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Recently, interested in LID and GI has been increasing for sustainable development. Rain water harvesting system is commonly used in various type as a form of low impact development. This study introduces a rain barrel sharing network, which is a connected system through water-sharing among individual RWHS users. In this study, we developed an evaluation procedure for the reliability, resiliency, and vulnerability of a RBSN based on a SRY relationship. The preliminary result shows that reliability and vulnerability increased with all the users connected. However, resiliency is degraded as the degree of sharing increases. Based on this, we analyzed the benefit from a RBSN with 73 observing data and RCP scenarios in South Korea and investigated the regional characteristics of benefits from the RBSN. The potential benefit from a RBSN implies the important role of social practices under water scarcity and extreme hydrologic events with climate change.
You Jeong Kwon; Yongwon Seo. Evaluation of a rain barrel sharing network for sustainable water management. 2020, 1 .
AMA StyleYou Jeong Kwon, Yongwon Seo. Evaluation of a rain barrel sharing network for sustainable water management. . 2020; ():1.
Chicago/Turabian StyleYou Jeong Kwon; Yongwon Seo. 2020. "Evaluation of a rain barrel sharing network for sustainable water management." , no. : 1.
The efficiency of urban drainage networks are very important within the framework of flood mitigation planning. This study suggests a methodology to evaluate the efficiency of urban drainage networks. Gibbs’s model was applied to 237 catchments in Seoul. If the parameter β is less than 100, it is regards as an inefficient network. Otherwise, it is an efficient network. The results show number of catchments with lower β is greater than with higher β. This is contradictory to common sense that urban drainage networks are efficient. Identifying the efficiency of an urban drainage networks suggest potential flood reduction by an alternative method, which is related to a layout of the networks.
Junshik Hwang; Yongwon Seo; Hyun Il Choi. Efficiency of Urban Drainage Networks: A Case Study in Seoul. 2020, 1 .
AMA StyleJunshik Hwang, Yongwon Seo, Hyun Il Choi. Efficiency of Urban Drainage Networks: A Case Study in Seoul. . 2020; ():1.
Chicago/Turabian StyleJunshik Hwang; Yongwon Seo; Hyun Il Choi. 2020. "Efficiency of Urban Drainage Networks: A Case Study in Seoul." , no. : 1.
The main goal of this study is to evaluate the application of participatory approaches in the planning of drinking water supply (DWS) and basic sanitation (BS) projects in rural communities of Colombia. Information was collected through interviews with experts, official and scientific publications. The analysis utilized qualitative methodologies (coding, integration, and triangulation of information) and the Business Model Canvas (non-profits). The results show the adopted different participatory approaches in the planning of the same kind of projects. In addition, the results suggest that the use of these methodologies in the planning of the projects allows the selection of technologies that adapt to the cultural, social and economic conditions of the beneficiary communities; it also generates a sense of belonging, and systems ownership, which results in their sustainability. However, the results indicate that institutional, social, financial, technical and political aspects limit its application. The analysis showed for the effective incorporation of participatory approach (PA) in the planning of DWS and BS in Colombia is necessary to define guiding instruments for the planning and development of participatory processes, to strengthen capacities of the professionals in charge of project planning, local governments and communities; and allocation of the financial resources to carry out the processes.
Coronel Picon Yulieth Rossio; Yongwon Seo. Participatory Approaches in the Planning of Drinking Water Supply and Basic Sanitation Projects in the Rural Areas of Colombia. KSCE Journal of Civil Engineering 2020, 24, 1374 -1382.
AMA StyleCoronel Picon Yulieth Rossio, Yongwon Seo. Participatory Approaches in the Planning of Drinking Water Supply and Basic Sanitation Projects in the Rural Areas of Colombia. KSCE Journal of Civil Engineering. 2020; 24 (4):1374-1382.
Chicago/Turabian StyleCoronel Picon Yulieth Rossio; Yongwon Seo. 2020. "Participatory Approaches in the Planning of Drinking Water Supply and Basic Sanitation Projects in the Rural Areas of Colombia." KSCE Journal of Civil Engineering 24, no. 4: 1374-1382.
