Spatio-temporal analysis of annual rainfall in Crete, Greece
Analysis of rainfall data from the island of Crete, Greece was performed to identify key hydrological years and return periods as well as to analyze the inter-annual behavior of the rainfall variability during the period 1981–2014. The rainfall spatial distribution was also examined in detail to identify vulnerable areas of the island. Data analysis using statistical tools and spectral analysis were applied to investigate and interpret the temporal course of the available rainfall data set. In addition, spatial analysis techniques were applied and compared to determine the rainfall spatial distribution on the island of Crete. The analysis presented that in contrast to Regional Climate Model estimations, rainfall rates have not decreased, while return periods vary depending on seasonality and geographic location. A small but statistical significant increasing trend was detected in the inter-annual rainfall variations as well as a significant rainfall cycle almost every 8 years. In addition, statistically significant correlation of the island’s rainfall variability with the North Atlantic Oscillation is identified for the examined period. On the other hand, regression kriging method combining surface elevation as secondary information improved the estimation of the annual rainfall spatial variability on the island of Crete by 70% compared to ordinary kriging. The rainfall spatial and temporal trends on the island of Crete have variable characteristics that depend on the geographical area and on the hydrological period.
KeywordsRainfall Spectral analysis Geostatistics North Atlantic Oscillation Crete
The authors would like to thank the Department of Water Resources Management of the Region of Crete for making the rainfall data available for public use through its website.
EAV written and edited the manuscript, performed the statistical and geostatistical analysis and the interpretation of the results, GAC contributed to the statistical interpretation, GPK contributed with his expertise to the results interpretation, and AK performed data management.
Compliance with ethical standards
Conflict of interest
The authors declare no competing financial interests.
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