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The Boryeong district, Chungnam western region, is well known as a chronic water-deficiency area; it is thus necessary to ensure that the operational system for the Boryeong Dam emergency facilities is sufficiently resilient to withstand the potential impacts of climate change, in particular irregular droughts with resultant low water inflows and low storage. This study was undertaken to determine the operational flexibility of the Boryeong Dam emergency diversion facilities and their ability to respond to water resources demand, even if the facilities have been operating on a simple open-close release rule, depending on dam storage levels. The precipitation and inflow in Boryeong district were forecasted according to the modelling of RCP (Representative Concentration Pathways) in combination with SSP (Shared Socio-economic Pathways) scenarios. This has led to recommendations for the flexible operation of the Dam’s diversion facilities in order to ensure a stable water supply based especially on SSP1-2.6 and SSP5-8.5; i.e., steady growth and dramatic growth scenarios were simulated. The result from these two scenarios was an average diversion rate of 39,600 m3/day and 39,900 m3/day, respectively. This was evaluated as reasonable water resource use because water deficit days were fewer, and the average diversion rate was less than the RCP scenarios.
Gunmuk Lim; Seonhui Noh; Minwoo Son; Kwansue Jung. Boryeong Dam Emergency Water Diversion Facility: Ensuring Operational Flexibility and Resilient Response to Climate Change. Journal of the Korean Society of Hazard Mitigation 2021, 21, 11 -22.
AMA StyleGunmuk Lim, Seonhui Noh, Minwoo Son, Kwansue Jung. Boryeong Dam Emergency Water Diversion Facility: Ensuring Operational Flexibility and Resilient Response to Climate Change. Journal of the Korean Society of Hazard Mitigation. 2021; 21 (3):11-22.
Chicago/Turabian StyleGunmuk Lim; Seonhui Noh; Minwoo Son; Kwansue Jung. 2021. "Boryeong Dam Emergency Water Diversion Facility: Ensuring Operational Flexibility and Resilient Response to Climate Change." Journal of the Korean Society of Hazard Mitigation 21, no. 3: 11-22.
Due to the recent appearance of shares socioeconomic pathway (SSP) scenarios, there have been many studies that compare the results between Coupled Model Intercomparison Project (CMIP)5 and CMIP6 general circulation models (GCMs). This study attempted to project future drought characteristics in the Cheongmicheon watershed using SSP2-4.5 of Australian Community Climate and Earth System Simulator-coupled model (ACCESS-CM2) in addition to Representative Concentration Pathway (RCP) 4.5 of ACCESS 1-3 of the same institute. The historical precipitation and temperature data of ACCESS-CM2 were generated better than those of ACCESS 1-3. Two meteorological drought indices, namely, Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI) were used to project meteorological drought while a hydrological drought index, Standardized Streamflow Index (SDI), was used to project the hydrological drought characteristics. The metrological data of GCMs were bias-corrected using quantile mapping method and the streamflow was obtained using Soil and Water Assessment Tool (SWAT) and bias-corrected meteorological data. As a result, there were large differences of drought occurrences and severities between RCP4.5 and SSP2-4.5 for the values of SPI, SPEI, and SDI. The differences in the minimum values of drought index between near (2021–2060) and far futures (2061–2100) were very small in SSP2-4.5, while those in RCP4.5 were very large. In addition, the longest drought period from SDI was the largest because the variation in precipitation usually affects the streamflow with a lag. Therefore, it was concluded that it is important to consider both CMIP5 and CMIP6 GCMs in establishing the drought countermeasures for the future period.
Jin Hyuck Kim; Jang Hyun Sung; Eun-Sung Chung; Sang Ug Kim; Minwoo Son; Mohammed Sanusi Shiru. Comparison of Projection in Meteorological and Hydrological Droughts in the Cheongmicheon Watershed for RCP4.5 and SSP2-4.5. Sustainability 2021, 13, 2066 .
AMA StyleJin Hyuck Kim, Jang Hyun Sung, Eun-Sung Chung, Sang Ug Kim, Minwoo Son, Mohammed Sanusi Shiru. Comparison of Projection in Meteorological and Hydrological Droughts in the Cheongmicheon Watershed for RCP4.5 and SSP2-4.5. Sustainability. 2021; 13 (4):2066.
