• Journal of Korea Water Resources Association
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• v.45 no.2
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• pp.203-215
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• 2012

The objective of this study is to develop a catchment hydrologic cycle assessment model which can assess the impact of urban development and designing water cycle improvement facilities. Developed model might contribute to minimize the damage caused by urban development and to establish sustainableurban environments. The existing conceptual lumped models have a potential limitation in their capacity to simulate the hydrologic impacts of land use changes and assess diverse urban design. The distributed physics-based models under active study are data demanding; and much time is required to gather and check input data; and the cost of setting up a simulation and computational demand are required. The Catchment Hydrologic Cycle Assessment Tool (hereinafter the CAT) is a water cycle analysis model based on physical parameters and it has a link-node model structure. The CAT model can assess the characteristics of the short/long-term changes in water cycles before and after urbanization in the catchment. It supports the effective design of water cycle improvement facilities by supplementing the strengths and weaknesses of existing conceptual parameter-based lumped hydrologic models and physical parameter-based distributed hydrologic models. the model was applied to Seolma-cheon catchment, also calibrated and validated using 6 years (2002~2007) hourly streamflow data in Jeonjeokbigyo station, and the Nash-Sutcliffe model efficiencies were 0.75 (2002~2004) and 0.89 (2005~2007).

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.276-277
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• 2005

• Journal of Wetlands Research
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• v.21 no.3
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• pp.191-198
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• 2019

High impervious surfaces increase the surface runoff during rainfall and reduces the underground infiltration thereby leading to water cycle distortion. The distortion of water cycle causes various urban environmental problems such as urban flooding, drought, water pollutant due to non-point pollution runoff, and water ecosystem damage. Climate change intensified seasonal biases in urban rainfall and affected urban microclimate, thereby increasing the intensity and frequency of urban floods and droughts. Low impact development(LID) technology has been applied to various purposes as a technique to reduce urban environmental problems caused by water by restoring the natural water cycle in the city. This study evaluated the contribution of hydrologic characteristics and water cycle recovery after LID application using long-term monitoring results of various LID technology applied in urban areas. Based on the results, the high retention and infiltration rate of the LID facility was found to contribute significantly to peak flow reduction and runoff delay during rainfall. The average runoff reduction effect was more than 60% at the LID facility. The surface area of the LID facility area ratio(SA/CA) was evaluated as an important factor affecting peak flow reduction and runoff delay effect.

• Journal of Environmental Science International
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• v.31 no.12
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• pp.1013-1025
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• 2022

This study was carried out to analyze water cycle characteristics and evaluate water retention function in Jeju Gotjawal forest from 2013 to 2017. The average ratio of throughfall, stemflow, interception loss in Seonhul Gotjawal (SH) and Cheongsu Gotjawal (CS) was 43.1%, 15.8%, and 41.1%, respectively. Rainfall-throughfall, rainfall-stemflow, and rainfall-interception loss were expressed as linear regression equation (p<0.001). The comparison results showed that SH was higher than CS (p<0.05), indicating that the canopy area had an important effect on the difference in stand structure. The average water resources retention rate of the Gotjawal region was 41.9%, which is similar to the total water resources retention rate (40.6%) of Jeju Special Self-Governing Province (JSSGP). Currently, the development of Gotjawal is in progress in JSSGP. The development of Gotjawal will lead to a decrease in the water resources retention rate due to changes in the surface environment such as an increase in impervious areas, which will affect the total groundwater content of JSSGP. Therefore, the conservation of the Gotjawal area is judged to be very important from the point of view of water conservation.

• Journal of Korea Water Resources Association
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• v.38 no.6 s.155
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• pp.449-460
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• 2005

In this study, a WEP (Water and Energy transfer Processes) model was used to simulate the water cycle of the Dorimcheon catchment which suffers from the distorted water cycle as a typical urban catchment. Two different land uses in the past (i.e. 1975) and at present (i.e. 2000) were incorporated into the simulation to investigate the runoff characteristics resulting from the increase of the impervious ratio due to urbanization. The simulation results show that the concentration time is decreased and the peak discharge and the total runoff are increased by urbanization while the infiltration and baseflow are reduced. In addition, the effects of infiltration trenches and permeable pavements were also simulated to search for alternatives that can restore the distorted water cycle. The simulation results prove that the installation of both alternatives can restore the runoff characteristics to that prior to urbanization.

