| Title: | Assessment of flood frequency alteration by dam construction via SWAT simulation |
| Authors: | Lee, J.E., J.-H. Heo, J. Lee and N.W. Kim |
| Year: | 2017 |
| Journal: | Water |
| Volume (Issue): | 9(4) |
| Pages: | |
| Article ID: | 264 |
| DOI: | 10.3390/w9040264 |
| URL (non-DOI journals): | |
| Model: | SWAT |
| Broad Application Category: | hydrologic only |
| Primary Application Category: | reservoirs, ponds, lakes and/or other impoundment effects |
| Secondary Application Category: | flood impacts and/or processes |
| Watershed Description: | Paldong Dam drainage area, which drains a portion of the Han River in north central South Korea. |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Abstract: | The purpose of this study is to evaluate the impacts of the upstream Soyanggang and
Chungju multi-purpose dams on the frequency of downstream floods in the Han River basin,
South Korea. A continuous hydrological model, SWAT (Soil and Water Assessment Tool), was
used to individually simulate regulated and unregulated daily streamflows entering the Paldang
Dam, which is located at the outlet of the basin of interest. The simulation of the regulated flows
by the Soyanggang and Chungju dams was calibrated with observed inflow data to the Paldang
Dam. The estimated daily flood peaks were used for a frequency analysis, using the extreme Type-I
distribution, for which the parameters were estimated via the L-moment method. This novel approach
was applied to the study area to assess the effects of the dams on downstream floods. From the
results, the two upstream dams were found to be able to reduce downstream floods by approximately
31% compared to naturally occurring floods without dam regulation. Furthermore, an approach to
estimate the flood frequency based on the hourly extreme peak flow data, obtained by combining
SWAT simulation and Sangal’s method, was proposed and then verified by comparison with the
observation-based results. The increased percentage of floods estimated with hourly simulated data
for the three scenarios of dam regulation ranged from 16.1% to 44.1%. The reduced percentages were
a little higher than those for the daily-based flood frequency estimates. The developed approach
allowed for better understanding of flood frequency, as influenced by dam regulation on a relatively
large watershed scale |
| Language: | English |
| Keywords: | SWAT; regulated and unregulated streamflows; flood frequency analysis; sangal’s method |