| Title |
Analyzing the Effect of an Extreme Turbidity Flow Event on the Dam Reservoirs in North Han River Basin |
| Authors |
박형석 ( Hyung-seok Park ) ; 정세응 ( Se-woong Chung ) ; 정선아 ( Sun-a Choung ) |
| DOI |
https://doi.org/10.15681/KSWE.2017.33.3.282 |
| Keywords |
CE-QUAL-W2; Extreme event; North Han River; Persistent turbidity; Turbidity flow |
| Abstract |
Persistent turbidity is defined as the long-term resuspension of small particles. It is one of the most important water qualities of the dam reservoir systems located in North Han River. Persistent turbidity results in aesthetic nuisance and harmful effect on the health of the ecosystem, in addition to elevated costs for water treatment for supplying drinking water supply to the Seoul metropolitan area. These harmful effects have been intensified with increasing strength and frequency of rainfall due to climatic changes in the basin. This study analyzed the effect of an extreme turbidity flow event that occurred in 2006, on the serial reservoir system (Soyang-Uiam-Cheongpyung-Paldang) located on the North Han River. The CE-QUAL-W2 model was set up and calibrated for the river and reservoir system, using the field data obtained in 2006 and 2007. The results showed that for 334 days, turbid water was released by the Soyang Reservoir, which was classified as having TSS concentration greater than 25 mg/L with peak TSS of 264.1 mg/L, after the extreme flood (592.7 mm) that occurred between 10th-18th July, 2006. The turbid water released by the Soyang Reservoir reached the most downstream Paldang Reservoir after about 20 days, and was sustained for 41 days, which was validated with water treatment plant data. Since the released water from Soyang Reservoir had low water temperature and high TSS, an underflow formed in the downstream reservoirs and vertically mixed at Paldang Reservoir due to dilution by sufficient inflow from the South Han River. |