The data set of the Warta discharges in Poznań (Poland) is one of the largest in the world as the daily observations of river stages have been conducted without interruptions since January, 1st, 1822. The Poznań measurement profile is situated in the 243.6 km and closes the catchment area of approximately 25 thousand square kilometers. The data used as the input in the paper were daily values of the Warta discharges in Poznań in the years 1822-2012. The climate in Poznań, a city situated in the centre of the Wielkopolska (Greater Poland) region, is relatively stable (Miler et al. 2005). Also the Warta River runoff shows considerable stability, especially in terms of mean annual values. Short-term trends are random in character. It was found that the Jeziorsko reservoir (total storage volume of 203 000 000 m3, officially put to use on September, 9th, 1987) significantly reduced daily variability of the flows and reduced peak discharge of the flood wave in the summer of 1997 on the Warta River at Poznań. The calculated periodogram for mean annual discharges of the Warta River in Poznań shows that there are main periodicities of ca. 10 year lengths. The research of the Provincial Inspectorate for Environmental Protection (WIOŚ) in Poznań shows a gradual improvement of water quality in the Warta River in Poznań.
The research was conducted at the Kwiatków site,1 in the Koło Basin (Central Poland). It included a fragment of a low terrace and the valley floor of the Warta river valley. The archaeological investigation documented over 100 wells that archaeological material indicates are associated with the Przeworsk culture. Geomorphological, lithological and geochemical studies were carried out at the archaeological sites and their surroundings. Selected for the presentation were two wells whose fillings were carefully tested and subjected to geochemical and lithological analyses. The wells showed a slightly different content of artifacts, as well as differences in their grain-size distributions, the structure of their filling deposits, and their geochemistry. This allows us to conclude that the two wells were used differently, but also probably about a different course for how each well was filled after the end of its operation.