The course of hydrological drought in the river Drawa catchment (Northern Poland) as characterized by the standardized runoff index

The paper presents the course of hydrological droughts in the Drawa River catchment in the period of 1981– 2010. The study utilizes daily values of the Drawa’s discharge recorded in the Drawiny hydrological station and and daily values precipitation in two meteorological stations (Wierzchowo and Krzyz). Hydrological drought characteristics have been determined on the basis of the Standardized Runoff Index (SRI), which is a common hydrological drought index. SRI values were calculated on the basis of average monthly discharges that were accumulated in 1-, 3-, 6-, 9-, and 12-month periods. The most acute hydrological droughts in the analysed multi-annual period occurred in the years 2003– 2007.