RAS layers


Stream Centerline

Used to identify the connectivity of the river network and assign river stations to computation points.

Cross-Sectional Cut Lines

Used to extract elevation transects from the DEM at specified locations and other cross-sectional properties.

Bank Lines

Used in conjunction with the cut lines to identify the main channel from overbank areas.

Flow Path Centerlines

Used to identify the center of mass of flow in the main channel and overbanks to compute the downstream reach lengths between cross


Land Use

Used to assign flow roughness factors (Manning’s n values) to the cross sections.

Inline Structures

Used to extract the weir profile from the DEM for inline structures (dams).