic structure such as washland as alternative of hydraulic facility. Because the flood control effect of small hydraulic structure are affected by runoff volume, hydrograph, storage capacity and weir crest elevation, and design frequency must be predetermined for the design of the hydraulic structure. Multiple washlands will be required to satisfy enough peak reduction effect so that considering washlands as a network, rather than individually, are critical to analysis of flood reduction effect. In this study, new index for determination of optimal location for washlands is presented and the existing model for this determination is modified by adopting the new index. Developed new model is applied to Ansung river basin for examination and the new model shows its' applicability as a decision making criteria for the determination of optimal location for washlands.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.2
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• pp.123-133
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• 2010

Due to climate change and difficulty in construction of large dam, it is on the increase to use small hydraulic facilities such as washland for the flood control purpose. Since there can be many potential locations for washland in a basin, it is important for determination of optimal location to calculate flood reduction effect of washlands substantially and exactly. In this study, a new scheme to increase flood reduction effect of washlands is suggested. Suggested scheme uses sensitivity analysis of flood reduction effect depending on washland characteristics such as storage volume, spillway elevation and spillway width. The characteristics of the washland is determined by results of sensitivity analysis to maximize flood reduction effect at basin outlet and downstream of a washland. The methodology is applied to Anseong river basin to show its applicability and applied result is compared with those of another studies.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.1
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• pp.145-150
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• 2009

Because it is difficult to install new large hydraulic structure, washland is considered as alternatives of hydraulic facility. As flood reduction effect of washland is dependent on flood, hydrograph, capacity of washland and spillway height, applying adequate spillway height is very important to maximize flood reduction effect of washland. In this study, effect of variation of spillway height on flood reduction effect of washlands is analyzed. The existing model developed to make decision for optimal location of washland using flood reduction effect as evaluation function and location of washland as decision variable was revised for this purpose. The spillway height of washland is added as decision variable and revised model finally give optimal location and spillway height of washland as result. The developed model has been applied to the Ansung River basin and application result was compared with that of existing model. The application result shows that developed model can give more efficient result than existing model.

• Journal of Korea Water Resources Association
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• v.44 no.7
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• pp.565-576
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• 2011

Within a basin, there are potentially multiple locations that can be used as a washland, given their relatively small size when compared with other hydraulic facilities such a dam. However, it is unreasonable to install washlands in all these potential locations due to economic and environmental considerations. In this study, a new methodology for determination of installation priority of washlands is presented. How to integrate the decision variables in this decision making problem has been a key issue in previous studies because a washland can provide many benefits such as flood reduction, agricultural benefit and recreational benefit. In particular, a methodology is needed to integrate all decision variables realistically, properly and reasonably, in situations where there is not sufficient data for direct integration of all these decision variables such as construction cost or benefits a washland can provide. This new methodology aims to suggest how to integrate methodologies used in previous studies. The suggested methodology uses four different rankings which are determined based on a flood reduction effect, a relative significance index, an economic analysis, and a space planning suitability index. These rankings are integrated to determine a final installation priority ranking of washlands by a multi-dimensional scaling method. The new methodology has been applied to the Anseong river basin, to show its applicability, and the application result compared with those of previous studies.

• Journal of Wetlands Research
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• v.10 no.2
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• pp.39-51
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• 2008

In recent days, the cases of using wetlands in treating waste water, storm events, mining leachate, and agriculture effluents are increasing. But there is the lack of the data for wetlands because of the difficulty in long term monitoring. Such an aspect makes the proper use of wetland impractical. In this study for the purpose of generating a long term hydrologic data, the time series of storage amount for Upo, Mokpo, Sajipo, and Jjokjibeol in Topyeong watershed is simulated using SWAT model. Based on the SWAT-Topyeong model involved in several scenarios for constructing new washlands in Topyeong watershed, the temporal behavior of new washlands is analyzed. It is also revealed that the constructed washland can affect the Upo in some degrees.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.956-960
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• 2007

