Methodology for deriving synthetic meteorological droughts and its application for Budapest

Abstract

In the recent years, nearly every part of Central Europe and the Balkans has experienced periods of reduced precipitation that can lead to droughts. Because of the complexity of the phenomenon and the different points of view from which the problem can be studied, it is difficult to decide when the drought started or when it ended. This paper presents a methodology for a stochastic analysis of meteorological droughts. This method is applied to precipitation and temperature data observed at a meteorological station of Budapest for the period of 1900–2000. The drought is defined as a consequence of a combined effect of temperature and prolonged dry period – consecutive days with daily precipitation below a chosen threshold for precipitation. The statistical analysis of the maximum meteorological droughts is performed by means of the peaks-over-threshold (POT) method. The proposed methodology provides probability distributions of the magnitude of droughts in terms of dry period duration and air temperatures, which can then be used to formulate synthetic design droughts for selected return periods.