QUANTIFYING SURFACE SUBSIDENCE ALONG US HIGHWAY 50, RENO COUNTY, KS USING TERRESTRIAL LIDAR AND SEISMIC METHODS: IMPLICATIONS FOR SINKHOLE DEVELOPMENT AND RISK ASSESSMENT ALONG RAPIDLY DEVELOPING URBAN CORRIDORS

Surface subsidence resulting from subsurface karsting is detrimental to the integrity of infrastructural features such as roads and utilities. When subsidence or sinkholes develop gradually, their lateral extent can be difficult to accurately determine. The construction of high-resolution digital elevation models of subsidence areas is one approach to identifying and studying sinkholes. The utilization of terrestrial LiDAR scanning provides a new approach for verifying if an area is actively subsiding as well as determining the spatial characteristics of a sinkhole.

In Reno County, KS along US-50, two subsidence areas have been identified. The Brandy Lake and Victory Road sinkholes have noticeable bowl shaped geometries and have deformed US-50 by causing potentially hazardous depressions along the road surface. Repaving projects have been conducted over the last several years on US-50 to compensate for the subsiding road surface. Ground deformation in south central Kansas is a result of underground karsting of the Lower Permian Hutchinson Salt Member. LiDAR data gathered iteratively over the last year has revealed that the surface of US-50 is not actively deforming which may indicate that subsidence has ceased. In addition, through post processing of the LiDAR data, the area of the sinkholes is able to be quantified by building a bare-Earth model of the ground surface. Interpretation of seismic reflection data over the Victory Road sinkhole has shown recent settling in the subsurface east of the sinkhole although no surface deformation can be visually observed. Therefore, future LiDAR scanning surveys will expand data coverage into this area to examine any potential surface subsidence.