Natural catchments have formed efficient river networks for a long time. similarly, urban drainage networks have been developed with the purpose of efficiently draining rainfall from catchments to flood mitigation. In this study, we analyzes and compares the characteristics between the naturally formed river networks for a long time and the artificially formed drainage networks using Gibbs’ Model. Gibbs’ Model is a stochastic stream network model, which can generate multiple realizations of stochastic networks based on a single parameter value of . Gibbs‘ Model was applied to a total number of 239 urban catchments in Seoul, South Korea and 70 natural catchments in the Midwestern areas of US. Topographic characteristics of catchments are analyzed along with the efficiency of drainage networks, which are presented by for both natural and urban catchments. The result of this study demonstrates the difference between natural and artificial drainage network characteristics and suggests a new alternative measures to mitigate flood risks in urban catchments facing extreme hydrologic events with climate change.
Kyungjae Kim; Yongwon Seo. Comparison of natural and urban drainage network characteristics based on Gibbs’ Model. 2020, 1 .
AMA StyleKyungjae Kim, Yongwon Seo. Comparison of natural and urban drainage network characteristics based on Gibbs’ Model. . 2020; ():1.
Chicago/Turabian StyleKyungjae Kim; Yongwon Seo. 2020. "Comparison of natural and urban drainage network characteristics based on Gibbs’ Model." , no. : 1.
In Korea, the temperature falls below 0 °C in winter and rises above 0 °C in spring. This change in temperature between the two seasons results in the ground alternatively freezing and thawing, which leads to road surfaces being damaged. Predicting the ground temperature becomes very important in identifying and responding to potential infrastructure damage due to the ground freezing and thawing. A simulation was conducted through numerical analysis using the Crank–Nicholson differential method to predict the temperature of each layer of a road. Moreover, the data gathered from measuring the temperature at each layer of a road over a period of 42 days in “Evaluation of Validity for Anti-frost Layer and Development of its Construction Criteria,” organized by the Ministry of Land, Transport and Maritime Affairs (2012), were used for the simulation. The training for temperature prediction of the anti-frost layer was performed using deep learning machine learning techniques with 650 days of measurement data by changing the number of hidden layers and nodes. With two hidden layers, 40 nodes, and 100 nodes, the reliability of the training result was close to 1. The reliability of the predictive model, a by-product of the training, was approximately 0.87.
Jaeho Son; Youngwon Seo; Youngmug Park; Gyutae Cho. Temperature Prediction of Anti-frost Layer using Machine Learning Techniques. Journal of the Korean Society of Hazard Mitigation 2020, 20, 9 -17.
AMA StyleJaeho Son, Youngwon Seo, Youngmug Park, Gyutae Cho. Temperature Prediction of Anti-frost Layer using Machine Learning Techniques. Journal of the Korean Society of Hazard Mitigation. 2020; 20 (1):9-17.
Chicago/Turabian StyleJaeho Son; Youngwon Seo; Youngmug Park; Gyutae Cho. 2020. "Temperature Prediction of Anti-frost Layer using Machine Learning Techniques." Journal of the Korean Society of Hazard Mitigation 20, no. 1: 9-17.
Historical, downscaled and projected data for six cities in South Korea were collected and analyzed using non-parametric Standardized Precipitation Index (SPI) across the Representative Concentration Pathways (RCPs) RCP4.5 and RCP8.5. SPI results were utilized in further analyses: intensity, decadal frequency, and temporal shifts. Non-parametric SPI was used as it produces more reliable results in terms of their statistical, spatial and temporal characteristics. RCP4.5 was taken to represent concentrations under the current emissions trajectory, while RCP8.5 represents the high-end scenario. Findings suggest that extreme precipitation events are more likely to increase in number than extreme drought across all timescales and RCPs. Variability was observed to increase when comparing SPI obtained from actual, measured and gridded precipitation. More extreme droughts are expected under RCP8.5 forcing as are the occurrence of multiyear droughts and extreme wet events relative to RCP4.5. A seasonal shift in extreme precipitation of up to 3 months earlier was observed. Generally, the period between 2080 and 2100 holds the highest probability to host extremely rare and persistent events.
