• Title/Summary/Keyword: hydrologic safety

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The Effect of Low Impact Development Techniques on Urban Runoff (저영향개발기법이 도시 유출에 미치는 영향)

  • Kim, Heesoo;Chung, Gunhui
    • Journal of Wetlands Research
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    • v.23 no.4
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    • pp.307-316
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    • 2021
  • Due to rapidly increased urbanization, impervious area has been extended and concerns about urban flooding has been increased as well. A lot of effort has been made to restore the urban water circulation. Low Impact Development (LID) technology that consist of retention, infiltration, and evapotranspiration has begun to attract attention to simulate the hydrologic phenomenon before and after development. Many researches on the technique is being actively conducted. In this study, the effect on reducing runoff in urban catchment was analyzed and evaluated by applying LID techniques using SWMM and six scenarios. A SWMM-LID model was built for the Gasan 1 rainwater pumping station basin, and Green Roof and Permeable Pavement were selected as LID techniques to be applied. As a result, the reduction effect of the permeable pavement was larger than green roof. In the future, the results could be used to design a LID facility using the characteristics of the watershed, and other urban water resource factors such as river and groundwater levels that affect each other should be considered, so that the entire system can be considered.

Prospects of future extreme precipitation in South-North Korea shared river basin according to RCP climate change scenarios (RCP 기후변화 시나리오를 활용한 남북공유하천유역 미래 극한강수량 변화 전망)

  • Yeom, Woongsun;Park, Dong-Hyeok;Kown, Minsung;Ahn, Jaehyun
    • Journal of Korea Water Resources Association
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    • v.52 no.9
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    • pp.647-655
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    • 2019
  • Although problems such as river management and flood control have occurred continuously in the Imjin and Bukhan river basin, which are shared by South and North Korea, efforts to manage the basin have not been carried out consistently due to limited cooperation. As the magnitude and frequency of hydrologic phenomena are changing due to global climate change, it is necessary to prepare countermeasures for the rainfall variation in the shared river basin area. Therefore, this study was aimed to project future changes in extreme precipitation in South-North Korea shared river basin by applying 13 Global Climate Models (GCM). Results showed that the probability rainfall compared to the reference period (1981-2005) of the shared river basin increased in the future periods of 2011-2040, 2041-2070 and 2071-2100 under the Representative Concentration Pathways (RCP)4.5 and RCP8.5 scenarios. In addition, the rainfall frequency over the 20-year return period was increased in all periods except for the future periods of 2041-2070 and 2071-2100 under the RCP4.5 scenario. The extreme precipitation in the shared river basin has increased both in magnitude and frequency, and it is expected that the region will have a significant impact from climate change.

A study on estimation of lowflow indices in ungauged basin using multiple regression (다중회귀분석을 이용한 미계측 유역의 갈수지수 산정에 관한 연구)

  • Lim, Ga Kyun;Jeung, Se Jin;Kim, Byung Sik;Chae, Soo Kwon
    • Journal of Korea Water Resources Association
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    • v.53 no.12
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    • pp.1193-1201
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    • 2020
  • This study aims to develop a regression model that estimates a low-flow index that can be applied to ungauged basins. A total of 30 midsized basins in South Korea use long-term runoff data provided by the National Integrated Water Management System (NIWMS) to calculate average low-flow, average minimum streamflow, and low-flow index duration and frequency. This information is used in the correlation analysis with 18 basin factors and 3 climate change factors to identify the basin area, average basin altitude, average basin slope, water system density, runoff curve number, annual evapotranspiration, and annual precipitation in the low-flow index regression model. This study evaluates the model's accuracy by using the root-mean-square error (RMSE) and the mean absolute error (MAE) for 10 ungauged, verified basins and compares them with the previous model's low-flow calculations to determine the effectiveness of the newly developed model. Comparative analysis indicates that the new regression model produces average low-flow, attributed to the consideration of varied basin and hydrologic factors during the new model's development.