Following the flood situations of the past years, integrated management of the rivers area must now improve the protection against floods. Hydrological studies into the effectiveness of flood reduction measures are an important principle of this process, from a planning point of departure. Though flood management in itself is not a CHR task, the organization is responsible for the study of hydrological principles for a new style of river management.
A CHR project (DEFLOOD) established within the scope of the IRMA SPONGE programme is currently being carried out. This project develops concepts and methods which facilitate specific hydrological assessment of the effectiveness of decentralized retention measures at the supra-regional level.
The general IRMA SPONGE project
This support programme comprises a package of innovative, transnational, mutually geared and supplementary projects concerned with the study of flood prevention and potential damage in the Rhine-Meuse basin. The insight from these projects is mainly aimed at further development of water management and physical planning. IRMA SPONGE comprises 13 projects in which approximately 30 institutes from all the countries in the Rhine-Meuse basin co-operate (the Netherlands, Germany, France, Belgium, Luxembourg and Switzerland).
The object of the general project is to integrate the wide ranging expertise amassed in the numerous national and international projects in future initiatives, which will then result in an extensive European strategy with regard to flood prevention and the general physical planning.
The CHR DEFLOOD project - Methods for analysis of the effectiveness of decentralized flood reduction measures
Decentralized flood reduction measures
Decentralized flood reduction measures are measures taken in the catchment area in order to combat possible damaging floods, as early as in the discharge formation. These include the modified soil processing of agricultural land, reforestation, the creation of decentralized storage locations and percolation areas or the management or provision of retention areas along smaller watercourses.
Targets and results of the DEFLOOD project
DEFLOOD signifies a step in the direction of a quantitative, hydrological assessment of these measures. A new methodology needs to be developed for this purpose, which offers the possibility of assessing the hydrological effectiveness of the various measures. It must also be possible to derive which retention measures are required, where and to what extent, in order to achieve measurable discharge reducing effects in the Moselle and the Rhine.
A methodical instrument will be made available in order to estimate the effect of the decentralized flood reduction measures, which can be deployed in various sizes of basin. This includes the formulation of flood discharge scenarios for various water levels in the Moselle and Rhine, devised with a view to the various hydro meteorological conditions and selected decentralized flood prevention measures. Estimation of the highest possible discharge will also play a role here.
Working method for the DEFLOOD project
In large river basins, the spatial, heterogeneous distribution of precipitation results in the occurrence of a variety of flood situations. Series of so-called reference conditions and maximum possible precipitation levels are therefore defined per area via the classification of historic and generated hydro meteorological series. In combination with
- scenarios of decentralized flood reduction measures, integrated basin modeling and
- the application of statistical analysis methods
- the hydrological effectiveness of decentralized flood reduction measures can be quantified.
The CHR project "Development of methods for analyzing the effectiveness of area-specific flood reduction measures in the Rhine catchment area on the basis of reference floods" (DEFLOOD) is carried out by the following institutes:
Federal Office for Hydrology, Koblenz
Universität Trier, Trier
Rijkswaterstaat - RIZA, Lelystad
Federal Office for Water and Geologie, Bern, ETH Zürich