Hemen Mark Butu; Yongwon Seo; Jeung Soo Huh. Determining Extremes for Future Precipitation in South Korea Based on RCP Scenarios Using Non-Parametric SPI. Sustainability 2020, 12, 963 .
AMA StyleHemen Mark Butu, Yongwon Seo, Jeung Soo Huh. Determining Extremes for Future Precipitation in South Korea Based on RCP Scenarios Using Non-Parametric SPI. Sustainability. 2020; 12 (3):963.
Chicago/Turabian StyleHemen Mark Butu; Yongwon Seo; Jeung Soo Huh. 2020. "Determining Extremes for Future Precipitation in South Korea Based on RCP Scenarios Using Non-Parametric SPI." Sustainability 12, no. 3: 963.
Multifractal modeling has originated from the study of turbulence to reproduce scale-invariant variations of the energy flux in different scales. Turbulent eddies partition themselves into finer ones in a multiplicative process that produces a population spread over a domain. The population generated is a union of subsets, where each subset is fractal with its own fractal dimension. In this study, we compare the multifractal exponents of jet turbulence intensities obtained through numerical simulation. Turbulence intensities were obtained from numerical jet discharge experiments based on Reynolds-Averaged Navier–Stokes (RANS) equations, where two types of nozzle geometry and two statistical turbulent closure models (i.e., k-ε model and the k-ω model) were tested. The simulation results by two closure models demonstrate in common that the RANS model reproduced hydraulic properties such as transversal velocity profile successfully compared to an analytical solution, but exhibit a limitation for reproducing the turbulence intensity decay in the longitudinal direction. Meanwhile, a common multifractal spectrum turns out to exist for turbulence intensity obtained from numerical simulation based on a statistically-averaged turbulence model. While two different turbulence models produced almost identical transverse velocity profiles, multifractal characteristics are quite distinct; the minimum Lipschitz–Hölder exponent (αmin) and entropy dimension (α1) are dependent on the turbulence as well as outfall nozzle geometry. Consequently, it is demonstrated that the multifractal exponents capture the difference in turbulence structures of hierarchical turbulence intensities produced with different experimental conditions.
Yongwon Seo; Haeng Sik Ko; Sangyoung Son. The effect of nozzle geometry on the turbulence evolution in an axisymmetric jet flow: A focus on fractals. Physica A: Statistical Mechanics and its Applications 2020, 550, 124145 .
AMA StyleYongwon Seo, Haeng Sik Ko, Sangyoung Son. The effect of nozzle geometry on the turbulence evolution in an axisymmetric jet flow: A focus on fractals. Physica A: Statistical Mechanics and its Applications. 2020; 550 ():124145.
Chicago/Turabian StyleYongwon Seo; Haeng Sik Ko; Sangyoung Son. 2020. "The effect of nozzle geometry on the turbulence evolution in an axisymmetric jet flow: A focus on fractals." Physica A: Statistical Mechanics and its Applications 550, no. : 124145.
Jaeho Son; Youngwon Seo; Youngmog Park; Gyutae Cho. Temperature Prediction of Road Anti-Frost Layer. Journal of the Korean Society of Hazard Mitigation 2019, 19, 39 -46.
AMA StyleJaeho Son, Youngwon Seo, Youngmog Park, Gyutae Cho. Temperature Prediction of Road Anti-Frost Layer. Journal of the Korean Society of Hazard Mitigation. 2019; 19 (7):39-46.
Chicago/Turabian StyleJaeho Son; Youngwon Seo; Youngmog Park; Gyutae Cho. 2019. "Temperature Prediction of Road Anti-Frost Layer." Journal of the Korean Society of Hazard Mitigation 19, no. 7: 39-46.
