Antoni Kuźniar, Stanisław Twardy, Marek Kopacz

the variability of THE CLIMATIC WATER BALANCE
IN THE SMALL PIENINY between 1960 and 2003

Key words: climatic water balance, precipitation, reference evapotranspiration

S u m m a r y

Based on standard observations (daily temperature, sunshine hours, air humidity and wind speed) conducted at IMUZ meteorological station at Jaworki, monthly values of the reference evapotranspiration ( ET _o ) in the growing seasons (Apr-Sep) were determined for the period 1960-2003 with the use of the CROPWAT computer model and Penman-Monteith formula [Allen et al ., 1998; Smith, 1992].

Probabilities of exceeding monthly precipitation and reference evapotranspiration were evaluated. The results are presented in graphical form. Trends of these factors were determined and an inconsiderable increase (but not statistically significant) was found for both precipitation and reference evapotranspiration. Positive climatic water balance ( P - ET _o ) ranged on average from 150 to 200 mm, in a few cases it exceeded 350 mm. There were only 7 years with climatic water deficit in the analysed period but in most cases the deficit did not exceed minus 50 mm.

Address: dr inż. A. Kuźniar, Małopolski Ośrodek Badawczy IMUZ , ul. Ułanów 21b, 31-450 Kraków; tel. +48 (12) 411-81-46, e-mail: imuzkrak@kki.pl