Drought tendencies in Hungary

Drought is a major climatic hazard, which is expressed as relative to a long term average. Drought is a recurrent feature in Hungary's climate and it can cause significant damage to the country's agriculture. Its importance is emphasized by recurrent drought events in the 1980s and 1990s. In this study, we examine long time series of the Palmer Drought Severity Index (PDSI) to characterize statistical features of drought in Hungary. Two statistical tests are presented which are appropriate tools for studying normal and extreme climatic features or events that can be characterized with thresholds. The two tests were applied to the PDSI series in order to capture changes in drought occurrence: (i) whether drought events tend to concentrate at one end of the time series, and (ii) whether droughts tend to recur in subsequent years. On a country-wide scale, results indicate that more droughts happened at the end of the time series, especially moderate and severe droughts. Moreover, moderate and severe droughts tend to occur in subsequent years. Most of the stations show the same results as the country-wide series, although some of them failed to indicate significant change. There are spatial differences, but at most of the stations a general drying tendency is apparent.