Land cover and population is key in considering sustainable management of the environment. An assessment focusing on the two may aid planning for sustainable management of the ecosystems. This is particularly vital for the water tower ecosystems which are extremely vulnerable. This paper provides a scientific assessment on the extent of land cover change in Mau Water Tower Ecosystem from 1986 to 2015 using satellite images. It analyzes the implications of observed population dynamics and forecasts the extent of land cover change in this resource. The results indicate a sharp increase in the area covered by grassland with a drastic decline in forest cover. Cropland showed marked fluctuations during the entire period. The change in forest cover had a very strong significant negative relationship with the rapid population increase. Forecast on land cover change, based on a “Business as Usual” (BAU) scenario, indicated further decline in forest cover and an increase in the area covered by grassland. The results of the study suggest that land cover change and population growth within the water towers are closely interlinked and cause significant effects on these ecosystems. These findings lay the foundation for a review of conservation and agricultural policies in order to enhance sustainable management of Mau Water Tower.
Simon Odawa; Yongwon Seo. Water Tower Ecosystems under the Influence of Land Cover Change and Population Growth: Focus on Mau Water Tower in Kenya. Sustainability 2019, 11, 3524 .
AMA StyleSimon Odawa, Yongwon Seo. Water Tower Ecosystems under the Influence of Land Cover Change and Population Growth: Focus on Mau Water Tower in Kenya. Sustainability. 2019; 11 (13):3524.
Chicago/Turabian StyleSimon Odawa; Yongwon Seo. 2019. "Water Tower Ecosystems under the Influence of Land Cover Change and Population Growth: Focus on Mau Water Tower in Kenya." Sustainability 11, no. 13: 3524.
According to the Intergovernmental Panel on Climate Change’s (IPCC) Fifth Assessment Report, the amount of precipitation in South Korea would increase regardless of the reduction of Greenhouse Gas (GHG) emissions. However, at the same time, it is expected that the temporal and spatial rainfall variation would also increase. Due to the impact from typhoons, 90% of the annual precipitation in Korea occurs in July, August, and September. Moreover, the Representative Concentration Pathways (RCP) scenario projected that the average precipitation in this period is expected to increase markedly, especially over the next 100 years. These predictions imply an increased variability of available water resources. In this study, we assessed a RBSN (rain barrel sharing network) as an efficient way to respond to the future climate change projections under the RCP scenarios when compared to the historical data. We proposed an evaluation procedure for the reliability, resilience, and vulnerability of RBSN based on a storage-reliability-yield (SRY) relationship. The result shows that the reliability and resiliency of a RBSN will improve but be more vulnerable compared to the results from the historical rainfall data. However, even in the climate change condition, the results showed that a RBSN still contributes to reduce vulnerability. The results of this study imply that a RBSN is an effective and alternative measure that can deal with the impacts of climate change in the future.
Youjeong Kwon; Junshik Hwang; Yongwon Seo. Performance of a RBSN under the RCP Scenarios: A Case Study in South Korea. Sustainability 2018, 10, 1242 .
AMA StyleYoujeong Kwon, Junshik Hwang, Yongwon Seo. Performance of a RBSN under the RCP Scenarios: A Case Study in South Korea. Sustainability. 2018; 10 (4):1242.
Chicago/Turabian StyleYoujeong Kwon; Junshik Hwang; Yongwon Seo. 2018. "Performance of a RBSN under the RCP Scenarios: A Case Study in South Korea." Sustainability 10, no. 4: 1242.
A turbulent jet bears diverse physical characteristics that have been unveiled yet. Of particular interest is to analyze the turbulent intensity, which has been a key factor to assess and determine turbulent jet performance since diffusive and mixing conditions are largely dependent on it. Multifractal measures are useful in terms of identifying characteristics of a physical quantity distributed over a spatial domain. This study examines the multifractal exponents of jet turbulence intensities obtained through numerical simulation. We acquired the turbulence intensities from numerical jet discharge experiments, where two types of nozzle geometry were tested based on a Reynolds-Averaged Navier–Stokes (RANS) equations. The [Formula: see text]-[Formula: see text] model and [Formula: see text]-[Formula: see text] model were used for turbulence closure models. The results showed that the RANS model successfully regenerates transversal velocity profile, which is almost identical to an analytical solution. The RANS model also shows the decay of turbulence intensity in the longitudinal direction but it depends on the outfall nozzle lengths. The result indicates the existence of a common multifractal spectrum for turbulence intensity obtained from numerical simulation. Although the transverse velocity profiles are similar for two different turbulence models, the minimum Lipschitz–Hölder exponent [Formula: see text] and entropy dimension [Formula: see text] are different. These results suggest that the multifractal exponents capture the difference in turbulence structures of hierarchical turbulence intensities produced by different turbulence models.
