Water Resources Engineering (WRE) connects engineering hydrology and hydraulics with global, economic, environmental and societal issues. Our student Aaron Fischer makes this connection here…

The news entitled, “From Rivers to Landslides: Charting the Slopes of Sediment Transport” was reported by the California Institute of Technology on December 29th, 2013 and found on the Science Daily Website. The news related to the WRE domain of hydrology and a reduction of natural disasters with increased knowledge of sedimentation. This article examines the transport of sediments through rivers and streams as they relate to bed failure and possible landslides. Before recent, it was believed that the greater the slope, the more sediment transport that occurred due to an increased gravity, but that is not the case. This research project proved that as slope increases, the sediment actually becomes more stable. (Most stable around 20 degrees). And with the increased slope of flow, there will be a lower water level and higher velocity. The true trouble comes when the amount of water increases above normal amounts, dislodging the sediment causing, at this slope, full bed failure. Further studies must take place to validate the findings of this research, but it is an important step in understanding the deposition and stream bed failure of landslide prone areas.

There are many economic, environmental and societal aspects affected by the research explained in this article. This research talks to the potential of understanding the true mechanisms behind landslides, which, once understood and proven, may act as a precautionary action against damages to property as well as lower deaths caused by these natural disasters. If we have a better understanding who what causes the streambed failure, we can better re-direct water and sediments.   This research also allows us to re-examine the rehabilitation efforts of aquatic animals such as salmon. Due to dams and natural changes, there is a high percentage of areas that are no longer suitable for salmon to nest. While there are efforts to re-build these habitats, not many activists and scientists are fully aware of the reality behind sediment transfer in areas with such extreme slopes and may not be able to properly replenish the environment.

Figure 1: Salmon Habitat in a river

Figure 1: Salmon Habitat in a river

Figure 2: Gradient slope of interest

Figure 2: Gradient slope of interest

References:

California Institute of Technology. (2014, January 29). From rivers to landslides: Charting the slopes of sediment transport. ScienceDaily. Retrieved February 6, 2014 from www.sciencedaily.com/releases/2014/01/140129165419.htm

Egholm, D. L., Knudsen, M. F., & Sanford, M. (2013). Lifespan of Mountain ranges scaled by feedbacks between landsliding and erosion by rivers. Nature , 498 (&455), 475.

Beechie, T., Beamer, E., & Wasserman, L. Estimating Coho Salmon Rearing Habitat and Smolt Production Losses in a Large River Basin, and Implications for Habitat Restoration. North American Journal of Fisheries Management , 14 (4).

 

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