LAUSR

Drought is a main water-related natural hazard due to its features, sensitivities and effects to all sectors. According to climate change scenarios, drought hazards are expected to be more devastating, especially in arid and semi-arid regions. Drought characterization is essential to be aware of expected negative effects of droughts as well as to devise water management plans including possible mitigation measures. To this end, many drought indices have been developed for drought analysis, one of which is the Standardized Precipitation Index (SPI) that is widely used worldwide. In this study, a new drought index is proposed, namely the Drought Power Index (DPI), based on the SPI with orientation by reliability-resilience-vulnerability (RRV) concept. The use of the RRV approach with the SPI time series empowers the drought characterization by considering the frequency of drought event, drought recovery period as well as the severity of droughts-once a drought has occurred. Since the drought is identified as an unfavorable phenomenon, the DPI ranges from 0 to 1 where the higher values indicate higher drought devastating features (probability, duration and extremity of drought) and vice versa. The proposed approach is illustrated with reference to the Southeastern Anatolia Region, Turkey. The long-term (19702017) monthly precipitation data of eight meteorological stations under the operation of General Directorate of Meteorological Services of Ministry of Forestry and Water Affairs are used in the study. The 12-month SPI time series, which were later used for calculations of DPI, were obtained by the use of SPI_SL_6 software. The study revealed that there has been an increasing trend in DPI values in the basin, especially after 1993. It is concluded that the DPI is a valuable indicator for (i) spatially and temporally evaluating the drought characteristics, (ii) analysing meteorological, agricultural and hydrological drought severity with its coherent capability with SPI, (iii) ranking the regions in accordance with the drought vulnerability conditions.