The aim of this thesis was to present the characteristic of precipitation conditions in Suwałki Lake District. Analysis was made on the base of daily sum of precipitation of six meteorological stations during 1971–2000 period. Frequency of months and seasons with defi cit or excess of precipitation according to Kaczorowska’s criterion, frequency of non-precipitation day sequences >10, >15 and 20 days in the periods April–May, June– July, August–September and April–September were taken into consideration. Numbers of days with-precipitation ≥ 0.1 mm, ≥ 1.0 mm, ≥ 10.0 mm, ≥ 20.0 mm and ≥ 30.0 mm was analyzed also. All examined weather stations indicate that precipitation shortages are characteristic for the 90”s. Not only total precipitation amount indicate that, but also their classifi cation presented according to Kaczorowska as well as precipitation – free periods.
Statistical data concerning yields in 30 administrative districts during 15 years (1959-1973) were the initial material. Multiple regression method by Ezekiel was used to determine effects of precipitation on the yields. Suitable practices were applied to eliminate factors other than climatic. Statistical distribution of precipitation in critical months for potatoes and sugar beets was studied. Maps of average yield losses in many-year periods were prepared for the area of Poland. They were based on the probability of precipitation in each 10-millimetre range of values and decreasing of yield according to the statistical empirical models.
PL
Materiał wyjściowy stanowiły dane statystyczne o plonach z 30 powiatów w 15-leciu 1959-1973. Określono związki wpływu opadów na plonowanie metodą regresji wielokrotnej Ezekiela. Zastosowano odpowiednie procedury eliminacji czynników pozaklimatycznych. Zbadano statystyczny rozkład opadów w krytycznych miesiącach dla ziemniaków i buraków cukrowych. Wykorzystując prawdopodobieństwo opadów w poszczególnych 10-milimetrowych przedziałach oraz obniżki plonów według modeli statystyczno-empirycznych, sporządzono mapy przeciętnych w wieloleciu strat plonów na obszarze Polski.