• Journal of Korea Water Resources Association
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• v.43 no.6
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• pp.559-569
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• 2010

This study proposes an empirical method for estimating the concentration time and storage coefficient of a basin using the Nash unit hydrograph. This method is based on the analytically derived concentration time and storage coefficient of the Nash model. More fundamentally, this method recursively searches convergent number of linear reservoirs and storage coefficient of linear reservoir representing the basin given. This method is to overcome the problem of HEC-HMS to use an optimization technique to estimate the basin concentration time and storage coefficient. The proposed method was applied to the Bangrim station of the Pyungchang river basin, also found to estimate physically reasonable values.

• Journal of Korean Society on Water Environment
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• v.31 no.4
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• pp.367-376
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• 2015

The momentum and kinetic turbulent energy carried by the wind to a stratified lake lead to basin-scale motions, which provide a major driving force for vertical and horizontal mixing. A three-dimensional (3D) hydrodynamic model was applied to Lake Tahoe, located between California and Nevada, USA, to simulate the dominant basin-scale internal waves in the deep lake. The results demonstrated that the model well represents the temporal and vertical variations of water temperature that allows the internal waves to be energized correctly at the basin scale. Both the model and thermistor chain (TC) data identified the presence of Kelvin modes and Poincare mode internal waves. The lake was weakly stratified during the study period, and produced large amplitude (up to 60 m) of internal oscillations after several wind events and partial upwelling near the southwestern lake. The partial upwelling and followed coastal jets could be an important feature of basin-scale internal waves because they can cause re-suspension and horizontal transport of fine particles from nearshore to offshore. The internal wave dynamics can be also associated with the distributions of water quality variables such as dissolved oxygen and nutrients in the lake. Thus, the basin-scale internal waves and horizontal circulation processes need to be accurately modeled for the correct simulation of the dissolved and particulate contaminants, and biogeochemical processes in the lake.

• Journal of Industrial Technology
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• v.22 no.A
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• pp.211-218
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• 2002

HEC-HMS model should be calibrated to be applied to these basins in Gangwon-do unlike the general basins. In the study, it is investigated whether the HEC-HMS model may be applied or not to Naerinchon basin where is the typical basin of Gangwon-do Additionally, the straightforword module of HEC-HMS for simulating the hydrologic characteristic of Gangwon-do basins well will be suggested by comparison of the numerical results with the observed data. The hydrologic results estimated by several modules such as Clark, SCS and Snyder methods in HEC-HMS model have been compared with the observed data for 1999~2000 storm events. It is concluded that Clark method are relatively applicable to the basins in Gangwon-do rather than the others methods. The parametric studies for HEC-HMS model should be studied further in order to apply to Gangwon-do basins more accurately.

• Water for future
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• v.22 no.1
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• pp.109-116
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• 1989

An attempt is made to describe the theory an computer algorithm of the SSARR model, and to try it's application to the small satershed, by using the estimation of the model parameters with the data of Bochong stream basin. The selected period of the hydrological data is from 1982 to 1988 for the modeling. The selected basin is the Bochong stream basin which is one of the tributaries of Geum river. The estimation of model parameters and sensitivity test are carried out for the analysis of the characteristics of model parameters.

• Journal of Korea Water Resources Association
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• v.52 no.9
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• pp.637-645
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• 2019

Among various ecosystem services provided by the basin, this study deals with water yield (WY) estimation in the Bagmati basin of Nepal. Maps of where water used for different facilities like water supply, irrigation, hydropower etc. are generated helps planning and management of facilities. These maps also help to avoid unintended impacts on provision and production of services. Several studies have focused on the provision of ecosystem services (ES) on the basin. Most of the studies have are primarily focused on carbon storage and drinking water supply. Meanwhile, none of the studies has specifically highlighted water yield distribution on sub-basin scale and as per land use types in the Bagmati basin of Nepal. Thus, this study was originated with an aim to compute the total WY of the basin along with computation on a sub-basin scale and to study the WY capacity of different landuse types of the basin. For the study, InVEST water yield model, a popular model for ecosystem service assessment based on Budyko hydrological method is used along with ArcGIS. The result shows water yield per hectare is highest on sub-basin 5 ($15216.32m^3/ha$) and lowest on sub-basin 6 ($10847.15m^3/ha$). Likewise, built-up landuse has highest WY capacity followed by grassland and agricultural area. The sub-basin wise and LULC specific WY estimations are expected to provide scenarios for development of interrelated services on local scales. Also, these estimations are expected to promote sustainable land use policies and interrelated water management services.