Chicago/Turabian StyleJin Hyuck Kim; Jang Hyun Sung; Eun-Sung Chung; Sang Ug Kim; Minwoo Son; Mohammed Sanusi Shiru. 2021. "Comparison of Projection in Meteorological and Hydrological Droughts in the Cheongmicheon Watershed for RCP4.5 and SSP2-4.5." Sustainability 13, no. 4: 2066.
The size distribution of suspended flocs is continuously changed by the flocculation process resulting from turbulent motion. This study aims to numerically investigate the effect of turbulent motion on the size distribution of suspended flocs. In this study, the methodology for modeling a floc size distribution is suggested by adopting the stochastic approach to modeling the flocculation process. The applicability of proposed methodology is examined by comparing numerical results with the field data measured in estuarine environments. It is known from the simulation results that the lognormal distribution can be used as a descriptor for unimodal size distribution of suspended flocs in the dynamic equilibrium state. The effect of turbulent motion on floc size distribution is further investigated by analyzing the floc size distributions at different elevations from bed. The bimodal size distribution of suspended flocs is replicated when the intensity of disaggregation and Kolmogorov length scale of turbulent eddy are considered. The disaggregation process of floc is mainly governed by the turbulent motion. Based on the relationship between disaggregation process and turbulent motion, it is insisted in this study that the shape of floc size distribution is significantly affected by turbulent motion.
J. Byun; M. Son. On the relationship between turbulent motion and bimodal size distribution of suspended flocs. Estuarine, Coastal and Shelf Science 2020, 245, 106938 .
AMA StyleJ. Byun, M. Son. On the relationship between turbulent motion and bimodal size distribution of suspended flocs. Estuarine, Coastal and Shelf Science. 2020; 245 ():106938.
Chicago/Turabian StyleJ. Byun; M. Son. 2020. "On the relationship between turbulent motion and bimodal size distribution of suspended flocs." Estuarine, Coastal and Shelf Science 245, no. : 106938.
The performance of general circulation models (GCMs) in a region are generally assessed according to their capability to simulate historical temperature and precipitation of the region. The performance of 31 GCMs of the Coupled Model Intercomparison Project Phase 5 (CMIP5) is evaluated in this study to identify a suitable ensemble for daily maximum, minimum temperature and precipitation for Pakistan using multiple sets of gridded data, namely: Asian Precipitation–Highly-Resolved Observational Data Integration Towards Evaluation (APHRODITE), Berkeley Earth Surface Temperature (BEST), Princeton Global Meteorological Forcing (PGF) and Climate Prediction Centre (CPC) data. An entropy-based robust feature selection approach known as symmetrical uncertainty (SU) is used for the ranking of GCM. It is known from the results of this study that the spatial distribution of best-ranked GCMs varies for different sets of gridded data. The performance of GCMs is also found to vary for both temperatures and precipitation. The Commonwealth Scientific and Industrial Research Organization, Australia (CSIRO)-Mk3-6-0 and Max Planck Institute (MPI)-ESM-LR perform well for temperature while EC-Earth and MIROC5 perform well for precipitation. A trade-off is formulated to select the common GCMs for different climatic variables and gridded data sets, which identify six GCMs, namely: ACCESS1-3, CESM1-BGC, CMCC-CM, HadGEM2-CC, HadGEM2-ES and MIROC5 for the reliable projection of temperature and precipitation of Pakistan.
Najeebullah Khan; Shamsuddin Shahid; Kamal Ahmed; Tarmizi Ismail; Nadeem Nawaz; Minwoo Son. Performance Assessment of General Circulation Model in Simulating Daily Precipitation and Temperature Using Multiple Gridded Datasets. Water 2018, 10, 1793 .
AMA StyleNajeebullah Khan, Shamsuddin Shahid, Kamal Ahmed, Tarmizi Ismail, Nadeem Nawaz, Minwoo Son. Performance Assessment of General Circulation Model in Simulating Daily Precipitation and Temperature Using Multiple Gridded Datasets. Water. 2018; 10 (12):1793.
