In Gangwon Province, the rainy season with an extremely high precipitation caused extreme flood event in the summer in 2006. A one dimensional (1D) hydraulic model was developed for mountainous river reaches located closely to the Yeongwol thermal power plant. Input data, including topographical data and river flow measured every 10 minutes from July 1st to September 30th, 2013 by Han River Flood Control Office (HRFCO), were imported to a 1D hydraulic model. The results were the simulated water levels, water discharges and average flow velocities at each cross-section. The simulated water levels in different years (including 2011, 2012 and 2014) were used to calibrate and validate the applied model. Climate change scenarios were estimated by referencing the climate change adaptation strategies of the Korean government and historical information about the extreme flood events.

1. In Gangwon Province, the rainy season with an extremely high precipitation caused extreme
flood event in the summer in 2006. A one dimensional (1D) hydraulic model was developed for
mountainous river reaches located closely to the Yeongwol thermal power plant. Input data,
including topographical data and river flow measured every 10 minutes from July 1st to September
30th, 2013 by Han River Flood Control Office (HRFCO), were imported to a 1D hydraulic model.
The results were the simulated water levels, water discharges and average flow velocities at each
cross-section. The simulated water levels in different years (including 2011, 2012 and 2014) were
used to calibrate and validate the applied model. Climate change scenarios were estimated by
referencing the climate change adaptation strategies of the Korean government and historical
information about the extreme flood events.
Scenario Strategy Upper Namhan Flow Dong River Flow
Sce.1
Do nothing
Normal (Q2013)
Extremely High
(Q = Q2006)
Sce.2 High (2 x Q2013)
Sce.3 Extremely High (3 x Q2013)
Sce.4
River-bed
widening
Normal (Q2013)
Sce.5 High (2 x Q2013)
Sce.6 Extremely High (3 x Q2013)
Scenario Sce.1 Sce.2 Sce.3 Sce.4 Sce.5 Sce.6
Reservoir A 5.6 6.5 6.9 8.7 10.0 10.4
Reservoir B 94.4 93.5 93.1 91.3 90.0 89.6
Prediction of Flood Risk under the Impact of Climate Change on the Thermal Power Plant
using One Dimensional Hydraulic Model
Nguyen Thanh Tuu1, Seungdo Kim1*, Van Pham Dang Tri2, Hyeonkyeong Kim3, Jeejae Lim1, Taeho Kim1, Beomsik Yu1, Cheongyu Park1
1 Department of Environmental Science and Biotechnology, College of Natural Sciences, Hallym University, South Korea
2 Department of Water Resources, College of Environment and Natural Resources, Can Tho University, Vietnam
3 Division of Information and Telecommunications, Hanshin University, South Korea
* Corresponding author, E-mail: sdkim@hallym.ac.kr
1. Introduction
2. Methodology
Table 1. Climate Change and Adaptation Strategy Scenarios
Table 2. Distribution of Flow to the Two Reservoirs (%)
Fig. 5. Maximum Velocities in the Part of River near Power Plant
1. Model Description
• Geometric data: 3 Stream lines
(Dong River, upper and lower
Namhan Rivers), 81 Cross-sections
created from 90m resolution digital
elevation model (DEM)
• Upstream boundaries: Stream flows
from Dong River and upper Namhan
River (Source: HRFCO).
• Downstream boundary: Friction
slope at lower Namhan River is
0.001.
• Manning’s n coefficient is 0.036 in
the mainstream lines for all rivers.
• Reservoirs: A (upper Namhan River)
and B (lower Namhan River).
• Program: HEC-RAS 5.0
2. Calibration and Validation
• Nash-Sutcliffe coefficient: R2 ranged
from 0.96 to .099
3. Results
1. Simulated Surface Elevations
• The highest elevation in 2013 is 193.3m, and the lowest elevation in 2014 is 186.9m, above mean
sea level (AMSL).
• The maximum velocity is ranged from 1.8 m.s-1 (2014) to 3.6 m.s-1 (2013).
• The depths in 2011 and 2012 are 191.7 m and 189.3m, respectively.
• Road elevation (RE): 195m; Power plant ground elevation (PPGE): 197m
Fig. 3. Maximum Surface Water Elevations from 2011 to 2014 (Max WS: Maximum
Water Surface Elevation)
• The inundation depths under Sce.1, Sce.4 and Sce.5 do not affect the power plant.
• Sce.2 and Sce.3 affect the power plant with the maximum depth are 0.43m and 1.52m above the
PPGE respectively.
• Despite widening the river-bed, Sce.6 still impacts on the PPGE with the maximum depth is
0.34m.
Fig. 4. Simulated Water Surface Elevations under Climate Change Scenarios
2. Velocities
• After widening the river bed, the velocities are reduced.
• Most of the maximum velocities under Sce.4 < Sce.1; Sce.5 < Sce.2; and, Sce.6 < Sce.3.
3. Lateral flows from the rivers to reservoirs
The percentage of distribution to reservoir A increases after widening (i.e. Sce.4 > Sce.1; Sce.5 >
Sce.2; and Sce.6 > Sce.3) and increasing upper Namhan River flow.
• The river-bed widening is an effective strategy for flood prevention for both road and power
plant in the case that the water flow at Dong River is extremely high (Q2006) and the flow at
upper Namhan River is normal (Q2013).
• River-bed widening can help reduce the water flow velocities
• The impact of high flow at upper Namhan River is more significant than Dong River.
• The widening strategy also helps to regulate flooding flow to the reservoirs.
4. Conclusions
Fig. 2. Model Calibration and Validation
Fig. 1. Geometric Data
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This research was supported by a grant (17IFIP-B113506-02) from development of plant
program funded by Ministry of Land, Infrastructure and Transport of Korean government.
Acknowledgement