• Water for future
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• v.22 no.1
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• pp.99-107
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• 1989

KEUM River downstream has some characteristics in which the dowunstream is affected with tidal motion, the several tributaries are forming a dendritic river system, and the channel cross-sections are irregular. The flood in this downstream can now be analyzed by the hydrological flood routing methods and under the assumption regarding the dendritic river system as a single reach. In this study the river system was used for the flood routing. The flood records which were measured in 1978 and 1987 were applied for calibration and verification of the unsteady flow model respectively. The results show that the flood at KANG-KYONG station was not affected with the tidal motion when the discharge at KONG-JU station exceeded about 5, 000$m^3$/sec, and that the bottle neck at IP-PO station intercepted the tidal influences.

• Magazine of the Korean Society of Agricultural Engineers
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• v.32 no.4
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• pp.81-88
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• 1990

The flow in a river reach where is influenced by tidal motion is characterized by unsteady flow. The flood analysis in the river reach needs depending upon the theory based on the complete unsteady flow equations. In this study the unsteady flow model which is called CRIUM (Channel Routing by Implicit Unsteady Flow Model) was developed and was applied to the Mankyong and Dongjin river in order to analyze the flood characteristics. The results, which were calibrated and verified by the flood records to be measured in the two rivers, show that unsteady flow mode] can be used for the derivation of the flood hydrograph. The peak flood discharges were estimated as 4,960 and $2,870m^3$/sec in 100 year frequency at the estuary of the Mankyong and Dongjin river, respectively. In addition, it was analyzed that the river reaches were not influenced by tidal motion when the discharge magnitude was larger than approximately $3,000m^3$/sec.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2001.10a
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• pp.74-79
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• 2001

A one-dimensional flood routing model was formulated to simulate the flood flow of drainage sub-canal using the continuity equation of paddy field and the momentum and continuity equation of drainage sub-canal. The model was applied for evaluating the hydraulic characteristics of drainage sub-canal at large-sized paddy fields. The model applicability was evaluated with field data and the simulated results were in good agreement with the observed data.

• The Journal of Engineering Geology
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• v.25 no.4
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• pp.623-627
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• 2015

To compile a flood hazard map it is essential to identify the potential risk areas. A scenario-based numerical modeling approach is commonly used to build a flood hazard map in the case of a levee-break. The model parameters that capture peak discharge, including breach formation and progress, are important in the modeling method. In this study an earth-levee-break model is constructed under the assumption that the failure mechanism and hydraulic processes are identical for all levee-break river activities. Estimation of the hydrograph at the outlet as a function of time is highlighted. The constructed hydrograph can then serve as an upper boundary condition in running the flood routing model downstream, although flood routing is not considered in this study.

• The Journal of the Korea Contents Association
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• v.11 no.1
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• pp.404-410
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• 2011

For the simulation of one-dimensional unsteady flow, the Taylor-Galerkin finite element method was adopted to the discretization of the Saint Venant equation. The model was applied to the backwater problem in a single channel and the flood routing in dendritic channel networks. The numerical solutions were compared with previously published results of finite difference and finite element methods and good agreement was observed. The model solves the continuity and the momentum equations in a sequential manner and this leads to easy implementation. Since the final system of matrix is tri-diagonal with a few additional entry due to channel junctions, the tri-diagonal matrix solution algorithm can be used with minor modification. So it is fast and economical in terms of memory for storing matrices.

• Magazine of the Korean Society of Agricultural Engineers
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• v.36 no.2
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• pp.79-87
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• 1994

A real-time flood forecasting system(FLOFS) was developed for the real-time and predictive determination of flood discharges and stages, and to aid in flood management decisions in the Keum River Estuary Dam. The system consists of three subsystems : data subsystem, model subsystem, and user subsystem. The data subsystem controls and manages data transmitted from telemetering systems and simulated by models. The model subsystem combines various techniques for rainfall-runoff modeling, tidal-level forecasting modeling, one-dimensional unsteady flood routing, Kalman filtering, and autoregressivemovingaverage(ARMA) modeling. The user subsystem in a menu-driven and man-machine interface system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.7
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• pp.3369-3385
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• 2019

There are various research challenges in vehicular ad hoc networks (VANETs) that need to be focused until an extensive deployment of it becomes conceivable. Design and development of a scalable routing algorithm for VANETs is one of the critical issue due to frequent path disruptions caused by the vehicle's mobility. This study aims to provide a novel road-aware routing protocol for vehicular networks named as Two-level hierarchical Hybrid Road-Aware (THERA) routing for vehicular ad hoc networks. The proposed protocol is designed explicitly for inter-vehicle communication. In THERA, roads are distributed into non-overlapping road segments to reduce the routing overhead. Unlike other protocols, discovery process does not flood the network with packet broadcasts. Instead, THERA uses the concept of Gateway Vehicles (GV) for the discovery process. In addition, a route between source and destination is flexible to changing topology, as THERA only requires road segment ID and destination ID for the communication. Furthermore, Road-Aware routing reduces the traffic congestion, bypasses the single point of failure, and facilitates the network management. Finally yet importantly, this paper also proposes a probabilistical model to estimate a path duration for each road segment using the highway mobility model. The flexibility of the proposed protocol is evaluated by performing extensive simulations in NS3. We have used SUMO simulator to generate real time vehicular traffic on the roads of Gangnam, South Korea. Comparative analysis of the results confirm that routing overhead for maintaining the network topology is smaller than few previously proposed routing algorithms.

• Proceedings of the Korea Water Resources Association Conference
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• 2003.05b
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• pp.847-850
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• 2003

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.4
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• pp.23-31
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• 2007

The objective of the study is to prepare input data for FIA (Flood Inundation Analysis) & FDA (Flood Damage Assessment) through rainfall-runoff simulation by HEC-HMS model. For HwaOng watershed (235.6 $km^{2}$), HEC-HMS was calibrated using 6 storm events. Geospatial data processors, HEC-GeoHMS is used for HEC-HMS basin input data. The parameters of rainfall loss rate and unit hydrograph are optimized from the observed data. HEC-HMS was applied to simulate rainfall-runoff relation to frequency storm at the HwaOng watershed. The results will be used for mitigating and predicting the flood damage after river routing and inundation propagation analysis through various flood scenarios.

• Journal of Environmental Science International
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• v.14 no.11
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• pp.995-1004
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• 2005

As a research establish reservoir safety operation for small dam systems. This study presents hydrologic analysis conducted in the Duckdong and Bomun dam watershed based on various rainfall data and increase inflow. Especially the Duckdong dam without flood control feature are widely exposed to the risk of flooding, thus it is constructed emergency gate at present. In this study reservoir routing program was simulation for basin runoff estimating using HEC-HMS model, the model simulation the reservoir condition of emergency Sate with and without. At the reservoir analysis results is the Duckdong dam average storage decrease $20\%$ with emergency gate than without emergency gate. Also, the Bomun dam is not affected by the Duckdong flood control augmentation.