In Taiwan, the shortage index is usually used as the criterion for water resources planning purposes. However, the index calculation is based on annual water deficient ratios, which might underestimate the magnitude of drought events. In order to reasonably quantify properties of drought events during dry seasons, this study developed drought severity-duration-frequency (SDF) curves to interpret the relation between severity, duration and frequency of drought events. Details of development of drought SDF curves were provided and Tsengwen-Wusanto reservoir system was selected as the study area to demonstrate potential applications of drought SDF curves, including mapping of historical hydrological drought events, drought impact assessment and water shortage evaluation during dry seasons. The important findings are given as follows: (1) The 2014-2015 hydrological drought event was mapping onto the current drought SDF curve. The mapping results show the return period of the event is around 10 years; (2) Typhoon Morakot caused serious sedimentation problems and led to overall water shortage rates of drought events for various durations and return periods increased in a range from 1.5% to 6.0%; (3) The results of water shortage evaluation suggest that there is a 24,000-ton gap between water supply and water demand (the water demand is around 400,000 ton per day). The gap could be taken into account for future water resources planning and management during dry seasons.
All Science Journal Classification (ASJC) codes
- Agricultural and Biological Sciences(all)