Premium
Bank erodibility of shallow sandbed streams
Author(s) -
Pizzuto James E.
Publication year - 1984
Publication title -
earth surface processes and landforms
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.294
H-Index - 127
eISSN - 1096-9837
pISSN - 0197-9337
DOI - 10.1002/esp.3290090203
Subject(s) - silt , geology , streams , geotechnical engineering , ultimate tensile strength , tension (geology) , bank erosion , erosion , channel (broadcasting) , compression (physics) , shear (geology) , geomorphology , hydrology (agriculture) , petrology , materials science , engineering , computer science , electrical engineering , computer network , metallurgy , composite material
Cross‐sections were surveyed at straight reaches of 16 sandbed streams in the midwestern U.S. Two stratigraphic horizons are found in the banks at each site, an upper cohesive unit usually composed of silt and clay, and a lower unit composed of sand. Bank erosion on these rivers occurs when the upper cohesive unit is undercut by scour at bends. The overhanging cohesive block fails by toppling forward into the channel. During failure, the soil is primarily in tension rather than compression or shear. Analysis of this failure mechanism leads to a field method for measuring the tensile strength of riverbanks. Measured values of the tensile strength are not correlated with the channel geometry. Thus, the erodibility of the cohesive bank sediments does not influence the geometry of the rivers studied.