• Water for future
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• v.15 no.3
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• pp.37-47
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• 1982

In the past, the design flow of the urban storm drainage systems has been used largely on a basis of empirical and experience, and the rational formula one of empirical method has been widely used for our country, as well as world wide. But the empirical method has insufficient factor because minimal consideration is given to the relationship of the parameters in the equation to the processes being considered, and considerable use of experience and judgment in setting values to the coefficients in the equation is made. The postcomputer era of hydrology has brought an acceleration development of mathematical methods, thus mathematical models are methods which will greatly increase our understanding in hydrology. On this study, a simple mathematical model of urban presented by British Road Research Laboratory is tested on urban watersheds in Ju An Ju Gong Apartment. The basin is located in Kan Seog Dong, Inchon. The model produces a runoff hydrograph by applying rain all to only the directly connected impervious area of the basin. To apply this model the basin is divided into contributing areas or subbasins. With this information the time area for contributing is derived. The rainfall hyetograph to design storm for the basin flow has been obtained by determination of total rainfall and the temporal distribution of that rainfall determined on the basis of Huff's method form historical rainfall data of the basin. The inflows from several subbaisns are successively routed down the network of reaches from the upstream end to the outlet. A simple storage routing technique is used which involves the use of the Manning equation to compute the stage discharge curve for the cross-section in question. To apply the model to a basin, the pattern of impervious areas must be known in detail, as well as the slopes and sizes of all surface and subsurface drains.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5801-5812
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• 2014

The retention basin is a hydraulic structure for flood mitigation by storing river flow over a design flood. In this study, numerical models were adopted to simulate the flood mitigation effects by a retention basin. The large flood condition was applied as a boundary condition to consider an abnormal flood caused by climate change. Furthermore, the two-dimensional numerical model was adopted to regenerate the complex flow pattern due to the topography and lateral flow near the retention basin. The numerical results of the one- and two-dimensional model were analyzed and compared. The results showed that the two-dimensional model is more applicable to assessing flood mitigation by the retention basin with a complex topography and lateral flow patterns.

• Journal of Korea Water Resources Association
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• v.36 no.6
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• pp.911-924
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• 2003

Many researches have been conducting on extracting geometry data and hydrologic parameters by using GIS technique. However, there is no clear standard on those methods yet. This study examines the changing pattern of runoff responses characteristics with applying lumped model on divided watershed. WMS is used in order to divide watershed and calculate hydrologic geometry data and parameters by GIS technique. HEC-1 is adopted as a hydrologic model to establish runoff responses. The basin is divided into small watersheds, which are approximately same size. This research conducted runoff response simulation of Pyoungchang River and Wichon River Basin. Especially, research was focused on what is the most appropriate level as a divined sub-basin, and tested the effect of size of sub-basin for the runoff response simulation. The results showed the size of sub-basin was not an important factor for the simulation results after a certain size. The results of this study can be applied as an appropriate guidance to select optimal simulation size of watershed for the lumped model in a specific watershed.

• The Journal of Engineering Geology
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• v.28 no.3
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• pp.397-409
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• 2018

Izumi sedimentary basin (ISB), west of Shikoku, Japan, is widely distributed across the western side of the Sakuragi Bend of the Japan Median Tectonic Line (MTL). It is not obvious how the ISB formed, but this feature is similar to an asymmetric pull-apart basin. The stratigraphic succession and tuff layers show that ages tend to decrease toward the Sakuragi Bend. We investigate whether the ISB is an asymmetric pull-apart basin using analogue model experiments with running sand. A pull-apart basin of length 60 cm and width 20 cm is formed, and secondary normal faults appear on the surrounding surface. A cross-section parallel to the direction of displacement shows that the stratigraphic succession of the pull-apart basin becomes younger toward the releasing bend. A listric normal fault, which has the opposite dip to the master fault, is observed in a cross-section perpendicular to the direction of displacement. These results are consistent with the observed properties of the ISB west of Shikoku, thereby supporting the possibility that the ISB is an asymmetric pull-apart basin.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.5
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• pp.561-569
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• 2016

In this paper a concept of the paradigm shift in the operations of Water and Wastewater systems regarding the production and usage of water was introduced. Based on this concept the interrelationships between the water quality in the upper basin of NakDong River relative to Busan and the degree of satisfaction of the customers on the water supply service in Busan were modeled using the System Dynamics modeling methodology. SamRangJin basin area was determined as the upper basin of Busan after analyzing the relationships between the water quality of MoolGeum water intake point and water quality data of various mid- and upper water intake points along NakDong River. The amount of contaminants generated in SamRangJin basin was modeled using the Gross Regional Domestic Product in the area and the treated amount was calculated using the efficiency of wastewater treatment and the degree of improvement of environmental condition per investment. The water quality at MoolGeum water intake point was modeled to take the effects of the remaining amount of contaminants after treatment and the non-point source contaminants in SamRangJin basin. Using the developed System Dynamics model the effects of the investment for the improvement of environmental condition in SamRangJin basin were compared to the case of alternate water source development for Busan in terms of the degree of satisfaction of the customers on the water supply service in Busan.