• Journal of Korea Water Resources Association
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• v.57 no.3
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• pp.165-179
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• 2024

It is crucial to have a comprehensive understanding of inundation and water cycle in urban areas for mitigating flood risks and sustainable water resources management. In this study, we developed a Cellular Automata-based integrated Water cycle model (CAW). A comparative analysis with physics-based and conventional cellular automata-based models was performed in an urban watershed in Portland, USA, to evaluate the adequacy of spatiotemporal inundation simulation in the context of a high-resolution setup. A high similarity was found in the maximum inundation maps by CAW and Weighted Cellular Automata 2 Dimension (WCA2D) model presumably due to the same diffuse wave assumption, showing an average Root-Mean-Square-Error (RMSE) value of 1.3 cm and high scores of binary pattern indices (HR 0.91, FAR 0.02, CSI 0.90). Furthermore, through multiple simulation experiments estimating the effects of land cover and soil conditions on inundation and infiltration, as the impermeability rate increased by 41%, the infiltration decreased by 54% (4.16 mm/m²) while the maximum inundation depth increased by 10% (2.19 mm/m²). It was expected that high-resolution integrated inundation and water cycle analysis considering various land cover and soil conditions in urban areas would be feasible using CAW.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6597-6601
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• 2013

This study aims at suggesting a evaluation method of water cycle soundness in U-City. The distortion of water cycle soundness induced industrialization and urbanization was quantitatively analyzed. In order to evaluate the soundness of water cycle in U-City the reduction ratio of runoff was evaluated in comparison of before the construction of the water recycling facilities for natural water cycle, the reduction ratio of urban water was evaluated in comparison of before the introduction of the artificial recycling facilities for artificial water cycle.

• Journal of Korean Society on Water Environment
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• v.36 no.2
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• pp.109-115
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• 2020

Recently, since impervious areas have increased due to urban development, the water cycle system of urban watersheds has been destructed. Hence, researches on LID (Low Impact Development) technique have been conducted to solve such problems environmentally. In order to verify suitability with the scale and arrangement of LID technique, the runoff reduction effect of the LID technique should be analyzed per small watershed unit. In this study, pre-post difference of the runoff by applying the LID was estimated using the rational method and rainwater treatment capacity equation. As a result, the runoff before and after the application of LID were estimated as 22,533.5 ㎥ and 14,992.1 ㎥, respectively. In addition, rainfall-runoff simulations were carried out using SWMM to evaluate the efficiency of the LID technique. The SWMM simulation results showed that the runoff before and after the application of LID were 21,174 ㎥ and 15,664 ㎥, respectively. Based on the results of the two methods, the scale and arrangement of the LID technique were revised in order to maximize the effect of the water cycle improvement. Rainfall-runoff simulations were carried out using the SWMM with the revised LID techniques. As a result, despite 34.8 % reduction of pervious pavement area, the rate of runoff reduction increased by 2.1 %. These results indicate that designing the scale and arrangement of LID technique, while considering the total amount of inflow entering into each LID techniques, is essential to effectively achieve the goals of runoff reduction in urban development.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5330-5336
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• 2011

It becomes more and more important to develop various infiltration facilities for healthy water cycle and reduction of urban storm water runoff. In this study, a infiltration facility by utilizing tree box was developed. The developed facility is capable of reducing storm water road runoff, improving urban water cycle, and performing other sustainable and environmental functions. Because the facility can be manufactured to a smaller size than an existing runoff reduction facility, it can be installed at various road types of not only existing urban areas, but new developed areas. If the facility is applied to four-lane roadways, it is expected to reduce 65% of rainfall runoff discharge. Urban flood control improvement can be accomplished by a wide application of the developed technique.

• Land and Housing Review
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• v.8 no.4
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• pp.267-274
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• 2017

Since LID design process for the urban regeneration has not yet been established in Korea, this study was extablished in LID design process through reterauture reviews and expert opinions. But the extablished LID design processes have many limitations to be applied to proper LID facilities to the site because of not considering characteristics and water flow of the site. To solve the limitations of existing design processes, it is necessary for analysis of water flow through GIS analysis at the site. After analysis of water flow, it is important to find areas cut off water flow and to install LID facilities at those points. Through these considerations, this study present the improved LID design process to apply to urban regeneration.