Summary:

Atmospheric and hydrological droughts are characteristic feature of natural environment in Poland. Observed changes of meteorological and hydrological conditions during the last 20-30 years may strengthen this phenomenon. Meteoro-logical and hydrological factors can influence negatively the amount of water ac-cessible for plants needs causing very serious problems for agriculture, especially in these regions of Poland where crop production is the basis of economy. One of such a regions is Wielkopolska. The main aim of this article is the analysis of trends of hydro-meteoro-logical indexes which can influence plant production in Wielkopolska Voivodship. The analysis is based on data from hydro-meteorological stations for growing season (April-September) covering years 1966-2005. The results of the analysis show that changes of precipitation, and as a consequence - runoff, were small and statistically not significant. The trends of the air temperature, sunshine duration and evapotranspiration were positive and statistically significant. As a result of these changes, the values of climatic water balance decreased. Direction of changes of the described indices in the Wielkopolska region indicates that water deficit during growing season will continue to worsen.