|Peterson, Joel - PURDUE UNIVERSITY|
Submitted to: American Society of Agricultural Engineers Meetings Papers
Publication Type: Abstract Only
Publication Acceptance Date: June 1, 2002
Publication Date: July 28, 2002
Citation: Peterson, J.R., Flanagan, D.C., Robinson, K.M. Channel evolution and erosion in PAM-treated and untreated experimental waterways. American Society of Agricultural Engineers Meetings Papers. 2002. Paper No. 02-2170. Technical Abstract: Unprotected earthen waterways (e.g. grassed waterway before vegetation) and ephemeral gullies are prone to severe erosion. Previous research has suggested that polyacrylamide (PAM) may reduce erosion in areas of concentrated flow. This research tested the hypothesis that a PAM-treated channel would result in significantly less erosion than untreated soil in a pre-formed, trapezoidal channel. Channel geometry and sediment concentration were measured for each of four inflow rates (0.0016, 0.0032, 0.0063, and 0.0126 m3·s-1). A secondary objective was to measure the influence of PAM on headcut rate advance. Measured sediment yield rate was significantly less from PAM-treated channels than from the control. Reductions in sediment yield rate ranged from 93 to 98%. Channel incision depth was not different between the two treatments; however, effective flow widths (assuming rectangular channel geometry) were significantly greater for the untreated control channel. Headcut advance rates were greatly reduced in PAM-treated channels (0.06 to 0.6 m·h-1) compared to the untreated channel (17.8 m·h-1) in our limited data. These results show that PAM can be a very effective means of controlling erosion in a channel or gully subject to high-volume concentrated flows. This research impacts agency personnel, erosion control specialists and others who are trying to control erosion by flow detachment in ephemeral gullies, newly-established grass waterways and other concentrated flow channels. Use of PAM may help maintain a channel during initial vegetation establishment, or perhaps reduce channel erosion as an emergency measure on spillways for earthen dams.