GEOLOGICAL MAPPING AND INTEGRATED DATA DELIVERY FOR LANDSLIDE ASSESSMENT IN KENTUCKY

The Kentucky Geological Survey is working to develop and distribute digital three-dimensional geologic data to support slope stability assessment and land-use planning for landslide mitigation.

The natural geology of eastern Kentucky is highly susceptible to landslides. Landslides and unstable slopes damage existing infrastructure and cause millions of dollars in losses, discouraging economic development and major construction in eastern Kentucky. Landslides are commonly viewed as unpredictable, but knowledge of ground conditions (topography, geology, drainage) combined with well-planned construction can reduce exposure to the hazard and help to reduce landslide-related losses.

Ongoing consultations with the Kentucky State Geologic Mapping Advisory Committee as well as with technical users of geologic map products have identified characterization of geologic unit properties and depth to bedrock as two primary needs for geotechnical practitioners. New geologic mapping projects undertaken at the Kentucky Geological Survey, combined with Internet-based delivery of digital data, are being integrated to offer an interactive data source for geotechnical professionals.

Active field mapping is delineating unconsolidated materials (engineering soils); the resulting map units represent genetic origin and material thickness. Alluvium is differentiated by relative age; colluvium and residuum are differentiated by thickness and continuity of the deposit/material. Areas disturbed by mining, construction or excavation are noted and delineated. Fracture mapping in natural and artificial exposures is documenting orientation and spacing trends of bedrock discontinuities. The inferred genetic origin of different fracture sets, such as regional tectonic or local stress-relief fractures, are being noted in the digital fracture database. Depth to bedrock and lithologic data from existing KGS databases including oil and gas, coal, and water well data, as well as geotechnical data from the Kentucky Transportation Cabinet, are being migrated into the mapping database. The complex, integrated, three-dimensional datasets are being made available to technical professionals through the KGS Geologic Map Service via the World Wide Web.