Chicago/Turabian StyleNajeebullah Khan; Shamsuddin Shahid; Kamal Ahmed; Tarmizi Ismail; Nadeem Nawaz; Minwoo Son. 2018. "Performance Assessment of General Circulation Model in Simulating Daily Precipitation and Temperature Using Multiple Gridded Datasets." Water 10, no. 12: 1793.
Minwoo Son; Fabián A. Bombardelli; Byeoungeun Park; Jisun Byun. On the Inverse Relationship between Concentration and Size of Cohesive Sediment. Journal of Coastal Research 2018, 85, 56 -60.
AMA StyleMinwoo Son, Fabián A. Bombardelli, Byeoungeun Park, Jisun Byun. On the Inverse Relationship between Concentration and Size of Cohesive Sediment. Journal of Coastal Research. 2018; 85 ():56-60.
Chicago/Turabian StyleMinwoo Son; Fabián A. Bombardelli; Byeoungeun Park; Jisun Byun. 2018. "On the Inverse Relationship between Concentration and Size of Cohesive Sediment." Journal of Coastal Research 85, no. : 56-60.
Due to global climate change, it is possible to experience the new trend of flood in the near future. Therefore, it is necessary to consider the impact of climate change on flood when establishing sustainable water resources management policy. In order to predict the future flood events, the frequency analysis is commonly applied. Traditional methods for flood frequency analysis are based on the assumption of stationarity, which is questionable under the climate change, although many techniques that are based on stationarity have been developed. Therefore, this study aims to investigate and compare all of the corresponding effects of three different data sets (observed, RCP 4.5, and 8.5), two different frequency models (stationary and non-stationary), and two different frequency analysis procedures (rainfall frequency first approach and direct discharge approach). As a result, the design flood from the observed data by the stationary frequency model and rainfall frequency first approach can be concluded the most reasonable. Thus, the design flood from the RCP 8.5 by the non-stationary frequency model and rainfall frequency first approach should be carefully used for the establishment of flood prevention measure while considering climate change and uncertainty.
Sang Ug Kim; Minwoo Son; Eun-Sung Chung; Xiao Yu. Effects of Non-Stationarity on Flood Frequency Analysis: Case Study of the Cheongmicheon Watershed in South Korea. Sustainability 2018, 10, 1329 .
AMA StyleSang Ug Kim, Minwoo Son, Eun-Sung Chung, Xiao Yu. Effects of Non-Stationarity on Flood Frequency Analysis: Case Study of the Cheongmicheon Watershed in South Korea. Sustainability. 2018; 10 (5):1329.
Chicago/Turabian StyleSang Ug Kim; Minwoo Son; Eun-Sung Chung; Xiao Yu. 2018. "Effects of Non-Stationarity on Flood Frequency Analysis: Case Study of the Cheongmicheon Watershed in South Korea." Sustainability 10, no. 5: 1329.
Kyung Joon Shin; Wonho Bae; Seul-Woo Choi; Minwoo Son; Kwang Myong Lee. Parameters influencing water permeability coefficient of cracked concrete specimens. Construction and Building Materials 2017, 151, 907 -915.
AMA StyleKyung Joon Shin, Wonho Bae, Seul-Woo Choi, Minwoo Son, Kwang Myong Lee. Parameters influencing water permeability coefficient of cracked concrete specimens. Construction and Building Materials. 2017; 151 ():907-915.
Chicago/Turabian StyleKyung Joon Shin; Wonho Bae; Seul-Woo Choi; Minwoo Son; Kwang Myong Lee. 2017. "Parameters influencing water permeability coefficient of cracked concrete specimens." Construction and Building Materials 151, no. : 907-915.
K Won; S Kim; E Chung; M Son. Drought analysis of Cheongmicheon in Korea based on various drought indices. Civil, Offshore and Environmental Engineering 2016, 311 -315.
AMA StyleK Won, S Kim, E Chung, M Son. Drought analysis of Cheongmicheon in Korea based on various drought indices. Civil, Offshore and Environmental Engineering. 2016; ():311-315.
Chicago/Turabian StyleK Won; S Kim; E Chung; M Son. 2016. "Drought analysis of Cheongmicheon in Korea based on various drought indices." Civil, Offshore and Environmental Engineering , no. : 311-315.
