The Ocean Pines Drive sinkhole collapse of July 14, 2017 in Land O Lakes, Florida, started as a depression in the front yard of a property near Saxon Lake, and caused the destruction of two homes and the evacuation of nine additional residences. The sinkhole is slightly oval with dimensions of approximately 51 meters east-west and 42 meters north-south, was nearly 40 feet deep. This is presumably the largest sinkhole to form in Pasco County during the last 30 years. The surface collapse happened rapidly and continued over three days, with slumping and erosion increasing the size. The site is located near two natural lakes in a 1960s era housing development. This occurrence is within an area of well-developed karst that has a number of natural sinkhole formation lakes.

3D mapping of surface features in our project included photogrammetric detection and ranging (PhoDAR) using Structure from Motion (SfM) techniques from a drone-based platform, as well as ground-based methods using terrestrial laser scanning (TLS) and global positioning system (GPS) control and targeting survey. While PhoDAR has been a trending method in close-range sensing, a sequencing of survey integration using TLS and GPS ground based measurements provided a more robust and simplified workflow that was used to create Geographic Information System database applications, incorporating geophysical and other types of geospatial data. The GIS incorporates georeferenced historic land use information such as historic aerial imagery and topographic maps, which provide a useful foundation of information in identifying subsidence indicators and areas of land modification and change that may have relationship to present-day condition. Aerial LiDAR from available years of survey, and environmental GIS data relating to soils and groundwater were also considered. Geophysical survey techniques, including GPR, seismic survey, and bottom profiling were brought together, working with a number of researchers from USF, and with these data we have constructed living documentary platform for inclusion and incorporation of ongoing results and analyses.

See our 3D models here.

See our interactive GIS dashboard tool here.

See our drone-based imagery comparison tool here.