3.1.3. Topography (Slope): A Reduced Effect in a Flat Setting

Using the "slope" tool in ArcGIS, slope angles were extracted from the DEM. Figure 5 displays the slope of the Claise basin and the adapted reclassified raster following CORINE classification.

**Figure 5.** (**a**) Slope angle of the Claise and (**b**) the corresponding CORINE indices description.

From Figure 5, it can be observed that the Claise presents a dominantly flat topography with a maximum slope of 15◦. In CORINE terms, 99.3% (702.051 km2) of the study area corresponds to "very gentle to flat" slope class (<5◦) and 0.7% (4.94 km2) to the "gentle" slope category (5◦–15◦). The particular setting of low relief and small slope significantly plays a role in the reduction of erosion generated by runoff [79], despite the high soil erodibility risks.