Yongwon Seo; Haeng Sik Ko; Sangyoung Son. MULTIFRACTAL CHARACTERISTICS OF AXISYMMETRIC JET TURBULENCE INTENSITY FROM RANS NUMERICAL SIMULATION. Fractals 2018, 26, 1 .
AMA StyleYongwon Seo, Haeng Sik Ko, Sangyoung Son. MULTIFRACTAL CHARACTERISTICS OF AXISYMMETRIC JET TURBULENCE INTENSITY FROM RANS NUMERICAL SIMULATION. Fractals. 2018; 26 (1):1.
Chicago/Turabian StyleYongwon Seo; Haeng Sik Ko; Sangyoung Son. 2018. "MULTIFRACTAL CHARACTERISTICS OF AXISYMMETRIC JET TURBULENCE INTENSITY FROM RANS NUMERICAL SIMULATION." Fractals 26, no. 1: 1.
The existence of impervious areas is one of the most distinguishing characteristics of urban catchments. They decrease infiltration and increase direct runoff in urban catchments. The recent introduction of green infrastructure in urban catchments for the purpose of sustainable development has contributed to the decrease in directly connected impervious areas (DCIA) by isolating existing impervious areas, and consequently, has also contributed to flood risk mitigation. This study coupled the width function-based instantaneous hydrograph (WFIUH), which is able to handle the spatial distribution of the impervious areas, with the concept of the DCIA to assess the impact of decreasing DCIA on the shape of direct runoff hydrographs. Using several scenarios for typical green infrastructure and the corresponding changes of DCIA for a test catchment in Seoul, South Korea, this study evaluated the effect of green infrastructure on the shape of the resulting direct runoff hydrographs and reducing peak flows. The results showed that the changes in the DCIA immediately affect the shape of the direct runoff hydrograph, and decrease peak flows by up to 12% depending on spatial implementation scenarios in the test catchment. This study demonstrates the importance of the DCIA concept for the evaluation of green infrastructures in urban catchments, enabling quantitative assessment of the spatial distribution of impervious areas, and also changes to the DCIA by various types of green infrastructure. The results of this study also suggest that more effective and well-planned green infrastructures could be introduced in urban environments for the purpose of flood risk management.
Junshik Hwang; Dong Sop Rhee; Yongwon Seo. Implication of Directly Connected Impervious Areas to the Mitigation of Peak Flows in Urban Catchments. Water 2017, 9, 696 .
AMA StyleJunshik Hwang, Dong Sop Rhee, Yongwon Seo. Implication of Directly Connected Impervious Areas to the Mitigation of Peak Flows in Urban Catchments. Water. 2017; 9 (9):696.
Chicago/Turabian StyleJunshik Hwang; Dong Sop Rhee; Yongwon Seo. 2017. "Implication of Directly Connected Impervious Areas to the Mitigation of Peak Flows in Urban Catchments." Water 9, no. 9: 696.
