ABSTRACT
A planned drought management is considered as an aid tool for droughts decision making that managers must adopt to minimize their impacts (Estrela & Vargas, 2011), and that has been applied since the end of last century in the Júcar Hydrological District, where the availability of water resources is limited. Drought indices are hence effective planning tools in the detection, evaluation and monitoring of the status of drought conditions. A large number of different indices have been globally developed. The Spanish Water Authorities monitor the State Index (CHJ, 2007). This operational drought index is complemented by others: for the meteorological drought, the Standard Precipitation Index, SPI (McKee et al., 1993), and for soil droughts, the Palmer Drought Severity Index, PDSI (Palmer, 1965) and the Normalised Difference Vegetation Index, NDVI (Rouse, 1974).
