2012
Yager, E. M.; Dietrich, W. E.; Kirchner, J. W.; McArdell, B. W.
Prediction of sediment transport in step-pool channels Journal Article
In: Water Resources Research, vol. 48, no. 1, 2012.
Abstract | Links | BibTeX | Tags: sediment transport, steps on flow
@article{Yager2012b,
title = {Prediction of sediment transport in step-pool channels},
author = {E. M. Yager and W. E. Dietrich and J. W. Kirchner and B. W. McArdell},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Yager_2012_WatResoRese.pdf},
doi = {10.1029/2011WR010829},
year = {2012},
date = {2012-01-27},
journal = {Water Resources Research},
volume = {48},
number = {1},
abstract = {In mountainous drainage networks, sediment mobilized on hillslopes must first pass through steep streams before reaching lower-gradient channels. The bed of steep channels is typically composed of large, relatively immobile boulders and finer, more mobile gravel. Most sediment transport equations overpredict sediment flux in steep streams by several orders of magnitude because they do not account for the stress borne by immobile grains and the limited availability of the more mobile sediment. We previously developed and tested (in flume experiments) a sediment transport equation that accounts for these two effects. Here we modify the Parker (1990) bed load equation to include the resistance borne by steps and selective transport of the relatively mobile sediment using a range of hiding functions. We test a number of resistance equations and hiding functions, combined with our modified and the original Parker equations, against measured flow and sediment transport in three steep channels. Our modified sediment transport equation generally predicts the transported sediment volumes to within an order of magnitude of the measured values, whereas the unmodified equations do not. The most accurate sediment flux predictions were obtained from using our modified equation, combined with a hiding function that calculates highly selective transport of the relatively mobile sediment. Furthermore, this hiding function has a critical Shields stress that is similar to those reported for lower gradient channels. The effects of the immobile steps on flow and sediment transport are not adequately captured by simply increasing the critical Shields stress to values reported in steep streams.},
keywords = {sediment transport, steps on flow},
pubstate = {published},
tppubtype = {article}
}
In mountainous drainage networks, sediment mobilized on hillslopes must first pass through steep streams before reaching lower-gradient channels. The bed of steep channels is typically composed of large, relatively immobile boulders and finer, more mobile gravel. Most sediment transport equations overpredict sediment flux in steep streams by several orders of magnitude because they do not account for the stress borne by immobile grains and the limited availability of the more mobile sediment. We previously developed and tested (in flume experiments) a sediment transport equation that accounts for these two effects. Here we modify the Parker (1990) bed load equation to include the resistance borne by steps and selective transport of the relatively mobile sediment using a range of hiding functions. We test a number of resistance equations and hiding functions, combined with our modified and the original Parker equations, against measured flow and sediment transport in three steep channels. Our modified sediment transport equation generally predicts the transported sediment volumes to within an order of magnitude of the measured values, whereas the unmodified equations do not. The most accurate sediment flux predictions were obtained from using our modified equation, combined with a hiding function that calculates highly selective transport of the relatively mobile sediment. Furthermore, this hiding function has a critical Shields stress that is similar to those reported for lower gradient channels. The effects of the immobile steps on flow and sediment transport are not adequately captured by simply increasing the critical Shields stress to values reported in steep streams.
2009
Roering, Joshua J.; Stimely, Laura L.; Mackey, Benjamin H.; Schmidt, David A.
Using DInSAR, airborne LiDAR, and archival air photos to quantify landsliding and sediment transport Journal Article
In: Geophysical Research Letters, vol. 36, no. 19, 2009.
Abstract | Links | BibTeX | Tags: DInSAR, landslide, LiDAR, sediment transport
@article{Roering2009,
title = {Using DInSAR, airborne LiDAR, and archival air photos to quantify landsliding and sediment transport},
author = {Joshua J. Roering and Laura L. Stimely and Benjamin H. Mackey and David A. Schmidt},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Roering_2009_GeophyResLet.pdf},
doi = {10.1029/2009GL040374},
year = {2009},
date = {2009-10-15},
journal = {Geophysical Research Letters},
volume = {36},
number = {19},
abstract = {We demonstrate the ability of coupled remote sensing tools to characterize large, slow-moving landslides in the Eel River catchment, northern California. From a stack of ALOS interferograms, we identified 5 large (>1 km long) landslides that exhibited significant activity from February 2007 to February 2008. For the Boulder Creek earthflow, we used orthorectified air photos taken in 1964 and unfiltered airborne LiDAR flown in 2006 to map the displacement of trees growing on the landslide surface. Combining those displacement orientations with stacked DInSAR data, we observed average downslope velocities of 0.65 m yr−1 through the central transport zone of the landslide. Given landslide depth estimates, minimum sediment transport and denudation rates are estimated to be 4100 m3 yr−1 and 1.6 mm yr−1, respectively. Our results demonstrate the highly erosive role of large, slow-moving landslides in landscape evolution and suggest that the superposition of dense, ephemeral gully networks and rapidly moving zones within the landslide may facilitate delivery of slide-mobilized sediment into adjacent fluvial channels.},
keywords = {DInSAR, landslide, LiDAR, sediment transport},
pubstate = {published},
tppubtype = {article}
}
We demonstrate the ability of coupled remote sensing tools to characterize large, slow-moving landslides in the Eel River catchment, northern California. From a stack of ALOS interferograms, we identified 5 large (>1 km long) landslides that exhibited significant activity from February 2007 to February 2008. For the Boulder Creek earthflow, we used orthorectified air photos taken in 1964 and unfiltered airborne LiDAR flown in 2006 to map the displacement of trees growing on the landslide surface. Combining those displacement orientations with stacked DInSAR data, we observed average downslope velocities of 0.65 m yr−1 through the central transport zone of the landslide. Given landslide depth estimates, minimum sediment transport and denudation rates are estimated to be 4100 m3 yr−1 and 1.6 mm yr−1, respectively. Our results demonstrate the highly erosive role of large, slow-moving landslides in landscape evolution and suggest that the superposition of dense, ephemeral gully networks and rapidly moving zones within the landslide may facilitate delivery of slide-mobilized sediment into adjacent fluvial channels.