2015/02/13 by Francis K. Rengers, Gregory E. Tucker, Greg E. Tucker
Agricultural and Biological Sciences · Environmental Science · #Hydrology and Sediment Transport Processes #Plant Water Relations and Carbon Dynamics #Soil erosion and sediment transport
paper · doi:10.1002/esp.3721
openalex publication_date 2015/02/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Abstract We present observations and analysis of gully headcut erosion, which differ from previous headcut studies in both spatial and temporal detail. Using ten terrestrial laser scanning (TLS) surveys conducted over a period of 3 years, we mapped headcut erosion with centimeter‐scale detail on a sub‐annual basis. Erosional change is observed through point cloud differencing, which expands on previous studies of headcut retreat rate by revealing the evolution of the headcut morphology. Headcut retreat observations are combined with hydrological measurements to explore the controlling factors of erosional retreat. We find that (i) mass failure due to wetting, (ii) saturation weakening of shale bedrock in plunge pools, and (iii) direct wash over the headcut face all appear to contribute to headcut retreat; however, mass failure via wetting appears to be the dominant process. Soil moisture was monitored near the study headcut at 0.4 m depth, and time‐lapse photos show that soil wetting tends to be concentrated along the headcut apex after rainfall and snowmelt runoff events. We find that moisture concentration at the headcut apex leads to more rapid erosion at that location than along the headcut sidewalls, resulting in a semi‐ellipsoidal plan view morphology that is maintained as the headcut migrates up‐valley. Copyright © 2015 John Wiley & Sons, Ltd.