Author(s): Minsung Kwon, Kyung Soo Jun

Linked Author(s): Minsung Kwon

Keywords: Dam Inflow Drought Index (DIDI), drought, ROC analysis, threshold

Abstract: This study developes a Dam Inflow Drought Index (DIDI) for Chungju Dam in Korea and evaluates the usability of the DIDI by comparing with Surface Water Supply Index (SWSI) and Standardized Precipitation Index (SPI). DIDI is calculated by the cumulative difference between the critical inflow and the observed inflow. The critical inflow means the essential inflow keeping the water supply criteria of the dam. Considering the limit of dam capacity, the upper limit of the cumulative difference, i. e. , threshold, has to be determined, and the threshold is estimated by performing Receiver Operating Characteristics (ROC) analysis. The Optimal threshold is determined by a value that represents maximum ROC score. The maximum ROC score of the DIDI was 0. 93, and the threshold at this point was 630 �106 m3. The maximum ROC score of the DIDI was 0. 21 higher than the score of SWSI and 0. 33, 0. 22, 0. 16, and 0. 17 greater than the score of SPI (3), SPI (6), SPI (9), and SPI (12), respectively. DIDI shows much better performance in monitoring dam droughts than SWSI and short-term and long-term SPI. The DIDI is useful for monitoring the dam inflow drought, and its application could help mitigate drought damages

DOI:

Year: 2017