Publications Details
Publications Details

Back

Title: NON-PARAMETRIC TREND ANALYSIS OF PRECIPITATION DATA IN PIERIA REGION (GREECE)*

Author: D. K. Karpouzos, S. Kavalieratou and C. Babajimopoulos

Year: 2009

Publisher: European Water Resources Association (EWRA)

Description:

Precipitation has been widely considered as a starting point towards the apprehension of climate changes courses, constituting one of the most substantial components of the hydrologic cycle. The purpose of this work is to investigate the temporal variability of precipitation in order to contribute to a better interpretation
of the hydrological status of the study area located in Northern Greece within the prefecture of Pieria. The Aison River basin drains the water of its central part, forming the greatest receiver of surface water. The precipitation data used refer to the period 1974-2007.The methodology adapts various statistical approaches in order to detect possible precipitation changes in annual, monthly and seasonal basis, including both tests for monotonic trend (Mann-Kendall test, Sequential version of the Mann-Kendall test, Sen’s estimator of slope) and a test for step
change (the distribution-free CUSUM test). The application of this trend analysis framework resulted in the identification of a few trends, occurred mainly at smaller than annual time scales. An overall downward trend, even though no statistically significant, has derived for the stations located at lower altitudes within the agricultural zone of Pieria. Regional (River Aison basin scale) total precipitation series has also displayed trends similar to those for the majority of stations. Among the four seasons, a noticeable decrease of precipitation is
observed in Spring by both ways of analysis (station based and regional).