Son, M., Byun, J., Kim, S., and Chung, E.-S., 2016. Effect of particale size on calibration of Schmidt number. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 148–152. Coconut Creek (Florida), ISSN 0749-0208. The effect of particle size on calibrating the Schmidt number (σc) is numerically investigated in this study. The experiments are carried out under different conditions of flow type and particle size. From calculation results, it is known that σc is calibrated to be 0.25 to 2.0 as the particle size changes from 320 μm to 130 μm. The value of σc shows the inverse-relationship with particle size. σc determines the particle diffusivity. When σc is smaller than 1.0, the particle diffusivity becomes larger than the momentum diffusivity. A large particle having large inertia can diffuse relatively more compared to small particle under the condition that the turbulent intensity decreases. Therefore, σc is calibrated to be small as the particle size increases. This idea is examined by calculating the Stokes number and sediment diffusivity. As the particle size increases, both of Stokes number and sediment diffusivity also increase.
Minwoo Son; Jisun Byun; Sang Ug Kim; Eun-Sung Chung. Effect of Particle Size on Calibration of Schmidt Number. Journal of Coastal Research 2016, 75, 148 -152.
AMA StyleMinwoo Son, Jisun Byun, Sang Ug Kim, Eun-Sung Chung. Effect of Particle Size on Calibration of Schmidt Number. Journal of Coastal Research. 2016; 75 (sp1):148-152.
Chicago/Turabian StyleMinwoo Son; Jisun Byun; Sang Ug Kim; Eun-Sung Chung. 2016. "Effect of Particle Size on Calibration of Schmidt Number." Journal of Coastal Research 75, no. sp1: 148-152.
Minwoo Son; Jisun Byun; Hyun-Doug Yoon; Tae-Hwa Jung. A Study on Trapping Efficiency of the Non-point Source Pollution in Cheongmi Stream Using VFSMOD-w. The Journal of the Korea Contents Association 2016, 16, 140 -150.
AMA StyleMinwoo Son, Jisun Byun, Hyun-Doug Yoon, Tae-Hwa Jung. A Study on Trapping Efficiency of the Non-point Source Pollution in Cheongmi Stream Using VFSMOD-w. The Journal of the Korea Contents Association. 2016; 16 (1):140-150.
Chicago/Turabian StyleMinwoo Son; Jisun Byun; Hyun-Doug Yoon; Tae-Hwa Jung. 2016. "A Study on Trapping Efficiency of the Non-point Source Pollution in Cheongmi Stream Using VFSMOD-w." The Journal of the Korea Contents Association 16, no. 1: 140-150.
This study provides a systematic three-step approach to prioritizing feasible locations for permeable pavement, taking into account environmental, economic, and social aspects. Step 1 is the identification of potential locations on the basis of spatial and economic feasibility, and on the receptiveness of the local government and residents. Step 2 involves the use of Visual MODFLOW software to simulate groundwater levels with and without permeable pavement. Step 3 is the prioritization of all feasible locations using three multi-criteria decision making methods: the weighted sum method, composite programming and TOPSIS. Weighting values were derived from iterative feedback surveys completed by 22 regional experts. This framework was applied to the Mokgamcheon watershed, central Korea, which suffers from instream flow deficit during the dry season. The results show that by considering anthropogenic factors and hydrological effectiveness, this approach effectively prioritizes feasible alternatives that can be implemented into comprehensive hydrological cycle rehabilitation plans.
Jeong-Seok Yang; Minwoo Son; Eun-Sung Chung; Il-Hwan Kim. Prioritizing Feasible Locations for Permeable Pavement Using MODFLOW and Multi-criteria Decision Making Methods. Water Resources Management 2015, 29, 4539 -4555.
AMA StyleJeong-Seok Yang, Minwoo Son, Eun-Sung Chung, Il-Hwan Kim. Prioritizing Feasible Locations for Permeable Pavement Using MODFLOW and Multi-criteria Decision Making Methods. Water Resources Management. 2015; 29 (12):4539-4555.
Chicago/Turabian StyleJeong-Seok Yang; Minwoo Son; Eun-Sung Chung; Il-Hwan Kim. 2015. "Prioritizing Feasible Locations for Permeable Pavement Using MODFLOW and Multi-criteria Decision Making Methods." Water Resources Management 29, no. 12: 4539-4555.
