M. Hudak

The Analysis of the Degree of Flood Risk in the Middle Bobr Valley

Abstract This paper presents the impact of rainfall on the degree of flood risk in the basin of the middle Bobr River in western Poland. When the average rainfall level reaches 15 to 20 mm, this apparently calm river may dramatically change its character within just one week. The most important flood risks are flood waves in the headwaters. Because of the mountain character of the river basin, during intensive rainfall there is a huge surface runoff and the water level rises rapidly in the river. This phenomenon was observed in June 2017 in the town of Zagan (Lubuskie Voivodeship). It has been shown that the course and dynamics of hydrological processes occurring in the Bobr River basin depend on its physical and geographical characteristics and the influence of anthropogenic factors. The location is one of the main cause of numerous floods for Zagan, on the other hand changes in land development plays significant meaning in flood hazards. Continuous monitoring of the river is the basis for a comprehensive forecast of flood risks.

Flood Protection on the Odra River in the Segment Between Nowa Sól and Cigacice

Abstract Existing river valley development methods which have been used for a significant period of time, as well as the use of land for construction of residential developments, have led to negative consequences for the environment. The agricultural use of land and its protection with hydraulic structures has restricted the natural flood area of the river. According to EU law, the risk of catastrophic flooding should be reduced, and its effects minimized. Sustainable water management determines the effectiveness of flood protection in the whole river basin. The paper presents the flood protection on the Odra River in the segment between Nowa Sól and Cigacice, with special emphasis on the possibility of reconstructing the former flood polders in the Middle Odra Region that existed before the year 1945, including the polder in Milsko.