This shows the official river length. Our calculated river length often differs from the official one. We calculate river length based on the drawn river curve on the map. Discrepancies exist due to different river start locations or different river curves through lakes and dams.
The computed slope uses EU-DEM digital elevation model data (25 m resolution). Because the model measures average surface height in each 25×25 m cell, it cannot precisely capture the depth of narrow river valleys — elevation differences and slope are therefore often smaller than in reality.