Tereny zalewowe w dorzeczu Prosny

Abstract

Based on the data provided in hydrographic maps of Poland (1:50000), we can present the range and calculate the flood-hazard area in the Prosna river basin. It has been established that the total flood-hazard area amounts to 190.5 sq. km, which represents almost 4% of the river catchment. The largest areas of the type are located directly in the Prosna river valley (127.1 sq. km) and in the Pratwa river catchment (24.5 sq. km). On top of that, historical data on the water levels at the Bogusław station have been juxtaposed (1951-1983). An analysis of the average levels and the extreme annual levels has indicated that in the former case, no trend has been detected, while the extreme levels tend to have been growing. Therefore, a rising trend has been noted with reference to the emergency levels (250 cm) and alarm levels (300 cm). The year 1979 was exceptional in this respect, as the alarm level was recorded fourteen times, and the emergency level was recorded twenty eight times.