Water scarcity management: part 2: satellite-based composite drought analysis

Abstract

The composite use of two drought indices, namely the Reconnaissance Drought Index (RDI) for meteorological drought and the Vegetation Health Index (VHI) for agricultural drought, is considered for drought quantification and monitoring leading to water scarcity. The results of 20-year monthly RDI for Thessaly, Greece, indicate that there are eight drought periods lasting 12 months each and the start of severe and extreme drought usually coincides with the beginning of the hydrological year, whereas for moderate droughts the start occurs in spring, both lasting until the end of the hydrological year. There is also an increase in the areal extent of drought with the maximum occurring in the summer. Similarly, the results of VHI indicate that drought occurs every year during the warm season with increasing severity and areal extent. The findings justify the composite use of drought indices of different drought types for drought assessment and monitoring.