• 한국전통조경학회지
• /
• 제35권4호
• /
• pp.126-133
• /
• 2017

본 연구는 조경기술기반 LID 시스템 적용에 따른 선릉 정릉 권역의 우수유출변화를 수문학적 관점에서 분석하였으며, 연구결과를 다음과 같이 정리할 수 있다. 첫째, 광화문 침수가 발생한 2011년 7월 27일 기준 최대순간강우량은 27일 10시에 기록된 183mm/hr로 시간당 최대강우량 57.5mm/hr에 비해 3배 이상의 강우강도가 10분간 집중된 것으로 확인되었다. 둘째, 토심기준 시나리오에서 담심 1,500mm의 경우 첨두유출량 제어가 가능하여 해당 조경기술기반 LID 시스템 적용 시 선릉 정릉 권역의 수해취약성을 개선할 수 있을 것으로 판단된다. 셋째, 담심 기준 시나리오에서 모든 토심 모형에서 첨두유출량 제어가 이루어지지 않았으나, 최초 우수유출을 토심 기준 시나리오에 비해 4시간 10분의 추가적인 지연효과를 기록하였다. 초기 우수유출저감에는 토심, 첨두유출량에는 담심이 상대적으로 중요한 지표로 해석되었다. 이를 통해 문화재 보호권역 내 경관친화적인 생태적 요소를 시스템화하여 적용할 경우 예상되는 수해방재효과를 이론적으로 확인할 수 있었다.

• 한국방재학회:학술대회논문집
• /
• 한국방재학회 2007년도 정기총회 및 학술발표대회
• /
• pp.632-635
• /
• 2007

Detention pond has an important role in peak flow reduction to mitigate flood damage. Design of detention pond is accomplished through the preliminary stage, planning stage, and design stage in general. New development projects produce increased peak flow and flow amounts. In this case it is necessary to design the detention pond easily and simply. The simple procedure of detention pond design is proposed in this study. The relevant variables are peak flow ratio ($\alpha$) for the before and after development, and storage ratio which is ratio of storage volume to flow amounts. Simplified method for the detention pond design with runoff reduction is easily used for practical purposes.

• 한국물환경학회지
• /
• 제31권2호
• /
• pp.166-180
• /
• 2015

Pollutant in watersheds comes from two major sources which are NPS (nonpoint source pollution) and PS (point source pollution). Most of the pollutant can be treated by wastewater treatment plants. However, wastewater treatment plants may not be an appropriate practice to improve water quality for the watersheds with large portion of NPS pollutant and NPS pollution from direct runoff and baseflow has different characteristics. Therefore the practices to improve water quality need to be comprehensive for pollutants by both direct runoff and baseflow. Riparian buffer, one of practices to manage pollutant in watershed, has been applied to reduce pollutant not only from direct runoff but also baseflow. In this study, the scenarios for pollutant reduction by wastewater treat plants and the nitrogen reduction by riparian buffer were simulated using SWAT-REMM to suggest an effective plan for pollutant reduction from baseflow. Riparian buffer provided nitrogen reduction of 0.2~75.0% in YbB watershed and 38.0~47.0% in GbA watershed. The result indicates that riparian buffer is effective to reduce the pollutant especially from baseflow, and it suggested as suitable for the a watershed which WWTP discharge is not capable to reduce enough pollutant.

• 한국농공학회논문집
• /
• 제56권3호
• /
• pp.31-38
• /
• 2014

Four actual cultivations were prepared and a variety of soybean was cultivated. A H-flume, an automatic water level gauge and an automatic water sampler were installed at the outlet of each plot equipped for the measurement of flow rate and its water quality. The amount of rainfall of the study area in 2013 was measured as 975.6 mm which was much lower than the annual average rainfall of 1,271.8 mm, resulting in less occurrences in rainfall-runoff events. Rainfall-runoff events were occurred three times during the rainfall event of 4~5 July, 23 and 24 August. The characteristics of NPS pollution discharge of the plots and the reduction effect of the selected BMPs were analyzed during these events. The reduction effect of straw mat and soil amendments (Polyacrylamide (PAM) and Gypsum) on runoff ratio ranged between 38.2 and 92.9% (average 71.6%). The NPS pollution load reduced between 27.7 and 95.1% (average 70.0%) by the application of rice straw mat and soil conditioner when compared with that of control plot. Soybean yield (2,133.3 kg/ha) of the straw mat covered plots increased by 14.3% when compared with control (1,866.7 kg/ha). The effect of straw mat on the yield was not economically viable if the material and accompanying labor costs were considered. The data collected and analyzed on different soil textures and crops in this study are expected to be a fundamental reference for the expansion of the results to the application nationwide and the development of NPS pollution management policies.

• 한국물환경학회지
• /
• 제24권6호
• /
• pp.806-816
• /
• 2008

In recent years, increases in impervious areas with rapid urbanization and land use changes are causing numerous hydrologic and environmental problems. In this study Low Impact Development (LID) was applied to investigate changes in runoff and peak runoff with LID plans. SWMM 5.0 was used to simulate LID Integrated Management Practices (IMPs) at study area. The SWMM estimated total runoff volume with conventional land use planning is (82.3%, 46.44 mm), (99%, 73.16 mm) greater than total runoff before urbanization, while total runoff with LID is (11.1%, 46.44 mm), (49%, 73.16 mm) greater than those before urbanization. With the LID adoption in land use planning, pervious area increases by 49.8% compared with that from the conventional urban land use planning, resulting in (32.7%, 46.44 mm), (23.6%, 73.16 mm) decrease in total runoff, and (32.6%, 46.44 mm), (18.5%, 73.16 mm) decreases in peak rate runoff. The results obtained from this study indicate that peak rate runoff, time to peak, and total runoff can be reduced with the LID in urban land use planning because the LID secures pervious areas with various LID IMPs. The SWMM simulated result using design storm data and the US EPA suggested CN values for various LID IMPs implies that how environment-friendly urban land use planning with the LID adoption is important for sustainable development at urbanizing watershed.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2015년도 학술발표회
• /
• pp.235-235
• /
• 2015

