Advertisement

Drought Index Over Greece as Simulated by a Statistical Downscaling Model

  • C. Anagnostopoulou
  • K. Tolika
  • P. Maheras
Conference paper
Part of the Springer Atmospheric Sciences book series (SPRINGERATMO)

Abstract

Drought is the least understood of all weather phenomena, since it differs from other natural hazards in several ways. The hazardous of drought can be better understood by analyzing drought indices. The Standardized Precipitation Index (SPI) has been one of the most widely used indices for drought studies, as it can provide satisfactorily results for the appearance, variability and intensity of drought. Moreover, SPI has been developed in order to quantify and record drought episodes on multiple time scales (3 months, 6 months, 1 year, 2 years). In the present study a statistical downscaling technique based on artificial neural network was employed for the estimation of SPI over Greece. The aim of the study is to evaluate the simulated SPI index against the observational one. The performance of the statistical downscaling model is assessed utilizing biases, standard deviation and correlation coefficient between observed and simulated indices. An overestimation of the simulated mean SPI indices accompanied by a decrease in standard deviation is evident for all stations and all time periods. The reproduction of SPI3 and SPI6 for winter, spring seasons display rather promising results.

Keywords

Standardize Precipitation Index Drought Index Palmer Drought Severity Index Statistical Downscaling Multiple Time Scale 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

  1. Alexanderson H (1986) A homogeneity test applied to precipitation data. J Climatol 6:661–675CrossRefGoogle Scholar
  2. Anagnostopoulou C (2003) A contribution of drought analysis in Greece. Ph.D. dissertation, Aristotle University of Thessaloniki, Thessaloniki, 215ppGoogle Scholar
  3. Giorgi F (1995) Perspectives for regional earth system modelling. Global Planet Change 10:23–43CrossRefGoogle Scholar
  4. Hayes M (1999) Drought indices, National Drought Mitigation Center. (Available on line: http://www.civil.utah.edu/~cv5450/swsi/indices.htm#deciles
  5. IPCC (2007) IPCC fourth assessment report: climate change 2007. Working group I report, “the physical science basis”, Chapter 11 “Regional climate projections”. pp 847–940Google Scholar
  6. Kalnay E, Kanamitsou M, Kistler R, Collins W, Deaven D, Gandin L, Irebell M, Saha S, White G, Woollen J, Zhu Y, Leetmaa A, Reynolds R, Chelliah M, Ebisuzaki W, Huggins W, Janowiak J, Mo KC, Ropelewski C, Wang J, Jenne R, Joseph D (1996) The NCEP/NCAR 40-year Reanalysis project. Bull Amer Meteor Soc 77:437–471Google Scholar
  7. Lana X, Serra C, Burgueno A (2001) Patterns of monthly rainfall shortage and excess in terms of the Standardized Precipitation Index for Catalonia (Spain). Int J Climatol 21:1669–1691CrossRefGoogle Scholar
  8. Loukas A, Vasiliadis L, Tzabiras J (2007) Evaluation of climate change on drought impulses in Thessaly, Greece. Eur Water J 1:17–18Google Scholar
  9. McKee TB, Doesken NJ, Kleist J (1993) The relationship of drought frequency and duration to time scale. In: Proceedings of the 8th conference of applied climatology, American Meteorological Society, Boston, pp 179–184Google Scholar
  10. Palmer WC (1965) Meteorological drought. Research paper no. 45, U.S. Department of Commerce Weather Bureau, Washington, DCGoogle Scholar
  11. Palmer WC (1968) Keeping track of crop moisture conditions, nationwide: the new crop moisture index. Weatherwise 21:156–161. doi: 10.1080/00431672.1968.9932814 CrossRefGoogle Scholar
  12. Thom HCS (1958) A note on the gamma distribution. Mon Weather Rev 86:117–122CrossRefGoogle Scholar
  13. Tolika K, Maheras P, Vafiadis M, Flocas HA, Arseni-Papadimitriou A (2007) Simulation of seasonal precipitation and raindays over Greece: a statistical downscaling technique based on artificial neural networks (ANNs). Int J Climatol 27:861–881. doi: 10.1002/joc.1442 CrossRefGoogle Scholar
  14. Vasiliadis L, Loukas A, Patsonas G (2009) Evaluation of a statistical downscaling procedure for the estimation of climate change impacts on droughts. Nat Hazards Earth Syst Sci 9:879–894. doi: 10.5194/nhess-9-879-2009 CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  1. 1.Department of Meteorology and ClimatologyAristotle University of ThessalonikiThessalonikiGreece

Personalised recommendations