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.

Thanks!

Matt Crawford

mcrawford@uky.edu