This dataset shows a digital surface model. It is a homogeneous and regular points grid which indicates the height above the surface of the earth, either the soil or any other permanent and visible element in the landscape (vegetation, construction,…). These data represent the situation of the landscape resulting from the July 2021 floods in het areas of the Vesdre, of part of the Meuse downstream from Liège and of the Demer.

DSM 1m is a homogeneous and regular point grid indicating the height of the Earth’s surface level in order to model its landscape. DSM 1m is achieved by interpolating in Lambert 2008 source data in Lambert 72 and at a 1m-resolution from the Flemish and Brussels Regions, and by adding Lambert 2008 data at 1m-resolution from the Walloon Region.

The hillshades are presented as a regular homogeneous grid of points indicating the grey level value resulting from their orientation with respect to the chosen fictitious light source. The 1m hillshade is the view obtained by hillshading of the 1m DTM. The 5m and 20m hillshades are the views obtained by hillshading of the 5m and 20m DTM.

The eTOD digital terrain model (DTM) is a homogeneous and regular point grid indicating the elevation of the ground level in order to make a model of its surface. This DTM is obtained by resampling raw altimetric source data from the Flemish and Walloon Regions, grouped in Lambert 72 and with a resolution of 1 m; as well as data obtained internally by direct photogrammetric recording of structure points and lines based on the most recent aerial photographs for all areas not covered by regional data. For this DTM, the resolution and coordinate reference system are used as defined by the eTOD specifications.

The contour lines are the set of lines connecting all points at the same elevation in a model used to represent the relief on a large scale.

This dataset contains the orthophotos of the floodable areas along the Meuse, the Vesdre and the Demer. These orthophotos are digital aerial photographs, taken by Hansa Luftbild following the floods of July 2021, in which the systematic distortions due to the central projection, relief and the not always perfectly vertical axis of shooting have been corrected. The orthophoto thereby obtained is metrically more accurate than an ordinary aerial photograph and is highly valuable as basic information. The resolution of the data is 6.5 cm (4 cm above the Hoëgne).

The DTM is a homogeneous and regular point grid indicating the height of the ground level in order to model its surface. The DTM 1m is achieved by interpolating in Lambert 2008 source data in Lambert 72 and at a 1m-resolution from the Flemish and Brussels regions, and by adding Lambert 2008 data at 1m-resolution from the Walloon Region. The DTM 5m has an additional source, namely drawn structure lines and points adapted during systematic and continuous update by photogrammetric surveys. The DTM 20m is obtained by resampling of the DTM 1m.

MapIndex is a regular grid of rectangular or square cells coded with alphanumeric characters. It has been defined for the Belgian territory and allows geolacating several events. The present version is a beta (v2)version which is submitted to the emergency services. It will evolve to a standard cartographic grid.