The recently observed hydrologic extremes are unlike what has been experienced so far. Both the magnitude and frequency of extremes are important indicators that determine the flood safety design criteria. Therefore, how are design criteria updated faced with these extremes? Both a sudden increase of design rainfall by the inclusion of these extremes and complete ignorance are inappropriate. In this study, the changes in extremes were examined and an alternative way to estimate the design rainfall amounts was developed using the data from 60 stations in South Korea. The minimum density power divergence estimator (MDPDE) with the optimal value of a tuning parameter, α, was suggested as an alternative estimator instead of the maximum likelihood estimator (MLE); its performance was evaluated using the Gumbel (GUM) and the generalized extreme value (GEV) distribution. The results revealed an increase in both the frequency and magnitude of extreme events over the last two decades, which imply that the extremes are already occurring. The performance of the MDPDE was evaluated. The results revealed decreased and adjusted values of the design rainfall compared to MLE. On the other hand, the MDPDE of the GEV distribution with a positive shape parameter, ξ, does not show its advantage conditionally because the GEV distribution has a heavier right tail than the GUM distribution (ξ = 0). In contrast, the results showed the high sensitivity of the MLE to the extremes compared to MDPDE.
Yongwon Seo; Junshik Hwang; Byungsoo Kim. Extreme Precipitation Frequency Analysis Using a Minimum Density Power Divergence Estimator. Water 2017, 9, 81 .
AMA StyleYongwon Seo, Junshik Hwang, Byungsoo Kim. Extreme Precipitation Frequency Analysis Using a Minimum Density Power Divergence Estimator. Water. 2017; 9 (2):81.
Chicago/Turabian StyleYongwon Seo; Junshik Hwang; Byungsoo Kim. 2017. "Extreme Precipitation Frequency Analysis Using a Minimum Density Power Divergence Estimator." Water 9, no. 2: 81.
Junshik Hwang; Yongwon Seo; Jin Young Jung. Implication of the Saemaul Undong on water resources development in rural communities during 1970’s. Journal of the Korean Society of Water and Wastewater 2016, 30, 699 -705.
AMA StyleJunshik Hwang, Yongwon Seo, Jin Young Jung. Implication of the Saemaul Undong on water resources development in rural communities during 1970’s. Journal of the Korean Society of Water and Wastewater. 2016; 30 (6):699-705.
Chicago/Turabian StyleJunshik Hwang; Yongwon Seo; Jin Young Jung. 2016. "Implication of the Saemaul Undong on water resources development in rural communities during 1970’s." Journal of the Korean Society of Water and Wastewater 30, no. 6: 699-705.
This study examines the difference in the predictions of flood wave propagation in open channels depending on the flow resistance formulae, such as the Chézy and Manning’s equation. The celerity and diffusion coefficient are functions of the channel geometry, slope, roughness as well as the resistance formulae. The results suggest that substituting the Chézy equation with Manning’s equation results in different characteristics of flood propagation, which are consistent regardless of the cross-sectional geometry except for a circular cross-section: increasing celerity and decreasing diffusion coefficient. The celerity is more sensitive to the selection of resistance formulae than the diffusion coefficient. Geometry has a greater effect on the celerity and diffusion coefficient, and consequently on the resulting hydrographs. Manning’s equation results in a larger difference in celerity and diffusion coefficient compared to Chézy equation regardless of the water depth. Overall, this study shows that the selection of resistance formulae is important in terms of the resulting hydrographs and peak flow.
Yongwon Seo; Sun Young Park; Arthur R. Schmidt. Implication of the flow resistance formulae on the prediction of flood wave propagation. Hydrological Sciences Journal 2016, 61, 683 -695.
AMA StyleYongwon Seo, Sun Young Park, Arthur R. Schmidt. Implication of the flow resistance formulae on the prediction of flood wave propagation. Hydrological Sciences Journal. 2016; 61 (4):683-695.
Chicago/Turabian StyleYongwon Seo; Sun Young Park; Arthur R. Schmidt. 2016. "Implication of the flow resistance formulae on the prediction of flood wave propagation." Hydrological Sciences Journal 61, no. 4: 683-695.