천변저류지의 운영은 홍수기와 평상시 운영으로 구분된다. 본류하천의 홍수저감을 위한 홍수시 저류지 운영을 단기적 운영이라 한다면, 평시 저류지의 수량 관리와 같은 평시 저류지 운영은 장기적 운영이라 할 수 있다. 단기적 운영을 통하여 홍수후 저류지내 퇴적된 토사는 계획홍수조절용량을 감소시킬 뿐만 아니라 평시 저류지내 생태계에 영향을 미친다. 장기적 운영을 위한 평시 저류지내 수위는 저류지내 수질, 생태, 조경, 친수활동 등에 영향을 미친다. 또한 평시 저류지 수위부터 홍수시 수위까지 영역에 관한 수문, 생태, 친수공간, 조경 등의 고려가 필요하다. 본고에서는 천변저류지 조성 계획시 홍수저감, 유입토사 및 평시운영을 위한 수리 및 수문학적 설계기준에서 검토할 내용을 제시하고자 하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1510-1514
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• 2010

강변저류지는 홍수터, 하천연안 저지대 농경지 등을 이용하여 기존 제방의 일부 구간에 취수부를 설치하고 계획홍수 초과 또는 일정 수위 이상 발생 시 이를 일시 저류함으로써 하류의 홍수량을 경감시키는 소규모 수공구조물이다. 이러한 강변저류지와 같은 소규모 수공구조물의 홍수조절효과에 가장 큰 영향을 미치는 인자로는 저류용량이 있으나, off-line 형식을 강변저류지에 적용할 경우 저류용량 이외에도, 취수부의 형식(월류제, 수문)과 취수부의 제원(월류고, 월류폭 등)은 강변저류지의 홍수조절효과에 큰 영향을 미친다. 본 연구에서는 저류용량변화에 따른 홍수조절효과 변화에 초점을 맞춰 수행된 기존의 연구들과 달리, 취수부형식과 취수부 제원 변화에 따른 강변저류지의 홍수조절효과 개선방안을 제시하고자 한다.

• Journal of Korea Water Resources Association
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• v.41 no.7
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• pp.725-735
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• 2008

Due to recent climate change, flood damages have been increased, but it is difficult to construct large hydraulic structure for flood control such as dam because of environmental, economical and political problems. For this reason, several researches and studies have tried to use washland as an alternative of hydraulic facility. Because sizes of washlands are usually smaller than those of dams or reservoirs, there can be many available locations for washlands in a basin and proper combination of these locations can reduce flood disasters efficiently. However, in case there are many available locations for washland and many combinations to consider, it is very difficult to determine the optimal combination which yields to provide the maximum benefit. For the more, hydraulic approach that used in previous studies to calculate flood reduction effect needs a lot of time for calculation and sometimes can not give the final result. In this study, the flood reduction effect of washland is calculated by hydrologic approach and decision making model for optimal location of washland using genetic algorithm for determination of optimal solution is developed. The developed model has been applied to the Ansung River basin in order to examine the applicability and the application result shows that developed model can be used as decision making model for washland.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1240-1244
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• 2009

최근 들어 홍수조절을 위한 대안으로 검토되기 시작한 천변저류지는 적은 저류용량으로 인해 목표하는 홍수저감효과를 얻기 위해 다수의 천변저류지가 설치되어야 하며, 이들 천변저류지군의 홍수조절효과는 저류지군을 연계한 수문네트워크의 분석에 의해 산정되어야 한다. 특히 천변저류지 등과 같은 소규모 수공구조물은 설계빈도, 저류지 제원 등과 같은 수문학적 및 수리학적 조건에 따라 홍수저감효과가 민감하게 반응한다. 즉 설계빈도 변화에 따른 천변저류지의 홍수조절효과를 분석하고, 이를 바탕으로 목표하는 설계빈도 결정이 선행된 후, 천변저류지의 상세 제원에 대한 설계가 가능할 것이다. 본 연구에서는 설계빈도 변화에 따른 유역의 유입수문곡선변화가 천변저류지군의 홍수저감효과에 미치는 영향을 분석해 보았다. 이를 위해 천변저류지의 최적위치를 결정하기 위해 개발된 기존의 의사결정모형을 안성천 유역에 적용하여 다양한 설계빈도에 따른 천변저류지의 홍수저감효과를 분석해 보았다.