Existing flocculation models for cohesive sediments are classified into two groups: population balance equation models (PBE) and floc growth models. An FGM ensures mass conservation in a closed system. However, an FGM determines only the average size of flocs, whereas a PBE has the capability to calculate a size distribution of flocs. A new stochastic approach to model the flocculation process is theoretically developed and incorporated into a deterministic FGM in this study in order to calculate a size distribution of flocs as well as the average size. A log-normal distribution is used to generate random numbers based on previous laboratory experiments. The new stochastic flocculation model is tested with three laboratory experiment results. It was found and validated with measured data that the new stochastic flocculation model has the capability to replicate a size distribution of flocs reasonably well under different sediment and carrier flow conditions. Three more distributions (normal; Pearson type 3; and generalized extreme value distributions) were also tested. From the comparison with results of different distribution functions, it is shown that a stochastic FGM using a log-normal distribution has a comparative advantage in terms of simplicity and accuracy.
Hyun Jung Shin; Minwoo Son; Guan-Hong Lee. Stochastic Flocculation Model for Cohesive Sediment Suspended in Water. Water 2015, 7, 2527 -2541.
AMA StyleHyun Jung Shin, Minwoo Son, Guan-Hong Lee. Stochastic Flocculation Model for Cohesive Sediment Suspended in Water. Water. 2015; 7 (12):2527-2541.
Chicago/Turabian StyleHyun Jung Shin; Minwoo Son; Guan-Hong Lee. 2015. "Stochastic Flocculation Model for Cohesive Sediment Suspended in Water." Water 7, no. 12: 2527-2541.
Cohesive sediment has different characteristics compared to non-cohesive sediment. The density and size of a cohesive sediment aggregate (a so-called, floc) continuously changes through the flocculation process. The variation of floc size and density can cause a change of volumetric concentration under the condition of constant mass concentration. This study investigates how the volumetric concentration is affected by different conditions such as flow velocity, water depth, and sediment suspension. A previously verified, one-dimensional vertical numerical model is utilized here. The flocculation process is also considered by floc in the growth type flocculation model. Idealized conditions are assumed in this study for the numerical experiments. The simulation results show that the volumetric concentration profile of cohesive sediment is different from the Rouse profile. The volumetric concentration decreases near the bed showing the elevated maximum in the cases of both current and oscillatory flow. The density and size of floc show the minimum and the maximum values near the elevation of volumetric concentration maximum, respectively. This study also shows that the flow velocity and the critical shear stress have significant effects on the elevated maximum of volumetric concentration. As mechanisms of the elevated maximum, the strong turbulence intensity and increased mass concentration are considered because they cause the enhanced flocculation process. This study uses numerical experiments. To the best of our knowledge, no laboratory or field experiments on the elevated maximum have been carried out until now. It is of great necessity to conduct well-controlled laboratory experiments in the near future.
Jisun Byun; Minwoo Son; Jeong-Seok Yang; Tae-Hwa Jung. Volumetric Concentration Maximum of Cohesive Sediment in Waters: A Numerical Study. Water 2014, 7, 81 -98.
AMA StyleJisun Byun, Minwoo Son, Jeong-Seok Yang, Tae-Hwa Jung. Volumetric Concentration Maximum of Cohesive Sediment in Waters: A Numerical Study. Water. 2014; 7 (12):81-98.
Chicago/Turabian StyleJisun Byun; Minwoo Son; Jeong-Seok Yang; Tae-Hwa Jung. 2014. "Volumetric Concentration Maximum of Cohesive Sediment in Waters: A Numerical Study." Water 7, no. 12: 81-98.
Ji-Sun Byun; Minwoo Son. Effect of Schmidt Number on Cohesive and Non-cohesive Sediment Suspension Modeling. Journal of Korea Water Resources Association 2014, 47, 703 -715.
AMA StyleJi-Sun Byun, Minwoo Son. Effect of Schmidt Number on Cohesive and Non-cohesive Sediment Suspension Modeling. Journal of Korea Water Resources Association. 2014; 47 (8):703-715.
