Development of drought severity-duration-frequency curves in Victoria, Australia

One of the many ways in preparing for drought is to carry out a drought risk assessment by characterisation of the frequency, severity and duration of a drought. Therefore, the current study aimed at the development of severity-duration-frequency (SDF) curves to provide a comprehensive characterisation of the droughts for 10 selected stations in Victoria, Australia. The development of the frequency curves is based on the precipitation defi cits which were computed based on the Standardised Precipitation Index (SPI). Instead of using SPI values, the precipitation thresholds were used to compute the severity of the droughts. This would be very helpful in delivering information that can be understood easily by ordinary users and decision-makers. The SDF curves were developed using the partial duration series (PDS) technique. Log Pearson Type III distribution was chosen and fi tted well to the precipitation defi cits for different durations of drought. Overall, SDF curves were successfully derived for 10 stations in Victoria and can provide useful information for medium/long term planning, such as in planning irrigation supply and developing drought relief policies.