Partnership agreement n° 10 : IRMA-SPONGE in framework of the INTERREG IIC programme IRMA (project 3 FRHYMAP)



A spatially distributed raster-based rainfall-runoff model for prediction of peak discharges and hydrographs is developed. Pre-processing of input data to and post-processing of output data from the model are performed within an Arc/Info GIS framework. Basin related parameters of the model are derived from three maps: a digital elevation model (DEM), a land use map and a soil map. The DEM was created from the elevation contours using the Arc/Info topogrid function. All the necessary terrain features such as flow direction, flow accumulation, stream network, stream order, sub basins and slope among others were derived directly from this DEM. The land use map was constructed from land use polygon coverage and the Manning coefficient and root depth grids were derived from it. Similarly, the soil map was created from soil polygon coverage. For each grid cell, runoff coefficients are calculated as a function of slope, land use and soil types.

The runoff velocity in a grid was computed using the Manning equation. Two DEM derived parameters (i.e. the hydraulic radius and slope), and one land use derived parameter (i.e. the Manning coefficient) were used for this calculation. The flow length and travel times from each cell to the basin or sub-basin outlet is computed with the Arc/Info flowlength function. To account for the spatial distribution of the rainfall, the Thiessen polygon method was adopted. The generation of runoff in each grid cell was computed as a function of rainfall and soil moisture status. This runoff is routed to the basin and/or sub-basin outlet along the topographically derived flow paths using a response function. Finally, total discharge is computed by convolution of the flow response from all grid cells.

The model will be applied, with a 50x50m pixel resolution, to the 1100 km2 area of the Alzette basin. This basin is located predominantly in the Grand Duchy of Luxembourg, and partly in France and Belgium. All the necessary input data for the model will be obtained from the Centre de Recherche Public - Gabriel Lippmann (Luxembourg). The model will have the advantage of reflecting the influence of changes in land use and/or soil cover on the hydrological behaviour of the river basin.
Effectieve start/einddatum26/05/0031/12/01

Flemish discipline codes

  • Mechanical and manufacturing engineering