FLOODS IN FORESTED WATERSHED, THE ORLICKE HORY MTS. (CZECH REPUBLIC)

The objective of our study is to investigate a relationship of mountain forest and occurrence of floods within the forested watershed. Floods have received much attention lately, especially in terms of extreme peak discharges being lowered by forests. Our study is theoretically based on unit hydrograph (JH) and modified three linear reservoirs model (TLN). Eight flood events between 2005 and 2008, and one extraordinary event in 2000 were transformed in both models deriving precipitation of 100-year periodicity. We derived parameter x expressing influence of forest; it was based on underground retention space of forest soil and its impact on floods. Parameter xis a variable depending on the retention space as the particular events occur. Mitigation of floods depends on filling of retention soil space with infiltrated water. The parameter x varied between 0.61-0.69 depending on real retention of precipitation water in soil and given amount of rainfall causing floods.