| Abstract: | ![]()
Riverbed depression of a prealpine river by several metres during the last decades has lead to various environmental damages such as bank instability and lowering of groundwater level. In consequence forests adjacent to the river are suffering from dehydration. To prevent further riverbed degradation due to insufficient bedload replenishment, widening of the riverbed in certain areas is being investigated. The widening has to be dimensioned that the overall annual transport reaches a new state of equilibrium. To find the right size of widening calculations with seventeen bedload formulas were made. The quality of the formulas depends mainly on reliable reproduction of the nature data of transport rate, total annual transport and discharge which contribute most to annual sediment transport. After choosing a suitable formula, a forecast calculation could be made. Accordingly a new stabilization of the river bed can be attained with widening the cross section from 100 m up to 160 m or 170 m bedwidth. |
