Paper Title
Using Threshold, Severity, Duration and Frequency Diagrams to Identify the Occurrence of Drought Conditions in the Western Cape: South Africa

Abstract
Droughts are one of the serious water supply challenges that water resource managers face, as prolonged dry periods can stress and cause the failure of water supply systems. From 2015 to 2018, the city of Cape Town, South Africa, faced a severe drought that threatened its water supplies. The aim of this research was to support water resource managers in the region in a future drought by producing drought curves and diagrams that can be used to identify the occurrence and severity of a drought in time, specifically at a local water catchment level. Based on the Standardised Precipitation Index, drought threshold tables and severity curves were produced to allow the occurrence and severity of droughts to be read off these tables and curves, using only rainfall measurements. Maps of the data were also produced to allow drought properties to be determined spatially across the south Western Cape region. Keywords - Drought, SPI, Severity-Duration-Frequency Curves, Threshold.