| Title |
Comparative Study on Evaluating Standard Flow in Partially Gauged and Ungauged Watershed |
| Authors |
김경훈 ( Gyeonghoon Kim ) ; 김정민 ( Jeongmin Kim ) ; 정현기 ( Hyunki Jeong ) ; 임태효 ( Taehyo Im ) ; 김성민 ( Seongmin Kim ) ; 김용석 ( Yongseok Kim ) ; 서미진 ( Mijin Seo ) |
| DOI |
https://doi.org/10.15681/KSWE.2019.35.6.481 |
| Keywords |
Flow duration curve; Partially gaugedwatershed; Standard flow; Streamflow record extension technique |
| Abstract |
The Ministry of Environment has measured streamflow at eight-day intervals for the estimation of standard flow of the Total Maximum Daily Loads (TMDL) system. This study identified the availability of the partially measured the eight-day interval data for estimating standard flow and found the optimal extension techniques of standard flow. The study area was selected for the Nakbon-A watershed in the Nakdong River, and four streamflow record extension techniques of standard flow were considered: extension, percentile, drainagearea, and regional regression methods. The flow duration curve (FDC) using the eight-day interval streamflow data indicated very high Nash and Sutcliffe Efficiency (NSE) values above 90 % from FDC-II to FDC-VII compared to FDC-VIII, the standard FDC. This result demonstrates that FDC using daily data of three-six cumulative years could represent standard FDC fairly well. For the streamflow record extension techniques of standard flow, the percentile method was selected as the optimal alternative, showing the minimal difference from FDC-VIII. These results validate the availability of the eight-day interval streamflow data in the standard flow estimation and the application of extension techniques. It seems that these results could reduce the uncertainty of partially measured streamflow data for water quantity and quality management. |