PRECIPITATION EXTREMES TRENDS IN EAST AND SOUTH BULGARIA FROM 1961 TO 2010

For the analysis of the spatial distribution and temporal trends of seasonal and annual values of precipitation over East and South Bulgaria, precipitation indices were applied. The indices characterize the intensity (90th percentile of rainday amounts, Greatest 5-day total rainfall, Simple Daily Intensity), frequency (Max number of consecutive dry days, Number of events greater than long-term 90th percentile of raindays) and the proportion of total rainfall (Percent of total rainfall from events greater than long-term 90th percentile of rainday amounts). Indices were calculated using R-software developed for statistical calculations project STARDEX. Mann-Kendall and Sen's slope estimator were applied for trend detection and assessment of significance. The indices were used as a climatic variability indicator.