Drainage networks are essential compartments in an urban infrastructure system for the efficient collection and prompt drainage of flood water. In addition to the advances in numerical techniques on urban flood simulation, the topological characteristics of urban drainage networks and their impacts on flooding have not been investigated thoroughly despite their importance. This study evaluated the urban drainage networks in Seoul, South Korea, in terms of the network configuration and its implication for peak flows and flood mitigation. Gibbs’ model was used to analyze the network configuration of 31 urban catchments with various slope ranges. The results showed that urban drainage networks can be less efficient than river in nature in terms of the drainage time, which is counter-intuitive. On the other hand, the analysis showed that efficient networks have risks of flood concentration and, hence, increase potential flood risks. This study showed that efficient networks tend to have higher peak flows at the outlet and vice versa. Therefore, an alternative drainage network layout, which is less efficient and more sinuous, was introduced and it resulted in reduced peak flows and flooding. This result shows managing a proper drainage network layout can contribute to flood mitigation in urban catchments.
Yongwon Seo; Junshik Hwang; Seong Jin Noh. Analysis of Urban Drainage Networks Using Gibbs’ Model: A Case Study in Seoul, South Korea. Water 2015, 7, 4129 -4143.
AMA StyleYongwon Seo, Junshik Hwang, Seong Jin Noh. Analysis of Urban Drainage Networks Using Gibbs’ Model: A Case Study in Seoul, South Korea. Water. 2015; 7 (12):4129-4143.
Chicago/Turabian StyleYongwon Seo; Junshik Hwang; Seong Jin Noh. 2015. "Analysis of Urban Drainage Networks Using Gibbs’ Model: A Case Study in Seoul, South Korea." Water 7, no. 12: 4129-4143.
The multifractal measure enables an examination of the characteristics of a quantity distributed over a domain. This study examined the multifractal properties of turbulent intensities obtained from jet discharge experiments, where three types of nozzle geometries were examined in terms of the velocity fields and turbulent characteristics using particle image velocimetry. Depending on the nozzle geometry, the experimental results showed that the distribution of turbulent intensities and resulting dilution exhibited different behaviors. The experiment also showed that the transversal velocity profiles are similar to each other regardless of the outfall nozzle shapes and demonstrates the traditional similarity assumption at the same time. The multifractal exponents of the turbulent intensities were obtained with Box Count Method in a two-dimensional space. The results showed that the turbulent intensities obtained in two-dimensional space have a common multifractal spectrum, which was not the case for the velocity or shear stress observed in the same space. Although the transversal velocity profiles are similar, the multifractal exponent clearly shows a difference depending on the outfall geometries. In particular, the minimum value of the Lipschitz–Hölder exponent (α min) and the entropy dimension (α 1) tends to increase as turbulent intensity and dilution increase. These results suggest that the multifractal properties can be utilized potentially to categorize and evaluate the discharge outfall capabilities in terms of the resulting dilution.
Yongwon Seo; Siwan Lyu. Multifractal characteristics of the jet turbulent intensity depending on the outfall nozzle geometry. Stochastic Environmental Research and Risk Assessment 2015, 30, 653 -664.
AMA StyleYongwon Seo, Siwan Lyu. Multifractal characteristics of the jet turbulent intensity depending on the outfall nozzle geometry. Stochastic Environmental Research and Risk Assessment. 2015; 30 (2):653-664.
Chicago/Turabian StyleYongwon Seo; Siwan Lyu. 2015. "Multifractal characteristics of the jet turbulent intensity depending on the outfall nozzle geometry." Stochastic Environmental Research and Risk Assessment 30, no. 2: 653-664.
Rain barrels can be technically shared through social practices or mutual agreement between individual households. This study proposes the evaluation system for a rain barrel sharing network (RBSN) considering three performance criteria of reliability, resiliency, and vulnerability, under plausible climate change scenarios. First, this study shows how the system can be improved in terms of the performance criteria using historical daily rainfall data based on the storage-reliability-yield relationship. This study then examined how the benefits from RBSN are affected by climate change after 100 years. Three climate change scenarios (A1B, A2 and B2) and three global circulation models were used for this purpose. The results showed that the reliability and vulnerability are improved due to sharing and their improvements become larger under climate change conditions. In contrast, the resiliency reduces slightly due to sharing and its reduction is attenuated under climate change conditions. In particular, vulnerability will be reduced significantly under climate change. These results suggest that the sharing of various water resources systems can be an effective climate change adaptation strategy that reduces vulnerability and increases the reliability of the system.
