The abandoned, pre-landslide stream bed was evident at the toe of the slope.
Incision into the dams is slowed when the post-landslide stream encounters the pre-landslide channel.
The post-landslide stream channel cut through a point bar attached to the opposite stream bank, abandoning the pre-landslide channel Fig. 11 The 2013 Pouce Coupe River landslide and dam, captured at the Landry Road bridge, looking downstream.
The post-landslide streams form new channels around the toes of the landslides.
Generally, landslide dams, stream banks and soil slopes are composed of unconsolidated materials which exist in unsaturated conditions.
This is especially true for volcanic terrains where volcanic activity can trigger voluminous landslides along stream systems by sector and flank collapse and where high seasonal rainfall on terrains covered by poorly consolidated materials produces small but hazardous landslides and debris flows that occur continually along stream systems during the volcanic repose periods.
In the Hawke's Bay region sediment yields from a pasture catchment (mainly from shallow landslides and stream bank erosion) were estimated to exceed yields from a planted forest catchment over the duration of a forestry cycle in spite of the short-term elevated sediment yields during harvesting (Figure 3) (Eyles and Fahey 2006).
These groups are mainly including marl, marl limestone, limestone, shale associated with old landslides, and rock stream traces which mostly are fissile, soluble and easily weathered materials.
Visual inspection of landslide damage, rainfall, and stream flow data together suggest that the March 1995 storm encompassed an area of approximately 40 km2 h.
Another important consideration is that, unlike stream flows, landslides and debris flows accelerate from statically balanced initial states.
Finally, extremely large paleolandslides have no historical analogs; their study yields insights into unusual effects that have not been witnessed, including large-scale liquefaction, undrained loading of the substrate over which a large landslide travels, and the streaming behavior of rock avalanches.
