High spatial resolution climatology of drought events for Spain: 1961–2014

• Published in: International journal of climatology Vol. 39; no. 13; pp. 5046 - 5062
• Main Authors: Domínguez‐Castro, Fernando, Vicente‐Serrano, Sergio M., Tomás‐Burguera, Miquel, Peña‐Gallardo, Marina, Beguería, Santiago, El Kenawy, Ahmed, Luna, Yolanda, Morata, Ana
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 15-11-2019; Wiley Subscription Services, Inc
• Subjects: Climate; Climatology; Drought; Drought characteristics; Drought index; Duration; Environmental assessment; Environmental impact; Evapotranspiration; Meteorological data; Precipitation; Regions; Resolution; Spain; Spatial analysis; Spatial discrimination; Spatial resolution; Spatial variations; SPEI; SPI; Standardized precipitation index; Temporal variability; Temporal variations; Spain
• ISSN: 0899-8418; 1097-0088
• DOI: 10.1002/joc.6126

This study characterizes the climatology of drought events over the mainland Spain and the Balearic Islands using high‐resolution (1.21 km2) meteorological data from 1961 to 2014. The climatology of drought was assessed based on two widely‐recognized drought indices: the Standardized Precipitation Index (SPI) and the Standardized Precipitation‐Evapotranspiration Index (SPEI), considering four different timescales (1‐, 3‐, 6‐ and 12‐months). Drought events were simply defined as sequences of months with negative values of the indices. We analysed the spatial and temporal variability of the frequency, duration and magnitude of the drought events. In general, the frequency of drought events is higher in the northern than in the southern regions. Conversely, the average duration and magnitude of the drought events in central and southwestern regions duplicate those recorded in northern areas. Although drought characteristics exhibit a general north–south gradient irrespective of the drought timescale and the drought index analysed, we found important spatial differences in terms of both drought duration and severity. As opposed to the SPI, the SPEI shows, on average, higher drought durations and magnitudes at 1‐, 3‐ and 6‐months timescales. Albeit of the absence of significant temporal changes in drought duration or magnitude at the regional scale, a nonsignificant tendency toward higher drought duration and magnitude is observed over the majority of Spain. Our result provide valuable guidance to stakeholders and decision‐makers on detecting, monitoring and adapting to drought impacts at local, regional and national scale in Spain.
This study presents the first climatology of drought events for mainland Spain and the Balearic Islands considering different drought timescales (1, 3, 6 and 12 months) and two different drought indices, that is, Standardized Precipitation Index (SPI) and Standardized Precipitation‐Evapotranspiration Index (SPEI).
In northern Spain, the drought episodes are more frequent than in the centre and south. But the drought duration tends to be shorter in the north, and the drought magnitude also tends to be lower.
The general spatial patterns of drought indices show strong differences, as a function of the timescales. Drought duration and magnitude were in general higher for the SPEI than for the SPI.