R-View is a visual guide for selecting Manning’s  roughness values in natural rivers and man-made channels using photographic information.  It is based on U.S. Geological Survey’s publication entitled “Roughness Characteristics of Natural Channels” by Harry H. Barnes, Jr., Water Supply Paper 1849.  R-view is intended for use by hydrologists, hydraulic engineers, geologists, geomorphologists, and practitioners of environmental engineering.  In R-view a total of 100 photographic images is included to cover a wide range of channel conditions.

R-View Picture