Chicago/Turabian StyleJi-Sun Byun; Minwoo Son. 2014. "Effect of Schmidt Number on Cohesive and Non-cohesive Sediment Suspension Modeling." Journal of Korea Water Resources Association 47, no. 8: 703-715.
Minwoo Son; Guan-Hong Lee. On effects of skewed and asymmetric oscillatory flows on cohesive sediment flux: Numerical study. Water Resources Research 2013, 49, 4409 -4423.
AMA StyleMinwoo Son, Guan-Hong Lee. On effects of skewed and asymmetric oscillatory flows on cohesive sediment flux: Numerical study. Water Resources Research. 2013; 49 (7):4409-4423.
Chicago/Turabian StyleMinwoo Son; Guan-Hong Lee. 2013. "On effects of skewed and asymmetric oscillatory flows on cohesive sediment flux: Numerical study." Water Resources Research 49, no. 7: 4409-4423.
A new boundary treatment technique which can be applied to axi-symmetric topography with inclined bottom was developed. Although the finite element method is good for complex geometry, there is no proper boundary treatment when a boundary is not a vertical section because the water depth at the coastline becomes zero. In this study, we developed a new boundary treatment for inclined bottom using the analytical solution for long wave. To develope a model, the mild-slope equation was used and then, a computational domain is divided into an analytical region and a numerical region. By combining a numerical and an analytical solutions, a complete solution was obtained. The developed solution was validated by comparing with a previous analytical solution.
Tae-Hwa Jung; Hyun-Jung Shin; Minwoo Son. Boundary Treatment for Axi-symmetric Topography. The Journal of the Korea Contents Association 2013, 13, 505 -511.
AMA StyleTae-Hwa Jung, Hyun-Jung Shin, Minwoo Son. Boundary Treatment for Axi-symmetric Topography. The Journal of the Korea Contents Association. 2013; 13 (2):505-511.
Chicago/Turabian StyleTae-Hwa Jung; Hyun-Jung Shin; Minwoo Son. 2013. "Boundary Treatment for Axi-symmetric Topography." The Journal of the Korea Contents Association 13, no. 2: 505-511.
Min-Woo Son; Guan-Hong Lee; Kil-Seong Lee; Du-Han Lee. Comparative Study on k-ε and k-ω Closures under the Condition of Turbulent Oscillatory Boundary Layer Flow at High Reynolds Number. Journal of Korea Water Resources Association 2011, 44, 189 -198.
AMA StyleMin-Woo Son, Guan-Hong Lee, Kil-Seong Lee, Du-Han Lee. Comparative Study on k-ε and k-ω Closures under the Condition of Turbulent Oscillatory Boundary Layer Flow at High Reynolds Number. Journal of Korea Water Resources Association. 2011; 44 (3):189-198.
Chicago/Turabian StyleMin-Woo Son; Guan-Hong Lee; Kil-Seong Lee; Du-Han Lee. 2011. "Comparative Study on k-ε and k-ω Closures under the Condition of Turbulent Oscillatory Boundary Layer Flow at High Reynolds Number." Journal of Korea Water Resources Association 44, no. 3: 189-198.
[1] Flocculation and bed erodibility are two main processes causing the transport of cohesive sediments to be more complicated than typical noncohesive sediments. Earlier flocculation models assume a constant fractal dimension and/or a constant floc yield strength. However, recent studies have shown that considering both the fractal dimension and the floc yield strength to be variable is critical to the prediction of temporal evolution of floc size. Due to consolidation, it is also well established that critical bed shear stress of a mud bed cannot be parameterized as a constant. This study further investigates how flocculation models with different degrees of complexity and bed erodibility can affect the resulting cohesive sediment resuspension driven by tidal flows. A one‐dimensional vertical numerical model for sediment transport is revised to incorporate modules for flocculation and bed erodibility. Model results are compared with data measured in the Ems/Dollard estuary. Model study suggests that it is important to incorporate variable critical shear stress in order to properly model the supply of sediment from the bed. When flocculation is neglected or incorporated incompletely, numerical model predicts nearly zero sediment concentration during slack water and very steep concentration gradient, which are inconsistent with the observed data. When the fractal dimension and the floc yield strength are both considered to be variable, the numerical model predicts much smaller settling velocity and hence captures the more well‐mixed condition consistent with field observations.