This study investigates the impact of event characteristics on runoff dynamics during extreme flood events observed in a $8.5km^2$ experimental watershed located in South Korea. The 37 most extreme flood events with event rainfall in excess of 50 mm were analysed using an event-based rainfall-runoff model; the Revitalised Flood Hydrograph (ReFH) routinely used for design flood estimation in the United Kingdom. The ReFH model was fitted to each event in turn, and links were investigated between each of the two model parameters controlling runoff production and response time, respectively, and event characteristics such as rainfall depth, duration, intensity and also antecedent soil moisture. The results show that the structure of the ReFH model can effectively accommodate any nonlinearity in runoff production, but that the linear unit hydrograph fails to adequately represent a reduction in watershed response time observed for the more extreme events. By linking the unit hydrograph shape directly to rainfall depth, the consequence of the observed nonlinearity in response time is to increase design peak flow by between 50% for a 10 year return period, and up to 80% when considering the probable maximum flood (PMF).

• 한국농공학회논문집
• /
• 제61권1호
• /
• pp.21-29
• /
• 2019

This study analyzed the variability of drought risk based on trend analysis of dry-seasonal dam inflow located in upper river basins. To this, we used areal averaged precipitation and dam inflow of three upper river dams such as Soyang dam, Chungju dam, and Andong dam. We employed Mann-Kendall trend analysis and change point detection method to identify the significant trends and changing point in time series. Our results showed that significant decreasing trends (95% confidence interval) in dry-seasonal runoff rates (= dam inflow/precipitation) in three-dam basins. We investigated potential causes of decreasing runoff rates trends using changes in potential evapotranspiration (PET) and precipitation indices. However, there were no clear relation among changes in runoff rates, PET, and precipitation indices. Runoff rate reduction in the three dams may increase the risk of dam operational management and long-term water resource planning. Therefore, it will be necessary to perform a multilateral analysis to better understand decreasing runoff rates.

• 한국지형학회지
• /
• 제23권1호
• /
• pp.77-85
• /
• 2016

To understand the difference of runoff discharge processes between Gwangneung deciduous and coniferous forest catchments, we collected hydrological data (e.g., precipitation, soil moisture, runoff discharge) and conducted hydrochemical analyses in the deciduous and coniferous forest catchments in Gwangneung National Arboretum in the northwest part of South Korea. Based on the end-member mixing analysis of the three storm events during the summer monsoon in 2005, the hillslope runoff in the deciduous forest catchment was higher 20% than the coniferousforest catchment during the firststorm event. Howerver, hillslope runoff increased from the second storm event in the coniferous catchment. We conclude that low soil water contents and topographical gradient characteristics highly influence runoff in the coniferous forest catchment during the first storm events. In general, coniferous forests are shown high interception loss and low soil moisture compared to the deciduous forests. It may also be more likely to be a reduction in soil porosity development when artificial coniferous forests reduced soil biodiversity. The forest soil porosity is an important indicator to determine the water recharge of the forest. Therefore, in order to secure the water resources, it should be managed coniferous forests for improving soil biodiversity and porosity.

• 한국농공학회:학술대회논문집
• /
• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
• /
• pp.525-530
• /
• 1999

A modified SCS TR-20 model that may be applied to a watershed having rice paddies as a land use type, was formulated and applied to a gauaged watershed. The model was applied to the Balan watershed of 26$\textrm{km}^2$ in size for estimation strorm hydrographs . And the simulation results from the model were also compared with thoses from the SCS model. The results showed that paddy fields play an important role to reduce peak runoff. When fractions of paddies are left to fallow conditions or when rice crop is replaced by other, the peak runoff was found to increase up to 10 to 20 percentg . The reduction rates in peak runoff appear to become greater for heavier storms or higher antecedent moisture conditions.

• 한국산학기술학회논문지
• /
• 제18권1호
• /
• pp.282-286
• /
• 2017

급격한 산업화 및 도시화로 인해 불투수 지역이 증가됨에 따라 유출량 또한 증가되어 도시지역에 침수를 발생시켜 피해를 주고 있다. 본 연구에서는 관 조도계수의 개선이 유출 및 월류에 미치는 효과를 강우-유출 모의를 통하여 분석하였다. 이를 위해 총 관로 연장 대비 조도계수 개선 비율에 따른 효과, 관경별 조도계수 개선 적용 효과, 주요 관거 중심의 조도계수 개선 효과 등 3가지 시나리오로 구분하여 모의하였으며, 도시지역에서의 강우-유출 해석 모의에 많이 사용되는 SWMM모형을 이용하여 분석하였다. 연구 결과 관로연장이 길고, 관경이 큰 주요 간선을 우선적으로 개선하는 것이 월류저감에 효과적인 것으로 나타났다. 대부분의 간선 관거의 특성상 관의 크기 및 길이가 길기 때문에 유출구로 유출되기까지의 유속을 증가시켜 관의 통수능 확보 및 월류저감에 효과가 있는 것으로 판단된다. 또한, 본 연구 결과는 관거 교체의 우선순위 선정에 참고가 될 것으로 판단된다. 향후 조도계수 개선을 위한 경제성을 고려한 최적화 분석이 이루어진다면 최적의 홍수재해저감에 기여할 것으로 판단된다.