Slope Stability Analysis
Do you know where the highest risk from landslides and debris flows are located in your watershed?
Landslides and debris flows pose serious risks to lives and properties. They can also affect aquatic ecosystems, including fish habitats. In managed forested environments, roads and timber harvest can contribute to landslides and debris flows.
In many mountain landscapes, landslides are naturally occurring and play important roles in maintaining aquatic and riparian environments under the right conditions.
NetMap contains tools to identify landslide and debris flow prone locations. They are used to better manage landslide risks and to better understand the ecological role of landslides and debris flows on aquatic and riparian ecosystems.
Topographic models of shallow landslides target steep and convergent landforms as shown in this paired set of photos, with the right hand one showing the landslide susceptibility prediction.
A) Landslides occur naturally post wildfire in the Oregon Coast Range.
(B) Landslides can trigger debris flows in headwater streams.
(C) Debris flows deposit sediment and wood into larger channels at headwater tributary confluences.
Large storms can also naturally trigger numerous landslides and debris flows, as illustrated in old growth forests on the Olympic Peninsula, Washington (right).
NetMap tools allow are used to identify landslide and debris flow susceptibility, shown here for an area in southeast Alaska.
Landslide hazards can be categorized into high, moderate and low using a method that links map polygons or cells to the proportion of land area they encompass.
For instance, the highest landslide hazard can be associated with just 5%, 15% or 25% of the total land area.
Overlay GIS forest roads onto NetMap landslide susceptibility map to identify road segments that may be at risk of landslides or that may contribute to landslide occurrence.
The resolution of digital elevation models matters. Higher resolution LiDAR provides greater spatial detail on potential landslide and debris flow susceptibility.
NetMap contains other erosion mapping tools including for:
flash floods
gully
surface erosion, including post-wildfire