Stochastic Environmental Research and Risk Assessment

, Volume 27, Issue 5, pp 1155–1170

Power spectral characteristics of drought indices in the Ebro river basin at different temporal scales

  • L. Telesca
  • S. M. Vicente-Serrano
  • J. I. López-Moreno
Original Paper

DOI: 10.1007/s00477-012-0651-4

Cite this article as:
Telesca, L., Vicente-Serrano, S.M. & López-Moreno, J.I. Stoch Environ Res Risk Assess (2013) 27: 1155. doi:10.1007/s00477-012-0651-4

Abstract

A deep spectral investigation of the monthly time series of Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI) in 45 meteorological stations in the Ebro basin (Spain) from 1950 to 2006 for timescales ranging from 1 to 48 months was performed. In order to summarize the results for the whole basin, the spectral analysis was also carried out on the four principal components of SPI and SPEI. Results confirm that SPI and SPEI presents very similar spectral characteristics. At the shorter time scales, the signal of SPI and SPEI is characterized by purely random temporal fluctuations. The longer time scales tend to feature the signal as a smoothly varying time series or persistent, mostly due to the aggregated nature of the indices calculation. The comparative analysis of the spectral properties of the drought indices for all the 45 sites in the Ebro basin lead to the identification of global or regional effects discriminated by local effects. It was found that some periodical signals are common to almost all the sites, while others where only identified in specific meteorological stations.

Keywords

Standardized Precipitation IndexStandardized Precipitation Evapotranspiration IndexPower spectrumPrincipal component analysis

Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • L. Telesca
    • 1
  • S. M. Vicente-Serrano
    • 2
  • J. I. López-Moreno
    • 2
  1. 1.National Research CouncilInstitute of Methodologies for Environmental AnalysisTitoItaly
  2. 2.Instituto Pirenaico de Ecología, CSICZaragozaSpain