PRECIPITATION VARIATION IN THE WIDAWA RIVER BASIN IN THE MULTI-YEAR PERIOD 1956-2012

The paper analyses results of measurements of precipitation amounts in the Widawa River basin in the multi-year period 1956-2012. Analysed were annual, monthly and daily precipitation totals and the numbers of days with precipitation in a year and in a month. Trends of changes were determined and extreme monthly and daily precipitation totals were analysed. Annual precipitation totals over the analysed multi-year period were very strongly diversified. Despite a considerable spread of results, the distribution in time did not reveal any clear tendency of changes, the trend line was almost horizontal. The number of days in a year with precipitation revealed an obvious decreasing trend, particularly within the fraction of days with precipitation <1mm. Average daily precipitation obtained from the ratio of annual precipitation total and the number of days with precipitation showed a growing tendency. December was the month in which the highest number of days with precipitation was noted during the multi-year period 1956-2012. Considering the fewest number of days with precipitation, similar results were obtained for three months. In May and September the least number of days with precipitation was registered eleven times. Only once a less often mentioned number of days occurred in October. A summary ...