Santos, João; Portela, Maria; Pulido-Calvo, Inmaculada - In: Water Resources Management 25 (2011) 14, pp. 3537-3558
This study investigated the frequency of droughts for the period September 1910 to October 2004 in mainland Portugal, based on monthly precipitation data from 144 rain gauges distributed across the country. The drought events were characterized using the standardized precipitation index (SPI)...