Climate Variability and Change—Hydrological Impacts (Proceedings of the Fifth FRIEND World Conference held at Havana, Cuba, November 2006), IAHS Publ. 308, 2006, 180–185.


 

Impact assessment of measures in the upstream part of Dutch basins to reduce flooding

 

ERIK QUERNER & MENNO RAKHORST

 

Alterra, PO Box 47, 6700 AA Wageningen, The Netherlands

erik.querner@wur.nl

 

Abstract Flooding in the northern part of The Netherlands has caused serious economic threats to densely populated areas. Therefore a project has been carried out in a 1200 km2 area to assess the retention of water in the upper parts of river basins as a way to reduce the downstream flooding. The physically-based groundwater and surface water model SIMGRO was used to model the hydrology of the basins. The model was calibrated using discharges and groundwater levels. Scenarios of measures to assess the possibility of retaining water in the upper parts of the basin were defined and tested. One measure was the retention of higher discharges using culverts or gates, the other was to make the streams shallower and thereby, increase flood plain storage. The analysis indicates that holding water in the upstream parts of the basins proved to be feasible and can result in significant reductions of peak flows.

 

Key words drainage basin; rainfall; evapotranspiration; groundwater; surface water; modelling; river basin; scenario