Minwoo Son; Tian-Jian Hsu. The effects of flocculation and bed erodibility on modeling cohesive sediment resuspension. Journal of Geophysical Research 2011, 116, 1 .
AMA StyleMinwoo Son, Tian-Jian Hsu. The effects of flocculation and bed erodibility on modeling cohesive sediment resuspension. Journal of Geophysical Research. 2011; 116 (C3):1.
Chicago/Turabian StyleMinwoo Son; Tian-Jian Hsu. 2011. "The effects of flocculation and bed erodibility on modeling cohesive sediment resuspension." Journal of Geophysical Research 116, no. C3: 1.
The flux of cohesive sediment in an estuary is determined by many factors, including tidal asymmetry, wave effect, fluvial influence, phase difference between tidal velocity and tidal level fluctuations, sediment properties, flocculation, bed erodibility, bathymetry effect and other nonlocal effects. Our capability in predicting sediment fluxes in tide-dominant environments is critical to the morphodynamics and water quality of estuaries. Due to the difficulties in carrying out detailed measurement of sediment flux with high spatial and temporal resolutions, an one-dimensional-vertical (1DV) numerical model for cohesive sediment transport, previously verified and calibrated with field measured cohesive sediment concentration data, is utilized here to study some of the aforementioned factors in affecting tidal-driven sediment fluxes in idealized condition. Tidal-averaged sediment flux is shown to be correlated with tidal velocity skewness with a linear relationship. This linear relationship is different from that of non-cohesive sediment and it is demonstrated here to be mainly due to variable critical shear stress implemented for the mud bed in order to parameterize consolidation. The reason that tidal velocity skewness causes tidal-averaged residual sediment transport is shown to be due to nonlinear intra-tidal interactions between flow velocity and sediment concentration. Moreover, the effects of nonlinear intra-tidal interaction between tidal velocity and tidal level fluctuations is shown to mainly cause seaward transport, which is the most significant under progressive wave system (phase difference 90°) and almost negligible for standing wave system (phase difference 0°).
Minwoo Son; Tian-Jian Hsu. Idealized study on cohesive sediment flux by tidal asymmetry. Environmental Fluid Mechanics 2010, 11, 183 -202.
AMA StyleMinwoo Son, Tian-Jian Hsu. Idealized study on cohesive sediment flux by tidal asymmetry. Environmental Fluid Mechanics. 2010; 11 (2):183-202.
Chicago/Turabian StyleMinwoo Son; Tian-Jian Hsu. 2010. "Idealized study on cohesive sediment flux by tidal asymmetry." Environmental Fluid Mechanics 11, no. 2: 183-202.
A new formulation for floc yield strength of cohesive sediment is theoretically derived and incorporated into a flocculation model based on variable fractal dimension. The new flocculation model is validated with existing data on the temporal evolution of floc size measured in the laboratory. Comparing with existing flocculation models using a constant yield strength, it is found that new flocculation model based on variable yield strength and variable fractal dimension is superior in predicting the temporal evolution of floc size. It is also demonstrated that the present model results are very similar to that using an empirical formulation of variable yield strength suggested by Sonntag and Russel (1987. Structure and breakup of floccs subjected to fluid stressses. II. Theory. J. Colloid Interface Sci. 115(2), 378–389) when the empirical coefficient is specified according to our theoretical value. Hence, it is concluded that the new variable yield strength formulation derived in this study and the variable fractal dimension are effective in improving the prediction of flocculation process.
M. Son; T.-J. Hsu. The effect of variable yield strength and variable fractal dimension on flocculation of cohesive sediment. Water Research 2009, 43, 3582 -3592.
AMA StyleM. Son, T.-J. Hsu. The effect of variable yield strength and variable fractal dimension on flocculation of cohesive sediment. Water Research. 2009; 43 (14):3582-3592.
Chicago/Turabian StyleM. Son; T.-J. Hsu. 2009. "The effect of variable yield strength and variable fractal dimension on flocculation of cohesive sediment." Water Research 43, no. 14: 3582-3592.