Matt Crawford
KYTC Trans-GIS Conference
Frankfort, KY March 29th, 2012
database
Natural geology, topography, and decades of slope modification make this area susceptible to landslides…recurring landslides
Example costs:
•KYTC Maintenance Database total costs, 2003-2009 – approx. $1.4 million
•68 KYTC Landslide Geotechnical Project Reports (1973-present) in Kenton and Campbell – unknown cost
•April-May 2011 storms cost KYTC District 6 over $4 million
•FEMA is about to submit a letter of intent for a 2.5 million dollar stabilization project in Bellevue, Ky. Campbell Co.
From the Newport and Withamsville quadrangle by Gibbons (1973):
“The shale of the Kope Formation slumps readily when wet. Structures built on the Kope should be provided with adequate drainage and oversteepened slopes should be avoided.”
From Potter, 1996
• Purpose: develop a methodology for using LiDAR data in the geologic setting of Kenton and Campbell Co. and document preexisting landslides.
• Modeled after other states: OR, WA
• LiDAR data provided by the NKAPC
• Grant from the USGS Landslides Hazards Program
LiDAR Project
Methodology • Used Quick Terrain Modeler to
create hillshade DEM’s from the LAS files
• Add DEM’s to ArcMap for visualization, spatial analysis, and digitization
• Systematic panning looking for Hummocky surface Steep scarp, flanks Thick toe Concavity
• Reexamined potential landslides in QTM
• Performed field checking
• Topographic contours
• 1:24,000-scale geology
• Slope
• Leaf-off aerial photography
• Roads
• Bing!
Landslide example: LiDAR derived hillshade DEM with 2ft contours
~450 ft down axis of slide
Landslide example: LiDAR derived hillshade DEM
~750 ft down axis of slide
Landslide example: LiDAR derived hillshade DEM with 2 ft contours
~280 ft down axis of slide
Landslide example: Reexamination of
landslide with QT Modeler
• 230 potential landslide extents digitized (polys)
• Approximately 10% were initially attributed with high confidence, rest were questionable
• LiDAR hillshade geomorphology,
geology, and proximity to
urbanized areas dictated
classification…subjective
• 20% (about 45) of these landslides were field checked
20 were confirmed 18 were likely or observed but
could not be determined 7 were not accessible
• Project successfully used LiDAR for identifying potential landslide extents
• Able to map potential slides in areas not accessible by roads.
• Urbanization of Kenton and Campbell Counties made visualization difficult and probably masked many existing slides
• Project was limited by time and ability to field check landslides identified
• Indication of future failure!!??
• As Kentucky acquires more LiDAR, similar projects will be very beneficial in other landslide prone parts of the state.