Seong Jin Noh; Eun-Sung Chung; Yongwon Seo. Performance of a Rain Barrel Sharing Network under Climate Change. Water 2015, 7, 3466 -3485.
AMA StyleSeong Jin Noh, Eun-Sung Chung, Yongwon Seo. Performance of a Rain Barrel Sharing Network under Climate Change. Water. 2015; 7 (12):3466-3485.
Chicago/Turabian StyleSeong Jin Noh; Eun-Sung Chung; Yongwon Seo. 2015. "Performance of a Rain Barrel Sharing Network under Climate Change." Water 7, no. 12: 3466-3485.
Hydraulic and hydrologic analysis in urban catchments is typically accompanied by a number of uncertainties, such as a lack of required information for modeling purposes or complex loops inside a drainage network. In this article, Gibbs’ stochastic network model is utilized in order to achieve a dendritic network that corresponds to a fully looped network in terms of the peak of the runoff hydrograph at the outlet. A synthetic catchment with a drainage network composed of 8 × 8 grids is introduced to investigate the behavior of a fully looped network for a given rainfall event using the Storm Water Management Model. Dendritic networks are generated from the Gibbsian model for a given value of the parameter, β. The results showed that the shape of the hydrograph and the peak flow of a fully looped network are heavily dependent on the catchment slope. Moreover, the results showed that it is possible to find the corresponding dendritic networks generated by the Gibbsian model that match the fully looped network depending on the catchment slope in terms of peak flows. The results of this study imply the potential improvement of drainage network analysis providing a relationship between the catchment slope of a fully looped network and the corresponding dendritic network generated by the Gibbsian model.
Yongwon Seo; Young-Ho Seo; Young-Oh Kim. Behavior of a Fully-Looped Drainage Network and the Corresponding Dendritic Networks. Water 2015, 7, 1291 -1305.
AMA StyleYongwon Seo, Young-Ho Seo, Young-Oh Kim. Behavior of a Fully-Looped Drainage Network and the Corresponding Dendritic Networks. Water. 2015; 7 (12):1291-1305.
Chicago/Turabian StyleYongwon Seo; Young-Ho Seo; Young-Oh Kim. 2015. "Behavior of a Fully-Looped Drainage Network and the Corresponding Dendritic Networks." Water 7, no. 12: 1291-1305.
A rainwater harvesting system (RWHS) is an alternative water resource that collects and stores rainwater from rooftops. It helps smooth out variations in water supply and sustainable water resources management. In this study, we investigated the potential benefits from sharing RWHS with nearby neighbors in a community. We introduced different mean, variance, and correlation in water demand for each water user. A simple case of a community composed of four prospective users is introduced to investigate the benefit from sharing RWHSs. Using the historical rainfall records from four catchments in South Korea, a storage-reliability-yield analysis is applied to obtain the required storage and corresponding reliability for a given yield ratio. The results indicate that the required total storage is reduced when RWHSs are shared among users and the rate of reduction is proportional to the degree of sharing. The required total storage was reduced down to 61% compared to the original storage when RWHSs are shared for a target reliability of 80%. The benefit from sharing also depends on the demands, which are different among users. Test cases with different means and variances as well as correlation disclose the conditions when the benefit from sharing RWHSs is maximized. The result showed that difference in mean and variance additionally reduces the required storage up to 3% and correlation in demand also as much affects the required storage.
Yongwon Seo; Sun Young Park; Young-Oh Kim. Potential Benefits from Sharing Rainwater Storages Depending on Characteristics in Demand. Water 2015, 7, 1013 -1029.
AMA StyleYongwon Seo, Sun Young Park, Young-Oh Kim. Potential Benefits from Sharing Rainwater Storages Depending on Characteristics in Demand. Water. 2015; 7 (12):1013-1029.
Chicago/Turabian StyleYongwon Seo; Sun Young Park; Young-Oh Kim. 2015. "Potential Benefits from Sharing Rainwater Storages Depending on Characteristics in Demand." Water 7, no. 12: 1013-1029.